CN110997822B

CN110997822B - Coloring composition containing xanthene dye, coloring agent for color filter and color filter

Info

Publication number: CN110997822B
Application number: CN201880034923.5A
Authority: CN
Inventors: 青木良和; 神田大三; 山县直哉
Original assignee: Hodogaya Chemical Co Ltd
Current assignee: Hodogaya Chemical Co Ltd
Priority date: 2017-06-29
Filing date: 2018-06-13
Publication date: 2023-01-03
Anticipated expiration: 2038-06-13
Also published as: JPWO2019003915A1; JP7091330B2; TW201905104A; KR20200023276A; TWI756440B; CN110997822A; WO2019003915A1

Abstract

A colorant for color filters, which comprises a coloring composition containing a compound represented by the following general formula (1)

A coloring composition of xanthene dye, wherein the number of diffraction peaks at diffraction angle (2 theta) in the range of 3-7 DEG in powder X-ray diffraction of CuK alpha ray is 0, and the coloring composition contains

Xanthene dyes.

Description

Xanthene dye-containing coloring composition, colorant for color filter, and color filter

Technical Field

The present invention relates to a coloring composition containing xanthene dye, a coloring agent for color filter using the composition and a color filter using the coloring agent.

Background

Color filters are sometimes used in liquid crystal and Electroluminescent (EL) display devices. The color filter is manufactured by laminating colored layers on a light-transmitting substrate such as glass by a dyeing method, a pigment dispersion method, a printing method, an electrophoresis method, or the like. Colorants used in the colored layer are broadly classified into pigments and dyes, and pigments that are considered to have excellent heat resistance and light resistance are widely used (see, for example, patent documents 1 to 3). However, since pigments are generally insoluble in solvents, they are present in fine particles in color filters comprising resins and the like. Therefore, it is known that a color filter using a pigment has a problem in that transmitted light is reflected and scattered on the surface of pigment particles in the color filter, and thus transparency and color purity are affected, and that a contrast ratio of a color liquid crystal display device is lowered due to a depolarization effect caused by reflection.

In order to solve such a problem of the decrease in the contrast ratio, a method of using only a dye as a colorant, a method of using a dye and a pigment in combination, or the like has been proposed. Since the dye is soluble in a solvent, a color filter using the dye suppresses a depolarization effect and has superior spectral characteristics, compared to a color filter using only a pigment as a colorant. Xanthene dyes and the like are known as dyes used for color filters, because of their excellent color-developing properties, heat resistance and light resistance (see, for example, patent documents 4 to 7). It is described that an excellent red hue is obtained by using a xanthene-based dye such as c.i. acid red 289 represented by the following formula (I) or c.i. acid red 52 represented by the following formula (II) in combination with an azopyridone-based dye (for example, see patent document 4). Wherein, c.i. means color index.

[ solution 1]

[ solution 2]

Further, it is known that a cyan color filter having a high contrast ratio and color purity can be produced by using these xanthene dyes or derivatives thereof in combination with a phthalocyanine dye (see, for example, patent documents 6 and 7). The color filter using the dye and the pigment in combination is considered to have an effect of suppressing oxidative decomposition of each other by forming an aggregate by mixing both of the dye and the pigment in different colors, and immediately causing charge transfer between dye molecules excited by light and pigment molecules in the vicinity of the dye molecules, and thus to maintain color developability and improve light resistance as compared with a color filter produced by using the dye alone.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2001-220520

Patent document 2: JP 2007-533802A

Patent document 3: japanese unexamined patent publication No. 2012-12498

Patent document 4: japanese patent laid-open publication No. 2002-265834

Patent document 5: japanese laid-open patent publication No. 2012-207224

Patent document 6: japanese laid-open patent publication No. 2010-254964

Patent document 7: japanese laid-open patent publication No. 2014-12814

Non-patent literature

Non-patent document 1: editors of society, organic Synthesis chemistry Association, "New edition dye Exhibit", wanshan Kabushiki Kaisha, 1970, page 426

Disclosure of Invention

Problems to be solved by the invention

However, conventional xanthene dyes are often insufficient in solubility and dispersibility in organic solvents for color filter production, even if their own color-developing properties and heat resistance are sufficient. In general, dyes such as xanthene dyes are water-soluble and have a positively charged nitrogen atom (= N) in the molecule as shown in formula (I) ⁺ <), negatively charged group (-SO) ₃ ^- Etc.) easily with water molecules (H) as polar molecules ₂ O), etc. form hydrogen bonds. However, molecules having a plurality of polar groups, such as xanthene dyes, form relatively strong bonds due to intermolecular forces (van der waals forces, hydrogen bonds, ionic bonds, and the like) that act between the same or different substituents, and form aggregates of several to several tens of units. If the dye molecules coagulateIf the polymer remains in a certain size, coating unevenness occurs during film formation, and light resistance and heat resistance are reduced, and the effect of eliminating the transmitted light such as a pigment is also complicated, and color developability as a color filter is further reduced.

When an organic pigment or an organic dye is hardly soluble in a solvent, a method of physically pulverizing the organic pigment or the organic dye using a device such as a bead mill to prepare a dispersion liquid in which the particle diameter of an aggregate of the pigment or the dye is reduced to about several tens of nm is generally employed. Therefore, as a property required for a xanthene-based dye for color filter production, it is necessary to develop a production method which does not require an extra additive and is easily dissolved or uniformly dispersed in a solvent.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a coloring composition containing a xanthene-based dye which is excellent in hue adjustment as a colorant for color filters and contains the xanthene-based dye in a solid (powder or the like) state necessary for exhibiting good solubility or dispersibility in a process for producing color filters, a colorant for color filters containing the coloring composition, and a color filter which uses the colorant for color filters and is excellent in color developability (brightness, contrast ratio or the like).

