WO2015096052A1

WO2015096052A1 - Anthraquinone dye used for a color filter of a lcd

Info

Publication number: WO2015096052A1
Application number: PCT/CN2013/090397
Authority: WO
Inventors: Guihong LIAO; Yang Li; Hua Ren; Chao He; Yanping Sun
Original assignee: Dow Global Technologies Llc
Priority date: 2013-12-25
Filing date: 2013-12-25
Publication date: 2015-07-02

Abstract

An anthraquinone compound which is suitable for forming a color filter used for a liquid crystal display device, a composition containing a resin and the anthraquinone compound, an article having a polymer layer formed from the composition and a color filter containing the compound are developed.

Description

ANTHRAQUINONE DYE USED FOR A COLOR FILTER OF A LCD

Field of the invention

[0001] The present invention relates to an anthraquinone dye which is suitable for forming a color filter used for a liquid crystal display device, a method for synthesis the anthraquinone dye, a composition containing a resin and the anthraquinone dye, an article having a polymer layer formed from the composition and a color filter comprising the dye.

Background of the invention

[0002] Liquid crystal display (LCD) currently dominates the display market because of its excellent performance and small thickness. As a key component of LCD device, translucent color filters play the critical role of generating Red/Green/Blue lights by filtering white light from a back sheet. This capacity originates from the Red/Green/Blue colorants comprised in color filter units. Each colorant possesses a characteristic absorbance spectrum and will show one of the three primary colors when illuminated with white visible light- wavelength ranges from 380 nm to 780 nm. The controlled mixing of primary colors from each color filter unit produced by colorant will generate the final color of pixels. So the efficiency of color filter determines LCD's performance directly.

[0003] Normally, the commercialized colorants used in a LCD color filter are exclusively pigments, because they have good stability against heat, light and chemicals. Unfortunately pigments must be ground into micro/nano particles before added into a color resist to make a color filter due to their intrinsic insolubility property. The agglomerated particle of a colorant causes light scattering. As a result lots of light signals will lose and transmittance will become low, which means more light energy must be applied to provide enough brightness of the LCD.

[0004] In contrast to pigments, dyes are soluble in many materials which ensure that they can be dispersed at molecular level. If dyes are used in a color filter instead of pigments, light scattering will be significantly reduced. So it could be imagined that the dye based color filter will have higher transmittance and energy cost will thus be reduced greatly. However, dye's stability against light, heat and chemical resistance is generally inferior to pigments. As a result, at present, the commercialized LCD color filters are almost pigment with limited exceptions for a few of pigment-dye hybrid ones.

[0005] Some anthraquinone colorants are used for color filters of a LCD, see e.g. CN102298263A, US7,615,322B, US7,456,316B, US2008/0206658A, US2003/0292462A, US8,148,358B, JP2001108815A and JP3,651,854B, but those dyes generally have insufficient themial stability or insoluble common organic solvent for a color filter.

[0006] Although the anthraquinone structure is stable, the low solubility of anthraquinone dyes in an organic solvent prevents the use of anthraquinone dyes for a color filter. Accordingly, an anthraquinone dye which is stable and satisfies the solubility in an organic solvent at the same time is still desired.

Summary of the invention

[0007] Inventors of this invention have now found that new type of anthraquinone compound which is stable and has good solubility in an organic solvent. Therefore, one aspect of the invention relates to an anthraquinone compound represented by the general formula (1)

[0008]

Formula (1) [0009] wherein RJ-RJO are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group, alkoxy group having 1 to 20 carbon atoms and a substituent represented by the following formula (2),

[0010]

[0011] wherein R_u is hydrogen atom or alkyl group having 1 to 6 carbon atoms and * means a position which bonds to the benzene ring of formula (1); and at least one of Ri-R₁₀ are the substituent represented by the formula (2).

[0012] Another aspect of this invention relates to a method for synthesis the compound, wherein the method comprises reacting a compound represented by the following formula (3)

0013]

[0014] wherein Ri-Rio are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group and alkoxy group having 1 to 20 carbon atoms; and at least one of Ri to Rj₀ is hydroxyl group: with a compound represented by the following formula (4);

[0015] wherein Rn and R₁₂ are independently selected from the group consisting of hydrogen atom and alkyl group having 1 to 6 carbon atoms.

