WO2019003915A1

WO2019003915A1 - Coloring composition containing xanthene-based dye, coloring agent for color filter, and color filter

Info

Publication number: WO2019003915A1
Application number: PCT/JP2018/022545
Authority: WO
Inventors: 良和青木; 大三神田; 直哉山縣
Original assignee: 保土谷化学工業株式会社
Priority date: 2017-06-29
Filing date: 2018-06-13
Publication date: 2019-01-03
Also published as: JPWO2019003915A1; TW201905104A; TWI756440B; JP7091330B2; KR20200023276A; CN110997822A; CN110997822B

Abstract

This coloring composition containing a xanthene-based dye is represented by general formula (1), and a coloring agent, which is for a color filter and contains the coloring composition containing the xanthene-based dye and having number of diffraction peaks of 0 in a range of 3°-7° of a diffraction angle (2ɵ) in a powder X-ray diffraction of CuKα radiation, provides a color filter having a high display contrast ratio.

Description

Colored composition containing xanthene dye, colorant for color filter and color filter

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

Color filters may be used in liquid crystal and electroluminescent (EL) display devices. The color filter is manufactured by laminating a colored layer on a light transmitting substrate such as glass by a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method or the like. The colorants used in the colored layer can be roughly classified into pigments and dyes, but pigments generally considered to be excellent in 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 the form of fine particles in color filters containing resins and the like. Therefore, a color filter using a pigment affects transparency and color purity by transmitting and reflecting light on the surface of the pigment particles in the filter, and has a depolarizing effect by reflection, so that color liquid crystal display It is known that the contrast ratio of the device is reduced.

In order to ameliorate the problem of such a reduction in contrast ratio, a method using only a dye as a colorant or a method using a dye and a pigment in combination has been proposed. Since the dye is soluble in the solvent, the color filter using the dye suppresses the depolarizing action as compared with the case where only the pigment is used as the colorant, and is excellent in spectral characteristics. As dyes used for color filters, xanthene dyes and the like are known from the viewpoint of having excellent color developability, heat resistance and light resistance (see, for example, Patent Documents 4 to 7). C.I. I. Acid Red 289 or a C.I. I. It is described that an excellent red color tone can be obtained by using a xanthene dye such as Acid Red 52 in combination with an azo pyridone dye (see, for example, Patent Document 4). Here, C.I. I. And means color index.

Further, it is known that a blue color filter having a high contrast ratio and color purity can be produced by using these xanthene dyes or derivatives thereof in combination with phthalocyanine dyes (see, for example, Patent Documents 6 and 7). A color filter using such a dye and a pigment in combination is oxidized because charge transfer occurs immediately between a photoexcited dye molecule and a nearby pigment molecule by forming an aggregate by mixing two different colors. It is considered that they also have the effect of suppressing the decomposition each other, and it is possible to maintain the coloring property and to improve the light resistance as compared with the color filter prepared by using the dye alone.

JP 2001-220520 A Special Publication 2007-533802 JP 2012-12498 A JP 2002-265834 A JP 2012-207224 A Unexamined-Japanese-Patent No. 2010-25496 JP, 2014-12814, A

However, many of the conventional xanthene dyes have sufficient solubility and dispersibility in organic solvents for producing color filters, although their color forming properties and heat resistance are sufficient. In general, dyes such as xanthene dyes are water-soluble and, as shown in formula (I), a nitrogen atom (= N ⁺ <) positively charged in the molecule, a negatively charged group (-SO ₃ ^- etc.) because it has), a water molecule (H 2 _O), etc. and easily hydrogen bond is a polar molecule. However, molecules having a plurality of polar groups, such as xanthene dyes, are relatively separated by the intermolecular force (van der Waals force, hydrogen bond, ionic bond, etc.) where the molecules act between identical or different substituents. A strong bond is formed to form an aggregate of several to several tens. If aggregates of these dye molecules remain at a certain size, coating unevenness occurs during film formation, light resistance and heat resistance decrease, and depolarizing action of transmitted light such as pigment also becomes complicated. The color developability as a color filter is further reduced.

When an organic pigment or organic dye is poorly soluble in a solvent, a method of physically pulverizing with an apparatus such as a bead mill to prepare a dispersion in which the particle size of the pigment or dye aggregate is micronized to about several tens of nm is general However, in order to keep the dispersed state of the particles in the solvent stable, additives such as surfactants are required, and when the dispersion is unstable, the particles reaggregate between the particles, The dispersion may gel. Therefore, as properties required for xanthene dyes for producing color filters, it is necessary to develop a preparation method that can be easily dissolved or uniformly dispersed in a solvent without the need for extra additives.

The present invention was made in order to solve the above-mentioned problems, and is a coloring composition containing a xanthene dye excellent in color tone adjustment as a coloring agent for color filters, which is good in the manufacturing process of color filters. Composition containing a xanthene dye having a solid (powder and the like) state necessary to exhibit good solubility or dispersibility, a coloring agent for color filter containing the coloring composition, and coloring for the color filter It is an object of the present invention to provide a color filter excellent in coloring properties (brightness, contrast ratio, etc.) using an agent.

The inventors have found an optimum preparation method of xanthene dye powder for color filter production, and further found that the characteristics of the solid powder can be analyzed by powder X-ray diffraction, such xanthene dyes By using a coloring composition containing a dye, it has been found that a color filter having excellent color developability (contrast ratio) can be obtained, resulting in the present invention.

That is, the present invention is obtained as a result of earnest research in order to achieve the above object, and the gist of the present invention is as follows.