Means for solving the problems

The present inventors have found an optimum method for producing a powder of a xanthene-based dye for use in the production of color filters, and have further found that the characteristics of a solid powder thereof can be analyzed by powder X-ray diffraction, and have found that a color filter having excellent color-developing properties (contrast ratio) can be obtained by using a coloring composition containing such a xanthene-based dye, and have completed the present invention.

That is, the present invention has been made as a result of intensive studies to achieve the above object, and the following points are set forth.

1. A coloring composition containing a xanthene dye represented by the following general formula (1),

the powder X-ray diffraction of CuK alpha ray has 0 diffraction peak number in the diffraction angle (2 theta) range of 3-7 DEG, and contains at least one xanthene dye.

[ solution 3]

[ in the formula, R ¹ ～R ⁴ Each independently represents a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a cycloalkyl group having 3 to 20 carbon atoms which may have a substituent, R ⁵ ～R ⁷ Each independently represents a hydrogen atom, a halogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 20 carbon atoms which may have a substituent, a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, a cycloalkoxy group having 3 to 20 carbon atoms which may have a substituent, or a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent, R ⁵ And R ⁶ May be bonded to each other to form a ring. M represents an alkali metal atom.]

2. A coloring composition, wherein, in the general formula (1), R ¹ ～R ⁴ Is a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent.

3. A coloring composition which contains 2 or more kinds of xanthene dyes represented by the general formula (1), wherein the weight concentration ratio of the total of the minimum 1 kind of xanthene dyes is 0.1 to 50% by weight, expressed by the weight concentration ratio of the total xanthene dyes.

4. A colorant for color filters, which contains the coloring composition.

5. A color filter using the colorant for color filters.

ADVANTAGEOUS EFFECTS OF INVENTION

The color filter produced using the color filter colorant containing the coloring composition containing the xanthene dye of the invention has excellent color-developing properties such as contrast ratio, and the xanthene dye of the invention can be used as a color filter colorant.

Drawings

Fig. 1 is a powder X-ray diffraction (XRD) pattern of the coloring compositions of the examples and comparative examples of the present invention.

Detailed Description

The embodiments of the present invention will be described in detail below. The present invention is not limited to the following embodiments, and can be implemented by being variously modified within the scope of the gist thereof. First, the xanthene-based dye represented by the above general formula (1) will be described.

In the general formula (1), as represented by R ¹ ～R ⁴ The "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" as used herein includes, specifically, linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl groups; and branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, and isooctyl.

In the general formula (1), as represented by R ¹ ～R ⁴ The "cycloalkyl group having 3 to 20 carbon atoms which may have a substituent" as used herein includes, specifically, cycloalkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl.

In the general formula (1), as represented by R ¹ ～R ⁴ The "substituent" in the "substituted linear or branched alkyl group having 1 to 20 carbon atoms" may specifically be exemplified

Halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; -SO ₃ ^- ；

Cycloalkyl groups having 3 to 19 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl;

a linear alkoxy group having 1 to 19 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, or a decyloxy group;

a branched alkoxy group having 3 to 19 carbon atoms such as an isopropoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, and an isooctyloxy group;

a cycloalkoxy group having 3 to 19 carbon atoms such as a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, etc.;

aromatic hydrocarbon groups or condensed polycyclic aromatic groups having 6 to 19 carbon atoms such as phenyl, naphthyl, biphenyl, anthryl, phenanthryl, pyrenyl, benzo [9,10] phenanthryl, indenyl, and fluorenyl groups;

and heterocyclic groups having 2 to 19 carbon atoms such as pyridyl, pyrimidyl, triazinyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, quinolyl, isoquinolyl, naphthyridinyl, indolyl, benzimidazolyl, carbazolyl, carbolinyl, acridinyl, phenanthrolinyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzothienyl, dibenzothienyl, oxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl and the like. These "substituents" may be contained in only 1 number, or may be contained in plural numbers, and in the case of containing plural numbers, they may be the same or different from each other. These "substituents" may further have the substituents exemplified above.

In the general formula (1), as represented by R ¹ ～R ⁴ The "substituent" in the "cycloalkyl group having 3 to 20 carbon atoms and having a substituent" mentioned above includes

A linear alkyl group having 1 to 14 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group;

branched alkyl groups having 3 to 14 carbon atoms such as isopropyl group, isobutyl group, sec-butyl group, tert-butyl group and isooctyl group;

cycloalkyl groups having 3 to 14 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl;

a linear alkoxy group having 1 to 14 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, or a decyloxy group;

branched alkoxy groups having 3 to 14 carbon atoms such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy and isooctyloxy;

a cycloalkoxy group having 3 to 14 carbon atoms such as a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, etc.;

an aromatic hydrocarbon group or a condensed polycyclic aromatic group having 6 to 14 carbon atoms such as a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, an indenyl group, and a fluorenyl group;

and heterocyclic groups having 2 to 14 carbon atoms such as pyridyl, pyrimidyl, triazinyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, quinolyl, isoquinolyl, naphthyridinyl, indolyl, benzimidazolyl, carbazolyl, carbolinyl, acridinyl, phenanthrolinyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzothienyl, dibenzothienyl, oxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl and the like. These "substituents" may be contained in only 1 number, or may be contained in plural numbers, and in the case of containing plural numbers, they may be the same as or different from each other. These "substituents" may further have the substituents exemplified above.

In the general formula (1), as R ⁵ ～R ⁷ Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. The "halogen atom" is preferably a fluorine atom or a chlorine atom.