[0016] Further aspects of this invention relate to a composition comprising a resin and the anthraquinone compound, an article having a polymer layer formed from the composition and a color filter comprising the compound.

[0017] This group of anthraquinone compounds has high enough solubility for an organic solvent used for a LCD manufacturing process. In addition, a layer formed from a composition comprising the anthraquinone compound has high thermal stability because the group represented by the formula (2) can be react with a resin or other components in the layer, so the anthraquinone compound of this invention is useful for a color filter used in a LCD.

Detailed description of the invention

[0018] As used throughout this specification, the abbreviations given below have the following meanings, unless the context clearly indicates otherwise: g = gram; mg - milligram; mm - millimeter; min = minute(s); s = second(s); hr.= hour(s); rpm = revolution per minute; °C = degree Centigrade. Throughout this specification, "(meth)acrylic" is used to indicate that either "acrylic" or "methacrylic" functionality may be present. As used throughout this

specification, the word 'resin' and 'polymer' is used interchangeably. The word 'alkaline soluble resin' and 'binder' is used interchangeably.

[0019] < Anthraquinone compound>

The present invention provides an antliraquinone compound represented by the general formula (1).

[0020] In the formula (1), Ri-Rio are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group, alkoxy group having 1 to 20 carbon atoms and a substituent represented by the following formula (2)

[0021]

[0022] In the formula (2), Rn is hydrogen atom or alkyl group having 1 to 6 carbon atoms and * means a position which bonds to the benzene ring of formula (1).

[0023] At least one of Rj-Rio are the substituent represented by the formula (2). Preferably, at least two of Ri-Rio are the substituent represented by the formula (2). More preferably, at least one of R Rs and at least one of R₆-Rio are the substituent represented by the formula (2).

[0024] The alkyl group has at least 1 carbon atom, and has less than 20 carbon atoms, preferably less than 5 carbon atoms. Examples of the alkyl group are; methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, isopropyl, sec-propyl, sec-butyl, tert-butyl, 2-ethylhexyl, cyclohexyl, 1-norbornyl and 1-adamantyl.

[0025] The alkoxyl group has at least 1 carbon atom, and has less than 20 carbon atoms, preferably less than 5 carbon atoms. Examples of the alkoxyl group are; methoxyl, ethoxyl, propoxyl, butoxyl, hexoxyl, octoxyl, sec-butoxyl and tert-butoxyl.

[0026] Preferably, Rn is hydrogen atom or alkyl group having 1 to 5 carbon atoms and more preferably, Rn is hydrogen atom or methyl group.

[0027] The anthraquinone dye of the present invention can be used as a mixture. For example, the anthraquinone dye having two substituents represented by the formula (2) and the anthraquinone dye having one substituent represented by the formula (2) can be used as a mixture. Another example is a mixture of anthraquinone dyes which have different substituents as R_t to Rio. A mixture of two or more of anturaquinone dyes can increase the solubility of dyes in various organic solvents.

[0028] The anthraquinone dye of the formula (1) is useful for a color filter of a LCD since the anthraquinone dye of the invention has excellent thermal stability and high enough solubility for an organic solvent used in the manufacture of LCD such as propylene glycol monomethyl ether acetate (PEGMIA). Without wishing to be bound to the theory, the inventors of this invention expect that since the substituent disclosed as formula (2) has carbonyl and ether structure same as an organic solvent used for the manufacture of a color filter of a LCD, the solubility of the anthraqinone dye in an organic solvent such as PEGMEA is increased. For thermal stability, the inventors of this invention expect that since the formula (2) structure is directly bonded to an aromatic ring of the anthraquinone dye without linking group, the thermal stability of the anthraquinone dye itself is high. In addition, since the unsaturated bond shown in formula (2) can be crosslinked with the resin or other components in a color filter, the thermal stability of the color filter comprising the dye is increased.

[0029] The anthraquinone dye of the present invention can be synthesized by the reaction of a compound shown in the formula (3) with a compound shown in the formula (4). [0030]

[0032] In the formula (3), Ri-Rio are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group and alkoxy group having 1 to 20 carbon atoms; and at least one of Ri to Ri₀ is hydroxyl group.

