Dye-based polarizing film, and polarizing plate and display device using same

Abstract

This polarizing film containing a base material is characterized in that the base material includes an azo compound represented by formula (1) or a salt thereof (compound A), and an azo compound represented by formula (2) or a salt thereof (compound B). (In formula (1), X1 represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, Q1 and R1 to R4 each independently represent an optional substituent, and m represents an integer of 1 to 3.) (In formula (2), X2 represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, Q2 and R5 to R8 each independently represent an optional substituent, R9 represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.)

Description

Dye-based polarizing film, and polarizing plate and display device using the same

[0001] The present invention relates to a dye-based polarizing film having a high degree of polarization, high contrast, and high durability, and to a polarizing plate and a display device using the same.

[0002] Polarizing plates, which have the function of transmitting and blocking light, are fundamental components of display devices such as liquid crystal displays (LCDs), along with liquid crystals, which have a light switching function. Applications of LCDs range from small devices such as early calculators and clocks to laptops, word processors, LCD projectors, LCD televisions, car navigation systems, and indoor and outdoor measuring instruments. Polarizing plates can also be applied to lenses with polarization functions, and have been used in sunglasses with improved visibility and, in recent years, polarized glasses compatible with 3D televisions. As the applications of polarizing plates expand widely, they are used under a wide range of conditions, from low to high temperatures, low to high humidity, and low to high light intensity, creating a demand for polarizing plates with high polarization performance and durability.

[0003] Currently, polarizing plates are manufactured by dyeing or impregnating a film of polyvinyl alcohol or its derivative with iodine or a dichroic dye, stretching it, and then orienting it, or by dehydrochlorinating a polyvinyl chloride film or dehydrating a polyvinyl alcohol film to produce a polyene, which is then oriented. Generally, iodine-based polarizing films using iodine have excellent polarization performance, but are vulnerable to water and heat, and suffer from poor durability when used for long periods of time under high-temperature and high-humidity conditions. To improve durability, methods such as treating the film with an aqueous solution containing formalin or boric acid or using a polymer film with low moisture permeability as a protective film have been considered, but these methods are not sufficiently effective.

[0004] Dye-based polarizing films using dichroic dyes can be used with multiple dyes to cover a wide variety of absorption bands, allowing polarizing films to be produced to suit various purposes. For example, by mixing any dye from yellow to orange, red to purple, or blue to green, it is possible to obtain a polarizing film that transmits and absorbs the entire visible wavelength range. On the other hand, dye-based polarizing films have better heat resistance, humidity and heat resistance, and light resistance than iodine-based polarizing films, but their optical properties are inferior.

[0005] In recent years, LED backlights have become the mainstream light source for display devices, and their photometry and colorimetry are defined in JIS Z8724:2015. This standard specifies the wavelength range of color-matching functions as 360 nm to 830 nm, and also specifies that when spectroscopic measurement of an LED light source is performed for colorimetry purposes, the wavelength range may be 380 nm to 780 nm. Therefore, it is self-evident that polarizing plates used in applications such as display devices that use LED backlights must have high optical properties in the wavelength range up to at least 780 nm.

[0006] Dye-based polarizing plates with various characteristics have been developed using typical dichroic dye formulations, as described in, for example, Patent Documents 1 to 5, 8, and 9. However, in applications relating to polarizing plates for display devices reported to date, in many cases "the wavelength range of 400 nm to 700 nm is described as the wavelength range for optical measurement" or "the wavelength range for optical measurement itself is not described," and therefore there has been little discussion of optical properties above 700 nm. In fact, the dye-based polarizing plate described in Patent Document 2 has low absorption performance above 700 nm, resulting in a phenomenon in which backlight light appears to leak through when the absorption axes of the two polarizing plates are arranged perpendicular to each other (hereinafter referred to as light leakage).

[0007] On the other hand, there are applications relating to dye-based polarizers that "describe the wavelength range of optical measurement as 380 nm to 780 nm," such as Patent Documents 10 and 11. However, there is a need to improve the polarization performance in the visible wavelength range of 380 nm to 780 nm.

[0008] Patent Document 3, for example, describes a combination of a "disazo-trisazo compound" or a "disazo-trisazo copper compound" in Example 13. However, the polarization performance of the dye itself is low, and the performance as a polarizing film has not reached a satisfactory level.

[0009] In recent years, tetrakis azo compounds and tetrakis copper dyes have been developed. Patent Documents 1 to 8 describe dichroic dyes with good polarization properties and examples of blends using them. For example, Example 8 of Patent Document 1 discloses a blend containing a tetrakis azo compound and a tetrakis azo copper compound. However, the described contrast is low, and no combination of a tetrakis azo compound and a tetrakis azo copper dye has been reported that provides sufficient polarization performance in the 380 to 780 nm wavelength range.