In the general formula (1), as represented by R ⁵ ～R ⁷ Of the "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent", "cycloalkyl group having 3 to 20 carbon atoms which may have a substituent", "linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent", "cycloalkoxy group having 3 to 20 carbon atoms which may have a substituent" or "linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent", the "linear or branched alkyl group having 1 to 20 carbon atoms", "cycloalkyl group having 3 to 20 carbon atoms", "linear or branched alkoxy group having 1 to 20 carbon atoms", "cycloalkoxy group having 3 to 20 carbon atoms" or "linear or branched alkenyl group having 2 to 20 carbon atoms", the concrete examples thereof include

Linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and the like;

branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, and isooctyl;

cycloalkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl;

a linear alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, or a decyloxy group;

branched alkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, and isooctyloxy;

cycloalkoxy groups such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy and the like;

vinyl group, 1-propenyl group, allyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 1-hexenyl group, isopropenyl group, isobutenyl group, or a straight or branched alkenyl group formed by combining a plurality of these alkenyl groups, and the like.

In the general formula (1), as R ⁵ ～R ⁷ The "substituent" of the "substituted group" represented by "linear or branched alkyl group having 1 to 20 carbon atoms having a substituent", "cycloalkyl group having 3 to 20 carbon atoms having a substituent", "linear or branched alkoxy group having 1 to 20 carbon atoms having a substituent", "cycloalkoxy group having 3 to 20 carbon atoms having a substituent" or "substituted alkenyl group having 2 to 20 carbon atoms having a substituent" may specifically be mentioned

Cycloalkyl groups having 3 to 17 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl and cyclooctyl;

a linear alkoxy group having 1 to 17 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, or a decyloxy group;

a branched alkoxy group having 1 to 17 carbon atoms such as an isopropoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, and an isooctyloxy group;

a cycloalkoxy group having 3 to 17 carbon atoms such as a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, etc.;

an aromatic hydrocarbon group having 6 to 18 carbon atoms such as a phenyl group, a naphthyl group, a biphenyl group, an anthracenyl group, or a condensed polycyclic aromatic group having 6 to 17 carbon atoms. These "substituents" may be contained in only 1 number, or may be contained in plural numbers, and in the case of containing plural numbers, they may be the same or different from each other. These "substituents" may further have the substituents exemplified above.

In the general formula (1), as R ¹ ～R ⁴ The alkyl group may have a substituent and may have a linear or branched alkyl group having 1 to 10 carbon atoms, and the cycloalkyl group may have a substituent and may have 5 to 12 carbon atoms are preferable, and the linear or branched alkyl group may have a substituent and may have 1 to 10 carbon atoms is more preferable.

In the general formula (1), R ¹ And R ² And R ³ And R ⁴ The combinations of (a) and (b) may be the same or different.

In the general formula (1), as R ⁵ ～R ⁷ The alkyl group is preferably a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a linear or branched alkoxy group having 1 to 20 carbon atoms which may have a substituent, and more preferably a hydrogen atom.

In the general formula (1), R ⁵ And R ⁶ The ring may be bonded to each other to form a ring, and as the ring formed in this case, a 5-membered ring or a 6-membered ring is preferable, and a 6-membered ring is more preferable.

In the general formula (1), "M" represents an alkali metal atom, preferably a lithium atom, a sodium atom or a potassium atom, more preferably a lithium atom or a sodium atom, and particularly preferably a sodium atom.

The xanthene dye represented by the general formula (1) can be synthesized by a known method (see non-patent document 1, etc.), for example, as described below. Condensing a sulfonyl aldehyde derivative having a substituent corresponding to benzaldehyde-2, 6-disulfonic acid sodium salt or the like with a hydroxyaniline derivative having a substituent corresponding to diethylaminophenol or the like in an acid aqueous solution such as sulfuric acid under appropriate heating conditions to obtain a mixtureAn intermediate represented by the following general formula (2). Next, the intermediate represented by the following general formula (3) is obtained by dehydrating the following general formula (2). Further, the following general formula (3) is mixed with iron (III) chloride (FeCl) in an acid aqueous solution under appropriate heating conditions ₃ ) The reaction is carried out to oxidize, and the product is neutralized with an alkaline aqueous solution such as sodium hydroxide (NaOH), and then salted out using a salt compound such as sodium chloride (NaCl), thereby obtaining a product containing the compound represented by the general formula (1).

[ solution 4]

[ solution 5]

[ solution 6]

In the above general formulae (2) and (3), R ¹ ～R ⁷ Means the same definition as in the general formula (1).

In the synthesis method of the xanthene-based dye represented by the general formula (1), when the precipitated xanthene-based dye is strongly attached to hinder stirring, an organic solvent may be mixed in order to eliminate or alleviate the adhesion. The organic solvent to be mixed is not particularly limited as long as it has sufficient solubility of the corresponding xanthene-based dye, and aromatic hydrocarbons such as toluene and xylene; ketones such as acetone, 2-butanone, 2-pentanone, and 3-pentanone; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, etc. may be used alone or in combination.

The xanthene dye represented by the general formula (1) can be obtained by purifying a product obtained by the above-mentioned synthesis method by column chromatography, if necessary; adsorption refining with silica gel, active carbon, active clay, etc.; by dispersing and washing with a solvent, recrystallizing, crystallizing, salting out, and other known purification methods. The solvent used in these purification methods is not particularly limited, and alcohols such as water, methanol, and ethanol; halogenated methanes such as dichloromethane and chloroform; toluene and the like are used alone or in combination.

As the xanthene dye of the present invention represented by the general formula (1), commercially available ones can be used. Specifically, xanthene dyes such as c.i. acid red 52, and compositions containing these dyes as a main component are commercially available. The coloring composition of the present invention can be produced by using these compounds as they are, or by using a product purified by the same method as that for the above-mentioned purification method of a xanthene dye.

Specific examples of the compounds preferred as the xanthene-based dye of the present invention represented by the general formula (1) are shown in the following formulae (a-1) to (a-10), and the present invention is not limited to these compounds. In the following structural formulae, a part of hydrogen atoms is omitted. In addition, even in the case where stereoisomers exist, the planar structural formula thereof is described.