1. It is a coloring composition containing a xanthene dye represented by the following general formula (1),
A coloring composition containing at least one xanthene dye, wherein the number of diffraction peaks in the range of 3 ° to 7 ° of diffraction angle (2θ) in powder X-ray diffraction of CuKα ray is zero.

[Wherein, R ¹ to R ⁴ are each independently
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 to R ⁷ each independently represent 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, or
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 as in the above general formula (1), wherein R ¹ to R ⁴ are a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent.

3. The xanthene dye represented by the general formula (1) contains two or more kinds, and the weight concentration ratio of the smallest xanthene dye is 0.1 in the weight concentration ratio of the total xanthene dyes. Colored composition which is ̃50% by weight.

4. The coloring agent for color filters containing the said coloring composition.

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

The color filter produced using the coloring agent for color filters containing the coloring composition containing the xanthene dye of the present invention is excellent in color development such as contrast ratio, and the xanthene dye of the present invention is a color filter It is useful as a coloring agent.

It is a figure of the powder X-ray diffraction (XRD) of the coloring composition of the Example of this invention, and a comparative example.

Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can variously deform and implement within the range of the summary. First, the xanthene dye represented by the general formula (1) will be described.

Specific examples of the “optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms” represented by R ¹ to R ⁴ in the general formula (1) include , Linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl; isopropyl, isobutyl, s-butyl, Examples thereof include branched alkyl groups such as t-butyl group and isooctyl group.

Specific examples of the “optionally substituted cycloalkyl group having 3 to 20 carbon atoms” represented by R ¹ to R ⁴ in the general formula (1) include cyclopropyl and cyclopentyl Examples thereof include cycloalkyl groups such as a group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group and a cyclodecyl group.

Specific examples of the “substituent” in the “C ¹ to C 20 linear or branched alkyl group having a substituent” represented by R ¹ to R ⁴ in the general formula (1) include ,
Fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as iodine atom; -SO ₃ ^-;
A cycloalkyl group having 3 to 19 carbon atoms, such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group;
A linear alkoxy group having 1 to 19 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like;
A branched alkoxy group having 3 to 19 carbon atoms such as isopropoxy group, isobutoxy group, s-butoxy group, t-butoxy group, isooctyloxy group;
Cycloalkoxy groups having 3 to 19 carbon atoms, such as cyclopropoxy, cyclobutoxy, cyclopentyloxy and cyclohexyloxy;
An aromatic hydrocarbon group having 6 to 19 carbon atoms or a fused polycyclic aromatic group such as phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, pyrenyl group, triphenylenyl group, indenyl group and fluorenyl group;
Pyridyl group, pyrimidinyl group, triazinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, triazolyl group, quinolyl group, isoquinolyl group, naphthyridinyl group, indolyl group, benzimidazolyl group, carbazonyl group, carborinyl group, acridinyl group, phenanthrolinyl group And heterocyclic groups having 2 to 19 carbon atoms, such as furanyl group, benzofuranyl group, dibenzofuranyl group, thienyl group, benzothienyl group, dibenzothienyl group, oxazolyl group, benzoxazolyl group, thiazolyl group, benzothiazolyl group, etc. And so on. One or more of these “substituents” may be contained, or two or more of these “substituents” may be contained in the same or different groups. Moreover, these "substituents" may further have the substituents exemplified above.

Specific examples of the “substituent” in the “C 3-20 cycloalkyl group having a substituent” represented by R ¹ to R ⁴ in the general formula (1) include a fluorine atom and a chlorine atom. , a bromine atom, a halogen atom such as iodine atom; -SO ₃ ^-;
Straight-chain alkyl groups having 1 to 14 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl;
Branched alkyl groups having 3 to 14 carbon atoms, such as isopropyl, isobutyl, s-butyl, t-butyl and isooctyl;
A cycloalkyl group having 3 to 14 carbon atoms, such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group;
A linear alkoxy group having 1 to 14 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like;
A branched alkoxy group having 3 to 14 carbon atoms, such as isopropoxy group, isobutoxy group, s-butoxy group, t-butoxy group, isooctyloxy group;
Cycloalkoxy groups having 3 to 14 carbon atoms such as cyclopropoxy, cyclobutoxy, cyclopentyloxy and cyclohexyloxy;
An aromatic hydrocarbon group having 6 to 14 carbon atoms or a fused polycyclic aromatic group such as phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, indenyl group and fluorenyl group;
Pyridyl group, pyrimidinyl group, triazinyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, triazolyl group, quinolyl group, isoquinolyl group, naphthyridinyl group, indolyl group, benzimidazolyl group, carbazonyl group, carborinyl group, acridinyl group, phenanthrolinyl group And heterocyclic groups having 2 to 14 carbon atoms such as furanyl group, benzofuranyl group, dibenzofuranyl group, thienyl group, benzothienyl group, dibenzothienyl group, oxazolyl group, benzoxazolyl group, thiazolyl group, benzothiazolyl group, etc. And so on. One or more of these “substituents” may be contained, or two or more of these “substituents” may be contained in the same or different groups. Moreover, these "substituents" may further have the substituents exemplified above.

Examples of the “halogen atom” represented by R ⁵ to R ⁷ in the general formula (1) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. As the "halogen atom", a fluorine atom or a chlorine atom is preferable.

