WO2016042171A2

WO2016042171A2 - A xanthene compound, and a colorant comprising the same

Info

Publication number: WO2016042171A2
Application number: PCT/EP2015/078659
Authority: WO
Inventors: Sangmin Han; Hyunsu Lee; Iljo Choi; Eunha Jeong; Seunghwan Lee
Original assignee: Iridos Ltd
Priority date: 2015-07-16
Filing date: 2015-12-04
Publication date: 2016-03-24
Also published as: JP2018522114A; KR20180020321A; KR20170010228A; CN108137933B; CN108137933A; WO2016042171A3; JP6735809B2; KR102522309B1; TW201704354A; TWI679247B

Abstract

A disclosure of the present invention includes xanthene compounds, methods for preparing the same, and colorants comprising the same.

Description

A xanthene compound, and a colorant comprising the same

This application claims priority to a Korean patent application No. 10- 2015-0101287 filed on July 16, 2015, the whole content of this application being incorporated herein by reference for all purposes.

TECHNICAL FIELD

The present invention relates to novel xanthene compounds, and methods for preparing the same. The present invention also concerns colorant

compositions for color filter comprising the compound, and display devices equipped with such color filter. BACKGROUND OF THE INVENTION

Xanthene dye compounds, such as C. I. Acid Red 52, are widely used in the industry, for instance in various paints, aqueous inks, oil-based inks, inkjet inks, and color filters.

Color filters are widely used in various applications, particularly used in display devices, such as liquid crystal display (LCD) and organic light-emitting display (OLED) and the like.

When forming the color filter, a color composition having a colorant material comprising a pigment and/or a dye is often used. Pigment usually shows better stability against heat and/or environment, but an achievable brightness is often insufficient compared with dye. On the other hand, when dye is used as the color filter colorant, satisfactory brightness of the color filter may be attained, but its stability, especially thermal stability, and/or contrast ratio are often insufficient. C. I. Acid Red 52 is often used as an auxiliary colorant in the color filters, especially blue and red color filters.

DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide a novel xanthene compound. Another purpose is to provide a xanthene compound which shows excellent thermal stability. Further purpose of the invention is to provide a novel xanthene compound which can be suitably used as an excellent auxiliary colorant in color filter application. Still further purpose of the present invention is to provide a xanthene compound which shows excellent brightness. Yet further purpose of the invention is to provide a xanthene compound which can attain outstanding contrast ratio in the color filter application.

Indeed, it has been surprisingly found by the present inventors that the particular compounds having two or three xanthene moieties according to the present invention show outstanding thermal stability. It has also been found that the xanthene compounds according to the present invention can be

advantageously used for the formation of color filter. In addition, it has been found that the compounds according to the present invention show excellent brightness and/or contrast ratio in the color filter application.

In the present invention, "alkyl groups" is understood to denote in particular a straight chain, branched chain, or cyclic hydrocarbon groups usually having from 1 to 20 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

In the present invention, "alkoxy groups" is understood to denote in particular a straight chain, branched chain, or cyclic hydrocarbon group usually having from 1 to 20 carbon atoms, preferably from 1 to 8 carbon atoms, singularly bonded to oxygen (Alk-O-).

In the present invention, "aryl groups" is understood to denote in particular any functional group or substituent derived from an aromatic ring. In particular, the aryl groups can have 6 to 20 carbon atoms (preferably 6 to 12 due to its easiness of synthesis at a low cost) in which some or all of the hydrogen atoms of the aryl group may or may not be substituted with other groups, especially alkyl groups, alkoxy groups, aryl groups, aryloxy groups, thioalkoxy groups, heterocycles, amino groups or hydroxyl groups. The aryl groups are preferably optionally substituted phenyl groups, naphthyl groups, anthryl group and phenanthryl group.

In the present invention, "heterocycles" is understood to denote in particular a cyclic compound, which has at least one heteroatom as a member of its one or more rings. Frequent heteroatoms within the ring include sulfur, oxygen and nitrogen. The heterocycles can be either saturated or unsaturated, aromatic or non-aromatic, and may be 3-membered, 4-membered, 5-membered, 6-membered or 7-membered ring. The heterocycles can be further fused with other one or more ring systems. Examples of the heterocycles include pyrrolidines, oxolanes, thiolanes, pyrroles, furans, thiophenes, piperidines, oxanes, thianes, pyridines, pyrans, pyrazoles, imidazoles, and thiopyrans, and their derivatives. The heterocycles can further be substituted by other groups, such as alkyl groups, alkoxy groups, aryl groups, thioalkoxy groups, amino groups or aryloxy groups as defined above.