[ solution 7]

[ solution 8]

[ solution 9]

[ solution 10]

[ solution 11]

[ solution 12]

[ solution 13]

[ solution 14]

[ solution 15]

[ chemical 16]

The xanthene-based dye represented by the general formula (1) of the present invention may be used in combination (e.g., mixed) with 1 or 2 or more kinds having different molecular structures, and the weight concentration ratio of the minimum 1 kind of the xanthene-based dye is 0.1 to 50% by weight based on the weight concentration ratio of the total xanthene-based dye. That is, the minimum amount of 1 of the 2 or more kinds of xanthene dyes accounts for 0.1 to 50 wt% of the total 2 or more kinds of xanthene dyes. The type of the xanthene-based dye is preferably 1 or 2.

The following describes in detail the coloring composition containing at least one xanthene dye represented by the general formula (1) of the present invention.

The coloring composition containing the xanthene-based dye of the present invention may be a synthetic dye or a commercially available dye, and may be in the form of a powder suitable for use as a color filter. Specific examples of the method for producing the powder of the coloring composition containing a xanthene dye of the present invention are shown below. As a method for obtaining a suitable coloring composition powder by changing the state of the powder, there can be mentioned a method of obtaining a coloring composition powder

(a) A method of obtaining a powder by changing the drying conditions (speed, temperature, air pressure) of the dye solution,

(b) A method of obtaining crystals or aggregates by changing the state of the dye solution (type of solvent, mixed solvent, pH, other solvent),

(c) A method of drying a powder by mixing solvent molecules, water, or other components other than the xanthene-based dye of the present invention,

(d) The drying method or the method of repeating purification of (a) to (c) is appropriately selected,

(e) A method of changing the state of the powder by externally heating the dried powder,

(f) A method of heating the powder in vacuum to sublimate it and recrystallizing it (sublimation purification),

(g) Method for changing powder state by physically applying force (pressurizing) to powder,

(h) Method for separating (classifying) from a mixture of powder states

And so on, all the methods are possible, and preferably several of the above-mentioned methods are selected to obtain a powder.

The powder containing the synthesized xanthene dye or the commercially available xanthene dye contains a solvent molecule, water, a component having a molecular structure other than that of the xanthene dye of the present invention, and other components. These powders can be used as they are, and preferably subjected to a purification treatment. However, although there may be some impurities in any purification method, any dye that can be produced or obtained at the present technical level may be used.

However, the coloring composition of the present invention may contain at least one xanthene-based dye represented by the general formula (1) as a main component in the solid component, and may contain water or other solvent molecules in a certain concentration range. The presence of moisture or the like in the coloring composition is considered to be one of the main factors of the change in the crystal structure of the xanthene-based dye powder, and as a result, the solubility of the xanthene-based dye in an organic solvent such as PGME is considered to change. For example, by adjusting the weight ratio (water content (% by weight)) of water in the entire weight of the coloring composition containing the xanthene-based dye, a coloring composition having high solubility in an organic solvent such as PGME can be obtained while maintaining heat resistance. The water content in the coloring composition can be arbitrarily adjusted within a range of 0.1 to 20 wt%.

As a method for producing a coloring composition containing the xanthene dye of the present invention, the following methods are mentioned as examples of the methods related to the above (a) to (d). In a container of an appropriate size, a powder containing a xanthene-based dye as a main component, activated carbon, and a solvent are placed, mixed, heated, and stirred for a certain period of time. After stirring, hot filtration was performed to obtain a filtrate. The filtrate was concentrated under atmospheric pressure or reduced pressure at an appropriate solvent evaporation rate to obtain a concentrate. The coloring composition containing the solvent and the like is taken out as a concentrate from the container and dried in a separate container. Further, the mixture was dried under reduced pressure at a constant temperature to remove the solvent. This gives a coloring composition containing at least one xanthene dye represented by the general formula (1).

Alternatively, any method may be used as long as it is used to obtain a solid (powder), and for example, after mixing the xanthene dye in the above-mentioned solvent, an appropriate acid or base is added to change the PH to precipitate crystals, and the precipitate is dried by the above-mentioned method. Further, instead of the acid or the base, another solvent or solid may be mixed in the solution, and the precipitated crystal may be dried.

The xanthene dye dissolved or dispersed in a liquid can be dried by evaporating the solvent as described above, and a coloring composition containing the xanthene dye of the present invention can be obtained by various methods such as appropriately changing the speed of the drying, and precipitating the dye in the solvent.

Among them, as materials for the stirring vessel, suitable materials can be selected and used, and for example, glass vessels such as 124671252312505, metal vessels, resin vessels, glass-lined vessels, and the like can be used.

The size of the stirring vessel may be various, and is preferably 1 to 5L per 100g of the powder. However, the amount of the solvent used is not limited to this range, and can be arbitrarily determined depending on the amount of the solvent required for dissolving the xanthene dye to be used.

When activated carbon is used for mixing in a solvent, powdered or fine powdered activated carbon is preferable in order to improve the adsorption ability of activated carbon.

The solvent may be one kind or a mixture of plural kinds, preferably alcohol, and in the case of alcohol, methanol, ethanol, propanol, isopropanol, butanol are preferable, and methanol is more preferable. The solvent may or may not be dehydrated.

The weight ratio of the xanthene-based dye (in the case of 2 or more types, the total thereof) to the solvent in the mixing in the solvent is preferably 3 to 10 times the weight of the solvent based on the weight of the xanthene-based dye. However, the amount of the xanthene dye to be used can be arbitrarily determined without being limited to this range.

As other components, in order to improve the performance of the coloring agent for color filters, which is the coloring composition of the present invention, organic compounds such as surfactants, dispersants, antifoaming agents, leveling agents, and additives mixed in the production of other coloring agents for color filters can be added. However, the content of these additives in the coloring composition is preferably an appropriate amount, and is preferably a content within a range in which the solubility in the solvent of the coloring composition of the present invention is not reduced or excessively improved, and the effect of other additives of the same kind used in the production of a color filter is not affected. These additives can be added at any timing for the preparation of the coloring composition.