[0010] International Publication No. WO 2017 / 135392 International Publication No. WO 2016 / 186183 JP 2021-002043 JP 2017-090903 International Publication No. WO 2020 / 050333 International Publication No. WO 2012 / 108169 International Publication No. WO 2012 / 108173 International Publication No. WO 2017 / 135391 International Publication No. WO 2019 / 117131 International Publication No. WO 2022 / 071201 International Publication No. WO 2022 / 071204

[0011] One object of the present invention is to provide a polarizing film having excellent (low) crossed transmittance at a wavelength of 730 nm, and a polarizing plate and display device (polarizing film, etc.) using the same. Another object of the present invention is to provide a high-performance polarizing film, etc. having a high degree of polarization, high contrast, and high durability, particularly a polarizing film, etc. having good contrast in the visible light region, specifically in the wavelength region of 380 to 780 nm and in the wavelength region of 400 to 700 nm. Another object of the present invention is to provide a polarizing film, etc. with little light leakage in the crossed direction. Another object of the present invention is to provide a high-performance polarizing film, etc. having excellent polarization performance and durability with improved durability (e.g., heat resistance, moist heat resistance, light resistance, etc.) even in harsh environments.

[0012] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have found that by blending two types of azo compounds having specific structures, i.e., a tetrakis azo compound and a tetrakis azo cuprated compound, as dichroic dyes, it is possible to obtain a polarizing film that reduces orthogonal light leakage at wavelengths of 700 nm or more, improves polarization performance, particularly the degree of polarization and contrast, and exhibits high durability in terms of heat resistance, moist heat resistance, light resistance, etc., as well as a polarizing plate and a display device using the same, and have completed the present invention.

[0013] That is, the present invention relates to, but is not limited to, the following [1] to [7]: [1] A polarizing film containing a substrate, wherein the substrate contains an azo compound represented by the following formula (1) or a salt thereof (compound A) and an azo compound represented by the following formula (2) or a salt thereof (compound B): (In formula (1), X １ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q １ and R １ ~R ４ each independently represents an arbitrary substituent, and m represents an integer of 1 to 3. (In formula (2), X ２ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q ２ and R ５ ~R ８ each independently represents an arbitrary substituent, R ９ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3. [2] In formula (1), R １ ~R ４ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４X is an alkoxy group of the formula １ is unsubstituted or one or two C １ -C ４ Alkyl or phenyl substituted C １ -C ４ Amino group having an alkyl group, or unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ Q is a phenylamino group, a naphthylamino group, a benzoylamino group, or a naphthotriazole group each having one or two substituents independently selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; １ is a hydrogen atom, a chlorine atom, a hydroxy group, a hydroxy group having a protecting group, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ an alkoxy group, a nitro group, a carboxy group, or a sulfo group, and in formula (2), R ５ ~R ８ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ X is an alkoxy group of the formula ２ is unsubstituted or one or two C １ -C ４ Alkyl or phenyl substituted C １ -C ４ Amino group having an alkyl group, or unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４Q is a phenylamino group, a naphthylamino group, a benzoylamino group, or a naphthotriazole group, each having one or two substituents independently selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; ２ is a hydrogen atom, a chlorine atom, a hydroxy group, a hydroxy group having a protecting group, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ [3] The polarizing film according to [1], wherein the azo compound represented by formula (1) or the salt thereof is an azo compound represented by formula (3) below or a salt thereof, and the azo compound represented by formula (2) or the salt thereof is an azo compound represented by formula (4) below or a salt thereof: (In formula (3), R １ ~R ４ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ and m represents an integer of 1 to 3. (In formula (4), R ５ ~R ８ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ R ９ represents a methyl group, and n represents an integer of 1 to 3. [4] The polarizing film according to [1], which contains one or more dichroic dyes other than compounds A and B. [5] The polarizing film according to [1], wherein the base material contains a polyvinyl alcohol-based resin. [6] A polarizing plate comprising a transparent protective film provided on one or both sides of the polarizing film according to any one of [1] to [5]. [7] A display device comprising the polarizing plate according to [6].

[0014] According to the present invention, a polarizing film or the like having an excellent crossed transmittance at a wavelength of 730 nm can be provided. As one aspect of the present invention, a polarizing film or the like having an excellent degree of polarization and contrast in the visible light region, the wavelength region of 380 to 780 nm and the wavelength region of 400 to 700 nm can be provided.

[0015] In this specification and claims, unless it clearly represents a free form, "azo compounds or salts thereof" may be simply referred to as "azo compounds." In this specification and claims, since "substituents" may contain hydrogen atoms, hydrogen atoms may be described as "substituents" for convenience. "Optionally substituted" means that the case where no substituent is present is also included. For example, "optionally substituted phenyl group" includes a simple unsubstituted phenyl group and a substituted phenyl group.

[0016] The polarizing film of the present invention is a polarizing film characterized in that it contains a base material, and an azo compound represented by the following formula (1) or a salt thereof (compound A) and an azo compound represented by the following formula (2) or a salt thereof (compound B) are contained in the base material: (In formula (1), X １ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q １ and R １ ~R ４ each independently represents an arbitrary substituent, and m represents an integer of 1 to 3. (In formula (1), X ２ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q ２ and R ５ ~R ８ each independently represents an arbitrary substituent, R ９ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.

