KR20050016667A - Filters for electronic displays - Google Patents

Abstract

A filter for an electronic display comprising a squarylium compound represented by the following formula (I) and capable of providing a clear image by blocking light having a wavelength that lowers color purity:

[Formula I]

[Wherein, R ¹ is hydrogen, alkyl or the like; R ² , R ³ and R ⁴ are each hydrogen, halogen, alkyl or the like; X is a group represented by formula A, etc.

           [Formula A]

(Wherein R ⁵ , R ⁶ , R ⁷ And R ⁸ are each hydrogen, halogen, alkyl and the like: R ⁹ and R ¹⁰ are each hydrogen, alkyl and the like).

Description

Filter for electronic display device {FILTERS FOR ELECTRONIC DISPLAYS}

The present invention relates to a filter for an electronic display device that can selectively block light of a wavelength that degrades color purity.

The electronic display device ideally displays a color image by a combination of three primary colors, that is, red, blue and green. However, in an actual display device, since the unwanted light (e.g., light with a wavelength of 550 to 600 nm: neon light emission) in the plasma display panel is also accompanied by the image, the color purity of the image is accompanied. There has been a problem of deterioration. In order to solve the above problem, a display device with a filter having a color correction function has been invented.

It is known that squarylium compounds are used as coloring agents for filters for electronic display devices. For example, Japanese Unexamined Patent Application No. 2001-192350 discloses a plasma display panel comprising a squarylium compound and the like represented by the following formula:

.

However, the plasma display panel is not satisfactory in practical use because of its insufficient light transmittance in the wavelength range near 500 nm.

Disclosure of the Invention

It is an object of the present invention to provide a filter for an electronic display device that can selectively block light of a wavelength that degrades color purity and provide a clear image.

The present invention provides the following [1] to [5].

[1] A filter for an electronic display device, comprising a squarylium compound represented by the following general formula (I):

[Wherein, R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group; R ² , R ³ and R ⁴ may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or Unsubstituted aryl group, nitro group, cyano group, hydroxyl group, formyl group, substituted or unsubstituted alkanoyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted amino group, or substituted or unsubstituted hetero Cyclic group;

X is a group represented by the following formula (A):

(Wherein R ⁵ , R ⁶ , R ⁷ And R ⁸ may be the same or different, each of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, A nitro group, cyano group, hydroxyl group, or a substituted or unsubstituted heterocyclic group: R ⁹ and R ¹⁰ may be the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl group , R ⁹ and R ¹⁰ together with adjacent nitrogen atoms form a substituted or unsubstituted heterocyclic group, alternatively R ⁶ and R ⁹ or R ⁸ and R ¹⁰ together with their adjacent NCC are substituted or unsubstituted Heterocyclic group), or a group represented by the following formula (B):

Wherein R ¹¹ and R ¹² may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or Unsubstituted aryl group, nitro group, cyano group, hydroxyl group, or substituted or unsubstituted heterocyclic group; R ¹³ represents hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted Or an unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group; R ¹⁴ represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or Unsubstituted aryl group, nitro group, cyano group, hydroxyl group, substituted or unsubstituted amino group, or substituted or unsubstituted heterocyclic group; p represents an integer of 0 to 4, and , R ¹⁴ s each may be the same or different), and when p is 2 to 4 at.

[2] A filter for an electronic display device, comprising a squarylium compound represented by the following general formula (II):

[Wherein, R ¹⁵ And R ¹⁷ may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, A nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, or a substituted or unsubstituted heterocyclic group; R ¹⁶ And R ¹⁸ may be the same or different and each is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group Represent; R ¹⁹ and R ²⁰ may be the same or different and each is a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, nitro A group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, or a substituted or unsubstituted heterocyclic group; m represents an integer of 0 to 4, wherein when m is 2 to 4, each of R ¹⁹ may be the same or different; n represents an integer of 0 to 4, where n is 2 to 4, each of R ²⁰ may be the same or different.

[3] The filter for electronic display device according to the above [2], wherein R ¹⁶ and R ¹⁸ in the formula may be the same or different and each represents an alkoxyalkoxy-substituted alkyl group.

[4] The filter for an electronic display device according to any one of [1] to [3], further comprising a binder.