The atmosphere in the vessel during mixing or stirring is not particularly limited, and examples thereof include air, nitrogen, and other inert gases. In view of safety against ignition due to static electricity during production, it is preferable to replace the container with an inert gas such as nitrogen.

For drying of the concentrate, the concentrate is transferred to a container such as a dish or a square plate for drying. The mixture was allowed to stand still under atmospheric pressure for 1 to 96 hours so that the water content became an equilibrium state, and then dried (primary drying). The temperature during drying is preferably in the range of 20 ℃ to 100 ℃. Among them, in the primary drying, it is preferable that the drying is not complete and some moisture remains.

The primarily dried xanthene dye-containing coloring composition is further dried (secondary drying) using a dryer having an exhaust device such as a vacuum dryer. The container can be air-dried on a square flat-bottom disk-shaped container with a large bottom area instead of a vacuum dryer. The temperature and time at the time of drying can be arbitrarily set to obtain a colored composition in a desired powder state, and are not particularly limited. When an alcohol is used as the solvent, the time at which the alcohol is removed as much as possible can be set as the end point of drying. Examples of the method of measuring the end point of drying include observation of a powder state, weight measurement, and analysis and quantification of a solvent component by nuclear magnetic resonance analysis (NMR), gas Chromatography (GC), and the like.

Examples of the method for measuring the water content of the colored composition prepared as described above include Karl Fischer (KF) method using coulometry and volumetric titration; thermal analysis using a thermogravimetric-differential thermal analysis (TG-DTA) apparatus; a heat drying method using a heat drying type moisture meter or the like; gas Chromatography (GC), infrared or near infrared absorption; nuclear magnetic resonance absorption; resistance method; dielectric constant method; distillation, and the like. Further, the analysis of the type and amount of impurities other than water can be similarly estimated by powder state observation, gravimetric measurement, NMR analysis, GC analysis, and the like.

As a method for producing a coloring composition containing the xanthene dye of the present invention, the following methods are mentioned as examples of the methods corresponding to the above (e) to (h).

The methods for producing the colored compositions (a) to (d) are wet methods, while the methods (e) to (h) described below are generally dry methods in which the crystal structure is changed while the purity of the resulting powder is maintained when the purity of the dye is further increased.

(e) The heat treatment of (2) is specifically usually used in the case of changing the crystal structure before and after heating from room temperature (around 25 ℃) to the melting point (or glass transition temperature) of a solid. The heating apparatus may be of any material and form, and may be heated on a commercially available hot plate, a commercially available oven, a quartz reaction furnace, or the like. The atmosphere may be air, and in general, nitrogen, an inert gas, or a reduced pressure is preferable in order to prevent decomposition or deterioration of the sample. The heating time may be set as appropriate.

In the sublimation purification of (f), since the powder is heated in vacuum to sublimate it, moisture, solvent molecules, and other impurities in the solid powder can be removed as much as possible, and the crystal structure is often changed during recrystallization compared to before sublimation. The apparatus is not limited as long as it can reduce the pressure to a high vacuum to an ultrahigh vacuum. The material of the heating container in which the sample is placed may be metal or glass.

When a high pressure is applied to the powder as in the method of applying pressure (g), the crystal system of the solid may irreversibly change. The pressure application method may be air pressure, or may be compression using a press of hard metal steel or the like.

(h) The classification of (3) is a method of separating a specific state component from a product having a size, a density and a crystal structure which are not single, in a powder obtained by any of the above-mentioned methods of obtaining a solid powder. The powder before separation may or may not be initially subjected to pulverization. When crystals of different components are bonded, the components may be easily separated by a pulverization treatment. When the classification is performed by size, a device such as a sieve is used. For the powders having different densities and weights, an apparatus for scattering the powders in a gas flow, separating the powders by a difference in flight distance, or performing centrifugal separation can be used.

The above-described method provides a powdery coloring composition containing at least one xanthene dye represented by the general formula (1). The following description will be made of a method for obtaining a powder having a state suitable for a color filter, which is a problem to be solved by the present invention.

The shape of the powder of the coloring composition of the present invention can be observed using an optical microscope, a Scanning Electron Microscope (SEM), or the like. The shape of the coloring composition of the present invention is not particularly limited, and the coloring composition is usually used in the form of a solid powder having a shape such as a crystal, a microcrystalline, a fine powder, a flake, a needle crystal, or a granule.

By measuring the particle size distribution, surface area, pore size distribution, powder density, and the like of the powder of the colored composition of the present invention, information on the overall and average shape of the powder is obtained in more detail. For example, measurement can be performed by a coulter method in which resistance of an electrolytic solution in which a powder is dispersed is measured, a centrifugal sedimentation method in which a stokes effective diameter is determined by measuring absorbance of a dispersion of a powder, a laser diffraction/scattering method in which a diffraction/scattering pattern of a dispersion of a powder is analyzed, or the like. The coloring composition of the present invention preferably has a particle diameter in the range of 0.1 μm to several mm, and the particle shape is changed depending on the production conditions and the method of recovering the dried powder, so that the particle diameter is not limited to a specific particle diameter, and for high solubility, the particle diameter is preferably smaller, and the median of the particle diameter distribution is preferably in the range of 0.1 to 100 μm.

By analyzing the elemental composition and structure of the surface of the powder of the coloring composition of the present invention, information on the fine structure at the molecular level and the atomic level can be estimated. Specifically, information on the surface of the sample, analysis of the composition of atoms inside the particles, and bonding between atoms is obtained using ultraviolet light, X-rays, and electron beams. In particular, in terms of powder X-ray diffraction (XRD) using X-rays, information on lattice constants, periodicities, and the like of the arrangement (crystal structure) of atoms and molecules is obtained.