[0017] In formulas (1) and (2), the ring structures drawn with solid and broken lines represent a phenyl (phenylene) group or a naphthyl (naphthylene) group.

[0018] In the above formulas (1) and (2), X １ and X ２ each independently represent an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent; Q １ and Q ２ , and R １ ~R ８ Each independently represents an optional substituent. １ and Q ２ , and R １ ~R ８ Examples of the optional substituent represented by the formula (I) include a diazenyl group, a heterocyclic amino group, a fused-ring heterocyclic amino group, an alkyl group, an alkoxy group, an alkoxy group having a sulfo group, an aryloxy group, an alkylcarbonylamino group, an arylcarbonylamino group, an alkylcarbonyloxy group, an arylcarbonyloxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkylcarbamoyl group, an arylcarbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonylamino group, an arylsulfonylamino group, an alkylsulfamoyl group, an arylsulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylthio group, an arylthio group, an alkylureido group, an arylureido group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylamino group, an arylamino group, a hydroxy group (—OH), a hydroxy group having a protecting group (—OP), a cyano group (—CN), a nitro group (—NO ２ ), mercapto group (—SH), halogen atom, carboxy group (—CO ２ H), sulfo group (-SO ３ H), amino group (-NH ２ ), a hydrogen atom, etc.

[0019] The heterocyclic amino group includes a 5- or 6-membered heterocyclic amino group containing 1 to 3 heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of such heterocyclic amino groups include: 5-membered heteroalicyclic amino groups such as pyrrolidinylamino, tetrahydrofurylamino, tetrahydrothiophen-2-ylamino, and tetrahydrothiophen-3-ylamino; 6-membered heteroalicyclic amino groups such as piperidinylamino, piperazinylamino, dioxan-2-ylamino, morpholinylamino, and thiomorpholinylamino; 5-membered aromatic heterocyclic amino groups such as pyrroleamino, pyrazoleamino, imidazoleamino, triazoleamino, furylamino, thiophen-2-ylamino, thiophen-3-ylamino, oxazoleamino, and thiazoleamino; and 6-membered aromatic heterocyclic amino groups such as pyridylamino, pyrazylamino, pyridazinylamino, and triazinylamino. The heterocyclic group preferably has an aromatic heterocyclic moiety, and the heteroatom constituting the heterocyclic ring is preferably selected from the group consisting of a nitrogen atom and a sulfur atom.

[0020] Examples of the fused heterocyclic amino group include fused 5- or 6-membered heterocyclic amino groups in which one benzene ring is fused to a 5- or 6-membered heterocyclic group containing 1 to 3 heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of such fused heterocyclic amino groups include: fused heteroalicyclic amino groups having a 5-membered alicyclic heterocyclic moiety, such as phthalanylamino; fused heteroalicyclic amino groups having a 6-membered alicyclic heterocyclic moiety, such as benzopyranylamino; fused aromatic heterocyclic amino groups having a 5-membered aromatic heterocyclic moiety, such as benzopyrroleamino, benzopyrazoleamino, benzimidazoleamino, benzotriazoleamino, benzofuranylamino, benzothiophen-2-ylamino, benzothiophen-3-ylamino, benzoxazoleamino, and benzothiazoleamino; and fused aromatic heterocyclic amino groups having a 6-membered aromatic heterocyclic moiety, such as quinolinylamino, cinnolinylamino, phthalazinylamino, quinazolinylamino, and quinoxalinylamino. The heterocyclic moiety of the heterocyclic group is preferably an aromatic ring. Furthermore, the heteroatom constituting the heterocycle is preferably selected from nitrogen and sulfur atoms.

[0021] The alkyl group is a linear, branched or cyclic alkyl group, preferably C １ -C １０ Examples of the alkyl group include C. １ -C １０ Specific examples of the alkyl group include linear C alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl. １ -C １０ Alkyl groups: branched C alkyl groups such as isopropyl, isobutyl, sec-butyl, t-butyl, isoamyl, t-amyl, isohexyl, t-hexyl, isoheptyl, t-heptyl, isooctyl, t-octyl, 2-ethylhexyl, isononyl, and isodecyl. ３ -C １０ an alkyl group; or a cyclic C group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or cycloheptyl. ３ -C７ Among these, linear or branched alkyl groups are preferred, and linear C １ -C ４ Alkyl groups are more preferred.

