KR20070078393A - Optical filter - Google Patents

Abstract

An optical filter is provided to be suitable for a screen display device having a sharp optical absorption in the wavelength region of 560-620nm. The optical filter contains a compound represented by the following formula (I). In the formula, R1 and R2 each is independently a hydrogen atom, a C1-8 alkyl group, a C6-20 aryl group, or a C7-20 arylalkyl group, R3, R4, R5, and R6 each is independently a hydrogen atom, a halogen atom, a C1-8 alkyl group, a C6-20 aryl group, a C7-20 arylalkyl group, a C2-20 heterocyclic group, an amino group, a cyano group, a hydroxyl group, or a nitro group, wherein the C1-8 alkyl group, C6-20 aryl group, C7-20 arylalkyl group, C2-20 heterocyclic group, and amino group represented by R1, R2, R3, R4, R5, and R6 may have substituents, methylene groups in the C1-8 alkyl group are substitutable with -CH=CH-, m and n each is independently an integer of 1-4, and s and t each is independently an integer of 1-5.

Description

Optical filter {OPTICAL FILTER}

The present invention relates to an optical filter using a squarylium compound having a specific molecular structure. The squarylium compound is particularly useful as a light absorbing agent to be contained in an optical filter for an image display device.

Compounds having high intensity absorption in the wavelength range of 500 to 700 nm, especially compounds having a maximum absorption (λmax) of 550 to 620 nm, are used in optical recording layers, liquid crystal display devices (LCDs), and plasma of optical recording media such as DVD ± R. It is used as an optical element in optical filters for image display devices such as display panels (PDPs), electroluminescent displays (ELDs), cathode ray tube displays (CRTs), fluorescent displays, and field emission displays.

For example, the use of an optical element in an optical filter for an image display device includes a light absorbing agent of a color filter. The image display device displays a color image by a combination of three primary colors of red, blue, and green. The light that displays color images causes deterioration of display quality, such as light having a wavelength of 550 to 600 nm between green and red. In addition, there is also a cause of reflection or reflection of external light such as light that causes the malfunction of the infrared remote control with a wavelength of 750 to 1100 nm, or a fluorescent lamp with a wavelength of 480 to 500 nm and 540 to 560 nm. Being light is included. Thus, optical filters containing light absorbers that selectively absorb light of these unnecessary wavelengths have been used.

Furthermore, recently, in order to make the color purity and color separation of a display element high enough to make image quality high, the light absorber which selectively absorbs the light of wavelength 560-620nm is calculated | required especially. These light absorbing agents are required to have a particularly steep light absorption, that is, a small half width of λ max, and not to lose function due to light or heat.

As an optical filter containing a light absorbing agent, for example, Patent Document 1 discloses an optical filter using a squarylium compound, and Patent Document 2 below discloses an optical filter as one of uses of a squarylium compound having a specific structure. Patent Document 3 discloses an optical filter using a dye having a maximum absorption wavelength in a wavelength range of 560 to 620 nm, and a squarylium compound is exemplified as one of the dyes. A front plate for an image display device having a squarylium compound or a cyanine compound is disclosed. However, the compounds used in these optical filters do not have satisfactory performance in terms of absorption wavelength characteristics or affinity with a solvent or a binder resin. Therefore, these optical filters did not show sufficient performance in the wavelength range of 560 ~ 620nm.

[Patent Document 1] Japanese Patent Publication No. 2000-265077

[Patent Document 2] Japanese Patent Application Laid-Open No. 2001-166131

[Patent Document 3] Japanese Patent Publication No. 2002-228829

[Patent Document 4] Japanese Patent No. 3641220

Accordingly, an object of the present invention is to provide an optical filter which is particularly suitable as an optical filter for an image display device having a steep light absorption, particularly in the wavelength range of 560 ~ 620nm.

As a result of many studies, the present inventors have found that optical filters made of squarylium compounds having a specific molecular structure have a steep light absorption in a specific wavelength range, which can significantly improve the image characteristics of an image display device. It was found.

This invention is made | formed based on the said knowledge, and provides the optical filter characterized by containing the compound represented by the following general formula (I).

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 20 carbon atoms, an arylalkyl group of 7 to 20 carbon atoms, or a heterocyclic group of 2 to 20 carbon atoms , An amino group, a cyano group, a hydroxyl group or a nitro group, wherein the alkyl group having 1 to 8 carbon atoms represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , and having 6 to 20 carbon atoms The aryl group, the arylalkyl group having 7 to 20 carbon atoms, the heterocyclic group having 2 to 20 carbon atoms, and the amino group may have a substituent, and the methylene group in the alkyl group having 1 to 8 carbon atoms may be substituted with -CH = CH-. , m and n each independently represent an integer of 1 to 4, and s and t each independently represent an integer of 1 to 5 Represents)

EMBODIMENT OF THE INVENTION Hereinafter, the optical filter of this invention is described in detail about the preferable embodiment.

First, the squarylium compound represented by the general formula (I) will be described.