The decomposition starting temperature of the powder can be analyzed by performing thermogravimetry-differential thermal analysis (TG-DTA) of the colored composition of the present invention. The decomposition initiation temperature is preferably 250 ℃ or higher, more preferably 300 ℃ or higher, and particularly preferably 360 ℃ or higher. In the case of application to a color filter, the higher the decomposition start temperature is, the more preferable.

The solubility of the powder of the coloring composition in the present invention is represented by solubility, and the solubility represents the proportion of the coloring composition in the maximum amount that the powdery coloring composition can be dissolved in a specific solvent, and is represented by, for example, a unit such as "weight% (solvent name, temperature)". The solubility can be obtained by, for example, mixing a sample in a specific solvent, stirring the solvent at a constant temperature for a constant time, and measuring the concentration of the prepared saturated solution, or by concentration measurement using Liquid Chromatography (LC), absorbance measurement, or the like in the dissolution part.

The coloring composition contained in the colorant for color filters is preferably highly soluble in an organic solvent, such as a resin, because it must be well dissolved or dispersed in the colorant for color filters and in the organic solvent containing the resin in the production process of the color filters. The organic solvent is not particularly limited, and specific examples thereof include esters such as ethyl acetate and n-butyl acetate; ethers such as diethyl ether and Propylene Glycol Monomethyl Ether (PGME); ether esters such as Propylene Glycol Monomethyl Ether Acetate (PGMEA); ketones such as acetone and cyclohexanone; alcohols such as methanol and ethanol; diacetone alcohol (DAA), etc.; aromatic hydrocarbons such as benzene, toluene, and xylene; amides such as N, N-Dimethylformamide (DMF) and N-methylpyrrolidone (NMP); dimethyl sulfoxide (DMSO), and the like. These solvents may be used alone, or 2 or more of them may be used in combination. Among these, the coloring composition containing the xanthene-based dye according to the present invention is preferably particularly excellent in solubility in PGME.

The spectral characteristics (transmittance, reflectance) of the powder of the colored composition of the present invention are important in the case of using a coloring matter alone as a coloring agent for a color filter or in the case of using the coloring matter in a mixture with other coloring matters, and directly affect the color characteristics of the color filter. As a measurement method, there is a method of measuring an absorption (or transmission) spectrum in a solution or dispersion state, or an absorption (or transmission) spectrum of a thin film coated on glass or a transparent resin substrate. Further, there is a method of directly irradiating a powder with light to measure light reflected and scattered on the particle surface or in the vicinity of the particle surface.

Among the above analysis methods, powder X-ray diffraction, thermal analysis, and solubility analysis are suitable as an analysis method for a coloring composition containing the xanthene-based dye of the present invention, and in particular, powder X-ray diffraction is suitable as a method for judging and estimating whether or not the powder has an appropriate crystal structure (powder characteristics) with respect to whether or not the powder is uniformly dispersed by being mixed and dissolved with other materials, whether or not a film having heat resistance and light resistance is obtained, whether or not the powder exhibits color characteristics suitable as a color filter, and the like. In powder X-ray diffraction, cuK α rays (h ν =8.048keV, wavelength λ =0.15418 nm) and MoK α rays (h ν =17.5keV, wavelength λ =0.071073 nm) are generally used as X-ray sources, and powder X-ray diffraction using CuK α rays is preferred.

In the present invention, in the measurement of powder X-ray diffraction of a colored composition containing at least one xanthene-based dye represented by the general formula (1), a characteristic diffraction peak is observed for 30 samples at maximum in the range of diffraction angle (bragg angle) 2 θ =2 ° to 35 °. When a peak appears in the range of 2 θ =2 ° to 35 ° in the powder X-ray diffraction, it indicates that the periodicity of the atoms of about 0.2nm to about 4.0nm exists in the solid powder sample. For example, in a xanthene molecule such as acid red 52, which is a typical xanthene-based dye, the shortest interatomic bonding distance is about 0.13 ± 0.02nm, and the distance of 2 nitrogen interatomic atoms is about 1nm. The maximum width of the molecule of the xanthene dye represented by the general formula (1) is 1 to 2nm, and the lattice of a general molecular crystal is about the same as the maximum width of the molecule. That is, the diffraction pattern observed in the above-mentioned diffraction angle range represents information on the arrangement between the atoms in the xanthene molecule and information on the arrangement between the xanthene molecules in the powder. For this reason, powder X-ray diffraction is excellent as a method for analyzing the internal state of a powder containing a xanthene-based dye.

Therefore, in the present invention, in the measurement of powder X-ray diffraction of CuK α rays, the maximum 30 diffraction peaks are preferably observed in the range of diffraction angles 2 θ =2 ° to 35 ° in the colored composition containing at least one xanthene-based dye represented by the general formula (1). In the range of the diffraction angle, peaks indicating periodicity such as carbon-carbon, carbon-nitrogen, carbon-oxygen (which may be directly bonded to each other and may have a space therebetween through another atom) and the like between each atomic distance in the xanthene molecule are observed in the range of 2 θ =18 ° to 35 °, and specifically, 5 or more and 20 or more significant peaks are preferably observed in the range of 2 θ =2 ° to 25 °.