[5] A squarylium compound represented by the following formula (Ia):

[Wherein R ¹ , R ² , R ³ and R ⁴ are each as defined above; X represents a group represented by the following formula (B):

             [Formula B]

Wherein each of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and p has the same meaning as defined above.

Hereinafter, the compound represented by the said general formula (I) is represented as compound (I). Compounds having other formula numbers are also indicated similarly.

In the definition of each group in the formulas, examples of the alkyl group and the alkyl moiety of the alkoxyl group, the alkanoyl group and the alkoxycarbonyl group include a linear or branched alkyl group having 1 to 6 carbon atoms, and a cyclic alkyl group having 3 to 8 carbon atoms. Included. Specific examples thereof include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, 2-methylbutyl group and tert-pentyl group , Hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like.

Examples of the aryl group include phenyl group, naphthyl group, anthryl group and the like.

Examples of the aralkyl group include an aralkyl group having 7 to 15 carbon atoms. Specific examples include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and the like.

Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom and iodine atom.

Examples of heterocycles in the heterocyclic group include aromatic heterocycles and aliphatic heterocycles.

Examples of aromatic heterocycles include 5- or 6-membered monocyclic aromatic heterocycles having one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms; And bicyclic or tricyclic condensed aromatic heterocycles having one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms, and wherein 3- to 8-membered rings are condensed. More specific examples include pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, quinoline ring, isoquinoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, naphthyridine ring, cynoline ring, pyrrole ring, Pyrazole ring, imidazole ring, triazole ring, tetrazole ring, thiophene ring, furan ring, thiazole ring, oxazole ring, indole ring, isoindole ring, indazole ring, benzimidazole ring, benzotriazole Ring, benzothiazole ring, benzoxazole ring, purine ring, carbazole ring and the like.

Examples of aliphatic heterocycles include 5- or 6-membered monocyclic aromatic heterocycles having one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms; And bicyclic or tricyclic condensed aliphatic heterocycles having one or more atoms selected from the group consisting of nitrogen, oxygen and sulfur atoms, and wherein 3- to 8-membered rings are condensed. More specific examples include pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, tetra Hydroisoquinoline ring, tetrahydrofuran ring, tetrahydropyran ring, dihydrobenzofuran ring, tetrahydrocarbazole ring and the like.

Examples of heterocycles formed by R ⁶ and R ⁹ or R ⁸ and R ^{10 together} with their adjacent NCC and heterocyclic groups formed together by R ⁹ and R ¹⁰ with their adjacent nitrogen atom include: 5- or 6-membered monocyclic heterocycle having one or more nitrogen atoms (the monocyclic heterocycle may comprise other nitrogen atoms, oxygen atoms or sulfur atoms); And bicyclic or tricyclic condensed heterocycles having one or more nitrogen atoms, to which 3- to 8-membered rings are condensed, wherein the condensed heterocycles may comprise other nitrogen atoms, oxygen atoms or sulfur atoms. . More specific examples thereof include pyrrolidine ring, piperidine ring, piperazine ring, morpholine ring, thiomorpholine ring, homopiperidine ring, homopiperazine ring, tetrahydropyridine ring, tetrahydroquinoline ring, Tetrahydroisoquinoline ring, pyrrole ring, imidazole ring, pyrazole ring, indole ring, indolin ring, isoindole ring and the like.

The substituents of the alkyl group, alkoxyl group, alkanoyl group and alkoxycarbonyl group are 1 to 3 substituents which may be the same or different. Specific examples of the substituent include a hydroxyl group, a carboxyl group, a halogen atom, an alkoxyl group, an alkoxyalkoxyl group and the like. The halogen atom and the alkoxyl group each have the same meaning as those defined above. The two alkoxy moieties in the alkoxyalkoxy group each have the same meaning as defined above.

The aralkyl group, aryl group, heterocyclic group, R ⁶ and R ⁹ or R ⁸ and R ¹⁰ and heterocycles formed together by their adjacent NCCs, and R ⁹ And the substituents of the heterocycle in the heterocycle formed by R ¹⁰ and their adjacent nitrogen atoms are 1 to 5 substituents which may be the same or different. Specific examples of the substituent include a hydroxyl group, a carboxyl group, a halogen atom, an alkyl group, an alkoxyl group, a nitro group, a substituted or unsubstituted amino group, and the like. The halogen atom, alkyl group, and alkoxyl group each have the same meaning as those defined above.