Examples of the alkyl group having 1 to 8 carbon atoms represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in the general formula (I) include methyl, ethyl, propyl, isopropyl, butyl, 2 butyl, 3 butyl, isobutyl, amyl, isoamyl, 3 amyl, hexyl, cyclohexyl, heptyl, isoheptyl, third heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, etc. R ¹ , R ² , R ³ , R ⁴ , R ⁵ Examples of the aryl group having 6 to 20 carbon atoms represented by R ⁶ include phenyl, naphthyl, anthracen-1-yl, phenanthrene-1-yl, and the like. R ¹ , R ² , R ³ , and R ⁴ Examples of the arylalkyl group having 7 to 20 carbon atoms represented by R ⁵ and R ⁶ include benzyl, phenethyl, 2-phenylpropane, diphenylmethyl, triphenylmethyl, styryl, and cinnamil ( cinnamyl), and the halogen atoms represented by R ³ , R ⁴ , R ⁵ and R ⁶ include fluorine, chlorine, bromine and iodine, and R ³ , R ⁴ , R ⁵ and R ⁶ Examples of the heterocyclic group having 2 to 20 carbon atoms include pyridyl, pyrimidyl, pyridyl, piperidyl, piperidyl, pyranyl, pyrazolyl, triadyl, pyrrolidyl and quinolyl, Isoquinolyl, imidazolyl, benzoimidazolyl, triazolyl, furyl, furanyl, benzofuranyl, thienyl, thiophenyl, benzothiophenyl, thiadiazolyl , Thiazolyl, benzothiazole Reyl, oxazolyl, benzoxazolyl, isothiazolyl, isoxazolyl, indolyl, uroridyl, morpholinyl, thiomorpholinyl, 2-pyrrolidinone-1-yl , 2-piperidone-1-yl, 2,4-dioxyimidazolidin-3-yl, 2,4-dioxyoxazolidin-3-yl, and the like, and R ³ , Amino groups represented by R ⁴ , R ⁵ and R ⁶ include amino, ethylamino, dimethylamino, diethylamino, butylamino, cyclopentylamino, 2-ethylhexylamino, dodecylamino, anilino, chlorophenylamino , Toluidino, anisidino, N-methyl-anilino, diphenylamino, naphthylamino, 2-pyridylamino, methoxycarbonylamino, phenoxycarbonylamino, acetylamino, Benzoylamino, formylamino, pivaloylamino, lauroylamino, carbamoylamino, N, N-di Tylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino, methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxy Cycarbonylamino, N-methyl-methoxycarbonylamino, phenoxycarbonylamino, sulfamoylamino, N, N-dimethylaminosulfonylamino, methylsulfonylamino, butylsulfonylamino, phenylsul Phenylamino etc. are mentioned.

^{R 1, R 2, R 3} , R 4, R 5 and an alkyl group of carbon atoms 1 to 8, which is represented by R ^6, carbon atoms, which is represented by ^{R 1, R 2, R 3} , R 4, R 5 and R ⁶ atoms Represented by a 6 to 20 aryl group, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , an arylalkyl group having 7 to 20 carbon atoms, represented by R ³ , R ⁴ , R ⁵ and R ⁶ The heterocyclic group having 2 to 20 carbon atoms and the amino group represented by R ³ , R ⁴ , R ⁵ and R ⁶ may all have a substituent. Examples of the substituent include the followings. In addition, R ¹ ~ R ⁶ is R ¹ ~ R ⁶ when having a substituent containing from group and also carbon atoms among their group substituent or less containing a carbon atom such as an alkyl group of the carbon atoms 1-8 of the, including the substituent The total number of carbon atoms shall satisfy the specified range.