In the general formula (1), “a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent,” represented by R ⁵ to R ⁷ , “having a substituent” "Optionally substituted cycloalkyl group having 3 to 20 carbon atoms", "optionally substituted linear or branched alkoxy group having 1 to 20 carbon atoms", "having a substituted group [1 carbon atom] in the optionally substituted cycloalkoxy group having 3 to 20 carbon atoms or "a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent (s)" To 20 linear or branched alkyl groups, "cycloalkyl groups having 3 to 20 carbon atoms", "linear or branched alkoxy groups having 1 to 20 carbon atoms", "number of carbon atoms" 3 to 20 cycloalkoxy group "or" 2 to 2 carbon atoms " The linear or branched alkenyl group ", specifically,
Straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl;
Branched alkyl groups such as isopropyl, isobutyl, s-butyl, t-butyl and isooctyl;
And cycloalkyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl and cyclodecyl;
Linear alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like;
Branched alkoxy groups such as isopropoxy group, isobutoxy group, s-butoxy group, t-butoxy group, isooctyloxy group;
Cycloalkoxy groups such as cyclopropoxy group, cyclobutoxy group, cyclopentyloxy group, cyclohexyloxy group and the like;
Linear group in which plural vinyl groups, 1-propenyl group, allyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 1-hexenyl group, isopropenyl group, isobutenyl group or a plurality of these alkenyl groups are bonded Alternatively, branched alkenyl groups can be mentioned.

In the general formula (1), “a linear or branched alkyl group having 1 to 20 carbon atoms having a substituent,” represented by R ⁵ to R ⁷ , “a carbon having 3 to 6 carbon atoms having a substituent” “20 cycloalkyl group”, “a substituted or unsubstituted linear or branched alkoxy group having 1 to 20 carbon atoms”, “a substituted cycloalkoxy group having 3 to 20 carbon atoms” or “a substituted group As the “substituent” of the linear or branched alkenyl group having 2 to 20 carbon atoms which has
Fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as an iodine atom; -SO ₃ ^-;
A cycloalkyl group having 3 to 17 carbon atoms, such as cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group and the like;
Linear alkoxy groups having 1 to 17 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like;
Branched alkoxy groups having 1 to 17 carbon atoms such as isopropoxy group, isobutoxy group, s-butoxy group, t-butoxy group, isooctyloxy group;
Cycloalkoxy groups having 3 to 17 carbon atoms such as cyclopropoxy, cyclobutoxy, cyclopentyloxy and cyclohexyloxy;
Examples thereof include aromatic hydrocarbon groups having 6 to 18 carbon atoms such as phenyl, naphthyl, biphenyl and anthracenyl, and fused polycyclic aromatic groups having 6 to 17 carbons. One or more of these "substituents" may be contained, or two or more of them may be contained. Moreover, these "substituents" may further have the substituents exemplified above.

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

In the general formula (1), the combination of R ¹ and R ^{2 and} the combination of R ³ and R ⁴ may be the same or different.

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

In the general formula (1), R ⁵ and R ⁶ may be bonded to each other to form a ring, and the ring formed in that case is preferably a 5- or 6-membered ring, and a 6-membered ring Is more preferred.

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 dyes represented by the general formula (1) can be synthesized, for example, as follows by a known method (see Non-Patent Document 1 and the like). A sulfonylaldehyde derivative having a corresponding substituent, such as sodium benzaldehyde-2,6-disulfonate, and a hydroxyphenylamine derivative having a corresponding substituent, such as diethylaminophenol, in an aqueous acid solution such as sulfuric acid are suitable. A condensation reaction is performed under heating conditions to obtain an intermediate represented by the following general formula (2). Next, the following general formula (2) is dehydrated to obtain an intermediate represented by the following general formula (3). Furthermore, the following general formula (3) was reacted with iron chloride (III) (FeCl ₃ ) in an aqueous acid solution under appropriate heating conditions for oxidation, and neutralized with a basic aqueous solution such as sodium hydroxide (NaOH) Thereafter, salting out with a salt compound such as sodium chloride (NaCl) gives a product containing the compound represented by the general formula (1).

In the above general formulas (2) and (3), R ¹ to R ⁷ mean the same definition as the general formula (1).

In the synthesis method of the xanthene dye represented by the general formula (1), even if the precipitated xanthene dye adheres firmly and interferes with stirring, even if an organic solvent is mixed in order to eliminate or alleviate it. Good. The organic solvent to be mixed is not particularly limited as long as it has sufficient solubility of the corresponding xanthene dyes, and aromatic hydrocarbons such as toluene and xylene; acetone, 2-butanone, 2-pentanone, 3-pentanone and the like Ketones; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, propanol, isopropanol, butanol, pentanol and hexanol, etc. can be used alone or in combination.

The xanthene dye represented by the general formula (1) may optionally be purified by column chromatography of the product obtained by the above synthesis method; adsorption purification by silica gel, activated carbon, activated clay, etc .; dispersion by solvent It can be obtained by performing known purification such as washing, recrystallization, crystallization, salting out and the like. The solvent used for these purification methods is not particularly limited, and alcohols such as water, methanol and ethanol; halomethanes such as dichloromethane and chloroform; toluene and the like can be used alone or in combination.

A commercial item can be used as a xanthene type-dye of this invention represented by General formula (1). Specifically, C.I. I. There are commercially available xanthene dyes such as Acid Red 52, or compositions containing these dyes as main components. These may be used as they are to prepare the coloring composition of the present invention, or to prepare the coloring composition of the present invention using one purified by the same method as the method for purifying xanthene dyes described above. it can.

Specific examples of compounds preferred as the xanthene dyes of the present invention represented by the general formula (1) are shown in the following formulas (A-1) to (A-10), but the present invention is limited to these compounds It is not a thing. In the following structural formula, hydrogen atoms are partially omitted. In addition, even when a stereoisomer exists, its plane structural formula is described.