Substituents of the amino group are one or two substituents which may be the same or different, specific examples of the substituent include an alkyl group and the like. The alkyl group has the same meaning as defined above.

As compound (II), preferred are compounds in which R ¹⁶ and R ¹⁸ , which may be the same or different, are each an alkoxyalkoxy-substituted alkyl group.

Each of compounds (I) and (Ia) can be prepared by known methods such as WO01 / 44233 or accordingly. Compound (II) can be prepared by known methods such as Dyes and Pigments, 49 , 161 (2001) or accordingly.

For example, compound (Ia) can be prepared as follows:

Scheme (1-a)

Scheme (1-b)

Scheme (1-c)

[Wherein R ¹ , R ² , R ³ , R ⁴ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and p are each as defined above and Y is the same halogen atom as defined above or Same alkoxyl group as defined].

Scheme (1-a)

Compound (V) is in an amount of 1 to 2 molar times based on compound (III) and compound (III) for 0.5 to 10 hours at 0 ° C. to 100 ° C., in the presence of a base such as pyridine, if necessary It is prepared by the reaction of Compound (IV).

Examples of the solvent that can be used include alcohols such as methanol, ethanol, propanol, butanol and the like; And other solvents such as chloroform, dichloromethane, 1,2-dichloromethane, ethyl acetate, diethyl ether, tetrahydrofuran, toluene, xylene and the like.

Scheme (1-b)

Compound (VI) is prepared by treating compound (V) in an acidic solvent at room temperature to 120 ° C. for 0.5 to 10 hours.

Examples of the acidic solvent include inorganic acids such as hydrochloric acid and sulfuric acid, or organic acids such as acetic acid and trifluoroacetic acid (10 to 90% by volume), tetrahydrofuran, dimethyl sulfoxide, N, N-dimethylformamide, Mixed solvents with water and the like are used.

Scheme (1-c)

Compound (Ia) is prepared by the reaction of compound (VII) in a 1 to 2 molar amount based on compound (VI) and compound (VI) for 1 to 15 hours at 80 ° C to 120 ° C.

Examples of the solvent that can be used include alcohol solvents such as ethanol, propanol, isopropyl alcohol, butanol, octanol and the like; And mixed solvents of alcohol solvents (50 vol% or more) with benzene, toluene, xylene and the like.

Preferred examples of compounds (I) and (II) will be given below. In the structural formulas for compounds 1 to 4, Me, Et, and Bu represent methyl, ethyl, and butyl, respectively.

The filter for an electronic display device of the present invention is described below.

Examples of electronic displays include liquid crystal displays, plasma displays, organic electroluminescent displays, and the like. Of these displays, plasma displays are preferred.

Compound (I) or (II) used for the filter for an electronic display device of the present invention is in an chloroform solution, preferably in an absorption range of 550 to 610 nm, more preferably in an absorption range of 570 to 610 nm. Indicates the absorption maximum. In the compound (I) or (II) used for the filter for an electronic display device of the present invention, the log value of the molar extinction coefficient is preferably 4.5 or more, more preferably 4.8 or more.

 In the filter for an electronic display device of the present invention, the absorption maximum is preferably in the absorption range of 550 to 610 nm, more preferably in the absorption range of 570 to 610 nm.

In order to manufacture the filter for an electronic display device of the present invention, the coating liquid of the compound (I) or (II) is preferably applied to a transparent substrate and then the organic solvent is removed by evaporation. If necessary, other transparent substrates can be bonded to the coated substrate.

The coating solution can be prepared by dissolving a binder in a solution of an organic solvent comprising compound (I) or (II).

Examples of the organic solvent include ethers such as dimethoxyethane, methoxyethoxyethane, tetrahydrofuran, dioxane and the like; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; And aromatic hydrocarbons such as benzene, toluene, xylene and monochlorobenzene. Preferably, the organic solvent is used in an amount of 10 to 3,000 times (by weight) based on compound (I) or (II).