In the present invention, a colored composition containing at least one xanthene-based dye represented by the general formula (1) can be considered to contain not only information on interatomic spacing within a xanthene molecule but also information on periodicity between 2 adjacent xanthene molecules, by observing a diffraction peak in a range of diffraction angles 2 θ =2 ° to 10 ° in the measurement of powder X-ray diffraction of CuK α rays, the diffraction peak being related to a distance equal to or greater than a distance between 2 nitrogen atoms of the xanthene molecule, for example. In the present invention, the inventors have found that a method for producing a powder of a xanthene-based dye, a powder X-ray diffraction pattern obtained as a result thereof, and color filter characteristics evaluated by using the dye, particularly color developability (contrast ratio) have a correlation. Specifically, a coloring composition containing at least one xanthene dye represented by general formula (1) has a significant peak and a non-significant peak at a diffraction angle (2 θ) =3 ° to 7 ° in powder X-ray diffraction of CuK α rays. For example, the presence or absence of a significant peak at 2 θ =5 ° indicates the presence or absence of a periodicity of 1.7 to 1.8nm in the coloring composition. It is estimated that the periodicity of 1.7 to 1.8nm corresponds to the distance between the xanthene molecules, and depending on the method of preparing the sample, it is suggested that the person who has arranged the xanthene molecules having the above-mentioned rules and the person who does not have the xanthene molecules having the above-mentioned rules may have different structures for obtaining crystals of the xanthene molecules. Since the difference in crystal structure also affects the magnitude and interaction of intermolecular force between xanthene molecules, the difference also has a large influence on solubility and dispersibility in a solvent and interaction with other pigments and resin materials for color filters, and thus the difference directly affects the physical properties of the color filters. As the colorant for color filters, it is preferable that the number of peaks at diffraction angles (2 θ) =3 ° to 7 ° in powder X-ray diffraction of CuK α rays is 0 (no significant peak is observed).

The colorant for color filters of the present invention comprises: a coloring composition containing at least one xanthene dye represented by general formula (1) and a component generally used in the production of color filters. In a general color filter, for example, in the case of a method using a photolithography step, a dye such as a dye or a pigment is mixed with a resin component (including a monomer or an oligomer) and a solvent, the prepared liquid is applied onto a substrate such as glass or resin, and is photopolymerized using a photomask to prepare a colored pattern of a dye-resin composite film soluble/insoluble in the solvent, and the colored pattern is cleaned and then heated to obtain the color filter. In addition, in the electrophoresis method and the printing method, a coloring pattern is also produced using a mixture of a coloring matter, a resin, and other components. Accordingly, specific components in the colorant for color filters of the present invention include at least one xanthene-based dye represented by the general formula (1), another dye, a pigment such as a pigment, a resin component, an organic solvent, and another additive such as a photopolymerization initiator. Further, these components may be selected from them, and other components may be added as necessary.

When the coloring composition containing the xanthene dye of the present invention is used as a colorant for color filters, it can be used for color filters of various colors, but is preferably used as a colorant for cyan or red color filters.

The colorant for color filters containing the xanthene-based dye of the present invention may be one of 1 type or 2 or more types of xanthene-based dyes, and for adjustment of color tone, other known colorants such as dyes and pigments may be mixed. When the colorant is used for a red color filter, the colorant is not particularly limited, and examples thereof include red pigments such as c.i. pigment red 177, c.i. pigment red 209, c.i. pigment red 242, and c.i. pigment red 254; other red-based lake pigments; red dyes such as c.i. acid red 88 and c.i. basic violet 10. When the colorant is used for a cyan color filter, the colorant is not particularly limited, and examples thereof include basic dyes such as c.i. basic blue 3, 7, 9, 54, 65, 75, 77, 99, 129; acid dyes such as c.i. acid blue 9 and 74; disperse dyes such as disperse blue 3, 7, 377, etc.; spiro (12473, \\ 125001252512531); cyanine series, indigo series, phthalocyanine series, anthraquinone series, methine series, triarylmethane series, indanthrene series, oxazine series, dioxazine series, azo series, xanthene series not belonging to the present invention; and cyan dyes and pigments such as other cyan lake pigments.

The mixing ratio of the other pigments in the colorant for color filters containing the xanthene-based dye of the present invention is preferably 5 to 2000% by weight, more preferably 10 to 1000% by weight, based on the xanthene-based dye (in the case of 2 or more types, the total of these). The mixing ratio of the coloring matter component such as a dye in the liquid coloring agent for color filters is preferably 0.5 to 70% by weight, more preferably 1 to 50% by weight, based on the entire coloring agent.

As the resin component in the colorant for color filters of the present invention, a known resin component can be used as long as it has properties necessary for the production method and use of the color filter resin film formed by using the colorant. Examples thereof include acrylic resins, olefin resins, styrene resins, polyimide resins, polyurethane resins, polyester resins, epoxy resins, vinyl ether resins, phenol (novolac) resins, other transparent resins, photocurable resins, and thermosetting resins, and the monomer or oligomer components thereof can be used in combination as appropriate. In addition, copolymers of these resins may be used in combination. The content of the resin in the colorant for color filters is preferably 5 to 95% by weight, and more preferably 10 to 50% by weight in the case of a liquid colorant.

Examples of other additives in the colorant for color filters of the present invention include components necessary for polymerization and curing of a resin, such as a photopolymerization initiator and a crosslinking agent, and surfactants and dispersants necessary for stabilizing the properties of the components in a liquid colorant for color filters. Any known additive for producing color filters can be used, and is not particularly limited. The mixing ratio of the total amount of these additives in the total solid content of the colorant for color filters is preferably 5 to 60% by weight, and more preferably 10 to 40% by weight.

Examples

The embodiments of the present invention will be specifically described below with reference to examples, but the present invention is not limited to only the following examples. In addition, the compounds obtained in the examples were identified by ¹ H-NMR analysis (Nuclear magnetic resonance device, JNM-ECA-600, manufactured by Nippon electronic Co., ltd.) was carried out.

[ example 1]

[ preparation of powder of coloring composition ]

A3L reaction vessel was charged with acid Red 52 (150 g) represented by the following formula (A-3) and 1.2L of methanol, and the mixture was dissolved at 50 ℃ and 7.5g of activated carbon (type: egret A-2, hereinafter referred to as "Egret") was added thereto and stirred for 1 hour. The reaction solution was filtered 2 times through a filter paper (model: GF-75, manufactured by ADVANTEC). The filtrate was concentrated, and dissolved in 1.12L of methanol at 50 ℃ to obtain a solution, and 1.12L of ethyl acetate was added thereto, followed by stirring for 3 hours and filtration. The filtrate was dried under reduced pressure at 60 ℃ for 24 hours to obtain a green crystalline coloring composition (104.4 g). NMR analysis of the colored composition confirmed that no component of an organic solvent such as methanol was observed.