[0033] In the formula (4), Rn and Rj₂ are independently selected from the group consisting of hydrogen atom and alkyl group having 1 to 6 carbon atoms. Preferably, Rn and R|₂ are selected from hydrogen atom or alkyl group having 1 to 2 carbon atoms, more preferably, Rn and R₁₂ are hydrogen atom or methyl. The compound of R and j₂ are hydrogen atoms is known as acrylic anhydride, and the compound of Rn and i₂ are methyl groups is known as methacrylic anhydride.

[0034] The compound represented by the formula (3) can be synthesized referring to documents such as US3,918,976 and US4,661,293. When the compound of R₃ and R₈ are hydroxyl groups and R], R₅, R₆, and Rio are methyl groups is synthesized, 1,4,9,10-tetrahydroxylantliracene and 2,6-dimethyl-4-hydroxylaniline are reacted shown in the following formula.

[0035] The reaction of the compound designated by the formula (3) and the compound designated by the formula (4) is conducted in the presence of a catalyst such as dimethylaminopyridine and a base catalyst such as triethylamine, or pyridine. The reaction is conducted under nitrogen atmosphere, at room temperature to 100 degrees C for 2 to 8 hours. A solvent which does not react with raw materials can be used during the reaction.

[0036] The mole ratio of the compound designated by the formula (3) and the compound designated by the formula (4) is preferably 0.8 or more, more preferably 1.0 or more. The mole ratio of the compound designated by the formula (3) and the compound designated by the formula (4) is preferably 3.0 or less, more preferably 2.0 or less.

[0037] The anthraquinone compound can be purified by a column chromato graphy.

[0038] <Composition>

The composition of the present invention comprises at least one compound as recited in formula (1) and a resin. The composition preferably additionally comprises a cross-linker (cross-linking agent), a solvent and a radiation-sensitive compound such as a photo initiator. The composition can form a film useful for a color filter.

[0039] The content of the dye as recited in formula (1) in the composition of the present invention varies depending on each molar absorption coefficient and required spectral characteristics, film thickness, or the like, but it is preferably at least 1 wt%, more preferably at least 2 wt%, the most preferably at least 5 wt% based on the total solid contents of the composition. The preferable content is less than 55 wt%, more preferably less than 45 wt%, most preferably less than 35 wt% based on the total solid contents of the composition.

[0040] The composition of the present invention can comprises other coloring materials in addition to the dye as recited in fomiula (1). Normally the use of additional coloring material is determined from the required spectral characteristics of a material to be formed from the composition.

[0041] The resin in the composition is preferably alkaline soluble resin. The alkaline soluble resin is also known as 'binder' in this technical art. Preferably, the alkaline soluble resin is dissolved in an organic solvent. The alkaline soluble resin can be developed with an alkaline solution such as tetramethyl ammonium hydroxide aqueous solution (TMAH) after forming a film.

[0042] The alkaline soluble resin (binder) is normally a linear organic polymer. The binder optionally has a crosslinkable group within the polymer structure. When the composition of the present invention is used as a negative type photosensitive composition, such crosslinkable group can react and form crosslink by exposure or heating so that the binder becomes a polymer which is insoluble in alkaline.

[0043] Many kinds of binder are known in this art. Examples of such binder are; (meth)acrylic resin, acrylamide resin, styrenic resin, polyepoxyde, polysiloxane resin, phenolic resin, novolak resin, and co-polymer or mixture of those resins. In this application, (meth)acrylic resin (polymer) includes copolymer of (meth)acrylic acid or ester thereof and one or more of other polymerizable monomers. For example, acrylic resin can be polymerized from acrylic acid and/or acrylic ester and any other polymerizable monomers such as styrene, substituted styrene, maleic acid or glycidyl (meth)acrylate.

[0044] The binder preferably has at least 1 ,000 of weight-average molecular weight (Mw), more preferably at least 2,000 of Mw measured by a GPC method using polystyrene as a standard. At the same time, the binder preferably has less than 200,000 of Mw, more preferably less than 100,000 of Mw measured by the same method described above.