[0022] The alkoxy group is a linear, branched or cyclic alkoxy group, preferably a C １ -C １０ Examples of the alkyl group include an alkoxy group. １ -C １０ Specific examples of the alkoxy group include linear C alkoxy groups such as methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexyloxy, n-heptoxy, n-octyloxy, n-nonyloxy, and n-decyloxy. １ -C １０ Alkoxy groups: branched C alkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, t-butoxy, isoamyloxy, t-amyloxy, isohexyloxy, t-hexyloxy, isoheptoxy, t-heptoxy, isooctyloxy, t-octyloxy, 2-ethylhexyloxy, isononyloxy, and isodecyloxy. ３ -C １０ an alkoxy group; or a cyclic C group such as cyclopropoxy, cyclobutoxy, cyclopentoxy, cyclohexyloxy, or cycloheptoxy; ３ -C ７ Among these, linear or branched alkoxy groups are preferred, and linear C １ -C ４ An alkoxy group is more preferred.

[0023] The alkoxy group having a sulfo group includes C １ -C ４ The sulfo group is preferably substituted at the terminal of the alkoxy group, more preferably at the terminal of the alkoxy group, more preferably at the terminal of the alkoxy group, and most preferably at the terminal of the alkoxy group, and most preferably at the terminal of the alkoxy group.

[0024] The aryloxy group is preferably C ６ -C １２It is an aryloxy group, and specific examples include phenoxy, naphthyloxy, biphenyloxy, and the like.

[0025] The alkylcarbonylamino group may be a linear, branched or cyclic alkylcarbonylamino group, preferably a C １ -C １０ Examples of the alkyl group include an alkylcarbonylamino group. １ -C １０ Specific examples of the alkylcarbonylamino group include straight-chain C alkylamino groups such as methylcarbonylamino (acetylamino), ethylcarbonylamino, n-propylcarbonylamino, n-butylcarbonylamino, n-pentylcarbonylamino, n-hexylcarbonylamino, n-heptylcarbonylamino, n-octylcarbonylamino, n-nonylcarbonylamino, and n-decylcarbonylamino. １ -C １０ alkylcarbonylamino groups; branched C alkylcarbonylamino groups such as isopropylcarbonylamino, isobutylcarbonylamino, sec-butylcarbonylamino, t-butylcarbonylamino, isoamylcarbonylamino, t-amylcarbonylamino, isohexylcarbonylamino, t-hexylcarbonylamino, isoheptylcarbonylamino, t-heptylcarbonylamino, isooctylcarbonylamino, t-octylcarbonylamino, 2-ethylhexylcarbonylamino, isononylcarbonylamino, and isodecylcarbonylamino; ３ -C １０ an alkylcarbonylamino group; or a cyclic C 1 group such as cyclopropylcarbonylamino, cyclobutylcarbonylamino, cyclopentylcarbonylamino, cyclohexylcarbonylamino, or cycloheptylcarbonylamino; ３ -C ７ Among these, a linear or branched alkylcarbonylamino group is preferred, and a linear alkylcarbonylamino group is more preferred.

[0026] The arylcarbonylamino group is preferably C ６ -C １２It is an arylcarbonylamino group, and specific examples include phenylcarbonylamino (benzoylamino), naphthylcarbonylamino, biphenylcarbonylamino, and the like.

[0027] The alkylcarbonyloxy group may be a linear, branched or cyclic alkylcarbonyloxy group, preferably a C １ -C １０ Examples of the alkyl group include an alkylcarbonyloxy group. １ -C １０ Specific examples of the alkylcarbonyloxy group include linear C alkylcarbonyloxy groups such as methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, n-butylcarbonyloxy, n-pentylcarbonyloxy, n-hexylcarbonyloxy, n-heptylcarbonyloxy, n-octylcarbonyloxy, n-nonylcarbonyloxy, and n-decylcarbonyloxy. １ -C １０ Alkylcarbonyloxy groups include branched C alkylcarbonyloxy groups such as isopropylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, t-butylcarbonyloxy, isoamylcarbonyloxy, t-amylcarbonyloxy, isohexylcarbonyloxy, t-hexylcarbonyloxy, isoheptylcarbonyloxy, t-heptylcarbonyloxy, isooctylcarbonyloxy, t-octylcarbonyloxy, 2-ethylhexylcarbonyloxy, isononylcarbonyloxy, and isodecylcarbonyloxy. ３ -C １０ an alkylcarbonyloxy group; or a cyclic C 1 group such as cyclopropylcarbonyloxy, cyclobutylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, or cycloheptylcarbonyloxy; ３ -C ７ Among these, a linear or branched alkylcarbonyloxy group is preferred, and a linear alkylcarbonyloxy group is more preferred.

[0028] The arylcarbonyloxy group is preferably C ６-C １２ It is an arylcarbonyloxy group, and specific examples include phenylcarbonyloxy, naphthylcarbonyloxy, biphenylcarbonyloxy, and the like.