Examples of the substituent include methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, second butyl, third butyl, isobutyl, amyl, isoamyl, third amyl, cyclopentyl, hexyl, 2-hexyl , 3-hexyl, cyclohexyl, bicyclohexyl, 1-methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, isoheptyl, third heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl Alkyl groups such as nonyl, isononyl and decyl; Methyloxy, ethyloxy, propyloxy, isopropyloxy, butyloxy, second butyloxy, tertiary butyloxy, isobutyloxy, amyloxy, isoamyloxy, tertiary amyloxy, hexyloxy, cyclohexyloxy Alkoxy groups such as heptyloxy, isoheptyloxy, third heptyloxy, n-octyloxy, isooctyloxy, third octyloxy, 2-ethylhexyloxy, nonyloxy and decyloxy; Methylthio, ethylthio, propylthio, isopropylthio, butylthio, second butylthio, third butylthio, isobutylthio, amylthio, isoamylthio, tertiary amylthio, hexylthio, cyclohexylthio, heptyl Alkylthio groups such as thio, isoheptylthio, third heptylthio, n-octylthio, isooctylthio, third octylthio and 2-ethylhexylthio; Vinyl, 1-methylethenyl, 2-methylethenyl, 2-propenyl, 1-methyl-3-propenyl, 3-butenyl, 1-methyl-3-butenyl, isobutenyl, 3-pentenyl, Alkenyl groups such as 4-hexenyl, cyclohexenyl, bicyclohexenyl, heptenyl, octenyl, desenyl, pentadecenyl, eicosenyl, tricosenyl and the like; Arylalkyl groups such as benzyl, phenethyl, diphenylmethyl, triphenylmethyl, styryl and cinnamil; Aryl groups such as phenyl and naphthyl; Aryloxy groups such as phenoxy and naphthyloxy; Arylthio groups such as phenylthio and naphthylthio; Pyridyl, pyrimidyl, pyridyl, piperidyl, peranyl, pyrazolyl, triadyl, pyrrolyl, quinolyl, isoquinolyl, imidazolyl, benzoimidazolyl, triazolyl, furyl, furanyl, benzo Furanyl, thienyl, thiophenyl, benzothiophenyl, thiadiazolyl, thiazolyl, benzothiazolyl, oxazolyl, benzooxazolyl, isothiazolyl, isoxazolyl, indolyl, 2-pyrrolidinone Heterocyclic groups such as -1-yl, 2-piperidone-1-yl, 2,4-dioxyimidazolidin-3-yl, and 2,4-dioxyoxazolidin-3-yl; Halogen atoms such as fluorine, chlorine, bromine and iodine; Acetyl, 2-chloroacetyl, propionyl, octanoyl, acryloyl, methacryloyl, phenylcarbonyl (benzoyl), phthaloyl, 4-trifluoromethylbenzoyl, pivalo 1, salicyloyl, oxaloyl, stearoyl, methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl, carbamoyl Acyl groups, such as); Acyloxy groups such as acetyloxy and benzoyloxy; Amino, ethylamino, dimethylamino, diethylamino, butylamino, cyclopentylamino, 2-ethylhexylamino, dodecylamino, anilino, chlorophenylamino, toluidino, ansidino, N-methyl- Anilino, diphenylamino, naphthylamino, 2-pyridylamino, methoxycarbonylamino, phenoxycarbonylamino, acetylamino, benzoylamino, formylamino, pivaloylamino, lauroylamino, carba Moylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino, methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino , n-octadecyloxycarbonylamino, N-methyl-methoxycarbonylamino, phenoxycarbonylamino, sulfamoylamino, N, N-dimethylaminosulfonylamino, methylsulfonylamino, butylsulfonylamino , Phenylsulfonylami A substituted amino group and the like; A sulfonamide group, a sulfonyl group, a carboxyl group, a cyano group, a sulfo group, a hydroxyl group, a nitro group, a mercapto group, an imide group, a carbamoyl group, a sulfonamide group, and the like, and these groups may be further substituted. In addition, the carboxyl group and sulfo group may form a salt.

As a squarylium compound which concerns on this invention represented by the said General formula (I), R <^5> and / or R <^6> is a C1-C8 alkyl group substituted by the halogen atom in the said General formula (I), It is preferable that especially R <^5> and / or R <^6> is a trifluoromethyl group, and what is represented by following General formula (II) is preferable because it has high solubility with respect to an organic solvent.

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms, and R ⁵ and R ⁶ are Each independently represent an alkyl group having 1 to 8 carbon atoms which may be substituted with a halogen atom, and s and t each independently represent an integer of 1 to 5).

The manufacturing method of the squarylium compound which concerns on this invention represented by the said General formula (I) is not specifically limited, It can obtain by the method using a well-known general reaction, For example, the following route (formula 3) Can be synthesized.

(Wherein, R ¹ to R ⁶ , m, n, s, t are the same as the general formula (I), and X represents a halogen atom)

The following compound Nos. 1-24 are mentioned as a preferable specific example of the squarylium compound which concerns on this invention represented by said general formula (I).

In the optical filter of the present invention, the content of the squarylium compound according to the present invention represented by the general formula (I) is usually 1 to 1000 mg / m 2, preferably 5 to 100 mg / m 2, and the content is If it is less than 1 mg / m 2, the light absorbing effect cannot be sufficiently exhibited. If it contains more than 1000 mg / m 2, the color of the filter may become so strong that the display quality may be degraded. There is a possibility that the brightness may decrease by increasing.

Next, the optical filter of this invention is demonstrated.

The optical filter of this invention contains the squarylium sulfide represented by the said general formula (I). Since the squarylium compound has an absorption maximum wavelength in or near the range of 560 to 620 nm and can selectively absorb and block some visible light, the optical filter of the present invention containing the squarylium compound is a display image. It is particularly suitable as an optical filter for an image display device that can be used for high quality. In addition to the image display device, the optical filter of the present invention can be used for various applications such as analytical device, semiconductor device manufacturing, astronomical observation, optical communication, spectacle lens, and the like.

The optical filter of the present invention is usually arranged on the front of the display. For example, the optical filter of the present invention may be directly attached to the surface of the display, or when the front plate is installed in front of the display, it may be attached to the front (outer) or the rear (display side) of the front plate. do.