[0045] The amount of the binder used in the composition of the present invention is preferably at least 10 wt%, more preferably at least 20 wt% based on the total solid contents of the composition. At the same time, the preferable amount of the binder is less than 80 wt%, more preferably less than 50 wt%, the most preferably less than 30 wt% based on the total solid contents of the composition.

[0046] The composition of this invention optionally further comprises a cross-linking agent to obtain a further hardened material. It is also called as a radical-polymerizable monomer. When the composition of this invention is used as a negative type photosensitive composition, such cross-linking agent can form a crosslink by exposure or heating and contribute to get a further hardened material. Well known cross-linking agent can be used for the composition of this invention. Examples of cross-linking agents are epoxy resin such as bisphenol A diglycidyl ether, ethyl eneglycol diglycidyl ether, butanediol diglycidyl ether, diphentaerythritol pentaglycidyl ether or dipentaerythritol hexaglycidyl ether and substituted nitrogen containing compound such as melamine, urea, guanamine or glycol uril.

[0047] The composition of this invention optionally further comprises a solvent. The solvent to be used for the composition is not limited, but preferably selected from the solubility of components of the composition such as alkaline soluble resin or anthraquinone dye. Examples of the preferable solvent include esters such as ethylacetate, n-butyl acetate, amyl formate, butyl propionate or 3-ethoxypropionate, ethers such as diethylene glycol dimethyl ether, ethylene glycol monomethyl ether or propylene glycol ethyl ether acetate and ketones such as methyl ethylketone, cyclohexanone or 2-heptanone.

[0048] When the composition of this invention is a negative type radiation-sensitive composition, the composition preferably comprises a photo initiator. Photo initiator also called as photopolymerization initiator and including radical initiator, cationic initiator and anionic initiator. Examples of a photo initiator include; oxime esther type initiator, sulfonium salts initiator, iodide salts initiator and sulfonate initiator.

[0049] The composition of this invention can comprise other radiation-sensitive compound such as a radiation sensitive resin or a photo acid generator.

[0050] <PoIymer layer>

The composition of the present invention described above can form a polymer layer on an article. The polymer layer also described as 'polymer film' in the specification.

[0051] The contents of the compound as recited in formula (1) in the polymer layer is depend on the required color of the film, but at least 1 wt %, preferably at least 10 wt% based on the polymer layer. At the same time, the content is less than 50 wt %, preferably less than 30 wt % based on the polymer layer. The polymer layer also comprises a binder which is disclosed above.

[0052] The polymer layer optionally comprises a photo initiator, a photo acid generator, a radiation sensitive resin and a crosslink agent disclosed above.

[0053] The method of forming the polymer layer on an article comprises the steps of; mixing the compound as recited in formula (1) with a binder and solvent, coating the mixture on an article which supports a layer and heating the article to form a polymer layer (film). Optionally, the method comprises one or more of steps of exposing a layer (film) or curing a layer to form crosslinked stable layer.

[0054] The binder and the solvent used to the method for forming the polymer layer are same as the one disclosed above.

[0055] Examples of an article which supports a layer (film) are glass, metal, silicon substrate and metal oxide coated material.

[0056] Any coating method can be used for the coating step, such as rotation coating, cast coating or roll coating.

[0057] The thickness of the layer (film) varies depending on the required properties of the film. The thickness of the layer is 0.1 to 5 micron, preferably 0.5 to 3 micron.

[0058] The layer (film) has high transmittance and thermal stability from the properties of the anthraquinone dye of this invention. The anthraquinone dye can be dissolved in an organic solvent, and has high thermal stability. Therefore the dye does not prevent the transmittance of a film and does not decrease the thermal stability of the film. Such property is important for a color filter of LCD. Therefore, the layer (film) of the present invention is useful as a color filter of LCD.

[0059] <Color filter>

The color filer of this invention comprises at least one compound as recited in formula (1). The layer (film) disclosed above can be used for the color filter. Normally, a color filter has multiple units which made from colored films comprising Red/Green/Blue colorants.

[0060] The contents of the compound as recited in formula (1) in a colored film for a color filter is same as the film disclosed above, at least 1 wt %, more preferably at least 10 wt % based on the total weight of the colored film. At the same time, the content is less than 50 wt %, preferably less than 30 wt % based on the total weight of the colored film.