[0029] The alkylcarbonyl group may be a linear, branched or cyclic alkylcarbonyl group, preferably a C １ -C １０ Examples of the alkyl group include an alkylcarbonyl group. １ -C １０ Specific examples of the alkylcarbonyl group include linear C alkylcarbonyl groups such as methylcarbonyl, ethylcarbonyl, n-propylcarbonyl, n-butylcarbonyl, n-pentylcarbonyl, n-hexylcarbonyl, n-heptylcarbonyl, n-octylcarbonyl, n-nonylcarbonyl, and n-decylcarbonyl. １ -C １０ Alkylcarbonyl groups include branched C alkylcarbonyl groups such as isopropylcarbonyl, isobutylcarbonyl, sec-butylcarbonyl, t-butylcarbonyl, isoamylcarbonyl, t-amylcarbonyl, isohexylcarbonyl, t-hexylcarbonyl, isoheptylcarbonyl, t-heptylcarbonyl, isooctylcarbonyl, t-octylcarbonyl, 2-ethylhexylcarbonyl, isononylcarbonyl, and isodecylcarbonyl. ３ -C １０ an alkylcarbonyl group; or a cyclic C group such as cyclopropylcarbonyl, cyclobutylcarbonyl, cyclopentylcarbonyl, cyclohexylcarbonyl, or cycloheptylcarbonyl; ３ -C ７ Among these, a linear or branched alkylcarbonyl group is preferred, and a linear alkylcarbonyl group is more preferred.

[0030] The arylcarbonyl group is preferably C ６ -C １２ It is an arylcarbonyl group, and specific examples include phenylcarbonyl (benzoyl), naphthylcarbonyl, biphenylcarbonyl, and the like.

[0031] The alkylcarbamoyl group may be a linear, branched or cyclic monoalkylcarbamoyl group or a dialkylcarbamoyl group.

[0032] The monoalkylcarbamoyl group is preferably a mono-C １ -C １０ Specific examples of the alkylcarbamoyl group include linear mono-C alkylcarbamoyl groups such as methylcarbamoyl, ethylcarbamoyl, n-propylcarbamoyl, n-butylcarbamoyl, n-pentylcarbamoyl, n-hexylcarbamoyl, n-heptylcarbamoyl, n-octylcarbamoyl, n-nonylcarbamoyl, and n-decylcarbamoyl. １ -C １０ Alkylcarbamoyl groups: branched mono-C alkylcarbamoyl groups such as isopropylcarbamoyl, isobutylcarbamoyl, sec-butylcarbamoyl, t-butylcarbamoyl, isoamylcarbamoyl, t-amylcarbamoyl, isohexylcarbamoyl, t-hexylcarbamoyl, isoheptylcarbamoyl, t-heptylcarbamoyl, isooctylcarbamoyl, t-octylcarbamoyl, 2-ethylhexylcarbamoyl, isononylcarbamoyl, and isodecylcarbamoyl. ３ -C １０ an alkylcarbamoyl group; or a cyclic mono-C group such as cyclopropylcarbamoyl, cyclobutylcarbamoyl, cyclopentylcarbamoyl, cyclohexylcarbamoyl, or cycloheptylcarbamoyl; ３ -C ７ Among these, a linear or branched monoalkylcarbamoyl group is preferred, and a linear monoalkylcarbamoyl group is more preferred.

[0033] The dialkylcarbamoyl group is preferably a diC １ -C １０Specific examples of the alkylcarbamoyl group include linear di-C alkylcarbamoyl groups such as dimethylcarbamoyl, diethylcarbamoyl, di-n-propylcarbamoyl, di-n-butylcarbamoyl, di-n-pentylcarbamoyl, di-n-hexylcarbamoyl, di-n-heptylcarbamoyl, di-n-octylcarbamoyl, di-n-nonylcarbamoyl, and di-n-decylcarbamoyl. １ -C １０ Alkylcarbamoyl groups include branched di-C alkyl groups having two branched chains, such as diisopropylcarbamoyl, diisobutylcarbamoyl, di-sec-butylcarbamoyl, di-t-butylcarbamoyl, diisoamylcarbamoyl, di-t-amylcarbamoyl, diisohexylcarbamoyl, di-t-hexylcarbamoyl, diisoheptylcarbamoyl, di-t-heptylcarbamoyl, diisooctylcarbamoyl, di-t-octylcarbamoyl, di-(2-ethylhexyl)carbamoyl, diisononylcarbamoyl, and diisodecylcarbamoyl. ３ -C １０ an alkylcarbamoyl group; or a cyclic di-C group having two rings, such as dicyclopropylcarbamoyl, dicyclobutylcarbamoyl, dicyclopentylcarbamoyl, dicyclohexylcarbamoyl, or dicycloheptylcarbamoyl; ３ -C ７ Among these, a linear or branched dialkylcarbamoyl group is preferred, and a linear dialkylcarbamoyl group is more preferred.

[0034] The arylcarbamoyl group includes a monoarylcarbamoyl group and a diarylcarbamoyl group.

[0035] The monoarylcarbamoyl group is preferably a monoC ６ -C １２ It is an arylcarbamoyl group, and specific examples include phenylcarbamoyl, naphthylcarbamoyl, biphenylcarbamoyl, and the like.