The shape of the optical filter of the present invention is not particularly limited, but usually, a transparent support is provided with respective layers such as an undercoat layer, an antireflection layer, a hard coating layer, a lubrication layer, a protective layer and the like, as necessary. It can be mentioned. As a method of including in the optical filter of the present invention an optional component of a light absorbing agent and various stabilizers which are a squarylium compound according to the present invention or a pigment compound other than the squarylium compound according to the present invention, for example, (1) A method of incorporating in a transparent support or any desired layer, (2) a method of coating on a transparent support or any desired layer, and (3) a light absorbing agent such as a squarylium compound according to the present invention, separately from any of the optional layers The method of forming the filter layer containing etc. is mentioned.

As a material of the said transparent support body, For example, inorganic materials, such as glass; Cellulose esters such as diacetyl cellulose, triacetyl cellulose (TAC), propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose and nitrocellulose; Polyamides; Polycarbonate; Polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate, polybutyl Polyesters such as lenterephthalate; polystyrene; Polyolefins such as polyethylene, polypropylene and polymethylpentene; Acrylic resins such as polymethyl methacrylate; Polycarbonate; Polysulfones; Polyethersulfones; Polyether ketones; Polyetherimide; Polymeric materials, such as a polyoxyethylene and norbornene resin, are mentioned.

It is preferable that the transmittance | permeability of the said transparent support body is 80% or more, and it is more preferable that it is 86% or more. The haze of the transparent support is preferably 2% or less, and more preferably 1% or less. It is preferable that the refractive index of the said transparent support body is 1.45-1.70.

Among the transparent supports, other light absorbers, infrared absorbers, ultraviolet absorbers, phenolic, phosphorus-based antioxidants, flame retardants, lubricants, antistatic agents, inorganic fine particles, light resistance imparting agents, aromatic nitrosos, and the like other than the squarylium compound according to the present invention A compound, an aluminum compound, an iminium compound, a bisiminium compound, a transition metal chelate compound, and the like can be added, and the transparent support can be subjected to various surface treatments.

As light absorbers other than the squarylium compound which concerns on said invention, when the optical filter is used for an image display apparatus use, for example, the light absorber for color adjustment, the light absorber for reflection of an external light and an anti-reflective agent are mentioned, for example. In the case where the image display device is a plasma display, a light absorbing agent for preventing the malfunction of the infrared remote controller is mentioned.

As said light absorbing agent for color adjustment, it is used for the removal of the orange light of wavelength 550-600 nm, Trimethine cyanine derivatives, such as a trimethine indolium compound, a trimethine benzoxazolium compound, a trimethine benzothiazolium compound; Pentamethine cyanine derivatives such as pentamethine oxazolium compound and pentamethinethiazolium compound; Squarylium pigment derivatives; Azomethine pigment derivatives; Xanthene pigment derivatives; Azo pigment derivatives; Oxonol pigment derivatives; Benzylidene pigment derivatives; Pyrromethene pigment derivatives; Azo metal complex derivatives; Rhodamine pigment derivatives; Phthalocyanine derivatives; Porphyrin derivatives; In addition to a dipyrromethene metal chelate compound, the squarylium compound etc. which have a molecular structure other than the squarylium compound which concerns on this invention represented by the said General formula (I) are mentioned.

As said light absorbing agent (wavelength 480-500 nm correspondence) for external light reflection and anti-reflection, trimethine city, such as a trimethine indoleium compound, a trimethine oxazolium compound, a trimethine thiazolium compound, an indolidene trimethine thiazolium compound Derivatives; Phthalocyanine derivatives; Naphthalocyanine derivatives; Porphyrin derivatives; Dipyrromethene metal chelate compound, etc. are mentioned.

As said light absorbing agent (wavelength 750-1100nm correspondence) for infrared remote control malfunction prevention, pentamethine cyanine derivatives, such as a bisminium derivative, a pentamethine benzo indolium compound, a pentamethine benzooxazolium compound, a pentamethine benzothiazolium compound, ; Heptamethine cyanine derivatives, such as a heptamethine indolium compound, a heptamethine benzo indolium compound, a heptamethine oxazolium compound, a heptamethine benzooxazolum compound, a heptamethine thiazolium compound, a heptamethine benzothiazolium compound; Squarylium derivatives; Nickel complexes such as bis (stilbenedithiolato) compounds, bis (benzenedithioratto) nickel compounds, and bis (camphordithioratto) nickel compounds; Squarylium derivatives; Azo pigment derivatives; Phthalocyanine derivatives; Porphyrin derivatives; Dipyrromethene metal chelate compound, etc. are mentioned.

In the optical filter of the present invention, the light absorbing agent for adjusting the color tone, the light absorbing agent for preventing reflection or reflection of external light, and the light absorbing agent (near-infrared absorber) for preventing infrared remote control malfunction are contained in the layer containing the squarylium compound according to the present invention. It may be contained in the same layer as that, and may be contained in another layer. The content of these light absorbing agents is usually in the range of 1 to 1000 mg / m 2 per unit area of the optical filter, and preferably 5 to 100 mg / m 2.

Examples of the inorganic fine particles that can be added to the transparent support include silicon dioxide, titanium dioxide, barium sulfate, calcium carbonate, talc, kaolin and the like.