[0061] A film used for a color filter can be formed by the following steps; coating a solution comprising the compound as recited in formula (1), binder, a photo initiator and solvent to form a radiation sensitive composition layer on a material, exposing the layer through a patterned mask, and developing the layer with an alkaline solution. Moreover, a curing step of further heating and /or exposing the layer after developing step may be conducted as needed.

[0062] Since a color filter comprises three colored films which comprise R/G/B colorant, the steps of forming each colored film are repeated, then a color filter having such three colored films are obtained.

EXAMPLES

[0063] Inventive Example 1

An anthraquinone dye (Dye 1) disclosed below was used in example 1.

Dye l

[0064] Synthesis of Dye 1

a. S

[0065] A mixture of 2.4 g (9.91 mmol) of 1.4,9.10-tetrahydroxylanthracene, 6.8 g (5 equiv.) of 2,6-dimethyl-4-hydroxylaniline, 2.0 g of boric acid and 12 mL of n-butanol was refluxed at normal pressure for 25 hours in an oil bath at 115 °C under N₂. The reaction mixture was cooled to room temperature and added thereto 1 mL 6N HCl solution while stirring. The major product was crystallized in ice-bath and filtered. The crude product was washed with water and dried. Finally the pure product was obtained by column chromatography on silica using methylene chloride and methanol as eluent. Yield: 60%. 1H NMR (DMSO-d6, ppm): 11.68 (s, 2H), 9.33 (br, 2H), 8.34 (m, 2H), 7.86 (m, 2H), 6.63 (s, 2H), 6.58 (s, 4H), 2.04 (s, 12H)

[0066] b. Synthesis of Compound 1

Into a 100 ml round glass three-necked flask equipped with an agitator, condenser, drop funnel and the tube for the introduction of gases, 1.1 5g l ,4-bis(2^,,6'-dimethyl-4'-hydroxyanilino)anthrquinone_(Mw:478; 0.0025mol, l.Oeq.), 0.847g methacrylic anhydride (Mw:154; 0.0055mol, 2.2eq), and 20ml THF were charged under nitrogen flow. A solution of 0.58 lg triethylamine (Mw:101; O.0058mol, 2.3eq) and 0.122g dimethylaminopyridine (Mw:122; 0.00 lmol, 0.4 eq) in 5ml THF is drop wise added with stirring at room temperature. The mixture is reacted at room temperature for 6 hrs. The solution was evaporated under reduced pressure. The crude product was purified by column chromatography on silica using methylene chloride and petroleum ether (60-90°C) as eluent. Yield: 80%. Absorption spectra: maximum peaks at 576 nm (log ε=4.14) and 623 nm (log £=4.17). ^]H NMR (CDCl_3i ppm): 11.62 (s, 2H), 8.34 (m, 2H), 7.67 (m, 2H)_} 6.84 (s, 4H), 6.52 (s, 2H), 6.24 (s, 2H), 5.65 (s, 2H), 2.12 (s, 12H), 1.98 (s, 6H)

[0067] Preparation of a color resist and a color film comprising an anthraquinone dye

0.15g of the synthesized anthraquinone dye, 1.35g of PGMEA and lg of alkaline soluble acrylic resin solution (MIPHOTO RPR4022, supplied from Mi wan Commercial Co., Ltd, 25 to 35 % of solid content in methyl 3-methoxypropinate) were mixed and stirred for 2 hours at room temperature using a shaker. The solution was filtered with a 0.45 micrometer PTFE filter to get rid of big particles. Then the filtered solution was spin coated onto a clean glass substrate with 400 rpm spin speed for 18 seconds. The obtained film was first dried at 90 °C under air atmosphere for 30 minutes, and then hard baked at 230 °C under air atmosphere for 1 hour. Optical performance after baking (ΔΕ_Β¾ value) was 8.5, and the one of after further baking was 2.5. A smaller AE_ab value indicates better heat resistance. The result is shown in Table 1.

[0068] Film thickness, transmittance and chromaticity coordinates of the obtained film were measured as disclosed below. Film thickness of the film was about 1.0 micron. Chromaticity coordinates measured by UltraScan Pro (Hunterlab) colorimeter was, x=0.207, y=0.242 and Y=36.5.