[0036] The diarylcarbamoyl group is preferably a di-C ６ -C １２It is an arylcarbamoyl group, and specific examples include diphenylcarbamoyl, dinaphthylcarbamoyl, and di(biphenyl)carbamoyl.

[0037] The alkoxycarbonyl group is a linear, branched or cyclic alkoxycarbonyl group, preferably a C １ -C １０ Examples of the alkyl group include an alkoxycarbonyl group. １ -C １０ Specific examples of the alkoxycarbonyl group include linear C alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butoxycarbonyl, n-pentoxycarbonyl, n-hexyloxycarbonyl, n-heptoxycarbonyl, n-octyloxycarbonyl, n-nonyloxycarbonyl, and n-decyloxycarbonyl. １ -C １０ Alkoxycarbonyl groups include branched C alkoxycarbonyl groups such as isopropoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, t-butoxycarbonyl, isoamyloxycarbonyl, t-amyloxycarbonyl, isohexyloxycarbonyl, t-hexyloxycarbonyl, isoheptoxycarbonyl, t-heptoxycarbonyl, isooctyloxycarbonyl, t-octyloxycarbonyl, 2-ethylhexyloxycarbonyl, isononyloxycarbonyl, and isodecyloxycarbonyl. ３ -C １０ an alkoxycarbonyl group; or a cyclic C alkoxycarbonyl group such as cyclopropoxycarbonyl, cyclobutoxycarbonyl, cyclopentoxycarbonyl, cyclohexyloxycarbonyl, or cycloheptoxycarbonyl; ３ -C ７ Among these, a linear or branched alkoxycarbonyl group is preferred, and a linear alkoxycarbonyl group is more preferred.

[0038] The aryloxycarbonyl group is preferably C ６ -C １２It is an aryloxycarbonyl group, and specific examples include phenoxycarbonyl, naphthyloxycarbonyl, biphenyloxycarbonyl, and the like.

[0039] The alkylsulfonylamino group may be a linear, branched or cyclic alkylsulfonylamino group, preferably a C １ -C １０ Examples of the alkylsulfonylamino group include alkylsulfonylamino groups. １ -C １０ Specific examples of the alkylsulfonylamino group include linear C alkylsulfonylamino groups such as methylsulfonylamino, ethylsulfonylamino, n-propylsulfonylamino, n-butylsulfonylamino, n-pentylsulfonylamino, n-hexylsulfonylamino, n-heptylsulfonylamino, n-octylsulfonylamino, n-nonylsulfonylamino, and n-decylsulfonylamino. １ -C １０ Alkyl sulfonylamino groups include branched C alkylsulfonylamino groups such as isopropyl sulfonylamino, isobutyl sulfonylamino, sec-butyl sulfonylamino, t-butyl sulfonylamino, isoamyl sulfonylamino, t-amyl sulfonylamino, isohexyl sulfonylamino, t-hexyl sulfonylamino, isoheptyl sulfonylamino, t-heptyl sulfonylamino, isooctyl sulfonylamino, t-octyl sulfonylamino, 2-ethylhexyl sulfonylamino, isononyl sulfonylamino, and isodecyl sulfonylamino. ３ -C １０ an alkylsulfonylamino group; or a cyclic C 1 group such as cyclopropylsulfonylamino, cyclobutylsulfonylamino, cyclopentylsulfonylamino, cyclohexylsulfonylamino, or cycloheptylsulfonylamino; ３ -C ７ Among these, a linear or branched alkylsulfonylamino group is preferred, and a linear alkylsulfonylamino group is more preferred.

[0040] The arylsulfonylamino group is preferably C ６ -C １２It is an arylsulfonylamino group, and specific examples include phenylsulfonylamino, toluenesulfonylamino, naphthylsulfonylamino, biphenylsulfonylamino, and the like.

[0041] The alkylsulfamoyl group may be a linear, branched or cyclic monoalkylsulfamoyl group or a dialkylsulfamoyl group.

[0042] The monoalkylsulfamoyl group is preferably a monoC １ -C １０ Specific examples of the alkylsulfamoyl group include linear mono-C alkylsulfamoyl groups such as methylsulfamoyl, ethylsulfamoyl, n-propylsulfamoyl, n-butylsulfamoyl, n-pentylsulfamoyl, n-hexylsulfamoyl, n-heptylsulfamoyl, n-octylsulfamoyl, n-nonylsulfamoyl, and n-decylsulfamoyl. １ -C １０ Alkylsulfamoyl groups: branched mono-C alkylsulfamoyl groups such as isopropylsulfamoyl, isobutylsulfamoyl, sec-butylsulfamoyl, t-butylsulfamoyl, isoamylsulfamoyl, t-amylsulfamoyl, isohexylsulfamoyl, t-hexylsulfamoyl, isoheptylsulfamoyl, t-heptylsulfamoyl, isooctylsulfamoyl, t-octylsulfamoyl, 2-ethylhexylsulfamoyl, isononylsulfamoyl, and isodecylsulfamoyl. ３ -C １０ an alkylsulfamoyl group; or a cyclic mono-C group such as cyclopropylsulfamoyl, cyclobutylsulfamoyl, cyclopentylsulfamoyl, cyclohexylsulfamoyl, or cycloheptylsulfamoyl; ３ -C ７ Among these, a linear or branched monoalkylsulfamoyl group is preferred, and a linear monoalkylsulfamoyl group is more preferred.