Examples of the various surface treatments that can be applied to the transparent support include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, Laser treatment, mixed acid treatment, ozone oxidation treatment and the like.

The undercoat layer which can be formed in the optical filter of the present invention is a layer used between the transparent support and the filter layer when forming a filter layer containing a light absorbing agent separately from any of the respective layers. The undercoat is formed of a layer containing a polymer having a glass transition temperature of -60 to 60 ° C., a layer having a rough surface on the side of the filter layer, or a layer containing a polymer having affinity with the binder polymer of the filter layer. do. The undercoat may be formed on the surface of the transparent support on which the filter layer is not formed, so as to improve the adhesion between the transparent support and the layer (for example, antireflection layer, hard coating layer) formed thereon, Moreover, you may form in order to improve the affinity of the optical filter and the adhesive agent for bonding an optical filter and an image display apparatus. 2 nm-20 micrometers are preferable, as for the thickness of the said undercoat layer, 5 nm-5 micrometers are more preferable, 20 nm-2 micrometers are more preferable, 50 nm-1 micrometer are especially preferable, and 80 nm-300 nm are the most preferable. The undercoat layer comprising a polymer having a glass transition temperature of -60 to 60 ° C. adheres the transparent support to the filter layer due to the adhesiveness of the polymer. Polymers having a glass transition temperature of -60 ° C to 60 ° C may be, for example, vinyl chloride, vinylidene chloride, vinyl acetate, butadiene, neoprene, styrene, chloroprene, acrylic acid ester, methacrylic acid ester, acrylonitrile or methyl vinyl ether polymerization. Or by copolymerization thereof. It is preferable that glass transition temperature is 50 degrees C or less, It is more preferable that it is 40 degrees C or less, It is more preferable that it is 30 degrees C or less, It is especially preferable that it is 25 degrees C or less, Most preferably, it is 20 degrees C or less. It is preferable that the elasticity modulus at 25 degrees C of the said undercoat layer is 1-1000 MPa, It is more preferable that it is 5-800 MPa, It is most preferable that it is 10-500 MPa. The undercoat layer whose surface on the filter layer side is a rough surface adhere | attaches a transparent support body and a filter layer by forming a filter layer on a rough surface. The undercoat with the rough surface of the filter layer side can be easily formed by application of a polymer latex. It is preferable that it is 0.02-3 micrometers, and, as for the average particle diameter of latex, it is more preferable that it is 0.05-1 micrometer. Examples of the polymer having affinity with the binder polymer of the filter layer include acrylic resins, cellulose derivatives, alginic acid, gelatin, casein, starch, polyvinyl alcohol, polyvinylbutyral, polyvinylpyrrolidone, soluble nylon and polymer latex. Can be. Moreover, you may form two or more undercoats in the optical filter of this invention. You may add the solvent which swells a transparent support body, a mat agent, surfactant, an antistatic agent, an application | coating adjuvant, a film-forming agent, etc. to an undercoat layer.

It is essential to have a low refractive index layer in the said antireflection layer which can be formed in the optical filter of this invention. It is preferable that the refractive index of the said low refractive index layer is lower than the refractive index of the said transparent support body, and is 1.20-1.55, and it is more preferable that it is 1.30-1.50. It is preferable that it is 50-400 nm, and, as for the thickness of a low refractive index layer, it is more preferable that it is 50-200 nm. The low refractive index layer is made of a fluorinated polymer having a low refractive index (Japanese Patent Laid-Open No. 57-34526, Japanese Patent Laid-Open No. 3-130103, Japanese Patent Laid-Open No. 6-115023, Japanese Patent Laid-Open No. 8) -313702, described in Japanese Patent Application Laid-Open No. Hei 7-168004, and a layer obtained by the sol-gel method (Japanese Patent Laid-Open Publication No. Hei 5-208811, Japanese Patent Application Laid-Open No. 6- 299091, and Japanese Patent Publication). (Patent disclosed in Japanese Patent Application Laid-Open No. 7-168003) or a layer containing fine particles (Japanese Patent Publication No. 60-59250, Japanese Patent Publication No. Hei 5-13021, Japanese Patent Publication No. Hei 6-56478, Japan And Patent Documents No. 7-92306 and Japanese Patent Application Laid-Open No. 9-288201. In the layer containing the microparticles, voids can be formed in the low refractive index layer as microvoids between the microparticles or in the microparticles. It is preferable that the layer containing microparticles | fine-particles has a porosity of 3-50 volume%, and it is more preferable to have a porosity of 5-35 volume%.