Examples of the binder include polyester resins, polycarbonate resins, polyacrylic acid resins, polystyrene resins, poly (vinyl chloride) resins, poly (vinyl acetate) resins, and the like. Preferably, the binder is used in an amount of 10 to 500 times (by weight) based on compound (I) or (II).

As the transparent substrate, a transparent resin or glass having low absorbance and low scattering coefficient can be used. Examples of the resin include polyester resins, polycarbonate resins, polyacrylic acid resins, polystyrene resins, poly (vinyl chloride) resins, poly (vinyl acetate) resins, and the like.

As a method of applying the coating liquid of the compound (I) or (II) to a transparent substrate, such as a bar-coating method, a spray method, a roll-coating method or a dipping method Known coating methods can be used (eg, US Pat. No. 2,681,294).

Compound (I) or (II) is very soluble in an organic solvent and is suitable for a method for producing a filter for an electronic display device using the above-described coating liquid.

In order to manufacture the filter for an electronic display device of the present invention, another method may be employed in which compound (I) or (II) is directly dissolved or dispersed in a resin constituting the transparent substrate and then molded into a film. If desired, other transparent substrates may be bonded to one or both sides of the coated substrate.

In films formed using compounds (I) or (II), preferably exhibit an absorption width of 50% transmittance near the absorption maximum wavelength (i.e. up to 50% transmission near the absorption maximum wavelength and the absorption maximum wavelength). Difference from the absorption minimum wavelength) is 80 nm or less. Preferably, the film formed using compound (I) or (II) has a sufficient transmittance in the range from 400 to 500 nm. For example, for the film in which the absorption maximum is in the absorption range of 550 to 610 nm, the transmittance at 500 nm is preferably 80% or more.

The filter for an electronic display device of the present invention can provide a clear image capable of selectively blocking light having a wavelength that lowers color purity while maintaining the brightness of a field of view, and having excellent color correction function and showing excellent color. have.

The filter for an electronic display device of the present invention can be used for a CRT, a fluorescent display tube, an electroluminescent panel, a light emitting diode, a plasma display panel, a heating bulb, a laser display, a liquid crystal display, an electrochromic display, and the like.

Optimal mode for the implementation of the invention

The invention is described in more detail based on the following examples and reference examples.

Reference Example 1 (Method for Producing Compound 1)

The dichloromethane solution (32 mL) in which 2.8 g of squaric acid dichloride was dissolved was cooled to 0 ° C to 5 ° C, and 1.5 g of pyridine was added thereto. Subsequently, a dichloromethane solution (20 mL) in which 5.3 g of N, N-diethylaniline was dissolved was added dropwise to the mixture over 30 minutes. The mixture was heated to room temperature and stirred for 4 hours. An ocher solid was obtained from the mixture by silica gel chromatography using dichloromethane as the developing solution. Acetic acid (4 mL) and water (4 mL) were added to the ocher solid and the reaction was carried out at 110 ° C. for 2 hours. The reaction solution was then cooled to 0-5 [deg.] C. Water (50 mL) was added to the reaction solution and the precipitated yellow solid was obtained by filtration. 2,4-dimethyl-3-ethylpyrrole (0.9 g), butanol (22 mL) and toluene (11 mL) were added to the yellow solid and the reaction was carried out at 110 ° C for 2 hours. The reaction solution was then cooled to 0-5 [deg.] C. Methanol (40 mL) was added to the reaction solution and the precipitate was obtained by filtration. This resulted in compound 1 (0.2 g).

¹ H-NMR δ (CDCl ₃ ) ppm: 1.09 (3H, t, J = 7.6 Hz), 1.23 (3H, t, J = 7.3 Hz), 2.36 (3H, s), 2.41 (2H, q, J = 7.6 Hz), 2.62 (3H, s), 3.48 (2H, q, J = 7.3 Hz), 6.71 (2H, d, J = 9.3 Hz), 8.24 (2H, d, J = 9.3 Hz), 10.3 (1H) , brs).

Reference Example 2 (Method for Producing Compound 2)

Compound 2 (0.5 g) was prepared as in Example 1 except 2,4-dimethylpyrrole (0.7 g) was used instead of 2,4-dimethyl-3-ethylpyrrole.