[ solution 17]

[ powder X-ray diffraction measurement ]

The powder of the coloring composition obtained as described above was subjected to powder X-ray diffraction (XRD) measurement (RINT-2200 Ultima model, sample horizontal X-ray diffractometer manufactured by Kokai corporation, RINT-1246063, X-ray source CuK alpha ray (h v =0.15418nm, 30kV, 30 mA), divergent slit: 1/2 °, scattering slit: 1/2 °, light-receiving slit: 0.15mm, scanning slit: 0.02 °, scanning speed: 2 °/min, scanning diffraction angle range: 2 θ =2 ° -35 °). The results are shown in fig. 1. The numbers of significant diffraction peaks observed in the ranges of 2 θ =2 ° to 7 °, 7 ° to 15 °, 15 ° to 25 °, and 25 ° to 35 ° are shown in table 1. However, no counts were made for peaks below about 5% of the maximum peak intensity and peaks where the shoulder was not evident.

[ Table 1]

[ color Filter characteristics ]

A color filter was produced by using the above-mentioned colored composition and forming a film by the following method, and the contrast ratio was measured. 30 parts of an evaluation resin prepared from benzyl methacrylate and methacrylic acid, 70 parts of PGME, and 2 parts of a dye were mixed to obtain a coloring composition. The coloring composition was applied onto a glass substrate (50X 0.7 mm) by means of a spin coater (manufactured by a company of\12511\1245912412469. The glass substrate was dried at 90 ℃ for 10 minutes. The obtained coated substrate was sandwiched by 2 polarizing plates, a backlight was turned on, and the brightness of the polarizing plates in a straight line and in a parallel line was measured. From the measured luminance ratio, the contrast ratio was calculated. The results are shown in table 1.

[ example 2]

Acid Red 52 (40 g) represented by the above formula (A-3) and 0.32L of methanol were charged into a 1L reaction vessel, dissolved at 60 ℃, and 2g of activated carbon (type: aigret) was added thereto and stirred for 1 hour. The reaction mixture was filtered 2 times at 50 ℃ through a filter paper (model: GF-75, manufactured by ADVANTEC). The filtrate was transferred to a square pan (30 cm. Times.40 cm), put into a vacuum drier, and dried under reduced pressure under conditions of temperature-heating time of 50 ℃ to 2 hours, 65 ℃ to 2 hours, 80 ℃ to 20 hours to obtain a colored composition (40.3 g) in the form of purple crystals. NMR analysis of the colored composition confirmed that no component of an organic solvent such as methanol was observed. The colored composition was measured for powder X-ray diffraction and contrast ratio in the same manner as in example 1, and the results are shown in fig. 1 and table 1.

Comparative example 1

A10-L reaction vessel was charged with acid Red 52 (700 g) represented by the above formula (A-3), 40g of activated carbon (type: aigret) and 6L of methanol, stirred at 55 ℃ for 1 hour, and then filtered at 50 ℃. The filtrate was concentrated under reduced pressure to 1/3 weight, poured into a square pan, air dried at 25. + -. 2 ℃ for 4 days, and dried under reduced pressure at 80 ℃ for 5 days. When the weight loss reached 0.4 wt% per 1 day, drying was completed, and a reddish purple powder of the coloring composition (715 g) containing the xanthene dye (A-20) was obtained. NMR analysis of the colored composition confirmed that no component of an organic solvent such as methanol was observed. For this coloring composition, powder X-ray diffraction and contrast ratio were measured, and the results are shown in fig. 1 and table 1.

Comparative example 2

The coloring composition obtained in comparative example 1 was pulverized in a mortar. For this coloring composition, powder X-ray diffraction and contrast ratio were measured, and the results are shown in fig. 1 and table 1.

As shown in fig. 1 and table 1, in the colored compositions of examples 1 and 2, the number of diffraction peaks at diffraction angles 2 θ =3 ° to 7 ° in the powder X-ray diffraction of CuK α rays was 0, and the contrast ratio of the color filter produced using the same was practically problematic when used in a color filter.

On the other hand, in the colored compositions of comparative examples 1 and 2, the number of diffraction peaks at diffraction angles 2 θ =3 ° to 7 ° in the powder X-ray diffraction of CuK α rays was 1, and the contrast ratio was lower than that in examples.

As described above, the color filter produced using the coloring composition containing the xanthene-based dye of the present invention has a high contrast ratio and is therefore useful as a colorant for color filters.

Industrial applicability

The colored composition containing the xanthene dye of the present invention can be used as a colorant for color filters, and can produce color filters having excellent contrast ratios.

Claims

1. A coloring composition which contains a xanthene dye represented by the following general formula (1) and has 0 diffraction peak number in the range of diffraction angle (2 theta) 3-7 DEG in powder X-ray diffraction of CuK alpha ray,

in the formula, R ¹ ～R ⁴ Each independently represents-CH ₂ CH ₃ ，

R ⁵ ～R ⁷ Each independently represents a hydrogen atom, and each independently represents a hydrogen atom,

m represents an alkali metal atom.

2. The coloring composition according to claim 1, wherein 2 or more types of the xanthene-based dyes represented by the general formula (1) are contained, and the weight concentration ratio of the minimum 1 type of the xanthene-based dyes is 0.1 to 50% by weight, based on the weight concentration ratio of the total xanthene-based dyes.

3. A colorant for color filters, which contains the coloring composition according to claim 1 or 2.

4. A color filter using the colorant for color filters according to claim 3.