In order to prevent reflection of a wide wavelength range, it is preferable to laminate | stack a layer (medium-high refractive index layer) with a high refractive index in addition to the low refractive index layer in the said antireflection layer. It is preferable that it is 1.65-2.40, and, as for the refractive index of a high refractive index layer, it is more preferable that it is 1.70-2.20. The refractive index of the medium refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. It is preferable that it is 1.50-1.90, and, as for the refractive index of the medium refractive index layer, it is more preferable that it is 1.55-1.70. It is preferable that the thickness of a medium and high refractive index layer is 5 nm-100 micrometers, It is more preferable that it is 10 nm-10 micrometers, It is most preferable that it is 30 nm-1 micrometer. The haze of the medium and high refractive index layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The medium and high refractive index layers can be formed using a polymer binder having a relatively high refractive index. Examples of the polymer having a relatively high refractive index include polystyrene, styrene copolymer, styrene-butadiene copolymer, polyvinyl chloride, polycarbonate, polyamide, melamine resin, phenol resin, epoxy resin, cyclic (alicyclic or aromatic) isocyanate and Polyurethane etc. which are obtained by reaction with a polyol are mentioned. Polymers having other cyclic (aromatic, heterocyclic or alicyclic) groups or polymers having a halogen atom other than fluorine as a substituent also have high refractive index. You may use the polymer formed by the superposition | polymerization reaction of the monomer which introduced the double bond and enabled radical hardening.

Further, in order to obtain a high refractive index, inorganic fine particles may be dispersed in the polymer binder. It is preferable that the refractive index of the said inorganic fine particle is 1.80-2.80. The inorganic fine particles are preferably formed from oxides or sulfides of metals. Examples of the oxides or sulfides of the metal include titanium oxide (for example, rutile, mixed crystal of rutile / anatase, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, and oxidation Zirconium, zinc sulfide, etc. are mentioned. Among these, titanium oxide, tin oxide and indium oxide are particularly preferable. The inorganic fine particles are mainly composed of oxides or sulfides of these metals, and may further contain other elements. A main component means the component with most content (mass%) among the components which comprise particle | grains. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S and the like. It is possible to disperse in a solvent to form a film, or to use a liquid inorganic material itself, such as alkoxides of various elements, salts of organic acids, coordination compounds (for example, chelate compounds) and active inorganic polymers in combination with coordination compounds. Thus, medium and high refractive index layers may be formed.

The surface of the antireflection layer may be provided with an anti-glare function (a function of scattering incident light from the surface to prevent the infarct around the film from moving to the surface of the film). For example, an antireflection layer having an antiglare function can be obtained by forming fine irregularities on the surface of the transparent film and forming an antireflection layer on the surface, or after forming the antireflection layer on the surface with an embossing roll. Can be. Antireflective layers having an antiglare function generally have a haze of 3 to 30%.

The hard coat layer which can be formed in the optical filter of the present invention has a hardness higher than that of the transparent support. It is preferable that the said hard coat layer contains the polymer bridge | crosslinked. The hard coat layer may be formed using an acrylic, urethane, or epoxy polymer, oligomer or monomer (for example, ultraviolet curable resin). It is also possible to form a hard coat layer from a silica based material.

A lubricating layer may be formed on the surface of the antireflection layer (low refractive index layer). The lubricating layer has a function of imparting slipperiness to the low refractive index layer surface and improving scratch resistance. The lubricating layer may be formed using polyorganosiloxane (for example, silicone oil), natural wax, petroleum wax, higher fatty acid metal salt, fluorine-based lubricant or derivatives thereof. It is preferable that the thickness of the said lubricating layer is 2-20 nm.

When adopting "(3) a method for forming a filter layer containing a light absorbing agent such as a squarylium compound or the like according to the present invention, unlike any of the respective layers", the squarylium compound according to the present invention is left as it is. Filter layer may be used to form a filter layer or may be dispersed in a binder to form a filter layer. Examples of the binder include natural polymer materials such as gelatin, casein, starch, cellulose derivatives and alginic acid, or polymethyl methacrylate, polyvinyl butyral, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl chloride, Synthetic polymer materials such as styrene-butadiene copolymer, polystyrene, polycarbonate and polyamide are used.

When the binder is used, an organic solvent can be used at the same time. The organic solvent is not particularly limited, and various known solvents can be suitably used, for example, alcohols such as isopropanol; Ether alcohols such as methyl cellosolve, ethyl cellosolve, butyl cellosolve and butyl diglycol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and diacetone alcohol; esters such as ethyl acetate, butyl acetate and methoxy ethyl acetate; Fluorinated alcohols such as acrylate esters such as ethyl acrylate and butyl acrylate and 2,2,3,3-tetrafluoropropanol; Hydrocarbons such as hexane, benzene, toluene and xylene; Chlorinated hydrocarbons, such as methylene dichloride, dichloroethane, and chloroform, etc. are mentioned. These organic solvents can be used individually or in mixture.

The undercoat, antireflection layer, hard coating layer, lubrication layer, filter layer and the like can be formed by a general coating method. As a coating method, a deep coating method, an air-knife coating method, a curtain coating method, a roller coating method, a wire-bar coating method, a gravure coating method ( a gravure coating method, an extrusion coating method using a hopper (described in the specification of US Pat. No. 2,268,942), and the like. You may form by apply | coating two or more layers simultaneously. For the simultaneous coating method, the specifications of U.S. Pat.No.2761791, U.S. Pat.No.2941898, U.S. Pat.No.3508947, U.S.3526528, and Harasaki Yuji, "Coating Engineering," page 235 (1973 Asakura, 1973) Bookstore issuance).