In the present invention, "millbase composition" is understood to denote in particular an intermediate composition which comprises at least a part of components to be included in a final composition for forming a color filter. The final composition for forming a color filter can be formulated by combining the millbase composition with other components. In the present invention, the millbase composition often comprises at least one or more colorant components to be included in the final composition for forming a color filter.

One aspect of the present invention concerns a compound having the formula (I) below:

In the formula (I), Rl to R4 in each xanthene moiety may be identical or different. Rl to R4 in each xanthene moiety are independently selected from the group consisting of hydrogen, alkyl groups and aryl groups. It is preferred that Rl to R4 are selected from alkyl groups. Examples of Rl to R4 include optionally substituted alkyl groups having 1 to 10 carbon atoms, such as ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, pentyl group, hexyl group, 2-ethylhexyl group, 2-methoxyethyl group, 2- ethoxyethyl group, 2-cyanoethyl group, and 2,2,2-trifluoroehtyl group, but the present invention is not limited thereto. More preferably, Rl to R4 are ethyl group. Rl and R2, or R3 and R4 may be bound together to form a ring structure. Such ring structure may comprise one or more heteroatoms, such as nitrogen, sulfur and oxygen. Examples of the ring comprise the following structure, but the present invention is not limited thereto:

In the formula (I), R13 in each xanthene moiety may be identical or different. R13 in each xanthene moiety is independently selected from the group consisting of hydrogen and alkyl groups. Examples of R13 include those alkyl groups mentioned in Rl to R4 in the above, and hydrogen. It is preferred that Rl 3 is hydrogen.

In the formula (I), "n" stands for the number of xanthene moieties in the compound, and as such, is an integer of 2 or 3. It is particularly preferred when "n" is 2.

In the present invention, L denotes a linking group to connect two or three xanthene moieties each of which structure may be identical or different. L has valency of "n" which is understood to stand for the number of xanthene moieties in the molecule. The linking group "L" in the present invention comprises at least one aromatic ring. Examples of the aromatic ring include hydrocarbon- based aromatic rings, such as benzene ring, naphthalene ring, tetralin ring, indene ring, fluorene ring, anthracene ring, phenanthrene ring, biphenyl, and terphenyl, and heterocyclic aromatic rings, including 5-membered rings, such as furan, thiophene, pyrrole, oxazole, thiazole, imidazole, and pyrazole; 6- membered rings, such as pyran, pyridine, pyridazine, pyrimidine, and pyrazine; and fused rings, such as benzofuran, thionaphthene, indole, carbazole, cumarine, quinoline, isoquinoline, acridine, quinazoline, and quinoxaline; but the present invention is not limited thereto. Such aromatic rings can be further substituted by substituents. Examples of such substituents include halogens, such as fluorine, chlorine, and bromine, alkyl groups, carboxyl group, and amino groups, but the present invention is not limited thereto. Preferably, "L" comprises hydrocarbon-based aromatic ring with 6 to 14 carbon atoms. More preferably, "L" comprises benzene group, or naphthalene group. Particularly, "L" is divalent phenylene group.

In the formulae (II) and (III), Rl to R12 are independently selected from the group consisting of hydrogen, alkyl groups and aryl groups. It is preferred that Rl to R12 are selected from alkyl groups. Examples of Rl to R12 include those alkyl groups mentioned in Rl to R4 in the formula (I). More preferably, Rl to R12 are ethyl group. Rl and R2, R3 and R4, R5 and R6, R7 and R8, R9 and RIO, or Rl 1 and R12 may be bound together to form a ring structure. Such ring structure may comprise one or more heteroatoms, such as nitrogen, sulfur and oxygen. Examples of the ring include those ring structures mentioned in Rl to R4 in the formula (I).

In the formulae (II) and (III), R13 to R15 is independently selected from the group consisting of hydrogen and alkyl groups. Examples of R13 to R15 include those alkyl groups mentioned in Rl to R4 in the above, and hydrogen. It is preferred that R13 to R15 are hydrogen.

Without wishing to be bound by theory, it is believed that the compound according to the present invention has excellent stability, in particular thermal stability, and/or outstanding dispersibility particularly from the steric hinderance point of view because of the existence of -CH₂- between L and the xanthene moiety.

Another aspect of the present invention concerns a method of preparing the xanthene compounds of the present invention. Such a method comprises reacting C. I. Acid Red 52 with at least one chlorinating agent to convert one of the sulfonic acid groups in C. I. Acid Red 52 to sulfonyl chloride group, and reacting the intermediate compound having the sulfonyl chloride group with at least one diamine or triamine compound. Examples of the chlorinating agent include chlorosulfonic acid, phosphorus pentachloride, phosphorous trichloride, thionyl chloride, oxalyl chloride, and any combination thereof, but the present invention is not limited thereto. Examples of the diamine and triamine compounds include m-xylylene diamine, /?-xylylene diamine and 1,3,5- tris(aminomethyl)benzene-trihydrochloride, but the present invention is not limited thereto.