¹ H-NMR δ (CDCl ₃ ) ppm: 1.26 (6H, t, J = 7.2 Hz), 2.40 (3H, s), 2.66 (3H, s), 3.50 (4H, q, J = 7.2 Hz), 6.17 (1H, m), 6.72 (2H, d, J = 9.3 Hz), 8.26 (2H, d, J = 8.5 Hz), 10.2 (1H, brs).

Example 1 (Method of Preparing Compound 3)

A mixture of 5.3 g of squaric dimethyl ester, 6.4 g of 1,3,3-trimethyl-2-methyleneindolin and 50 mL of ethanol was refluxed for 1 hour while heating, and the precipitated solid was obtained by filtration. The solid was introduced into a mixed solvent of 50 mL of N, N-dimethylformamide and 3 mL of 1 mol / L hydrochloric acid, and left at 80 ° C. for 2 hours. Aqueous methanol solution (50% by volume) (50 mL) was added to the mixture and the insolubles were obtained by filtration. The insoluble and 4.1 g of 2,4-dimethyl-3-ethylpyrrole were introduced into a mixed solvent of 65 mL of butanol and 33 mL of toluene, and the reaction was performed at 110 ° C. for 7 hours, and then cooled. Methanol (261 mL) was added to the mixture and the precipitate was obtained by filtration. This resulted in compound 3 (3.3 g).

¹ H-NMR δ (CDCl ₃ ) ppm: 1.08 (3H, t, J = 7.6 Hz), 1.63 (6H, s), 1.77 (3H, s), 2.32 (3H, s), 2.43 (2H, q, J = 7.6 Hz), 2.59 (3H, s), 3.61 (3H, s), 5.94 (1H, s), 7.04 (1H, d, J = 7.8 Hz), 7.17-7.21 (1H, m), 7.32- 7.38 (2 H, m), 9.95 (1 H, brs).

Reference Example 3 (Method for Producing Compound 4)

Squaric acid (20.0 g) and 1-butoxyethoxyethylindole (100 g) were added into a mixed solvent of 170 mL butanol and 170 mL toluene and the reaction was carried out at 100 ° C. to 110 ° C. for 5 hours. The reaction solution was then cooled to 70 ° C. and 220 mL of methanol was added thereto. The mixture was cooled to 15 ° C. and the precipitate was obtained by filtration. This resulted in compound 4 (33.3 g).

¹ H-NMR δ (CDCl ₃ ) ppm: 0.89 (6H, t, J = 7.3 Hz), 1.27-1.36 (4H, m), 1.47-1.54 (4H, m), 3.34-3.48 (10H, m), 3.51-3.54 (4H, m), 3.85 (4H, t, J = 5.6 Hz), 4.36 (4H, t, J = 5.6 Hz), 7.23-7.36 (6H, m), 9.21 (2H, d, J = 7.8 Hz).

Example 2

For each of the compounds 1 to 4, the maximum absorption wavelength (λmax) and the log value (logε) of the molar extinction coefficient in the chloroform solution were measured (800 to 300 nm). The results are shown in Table 1 below.

Example 3

Dimethoxyethane solution of compound 1 (0.5% by weight) and dimethoxyethane solution (20% by weight) of a polyester resin (VYLON 200 manufactured by Toyobo Co., Ltd.) were mixed at a ratio of 7: 2, and the The resulting mixture was applied by a bar coater onto a glass substrate and then dried. This formed a coating film. The transmittance curve of the obtained film was measured (800 to 300 nm), and the absorption maximum wavelength, the absorption width at 50% transmittance, and the transmittance at 500 nm were measured for the film. The results are shown in Table 2 below.

Example 4

A dimethoxyethane solution of compound 2 (0.1 wt%) and a dimethoxyethane solution (20 wt%) of a polyester resin (VYLON 200 manufactured by Toyobo Co., Ltd.) were mixed in a ratio of 7: 2, and the The resulting mixture was applied by a bar coater onto a glass substrate and then dried. This formed a coating film. The transmittance curve of the obtained film was measured (800 to 300 nm), and the absorption maximum wavelength, the absorption width at 50% transmittance, and the transmittance at 500 nm were measured for the film. The results are shown in Table 2 below.