The xanthene dyes represented by the general formula (1) of the present invention may be used alone or in combination of two or more different in molecular structure (for example, mixed), and the weight concentration ratio in the whole xanthene dyes The weight concentration ratio of the smallest one xanthene dye is 0.1 to 50% by weight. That is, of the two or more xanthene dyes, a minimum amount of one xanthene dye accounts for 0.1 to 50% by weight of the total of the two or more xanthene dyes. The type of xanthene dye is preferably one or two.

Hereinafter, the coloring composition containing at least 1 sort (s) of xanthene type dye represented by General formula (1) of this invention is demonstrated in detail.

The coloring composition containing the xanthene dye according to the present invention may be either a synthesized dye or a commercially available dye, and has a powdery state suitable for color filters. The specific example of the preparation method of the powder of the coloring composition containing the xanthene type dye of this invention is shown below. As a method of changing the state of a powder and obtaining a suitable colored composition powder,
(A) A method of obtaining a powder by changing the drying conditions (speed, temperature, 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, etc.),
(C) A method of mixing solvent molecules, moisture, or other components other than the xanthene dye of the present invention in a powder and drying it.
(D) A method of selecting the drying method of (a) to (c) as appropriate, or repeating and purifying it,
(E) A method of changing the state of powder by heat treating the dried powder from the outside,
(F) A method of heating and sublimating the powder in vacuum and recrystallization (sublimation purification),
(G) physically changing the powder state by applying pressure to the powder
(H) A method of separating (classifying) from a state in which a plurality of powder states are mixed,
Although any method may be used, it is preferable to select some of the above methods to obtain a powder.

Powders containing xanthene dyes obtained by synthesis or commercially available xanthene dyes contain solvent molecules, moisture, components of molecular structures other than the xanthene dyes of the present invention, and other components. Although all of these powders may be used as they are, those subjected to purification treatment are preferable. However, a certain percentage of impurities may be present by any purification method, but any dye that can be produced or obtained in the state of the art can be used.

However, the coloring composition of the present invention contains at least one xanthene dye represented by the general formula (1) as a main component among the components in the solid content, and water and other solvent molecules in a certain concentration range May be contained. The presence of water or the like in the coloring composition is considered to be one of the factors that change the crystal structure of the powder of the xanthene dye, and as a result, the solubility of the xanthene dye in an organic solvent such as PGME is It is believed to change. For example, the solubility in an organic solvent such as PGME can be maintained while maintaining heat resistance by adjusting the weight ratio (water content (% by weight)) of water to the total weight of the coloring composition containing a xanthene dye A highly colored composition can be obtained. The water content in the coloring composition can be optionally adjusted in the range of 0.1 to 20% by weight.

As a method of preparing a coloring composition containing the xanthene dye of the present invention, the methods related to the above (a) to (d) include, for example, the following methods. In a container of appropriate size, a powder containing xanthene dye as a main component, activated carbon and a solvent are added, mixed, heated and stirred for a fixed time. After stirring, the solution is filtered hot to obtain a filtrate. The filtrate is concentrated at an appropriate solvent evaporation rate while at atmospheric pressure or under reduced pressure to obtain a concentrate. The colored composition containing a solvent and the like is taken out of the container as a concentrate, and dried in another container. Further, the solvent is removed by drying under reduced pressure at a constant temperature. Thus, a colored composition containing at least one xanthene dye represented by the general formula (1) is obtained.

Alternatively, any method may be used as long as a solid (powder) is obtained, for example, after mixing the xanthene dye in the solvent as described above, an appropriate acid or base is added to change the pH, and crystals are obtained. The precipitate may be dried in the manner described above. Furthermore, instead of the acid or base, another solvent or solid may be mixed in the solution, and the precipitated crystals may be dried.

As described above, the xanthene dyes dissolved or dispersed in a liquid according to the present invention can be dried by evaporating the solvent, changing the speed appropriately, and precipitating in the solvent. A colored composition containing the xanthene dye of

Here, as a material of the container for stirring, an appropriate thing can be selected and used, For example, glass containers, such as Kolben, a metal container, a resin container, a container lined with glass, etc. are used. can do.

The size of the container for stirring may be various sizes, and is preferably 1 to 5 L for 100 g of powder. However, it is not limited to this range, and it can be optionally determined by the amount of solvent required to dissolve the used xanthene dye.

In the case of using activated carbon at the time of mixing in a solvent, powdered or pulverized activated carbon is preferable in order to enhance the adsorption capacity of the activated carbon.

The solvent may be one type or a mixture of a plurality of types, but is preferably an alcohol, and in the case of the alcohol, methanol, ethanol, propanol, isopropanol, butanol is preferable, and methanol is more preferable. The solvent may or may not be dehydrated.

The weight ratio of the xanthene dye (in the case of two or more types thereof) to the solvent upon mixing in the solvent is preferably 3 to 10 times the weight of the solvent relative to the weight of the xanthene dye. However, the amount is not limited to this range, and the amount necessary to dissolve the used xanthene dye can be arbitrarily determined.

As other components, surfactants, dispersants, antifoaming agents, leveling agents, and other colorants for color filters are mixed in order to enhance the performance of the coloring composition of the present invention as a color filter colorant. Additives, and organic compounds such as organic compounds can be added. However, the content of these additives in the coloring composition is preferably an appropriate amount, and the solubility of the coloring composition of the present invention in the solvent may be reduced or it may be improved more than necessary. It is preferable that it is a content rate of the range which does not affect the effect of the other same kind of additive used at the time of manufacture. These additives can be introduced at any time of preparation of the coloring composition.