The xanthene compound of the present invention is advantageously used as a dye, of which use can optionally be combined with at least one further dye or pigment. Therefore, further aspect of the present invention provides a colorant material comprising the compound according to the invention, and optionally at least another dye or pigment. Examples of the dyes and of the pigments can be found in PCT international patent application publication No. WO 2012/144521 Al and Japanese patent application publication No. JP 2014-108975 A, respectively, both are incorporated herein by reference by their entireties. In particular, the compound of the present invention can be used as a colorant material in combination with a blue pigment, such as ε-type copper

phthalocyanine particles or a blue dye, such as triarylmethane compound. Further, the compound of the present invention can be used as a colorant material in combination with a red colorant, such as quinacridone compound and Pigment Red 254.

The compound of the present invention can be suitably used for the formation of color filter. Accordingly, still further aspect of the present invention concerns a composition for forming color filter, comprising the compound or the colorant material according to the invention. The composition may optionally comprise at least one component selected from the group consisting of a pigment, a dye, a binder, a dispersion aid or dispersant, a polymerizable monomer, a solvent, an inhibitor, a polymerization initiator, and any combination thereof.

Further details of the above-mentioned components, including pigment, dye, binder, dispersion aid/dispersant, polymerizable monomer, solvent, inhibitor, and initiator, can be found for instance in the disclosures of WO 2012/144521, JP 2014-108975 A, and PCT international patent application publication No.

WO 2013/050431, of which disclosure is incorporated herein by reference by its entirety.

In the present invention, particular type of the dispersant includes those dispersant additives available from BYK CHEMIE. Examples thereof include BYK-LP series, such as BYK-LP N 21116, BYK-LP N 21324, and B YK-LP N 6919, and DISPERBYK series, such as DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2070, DISPERBYK-2150, DISPERBYK-2009, DISPERBYK- 2010, DISPERBYK-2020, DISPERBYK-2025, DISPERBYK-2050, and

DISPERBYK-2095, but the present invention is not limited thereto.

In the present invention, the binder may be selected from (meth)acrylate binders. Particular examples of (meth)acrylate binders include, but not limited to, ethyleneglycol di(meth)acrylate, polyethyleneglycol di(meth)acrylate (in which, number of ethylene group is 2~14), trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 2-trisacryloyl oxymethylethyl phthalic acid, polypropyleneglycol di(meth)acrylate (in which, number of propylene group is 2~14), dipentaerythritol penta(meth)acrylate, dipentaerythritol

hexa(meth)acrylate, and other compounds obtained by esterification of α,β- unsaturated carboxylic acid. By introducing the (meth)acrylate binder, washability during development of the color filter prepared from the composition can be improved. In the present invention, the (meth)acrylate binder comprising at least one pentaerythritol group, such as pentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,

dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate, can be preferably used. In the present invention, the (meth)acrylate binder comprising at least one pentaerythritol group may improve dispersibility in addition to washability improvement. One or more other binders, such as urethane-type, ester-type, cardo-type, epoxy-type, and siloxane-type binder, may be used alone or together with the (meth)acrylate binder in the composition for forming color filter according to the present invention.

In the present invention, the solvent may be selected from the group consisting of N-methyl-2-pyrrolidone, Ν,Ν-dimethylformamide, N,N- dimethylacetamide, dimethylsulfoxide, diethylacetamide, gamma-butyrolactone ketone, gamma-valerolactone ketone, m-cresol, ethyleneglycol monomethylether, ethyleneglycol monomethylether acetate, ethyleneglycol monoethylether, ethyleneglycol monoethylether acetate, ethyleneglycol monobutylether, ethyleneglycol monobutylether acetate, propyleneglycol monomethylether, propyleneglycol monomethylether acetate, propyleneglycol monoethylether, propyleneglycol monoethylether acetate, propyleneglycol monopropylether, propyleneglycol monopropylether acetate, propyleneglycol monobutylether, propyleneglycol monobutylether acetate, propyleneglycol dimethylether, propyleneglycol diethylether, propyleneglycol dipropylether, propyleneglycol dibutylether, ethyl lactate, butyl lactate, cyclohexanone, cyclopentanone, and any combination thereof. Use of propyleneglycol monomethylether acetate alone or in combination with other one or more organic solvents is particularly preferred for the millbase composition according to the present invention.