Example 5

A dimethoxyethane solution of compound 3 (0.5 wt%) and a dimethoxyethane solution (20 wt%) of a polyester resin (VYLON 200 manufactured by Toyobo Co., Ltd.) were mixed in a ratio of 7: 2, and the The resulting mixture was applied by a bar coater onto a glass substrate and then dried. This formed a coating film. The transmittance curve of the obtained film was measured (800 to 300 nm), and the absorption maximum wavelength, the absorption width at 50% transmittance, and the transmittance at 500 nm were measured for the film. The results are shown in Table 2 below.

Example 6

A tetrahydrofuran solution of compound 4 (0.6 wt%) and a dimethoxyethane solution (20 wt%) of a polyester resin (VYLON 200 manufactured by Toyobo Co., Ltd.) were mixed in a ratio of 7: 2, and the The resulting mixture was applied by a bar coater onto a glass substrate and then dried. This formed a coating film. The transmittance curve of the obtained film was measured (800 to 300 nm), and the absorption maximum wavelength, the absorption width at 50% transmittance, and the transmittance at 500 nm were measured for the film. The results are shown in Table 2 below.

As is evident from the results described above, the filter for an electronic display device of the present invention can block light at a wavelength that degrades color purity, so that a clear image can be provided.

According to the present invention, a filter for an electronic display device that can block light at a wavelength that lowers color purity and can provide a clear image can be provided.

Claims (5)

Containing a squarylium compound represented by the following formula (I) Filters for Electronic Display Devices: [Formula I] [Wherein, R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group; R ² , R ³ and R ⁴ may be the same or different and each is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or Unsubstituted aryl group, nitro group, cyano group, hydroxyl group, formyl group, substituted or unsubstituted alkanoyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted amino group, or substituted or unsubstituted hetero Cyclic group; X is a group represented by formula A:           [Formula A] (Wherein R ⁵ , R ⁶ , R ⁷ And R ⁸ may be the same or different, each of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, Nitro group, cyano group, hydroxyl group, or substituted or unsubstituted heterocyclic group; R ⁹ and R ¹⁰ may be the same or different and each represent a hydrogen atom or a substituted or unsubstituted alkyl group, or R ⁹ and R ¹⁰ together with an adjacent nitrogen atom form a substituted or unsubstituted heterocyclic group, R ⁶ and R ⁹ or R ⁸ and R ¹⁰ together with their adjacent NCC form a substituted or unsubstituted heterocycle, or a group represented by the following formula (B):             [Formula B] Wherein R ¹¹ and R ¹² may be the same or different and each represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted A substituted aryl group, nitro group, cyano group, hydroxyl group, or substituted or unsubstituted heterocyclic group; R ¹³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, substituted or Unsubstituted aralkyl group or substituted or unsubstituted heterocyclic group; R ¹⁴ represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted group A substituted aryl group, nitro group, cyano group, hydroxyl group, substituted or unsubstituted amino group, or substituted or unsubstituted heterocyclic group; p represents an integer of 0 to 4, wherein If the document p is 2 to 4, R ¹⁴ s may each be the same or different)]. A filter for an electronic display device comprising a squarylium compound represented by the following general formula (II): [Formula II] [Wherein, R ¹⁵ And R ¹⁷ may be the same or different and each represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, nitro A group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, or a substituted or unsubstituted heterocyclic group; R ¹⁶ And R ¹⁸ , which may be the same or different, represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group, respectively. ; R ¹⁹ and R ²⁰ may be the same or different and each represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a nitro group , A cyano group, a hydroxyl group, a substituted or unsubstituted amino group, or a substituted or unsubstituted heterocyclic group; m represents an integer of 0 to 4, wherein when m is 2 to 4, each of R ¹⁹ may be the same or different; n represents an integer of 0 to 4, where n is 2 to 4, each of R ²⁰ may be the same or different. 3. The filter for an electronic display device according to claim 2, wherein R ¹⁶ and R ¹⁸ , which may be the same or different, are each an alkoxyalkoxy-substituted alkyl group. The filter for an electronic display device according to any one of claims 1 to 3, further comprising a binder. A squarylium compound represented by the following general formula (Ia): Formula Ia [Wherein R ¹ , R ² , R ³ and R ⁴ each have the same meaning as defined above; X represents a group represented by the following formula (B):           [Formula B] Wherein each of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and p has the same meaning as defined above.