[0043] The dialkylsulfamoyl group is preferably a diC １ -C１０ Specific examples of the alkylsulfamoyl group include linear di-C alkylsulfamoyl groups such as dimethylsulfamoyl, diethylsulfamoyl, di-n-propylsulfamoyl, di-n-butylsulfamoyl, di-n-pentylsulfamoyl, di-n-hexylsulfamoyl, di-n-heptylsulfamoyl, di-n-octylsulfamoyl, di-n-nonylsulfamoyl, and di-n-decylsulfamoyl. １ -C １０ Alkyl sulfamoyl groups include branched di-C alkylsulfamoyl groups having two branched chains, such as diisopropylsulfamoyl, diisobutylsulfamoyl, di-sec-butylsulfamoyl, di-t-butylsulfamoyl, diisoamylsulfamoyl, di-t-amylsulfamoyl, diisohexylsulfamoyl, di-t-hexylsulfamoyl, diisoheptylsulfamoyl, di-t-heptylsulfamoyl, diisooctylsulfamoyl, di-t-octylsulfamoyl, di-(2-ethylhexyl)sulfamoyl, diisononylsulfamoyl, and diisodecylsulfamoyl. ３ -C １０ an alkylsulfamoyl group; or a cyclic di-C group having two rings, such as dicyclopropylsulfamoyl, dicyclobutylsulfamoyl, dicyclopentylsulfamoyl, dicyclohexylsulfamoyl, or dicycloheptylsulfamoyl; ３ -C ７ Among these, a linear or branched dialkylsulfamoyl group is preferred, and a linear dialkylsulfamoyl group is more preferred.

[0044] The arylsulfamoyl group includes a monoarylsulfamoyl group and a diarylsulfamoyl group.

[0045] The monoarylsulfamoyl group is preferably a monoC ６ -C １２ It is an arylsulfamoyl group, and specific examples include phenylsulfamoyl, naphthylsulfamoyl, biphenylsulfamoyl, and the like.

[0046] The diarylsulfamoyl group is preferably a diC ６ -C １２ It is an arylsulfamoyl group, and specific examples include diphenylsulfamoyl, dinaphthylsulfamoyl, and di(biphenyl)sulfamoyl.

[0047] The alkylsulfonyl group may be a linear, branched or cyclic alkylsulfonyl group, preferably a C １ -C １２ Examples of the alkylsulfonyl group include C. １ -C １２ Specific examples of the alkylsulfonyl group include linear C alkylsulfonyl groups such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, n-butylsulfonyl, n-pentylsulfonyl, n-hexylsulfonyl, n-heptylsulfonyl, n-octylsulfonyl, n-nonylsulfonyl, n-decylsulfonyl, n-undecylsulfonyl, and n-dodecylsulfonyl. １ -C １２ Alkyl sulfonyl groups include branched C alkylsulfonyl groups such as isopropyl sulfonyl, isobutyl sulfonyl, sec-butyl sulfonyl, t-butyl sulfonyl, isoamyl sulfonyl, t-amyl sulfonyl, isohexyl sulfonyl, t-hexyl sulfonyl, isoheptyl sulfonyl, t-heptyl sulfonyl, isooctyl sulfonyl, t-octylsulfonyl, 2-ethylhexyl sulfonyl, isononyl sulfonyl, isodecyl sulfonyl, isoundecyl sulfonyl, t-undecyl sulfonyl, isododecyl sulfonyl, and t-dodecyl sulfonyl. ３ -C １２ an alkylsulfonyl group; or a cyclic C group such as cyclopropylsulfonyl, cyclobutylsulfonyl, cyclopentylsulfonyl, cyclohexylsulfonyl, or cycloheptylsulfonyl; ３ -C ７ Among these, a linear or branched alkylsulfonyl group is preferred, and a linear alkylsulfonyl group is more preferred.

[0048] The arylsulfonyl group is preferably C ６-C １２ It is an arylsulfonyl group, and specific examples include phenylsulfonyl, naphthylsulfonyl, biphenylsulfonyl, and the like.