In the present invention, the composition for forming color filter may be a millbase composition for color filter. The millbase composition preferably comprises (A) a colorant material; (B) a solvent; and (C) a binder, wherein the colorant material (A) comprises the compound or the colorant material of the present invention. Alternatively, the millbase composition may comprise (A) a colorant material; (B) a solvent; (C) a binder; and (D) a dispersant, wherein the colorant material (A) comprises the compound or the colorant material of the present invention.

In the present invention, (A) the colorant material may be used in the amount of 1 to 20 wt %, preferably 5 to 15 wt %, relative to the total weight of the millbase composition. In the present invention, (C) the binder may be used in the amount of 1 to 10 wt %, preferably 4 to 8 wt %, relative to the total weight of the millbase composition.

In the present invention, (D) the dispersant may be used in the amount of 1 to 10 wt %, preferably 4 to 8 wt %, relative to the total weight of the millbase composition.

In the present invention, the amount of (B) the solvent may make up the remainder of the total weight of the millbase composition, in addition to the weight of other components in the millbase composition. In particular, the amount of (B) the solvent can be from 60 to 97 wt %, preferably from 69 to 87 wt %, relative to the total weight of the millbase composition.

The present invention also relates to a color filter comprising the compound or the colorant material of the present invention. Such color filters may be prepared by lithographic methods, especially through the following steps: combining the millbase composition according to the present invention with other additional components to form a composition for forming color filter, applying the composition for forming color filter on a substrate, drying, exposing and developing. The color filters are applicable for preparation of display devices, such as a liquid crystal display device, a light-emitting display device, or a solid-state image sensing device such as a charge coupled device (CCD) and the like.

The present invention therefore also relates to the use of the compound of the present invention as an auxiliary colorant for blue color or red color, and to the use of the compound or of the colorant material of the present invention for preparation of color filters, and in particular for forming the blue portion or red portion of color filters in display device.

Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

The following examples are intended to describe the invention in further detail without the intention to limit it.

Example

Example 1 : Conversion of C. I. Acid Red 52 to the sulfonyl chloride compound 2

1

The compound 1 (20 g, 34.47 mmol) was dissolved in DCM (200 ml), and the temperature was cooled down to 0 °C. Oxalyl chloride (14.5 ml, 172.35 mmol) was slowly added drop-wise, and then, DMF (0.5 ml) was added drop- wise. The temperature was raised to room temperature, and stirred for 16 hours. After the reaction, evaporation was conducted. After adding toluene (20 ml), evaporation was conducted again. Diethyl ether (200 ml) was added to the mixture, and stirred for 30 min. The produced solid was filtered, and washed with 100 ml of diethyl ether to obtain the compound 2.

Example 2: Synthesis of the xanthene dendrimer compound 3

C he mical Fo rmula: C_e2H_eBN_e0₁2S4

Molecular Weight: 1217.50 /?-xylylenediamine (5 g, 8.61 mmol) and TEA (3.6 ml, 25.83 mmol) were dissolved in DCM (50 ml), and the temperature was cooled down to 0 °C. The compound 2 (10.5 g, 18.08 mmol) dissolved in DCM (30 ml) was added drop- wise. The mixture was stirred at room temperature for 16 hours, and

concentrated under reduced pressure. The residue was subjected to Si0₂ column (DCM:MeOH = 9: 1) treatment to obtain the compound 3.

Example 3 (Comparative): Synthesis of the compound 4

Compound 4 To a 500 ml 4-neck flask, 216 parts (by weight) of chloroform, and 14.8 parts of dimethyl formamide were introduced, and stirred in ice bath. To the flask, 19 parts of thionyl chloride was added drop-wise in the manner not to exceed 12 °C of the solution temperature, and stirred for 30 minutes in ice bath. After the ice bath being removed, 26.1 parts of C. I. Acid Red 52 was added for 16 minutes, and stirred for 3 hours at 35 °C. 2.2 parts of thionyl chloride was further added, and stirred for 1.5 hours at 35 °C. Thereafter, the reaction solution was cooled down, and 2.4 parts of 1 ,4-phenylenediamine was added in the manner not to exceed 12 °C of the solution temperature. Subsequently, 46.6 parts of triethylamine (TEA) was added drop-wise, and stirred for 14 hours at room temperature. A water-insoluble layer was removed by filtration, and the reaction solvent was removed under reduced pressure. Then, 1000 parts of water was added, and 15% sodium carbonate solution was added. The suspension was stirred for 1 hour while maintaining the pH at 7.0-7.5, and filtered to obtain 50 parts of the compound 4 as wet cake. The obtained wet cake was suspended with 1000 parts of water once more, and stirred for 1 hour. 12 parts of the compound 4 (3.2 g) was obtained after filtration. Maximum absorption wavelength of the compound 4 was shown at 561 nm (MeOH).