The atmosphere in the container during mixing or stirring may be air, nitrogen, other inert gas, and the like, and is not particularly limited. It is preferable to replace the inside of the container with an inert gas such as nitrogen, in consideration of safety against ignition due to static electricity at the time of manufacture.

Drying of the concentrate is carried out by transferring to a container such as a dish or vat and drying. It is left to stand and dried (primary drying) for 1 to 96 hours under atmospheric pressure so that the moisture content is in an equilibrium state. The drying temperature is preferably in the range of 20 ° C to 100 ° C. Here, in temporary drying, it is preferable to leave the water to some extent without completely drying.

The primary-dried colored composition containing a xanthene dye is further dried (secondary drying) using a dryer having an exhaust device such as a vacuum dryer. Instead of a vacuum dryer, it may be air dried on a large bottomed bat-like container. The temperature and time of drying can be optionally set in order to obtain the desired powdery colored composition, and is not particularly limited. When alcohol is used as a solvent, the point at which the alcohol is removed as much as possible can be taken as the drying end point. Examples of the method for measuring the drying end point include methods for analysis and quantification of solvent components by powder state observation, weight measurement, nuclear magnetic resonance analysis (NMR), gas chromatography analysis (GC) and the like.

Karl Fischer (KF) method using coulometric or volumetric titration method; thermogravimetry-differential thermal analysis (TG-DTA) apparatus is used to measure the moisture content of the coloring composition prepared as described above Thermal analysis method used; heat drying method using heat drying type moisture meter etc .; gas chromatography (GC) method; infrared or near infrared absorption method; nuclear magnetic resonance absorption method; electrical resistance method; dielectric constant method; distillation method; And the like. In addition, analysis of types and amounts of impurities other than water can be similarly estimated by powder state observation, weight measurement, NMR analysis, GC analysis and the like.

As a method of preparing a coloring composition containing the xanthene dye of the present invention, methods corresponding to the above (e) to (h) include, for example, the following methods.

While the preparation method of the colored composition of the above (a) to (d) is wet, the methods of the following (e) to (h) are generally used to further increase the purity of the dye, It is a dry method in which the crystal structure changes while maintaining the purity of the resulting powder.

Specifically, the heat treatment of (e) is used when heating is generally performed from room temperature (about 25 ° C.) to about the melting point (or glass transition temperature) of a solid to change the crystal structure. The heating device may be of any material or form, may be heated on a commercially available hot plate, may be a commercially available oven, or may be a quartz reactor or the like. The atmosphere may be air, but in general, nitrogen or an inert gas or under reduced pressure is preferable in order to prevent decomposition or deterioration of the sample. The heating time may be appropriate.

Sublimation purification of (f) heats and sublimes the powder in a vacuum, so that water, solvent molecules and other impurities in the solid powder can be removed as much as possible, and during recrystallization, crystals before sublimation are removed. In many cases, the structure has changed. The apparatus is not limited as long as it can reduce the pressure from high vacuum to ultra-high vacuum. The material of the heating container for containing the sample may be metal or glass.

When the powder is pressurized as in the method of pressurization (g), the crystalline system of the solid may change irreversibly. The pressure may be applied according to the air pressure or may be compressed with a press such as metal steel with high hardness.

The classification of (h) is a method of separating components in a specific state from those whose size, density, and crystal structure are not single in the powder obtained by the method of obtaining any solid powder described above. The powder before separation may or may not be ground first. In the case where crystals of different components are bound, the pulverization treatment may facilitate separation of the components. When classifying by size, an apparatus such as a sieve is used. For products of different density or weight, a device that can fly powder by air flow and separate or centrifuge at a difference in flight distance can be used.

The coloring composition of the present invention, which contains at least one xanthene dye represented by the general formula (1), can be obtained by the above-described method, and the coloring composition in the form of powder can be obtained. Hereinafter, with respect to this powder, 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, will be described.

The shape of the powder of the colored 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 generally used in the form of a solid powder having a shape such as crystalline, microcrystalline, fine powder, flake, needle crystal, granular, etc., but is not particularly limited. .

By measuring the particle size distribution, surface area, pore size distribution, powder density, and the like of the powder of the coloring composition of the present invention, general and average information on the shape of the powder can be obtained in more detail. For example, Coulter method by measuring the electric resistance of the electrolyte in which the powder is dispersed, centrifugal sedimentation to determine the Stokes effective diameter by measuring the absorbance of the powder dispersion, laser diffraction / scattering method by diffraction scattering pattern analysis of the powder dispersion, etc. It can be measured using The coloring composition of the present invention preferably has a particle diameter in the range of 0.1 μm to several mm, but since the shape of the particles changes depending on the manufacturing conditions and the method of recovering the powder after drying, Although not limited, it is preferable that the particle size be smaller for high solubility, and that the median value of the particle size distribution be in the range of 0.1 to 100 μm.

The elemental composition of the surface of the powder of the coloring composition of the present invention and structural analysis can estimate information on the fine structure at the molecular level and atomic level. Specifically, ultraviolet light, X-rays and electron beams are used, and analysis of the composition of the atoms on the surface of the sample and in the particles and information on the bonds between atoms can be obtained. In particular, powder X-ray diffraction (XRD) using X-rays provides information on the lattice constant, the periodicity, and the like of the arrangement of atoms and molecules (crystal structure).

By performing thermogravimetry-differential thermal analysis (TG-DTA) of the coloring composition of the present invention, the decomposition initiation temperature of the powder can be analyzed. The decomposition initiation temperature is preferably 250 ° C. or more, more preferably 300 ° C. or more, and particularly preferably 360 ° C. or more. In the case of application to a color filter, the higher the decomposition initiation temperature, the better.