(1) Film thickness:

Film thickness is measured by scanning the difference in height across the boundary of film and glass substrate with atomic force microscope.

(2) Chromaticity coordinates:

The chromaticity coordinate of film on a glass sheet is directly recorded with UltraScan Pro (Hunterlab) colorimeter. The light source is D65/10.

(3) Thermal stability of films (Chromaticity):

The wet film after spin coating is dried in oven at 90 °C for 30 minutes and then soft baked at 150 °C for 15 minutes. The chromaticity coordinates (L, a, b) are recorded with UltraScan Pro (Hunterlab) colorimeter. D65/10 light source is used and results are based on CIE Lab coordinates. After that the film is hard baked at target temperature (230 °C) for lhour and the new chromaticity coordinates (L', a', b') are recorded with the method above. The thermal stability of a film is indicated by the difference of chromaticity coordinate before and after hard baking represented by the following formula;

ΔΕ= V(L - L')² + (a - a')² + (& ~ b')²

[0069] Comparative Examples 1 to 4

Same procedure was conducted excepting for the dyes disclosed below were used instead of Dye 1.

[0070] Dye used in Comparative Example 1

l,4-bis((isopropylamino)anthraquinone (Solvent Blue 36)

0 HN'

O HN„

[0071] Dye used in Comparative Example 2

l,4-bis(mesitylammo)anthraquinone (Solvent Blue 104)

[0072] D e used in Comparative Example 3

Dye 2

Dye used in Comparative Example 4

Dye 3 [0073]

Table 1

[0074] Referring to Table 1 , it can be found that Example 1 shows significant improvement in both thermal stability and solubility in PEGMEA compare with the Comparative Examples especially after one hour's baking at 230 °C which help dye 1 to be fully crosslinked with the matrix. Compared with Comparative Example 3 and 4, the solubility and thermal stability of dye 1 is much better than dye 2 and 3, which indicates that the phenyl substituent on 1, 4 position of anthraquinone is very necessary.

Claims

WHAT IS CLAIMED IS:

1. An anthra uinone com ound represented by the following formula ( 1 ) ,

wherein R Rio are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group, alkoxy group having 1 to 20 carbon atoms and a substituent represented by the following formula (2),

wherein Rn is hydrogen atom or alkyl group having 1 to 6 carbon atoms and * means a position which bonds to the benzene ring of formula (1); and

at least one of RrRio are the substituent represented by the formula (2).

The anthraquinone compound of claim 1, at least one of Rj-R₅ is the substituent represented by the formula (2) and at least one of R₆-Rio is the substituent represented by the formula (2).

The anthraquinone compound of claims 1 or 2, wherein Ri-Ri₀ are independently selected from the group consisting of alkyl group having 1 to 8 carbon atoms, hydrogen atom and a substituent represented by the formula (2).

A method for synthesis the compound of any of claims 1 to 3, wherein the method com rises reacting a compound represented by the following formula (3)

wherein Ri-R₁₀ are independently selected from the group consisting of alkyl group having 1 to 20 carbon atoms, halogen atom, hydroxyl group, hydrogen atom, cyano group, sulfonyl group, sulfo group, sulfato group, aryl group, nitro group, carboxyl group and alkoxy group having 1 to 20 carbon atoms; and

at least one of R[ to R₁₀ is hydroxyl group:

with a compound represented by the following formula (4);

wherem R_n and Rj₂ are independently selected from the group consisting of hydrogen atom and alkyl group having 1 to 6 carbon atoms.

The method of claim 4, wherein i-Rio are independently selected from the group consisting of alkyl group having 1 to 8 carbon atoms, hydroxyl group and hydroxyl group.

The method of claims 4 or 5, wherein the compound represented by the formula (4) is acrylic anhydride or methacrylic anhydride.

A composition comprising a resin and the compound of any of claims 1 to 3.

8. The composition of claim 7, further comprises a radiation-sensitive compound.

9. An article having a polymer layer formed from the composition of claims 7 or 8.

10. The article of claim 9 wherein the polymer layer is a negative-type layer.

11. A color filer comprising the compound of any of claims 1 to 3.