Example 4: Preparation of blue colorant composition 1

1.5 g of the xanthene compound 3 obtained according to Example 2, and

13.5 g of ε-type copper phthalocyanine particles kneaded in mixer were introduced to bead mill together with 6.75 g of DISPERBYK-2000 (available from BYK CHEMIE), 7.5 g of dipentaerythritol hexaacrylate, and 120.75 g of propyleneglycol monomethylether acetate (PGMEA), and ground for 6 to 8 hours at 40 °C using zirconia bead (size: 0.05-2 mm) to obtain the blue colorant composition 1.

Example 5 (Comparative): Preparation of blue colorant composition 2

The blue colorant composition 2 was obtained by repeating Example 4, except for using 1.5 g of the xanthene compound 4 obtained according to

Example 3 instead of the xanthene compound 3 obtained according to Example 2.

Performance tests

(1) Preparation of the film: The blue colorant composition was coated on a glass substrate (EAGLE-XG FUSION GLASS available from Corning) via spin coating (200-300 rpm for 15 sec.) to form a film of thickness about 2 micron and pre-baked at 90 °C for 90 seconds. Then, the film was subjected to 1^st post baking at 230 °C for 20 min. Then, the film was further subjected to 2^nd post baking at 240 °C for another 20 min.

(2) Measurement of color and brightness: Spectroscopy was performed on the film by using Otsuka Photal MCPD 3000 colorimeter to obtain x color coordinate (Bx) and brightness (Y). Results were obtained at target By=0.093.

(3) Measurement of contrast: Contrast was measured with a contrast tester Tsubosaka CT-1 (30,000:1).

The results of the performance tests are summarized in Table 1.

[Table 1 : Results of performance tests]

at By=0.093 1^st post baking 2^nd post baking ΔΥ Contrast

Bx Y Bx Y

Example 4 0.1387 11.06 0.1395 11.00 -0.18 9,933 (Inventive)

Example 5 0.1386 10.89 0.1395 10.45 -0.44 9,173 (Comparative)

As shown in Table 1 , the blue colorant composition comprising the xanthene dendrimer compound of the present invention exhibits not only better initial brightness (+ 0.17), but also improved thermal resistance of brightness (+ 0.55) as well as outstanding contrast (+ 760, 8% improvement) compared to that comprising the comparative xanthene compound.

Claims

C L A I M S

1. A compound having the formula (I) below:

wherein

Rl to R4 in each xanthene moiety may be identical or different and are independently selected from the group consisting of hydrogen, alkyl groups and aryl groups;

R13 in each xanthene moiety may be identical or different and is independently selected from the group consisting of hydrogen and alkyl groups; integer of 2 or 3; and

L is "n"-valent linking group comprising at least one aromatic ring.

2. The compound according to claim 1, wherein n is 2.

3. The compound according to claim 1 or 2, wherein L is divalent ylene group.

4. The compound according to claim 1, having the formula (II) or the formula (III) below:

hydrogen, alkyl groups and aryl groups; and

R13 to R15 are independently selected from the group consisting of hydrogen and alkyl groups.

5. The compound according to claim 4, wherein Rl to R12 are ethyl group, and R13 to R15 are hydrogen.

6. A method for preparing the compound according to any one of claims 1 to 5, comprising reacting C. I. Acid Red 52 with at least one chlorinating agent to convert one of the sulfonic acid groups in C. I. Acid Red 52 to sulfonyl chloride group, and reacting the intermediate compound having the sulfonyl chloride group with at least one diamine or triamine compound.

7. A colorant material comprising the compound according to any one of claims 1 to 5, and optionally at least another dye or pigment.

8. A composition for forming color filter, comprising the compound according to any one of claims 1 to 5 or the colorant material according to claim 7, and optionally at least one component selected from the group consisting of a pigment, a dye, a binder, a dispersion aid or dispersant, a polymerizable monomer, a solvent, an inhibitor, a polymerization initiator, and any

combination thereof.

9. A millbase composition for color filter, comprising (A) a colorant material; (B) a solvent; and (C) a binder, wherein the colorant material (A) comprises the compound according to any one of claims 1 to 5 or the colorant material according to claim 7.

10. Use of the compound according to any one of claims 1 to 5 or the colorant material according to claim 7 as an auxiliary colorant for blue color or red color.

11. Use of the compound according to any one of claims 1 to 5 or the colorant material according to claim 7 for the preparation of color filter for display device.