The solubility of the powder of the coloring composition in the present invention is expressed by the solubility, and the solubility represents the ratio in the coloring composition of the maximum amount that the powdery coloring composition can dissolve in a particular solvent. For example, it is represented by a unit such as "wt% (solvent name, temperature)". Solubility can be obtained, for example, by mixing a sample in a specific solvent, stirring the solvent at a constant temperature for a fixed time, and measuring the concentration of the prepared saturated solution, liquid chromatography (LC) or absorbance of the dissolved part It can also be obtained by measuring the concentration by measurement.

The coloring composition contained in the coloring agent for color filter needs to be well dissolved or dispersed in an organic solvent containing a resin or the like in the process for producing the coloring agent for color filter and the color filter, and therefore the solubility in the organic solvent Is preferably high. The organic solvent is not particularly limited, but specifically, esters such as ethyl acetate and n-butyl acetate; ethers such as diethyl ether and propylene glycol monomethyl ether (PGME); propylene glycol monomethyl ether acetate (PGMEA) Ether esters such as acetone); Ketones such as acetone and cyclohexanone; alcohols such as methanol and ethanol; diacetone alcohol (DAA) and the like; aromatic hydrocarbons such as benzene, toluene and xylene; N, N-dimethylformamide Amides such as (DMF), N-methyl pyrrolidone (NMP) and the like; dimethyl sulfoxide (DMSO) and the like. These solvents may be used alone or in combination of two or more. Among these, the coloring composition containing the xanthene dye according to the present invention is particularly preferably excellent in solubility in PGME.

The spectral characteristics (transmittance and reflectance) of the powder of the coloring composition of the present invention are important both when the dye is used alone as a colorant for color filters or when it is used by mixing with other dyes. Directly affect the color characteristics of the color filter. The measurement method may be a method of measuring an absorption (or transmission) spectrum of a solution or dispersion state, or an absorption (or transmission) spectrum of a thin film applied to a glass or a transparent resin substrate. Further, there is a method of irradiating the powder directly with light and measuring the light reflected / scattered on the particle surface or in the vicinity of the particle surface.

Among the analysis methods as described above, powder X-ray diffraction, thermal analysis or solubility analysis is suitable as an analysis method of the coloring composition containing the xanthene dye of the present invention, and in particular, powder X-ray diffraction is Whether the powder is mixed and dissolved with other materials and dispersed uniformly, or a film can be obtained which can obtain heat resistance and light resistance, or shows color characteristics suitable as a pigment for color filters, etc. Is suitable as a method for determining and inferring whether it has a suitable crystal structure (powder characteristics). In powder X-ray diffraction, CuKα rays (hν = 8.048 keV, wavelength λ = 0.15418 nm) and MoK α rays (hν = 17.5 keV, wavelength λ = 0.071073 nm) are usually used as an X-ray source. Powder X-ray diffraction using CuKα radiation is preferred.

In the present invention, the colored composition containing at least one xanthene dye represented by the general formula (1) has a diffraction angle (Bragg angle) 2θ of 2 ° to 35 ° in the measurement of powder X-ray diffraction. In the range, a maximum of 30 characteristic diffraction peaks are observed for each sample. When a peak appears in the range of 2θ = 2 ° to 35 ° in powder X-ray diffraction, this indicates that the periodicity of atoms of about 0.2 nm to about 4.0 nm is present in the solid powder sample. There is. For example, in a xanthene molecule such as Acid Red 52, which is a typical xanthene dye, the shortest interatomic bonding distance is about 0.13 ± 0.02 nm, and the distance between two nitrogen atoms is about 1 nm. It is. Further, the maximum width of the molecule of the xanthene dye represented by the general formula (1) is 1 to 2 nm, and the crystal lattice of a general molecular crystal is approximately the same as the maximum width of this molecule. That is, the diffraction pattern observed in the range of the above-mentioned diffraction angle indicates information on the arrangement between atoms in the xanthene molecule and information on the arrangement between xanthene molecules in the powder. For these reasons, powder X-ray diffraction is excellent as a method for analyzing the state inside the powder containing the xanthene dye.

Therefore, in the present invention, the colored composition containing at least one xanthene dye represented by the general formula (1) has a diffraction angle of 2θ = 2 ° to 35 ° in the measurement of powder X-ray diffraction of CuKα ray. Preferably, up to 30 diffraction peaks are observed in the range. In the range of 2θ = 18 ° to 35 ° in the range of this diffraction angle, the interatomic distance in the xanthene molecule, for example, carbon-carbon, carbon-nitrogen, carbon-oxygen (even if they are directly bonded to each other) A peak representing periodicity such as other atoms may be intervened or a space may be intervened is observed. Specifically, a prominent peak at 2θ = 2 ° to 25 ° It is preferable that five or more and at most 20 be observed.