EXAMPLE

Hereinafter, the present invention will be described in more detail with reference to Preparation Examples, Examples and Comparative Examples. However, the present invention is not limited to the following examples and the like.

The preparation examples 1 and 2 show the manufacture example of the squarylium compound which concerns on this invention, and Examples 1-4 show the Example of the optical filter of this invention using the squarylium compound obtained by manufacture example 1 or 2.

[Production Example 1]

Preparation of Compound No. 1

<Step 1>

Synthesis of N- (3,5-ditrifluoromethyl) -2-methylindole

2-methylindole 11.2 g (85.0 mmol), 3,5-ditrifluorobromobenzene 25.0 g (85.0 mmol), copper iodide 1.62 g (8.50 mmol), 1,2-diaminocyclohexane 1.95 g (17.0 mmol), 85.0 ml of toluene, and 36.0 g (85.0 mmol) of K ₃ PO ₄ were added thereto, and the mixture was heated and refluxed for 17 hours. After cooling to room temperature, the precipitates were separated by filtration, the solvent was distilled off from the filtrate and purified by column chromatography (n-hexane / ethyl acetate = 4/1; silica gel). The mixture was washed with methanol and washed with white crystals. -(3,5-ditrifluoromethyl) -2-methylindole was obtained (yield 32%).

<Step 2>

Synthesis of Compound No.1

5.00 g (15.0 mmol) of N- (3,5-ditrifluoromethyl) -2-methylindole obtained in Step 1, 0.83 g (7.30 mmol) of squaric acid, 16.7 g of n-butanol, and 8.40 toluene g was added and dehydrated and heated at 110 ° C. for 4 hours. After cooling to room temperature, the precipitate was separated by filtration, washed with methanol and dried to give a dark green solid (yield 70%). The obtained dark green solid confirmed that it was compound No. 1 which is a target object as a result of various analyzes. The analysis results of the obtained dark green solid are shown below.

(Analysis)

1 H-NMR (CDCl ₃ solvent)

(Chemical shift ppm of peak top; multiplicity; proton number)

(9.24; S; 2H), (8.19; d; 2H), (7.85; s; 4H), (7.48; d; 2H), (7.26; t; 2H), (6.82; t; 2H), (3.17 ; s; 6H)

UV absorption measurement (chloroform solvent)

λ max; 589.0 nm, ε; 1.46 × 10 ⁵

Decomposition temperature (TG-DTA: 100 ml / min in nitrogen stream, elevated temperature 10 deg. C / min)

  276 ° C .; Peak Top

Melting point (DSC: 100 ml / min in nitrogen stream, elevated temperature 10 ° C / min)

  277 ℃

[Production Example 2]

Preparation of Compound No. 2

<Step 1>

Synthesis of N- (3-trifluoromethyl) -2-methylindole

2-methyl indole 12.1 g (92.0 mmol), 3-trifluoro iodide benzene 25.0 g (92.0 mmol), copper iodide 1.75 g (9.20 mmol), 1,2-diaminocyclohexane 2.10 g (18.4 mmol) ), 92.0 ml of toluene and 39.0 g (183 mmol) of K ₃ PO ₄ were added thereto, and the mixture was heated and refluxed for 19 hours. After cooling to room temperature, the precipitates were separated by filtration, the solvent was distilled off from the filtrate and purified by column chromatography (n-hexane / ethyl acetate = 4/1; silica gel) to give N- (3- as a pale yellow oil. Trifluoromethyl) -2-methylindole was obtained (yield 68%).

<Step 2>

Synthesis of Compound No. 2

8.00 g (29.0 mmol) of N- (3-trifluoromethyl) -2-methyl indole obtained in Step 1, 1.66 g (15.0 mmol) of square acid, 27.4 g of n-butanol, and 13.7 g of toluene were added thereto, followed by dehydration. Heated at 2 h. After cooling to room temperature, the precipitate was separated by filtration, washed with water and ethyl acetate and dried to give a dark green solid (yield 53%). The obtained dark green solid confirmed that it was compound No. 2 which is a target object as a result of various analyzes. The analysis results of the obtained dark green solid are shown below.

(Analysis)

1 H-NMR (CDCl ₃ solvent)

(Ppm chemical shift ppm; multiplicity; proton number)

(9.25; d; 2H), (7.97-6.83; d; 14H), (3.14; s; 6H)

UV absorption measurement (chloroform solvent)

λ max; 587.0 nm, ε; 1.46 × 10 ⁵

Decomposition temperature (TG-DTA: 100 ml / min in nitrogen stream, elevated temperature 10 deg. C / min)

  280 ° C .; Peak Top

Melting point (DSC: 100 ml / min in nitrogen stream, elevated temperature 10 ° C / min)

  279 ℃

[Evaluation Example 1]

Solubility Assessment

The solubility to the ethyl methyl ketone at 20 ° C. was evaluated for compound Nos. 1, 2 and Comparative Compound Nos. 1 and 2 shown below. Evaluation was performed by adding the compound to ethyl methyl ketone in 0.05 mass% units in the range of 0.05-1.5 mass%, observing the dissolution and insoluble. The results are shown in Table 1.

compound Solubility Compound No. 1 1.5 mass% or more Compound No. 2 0.05 mass% or less dissolved, 0.1 mass% or more insoluble Comparative Compound No.1 Insoluble more than 0.05 mass% Comparative Compound No.2 Insoluble more than 0.05 mass%

Example 1

Creation of optical filter 1

The following formulations were melt mixed and kneaded at 260 ° C. for 5 minutes in a plaster mill. After mixing the mixture, it was extruded from a nozzle having a diameter of 6 mm to obtain a pigment-containing pellet by a water cooling pelletizer. The pellet was molded into a thin plate of 0.25 mm thickness at 250 ° C. using an electric press to obtain an optical filter. The absorption spectrum of the optical filter was measured by a spectrophotometer U-3500 manufactured by Hitachi Seisakusho Co., Ltd., and λmax was 589 nm and half-value width was 36 nm.

(combination)

Eupilon S-3000 100g

(Mitsubishi Gaskagaku Co., Ltd. product; polycarbonate resin)

Compound no. 1 0.01 g

Example 2

Making optical filter 2

The UV varnish was prepared by the following formulation, and the UV varnish was applied to a 188 µm thick polyethylene terephthalate film that was easily adhered to the film by barcoater # 9, and then dried at 80 ° C for 30 seconds. Then, 100 mJ of ultraviolet rays were irradiated with a high pressure mercury lamp to which an infrared cut film filter was attached, and an optical filter having a film layer having a cured film thickness of about 5 μm was obtained on a polyethylene terephthalate film. When the absorption spectrum of this optical filter was measured by Hitachi Seisakusho Co., Ltd. spectrophotometer U-3500, λmax was 589 nm and its half width was 36 nm.

(combination)

ADEKA OPTOMER KRX-571-65 100 g

(UV curing resin, resin powder 80 mass%) of Asahi Denka Kogyo Co., Ltd.

Compound No. 1 0.5g

Methyl ethyl ketone 60g

Example 3

Making Optical Filters 3

Compound no. An optical filter was prepared in the same manner as in Example 1 except that Compound No. 2 was used instead of 1. The absorption spectrum was measured by a spectrophotometer U-3010 manufactured by Hitachi Seisakusho Co., Ltd., and λmax. Was 587 nm and the half width was 36 nm.

Example 4

Creating an Optical Filter 4

The coating solution was prepared by the following formulation, and the coating solution was applied to a 188 μm-thick polyethylene terephthalate film that was easily adhered to the coating solution by using a bar coater # 9, and then dried at 100 ° C. for 3 minutes to produce a polyethylene terephthalate film. An optical filter having a filter layer having a film thickness of 10 µm was obtained on the phase. When the absorption spectrum of this optical filter was measured by Hitachi Seisakusho Co., Ltd. spectrophotometer U-3500, λmax was 589 nm and its half width was 36 nm.

(combination)

Adeka arcs (ADEKA ARKLS) R-103 100 g

(Asahi Denka Co., Ltd. product acrylic resin binder, resin 50 mass%)

Compound No. 1 0.1 g

Methyl ethyl ketone 50g

The result of the evaluation example 1 shown in Table 1 shows that the squarylium compound which concerns on this invention is excellent in solubility. In addition, as is apparent from Examples 1 to 4, the optical filter of the present invention containing the squarylium compound according to the present invention has a steep light absorption in a wavelength region of 560 to 620 nm, and is used for an image display device. It turns out that it is suitable as an optical filter.

The optical filter of the present invention has a steep light absorption in the wavelength range of 500 to 700 nm, particularly the wavelength range of 560 to 620 nm, and is an optical filter suitable for image display applications, particularly plasma display applications.

Claims (5)

An optical filter comprising the compound represented by the following general formula (I). [Formula 1]

(Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 20 carbon atoms, an arylalkyl group of 7 to 20 carbon atoms, a heterocyclic group of 2 to 20 carbon atoms, An amino group, a cyano group, a hydroxyl group, or a nitro group, an alkyl group having 1 to 8 carbon atoms represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , and an aryl having 6 to 20 carbon atoms The group, the arylalkyl group having 7 to 20 carbon atoms, the heterocyclic group having 2 to 20 carbon atoms, and the amino group may have a substituent, and the methylene group in the alkyl group having 1 to 8 carbon atoms may be substituted with -CH = CH-, m and n each independently represent an integer of 1 to 4, and s and t each independently represent an integer of 1 to 5; Indicates) The compound according to claim 1, wherein in Formula (I), R ⁵ And / or R ⁶ is an alkyl group having 1 to 8 carbon atoms substituted with halogen atoms. The optical filter according to claim 1 or 2, wherein in Formula (I), R ⁵ and / or R ⁶ are trifluoromethyl groups. The optical filter according to any one of claims 1 to 3, which is for an image display device. An optical filter according to claim 4, wherein the image display device is a plasma display.