In the present invention, the colored composition containing at least one xanthene dye represented by the general formula (1) has a diffraction angle 2θ of 2 ° to 10 ° in the measurement of powder X-ray diffraction of CuKα ray. Since, for example, a diffraction peak related to a distance equal to or greater than the distance between two nitrogen atoms of a xanthene molecule is observed, not only information on the atoms within the xanthene molecule but also the distance between two adjacent xanthene molecules It can be considered that it also contains information on the periodicity of In the present invention, the present inventors have prepared a powder of xanthene dye, a powder X-ray diffraction pattern obtained as a result, and color filter characteristics evaluated using the dye, particularly, coloring property (contrast ratio) Was found to be correlated. Specifically, a coloring composition containing at least one xanthene dye represented by the general formula (1) has a peak at a diffraction angle (2θ) of powdery X-ray diffraction of CuKα of 3 ° to 7 °. There are those that are remarkable and those that are not. For example, the presence or absence of a significant peak at 2θ = 5 ° indicates the presence or absence of periodicity of 1.7 to 1.8 nm in the coloring composition. The periodicity of 1.7 to 1.8 nm is presumed to correspond to the distance between xanthene molecules, and depending on the sample preparation method, there may or may not be this regular arrangement of xanthene molecules. It is obtained that suggests that different structures of xanthene molecular crystals can be obtained. The difference in crystal structure also affects the magnitude and interaction of the intermolecular force between xanthene molecules, and as a result, solubility in solvents, dispersibility, and other pigments and resin materials for color filters, etc. It greatly influences the interaction, and acts directly on the physical properties of the color filter. As a coloring agent for color filters, it is preferable that the number of peaks of diffraction angle (2θ) = 3 ° to 7 ° in powder X-ray diffraction of CuKα ray is 0 (no noticeable peak is observed).

The coloring agent for color filters of the present invention comprises a coloring composition containing at least one xanthene dye represented by the general formula (1), and a component generally used for producing a color filter. In a general color filter, for example, in the case of a method using a photolithography process, a liquid prepared by mixing a dye such as a dye or a pigment with a resin component (including a monomer or an oligomer) or a solvent is glass or resin The solution is applied onto a substrate of the above, photopolymerized using a photo mask, a colored pattern of a dye / resin composite film soluble / insoluble in a solvent is prepared, washed, and then heated. Moreover, also in the electrodeposition method and the printing method, a coloring pattern is produced using what mixed the pigment | dye with resin and other components. Therefore, as specific components in the colorant for color filters of the present invention, xanthene dyes represented by at least one general formula (1), dyes such as other dyes and pigments, resin components, organic solvents, And other additives such as a photopolymerization initiator. Moreover, you may choose from these components and may add another component as needed.

When the coloring composition containing the xanthene dye of the present invention is used as a coloring agent for color filter, it may be used for a color filter for each color, but it is preferable to use as a coloring agent for blue or red color filter.

The colorant for a color filter containing the xanthene dye of the present invention may use one or more xanthene dyes alone, and other dyes or pigments may be used to control color tone. Of pigments may be mixed. When used as a colorant for red color filters, it is not particularly limited. I. Pigment red 177, C.I. I. Pigment red 209, C.I. I. Pigment red 242, C.I. I. Pigment red 254 and other red pigments; other red lake pigments; C.I. I. Acid Red 88, C.I. I. Red dyes such as Basic Violet 10 and the like can be mentioned. When used as a colorant for blue color filters, C.I. I. Basic dyes such as Basic Blue 3, 7, 9, 54, 65, 75, 77, 99, 129; I. Acid dyes such as acid blue 9, 74; disperse dyes such as disperse blue 3, 7, 377; spiro dyes; cyanines, indigos, phthalocyanines, anthraquinones, methines, triarylmethanes, indanthrenes Blue dyes or pigments such as oxazine dyes, dioxazine dyes, azo dyes, xanthene dyes not belonging to the present invention; other blue lake pigments, etc. may be mentioned.

The mixing ratio of the other dyes in the colorant for a color filter containing the xanthene dye of the present invention is 5 to 2000% by weight based on the xanthene dye (in the case of two or more dyes, the total of them) Preferably, it is 10 to 1000% by weight. The mixing ratio of dye components such as dyes in the liquid color filter colorant is preferably 0.5 to 70% by weight, and more preferably 1 to 50% by weight, based on the entire colorant.

As a resin component in the coloring agent for color filters of the present invention, known ones may be used as long as they have the required production method of the color filter resin film formed using them and the properties necessary for use. it can. For example, acrylic resin, olefin resin, styrene resin, polyimide resin, urethane resin, polyester resin, epoxy resin, vinyl ether resin, phenol (novolak) resin, other transparent resin, photocurable resin or thermosetting resin can be mentioned. These monomer or oligomer components can be used in appropriate combination. Moreover, the copolymer of these resin can also be used combining. The content of the resin in these color filter colorants 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 coloring agent for color filter of the present invention include components necessary for polymerization and curing of the resin such as a photopolymerization initiator and a crosslinking agent, and further, components in the liquid coloring agent for color filter Surfactants and dispersants necessary for stabilizing the properties of Any of these may be used known ones for producing a color filter, and is not particularly limited. The mixing ratio of the total amount of these additives in the total solid content of the coloring agent for color filters is preferably 5 to 60% by weight, and more preferably 10 to 40% by weight.

Hereinafter, the embodiments of the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. The identification of the compounds obtained in the examples was carried out by ¹ H-NMR analysis (Nihon Denshi Co., Ltd. nuclear magnetic resonance apparatus, JNM-ECA-600).

Example 1
[Preparation of powder of coloring composition]
Acid Red 52 (150 g) represented by the following formula (A-3) and 1.2 L of methanol are placed in a 3 L reaction vessel, dissolved at 50 ° C., and dissolved in activated carbon (model number: white rattan A-2, the following "white rattan" ) Was added and stirred for 1 hour. The reaction solution was filtered twice with filter paper (model number: GF-75 manufactured by ADVANTEC). The filtrate was concentrated and dissolved in 1.12 L of methanol at 50 ° C., 1.12 L of ethyl acetate was added, and the mixture was stirred for 3 hours and filtered. The filtrate was dried under reduced pressure at 60 ° C. for 24 hours to obtain a green crystalline colored composition (104.4 g). The NMR analysis of this coloring composition was conducted, and it was confirmed that no component of the organic solvent such as methanol was observed.

[Powder X-ray diffraction measurement]
Powder X-ray diffraction (XRD) measurement (with a sample horizontal X-ray diffractometer manufactured by Rigaku Corporation) of the powder of the coloring composition obtained as described above (sample horizontal X-ray diffractometer RINT-2200 Ultima type, X-ray source: CuKα ray (hν = 0) .15418 nm, 30 kV, 30 mA), divergence slit: 1/2 °, scattering slit: 1/2 °, light receiving slit: 0.15 mm, scanning step: 0.02 °, scanning speed: 2 ° / min, scanning diffraction angle The range: 2θ = 2 ° to 35 °) was performed. The results are shown in FIG. Further, the number of prominent diffraction peaks observed in the range of 2θ = 2 ° to 7 °, 7 ° to 15 °, 15 ° to 25 °, and 25 ° to 35 ° is shown in Table 1. However, the peaks less than about 5% of the maximum peak intensity and those with unclear peak shoulders are not counted.

[Color filter characteristics]
It formed into a film by the following method using said colored composition, the color filter was produced, and contrast ratio was measured. A coloring composition was obtained by mixing 30 parts of a resin for evaluation prepared from benzyl methacrylate and methacrylic acid, 70 parts of PGME and 2 parts of a dye. This colored composition was applied onto a glass substrate (50 × 50 × 0.7 mm) using a spin coater (Mikasa Co., Ltd., model: MS-B100). The glass substrate was dried at 90 ° C. for 10 minutes. The coated substrate thus obtained was sandwiched between two polarizing plates, the backlight was turned on, and the brightness when the polarizing plates were in direct and in parallel was measured. The contrast ratio was calculated from the ratio of the measured luminance. The results are shown in Table 1.

Example 2
Acid Red 52 (40 g) represented by the above formula (A-3) and 0.32 L of methanol represented by the above formula (A-3) were put in a 1 L reaction vessel, dissolved at 60 ° C., 2 g of activated carbon (model number: white coral) added, and stirred for 1 hour . The reaction solution was filtered twice with filter paper (model number: GF-75 manufactured by ADVANTEC) at 50 ° C. The filtrate is transferred to a vat (30 cm × 40 cm), placed in a vacuum drier, dried under reduced pressure at 50 ° C.-2 hours, 65 ° C.-2 hours, 80 ° C.-20 hours temperature-heating time, and purple crystals The obtained colored composition (40.3 g) was obtained. The NMR analysis of this coloring composition was conducted, and it was confirmed that no component of the organic solvent such as methanol was observed. The results of measuring the powder X-ray diffraction and the contrast ratio of this colored composition in the same manner as in Example 1 are shown in FIG. 1 and Table 1.

Comparative Example 1
Acid Red 52 (700 g) represented by the above formula (A-3), 40 g of activated carbon (model number: white coral) and 6 L of methanol were added to a 10 L reaction vessel, stirred at 55 ° C. for 1 hour, and filtered at 50 ° C. . The filtrate was concentrated under reduced pressure to 1/3 weight, poured into a vat, air dried at 25 ± 2 ° C. for 4 days, and vacuum dried at 80 ° C. for 5 days. Drying was terminated when the weight loss was 0.4% by weight per day, and it was obtained as a colored composition containing a reddish-purple powder xanthene dye (A-20) (715 g). The NMR analysis of this coloring composition was conducted, and it was confirmed that no component of the organic solvent such as methanol was observed. The results of measuring the powder X-ray diffraction and the contrast ratio of this colored composition are shown in FIG. 1 and Table 1.

Comparative Example 2
The colored composition obtained in Comparative Example 1 was ground in a mortar. The results of measuring the powder X-ray diffraction and the contrast ratio of this colored composition are shown in FIG. 1 and Table 1.

As shown in FIG. 1 and Table 1, in the colored compositions of Example 1 and Example 2, the number of diffraction peaks in the range of diffraction angle 2θ = 3 ° to 7 ° in the powder X-ray diffraction of CuKα ray is 0. There is no problem in practical use as a color filter for the contrast ratio of color filters manufactured using the above.

On the other hand, in the colored compositions of Comparative Example 1 and Comparative Example 2, the number of diffraction peaks in the range of the diffraction angle 2θ = 3 ° to 7 ° in powder X-ray diffraction of CuKα ray is one, and the contrast ratio is implemented. Lower than the example.

As mentioned above, since the color filter produced using the coloring composition containing the xanthene type dye of this invention has high contrast ratio, it is useful as a coloring agent for color filters.

The coloring composition containing the xanthene dye according to the present invention is useful as a coloring agent for color filters, and it is possible to produce a color filter having an excellent contrast ratio.

Claims

It is a coloring composition containing a xanthene dye represented by the following general formula (1),
A coloring composition containing at least one xanthene dye, wherein the number of diffraction peaks in the range of 3 ° to 7 ° of diffraction angle (2θ) in powder X-ray diffraction of CuKα ray is zero.

[Wherein, R 1 to R 4 are each independently
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 to R 7 each independently represent 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, or
R 5 and R 6 may be bonded to each other to form a ring.
M represents an alkali metal atom. ]
The coloring according to claim 1, wherein in the general formula (1), R 1 to R 4 are a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent. Composition.
The weight concentration ratio of the xanthene dye represented by the general formula (1) is 2 or more, and the weight concentration ratio of the smallest one xanthene dye is 0.1 to The coloring composition of Claim 1 or Claim 2 which is 50 weight%.
A coloring agent for color filter comprising the coloring composition according to any one of claims 1 to 3.
A color filter using the colorant for color filters according to claim 4.