[0049] The alkylthio group may be a linear, branched or cyclic alkylthio group, preferably a C １ -C １０ Examples of the alkylthio group include C. １ -C １０ Specific examples of the alkylthio group include linear C alkylthio groups such as methylthio, ethylthio, n-propylthio, n-butylthio, n-pentylthio, n-hexylthio, n-heptylthio, n-octylthio, n-nonylthio, and n-decylthio. １ -C １０ Alkylthio groups include branched C alkylthio groups such as isopropylthio, isobutylthio, sec-butylthio, t-butylthio, isoamylthio, t-amylthio, isohexylthio, t-hexylthio, isoheptylthio, t-heptylthio, isooctylthio, t-octylthio, 2-ethylhexylthio, isononylthio, and isodecylthio. ３ -C １０ an alkylthio group; or a cyclic C thio group such as cyclopropylthio, cyclobutylthio, cyclopentylthio, cyclohexylthio, or cycloheptylthio; ３ -C ７ Among these, a linear or branched alkylthio group is preferred, and a linear alkylthio group is more preferred.

[0050] The arylthio group is preferably C ６ -C １２ It is an arylthio group, and specific examples include phenylthio, naphthylthio, biphenylthio, and the like.

[0051] The alkylureido group may be a linear, branched or cyclic monoalkylureido group or a dialkylureido group.

[0052] The monoalkylureido group is preferably a monoC １ -C １０Specific examples of the alkylureido group include linear mono-C alkylureido groups such as methylureido, ethylureido, n-propylureido, n-butylureido, n-pentylureido, n-hexylureido, n-heptylureido, n-octylureido, n-nonylureido, and n-decylureido. １ -C １０ Alkylureido groups: branched mono-C alkylureido groups such as isopropylureido, isobutylureido, sec-butylureido, t-butylureido, isoamylureido, t-amylureido, isohexylureido, t-hexylureido, isoheptylureido, t-heptylureido, isooctylureido, t-octylureido, 2-ethylhexylureido, isononylureido, and isodecylureido. ３ -C １０ an alkylureido group; or a cyclic mono-C group such as cyclopropylureido, cyclobutylureido, cyclopentylureido, cyclohexylureido, or cycloheptylureido; ３ -C ７ Among these, a linear or branched alkylureido group is preferred, and a linear alkylureido group is particularly preferred.

[0053] The dialkylureido group is preferably a diC １ -C １０ Specific examples of alkylureido groups include linear di-C alkylureido groups such as dimethylureido, diethylureido, di-n-propylureido, di-n-butylureido, di-n-pentylureido, di-n-hexylureido, di-n-heptylureido, di-n-octylureido, di-n-nonylureido, and di-n-decylureido. １ -C １０alkylureido group; branched di-C alkyl ureido groups having two branched chains, such as diisopropylureido, diisobutylureido, di-sec-butylureido, di-t-butylureido, diisoamylureido, di-t-amylureido, diisohexylureido, di-t-hexylureido, diisoheptylureido, di-t-heptylureido, diisooctylureido, di-t-octylureido, di-(2-ethylhexyl)ureido, diisononylureido, and diisodecylureido; ３ -C １０ an alkylureido group; or a cyclic di-C group having two rings, such as dicyclopropylureido, dicyclobutylureido, dicyclopentylureido, dicyclohexylureido, or dicycloheptylureido; ３ -C ７ Among these, a linear or branched dialkylureido group is preferred, and a linear dialkylureido group is more preferred.

[0054] The arylureido group includes a monoarylureido group and a diarylureido group.

[0055] The monoarylureido group is preferably a monoC ６ -C １２ It is an arylureido group, and specific examples include phenylureido, naphthylureido, biphenylureido, and the like.

[0056] The diarylureido group is preferably a diC ６ -C １２ It is an arylureido group, and specific examples include diphenylureido, dinaphthylureido, and di(biphenyl)ureido.

[0057] The alkoxycarbonylamino group may be a linear, branched or cyclic alkoxycarbonylamino group, preferably a C １ -C １０ Examples of the alkyl group include an alkoxycarbonylamino group. １ -C １０Specific examples of the alkoxycarbonylamino group include linear C alkoxycarbonylamino groups such as methoxycarbonylamino, ethoxycarbonylamino, n-propoxycarbonylamino, n-butoxycarbonylamino, n-pentoxycarbonylamino, n-hexyloxycarbonylamino, n-heptoxycarbonylamino, n-octyloxycarbonylamino, n-nonyloxycarbonylamino, and n-decyloxycarbonylamino. １ -C １０ Alkoxycarbonylamino groups include branched C alkoxycarbonylamino groups such as isopropoxycarbonylamino, isobutoxycarbonylamino, sec-butoxycarbonylamino, t-butoxycarbonylamino, isoamyloxycarbonylamino, t-amyloxycarbonylamino, isohexyloxycarbonylamino, t-hexyloxycarbonylamino, isoheptoxycarbonylamino, t-heptoxycarbonylamino, isooctyloxycarbonylamino, t-octyloxycarbonylamino, 2-ethylhexyloxycarbonylamino, isononyloxycarbonylamino, and isodecyloxycarbonylamino. ３ -C １０ an alkoxycarbonylamino group; or a cyclic C alkoxycarbonylamino group such as cyclopropoxycarbonylamino, cyclobutoxycarbonylamino, cyclopentoxycarbonylamino, cyclohexyloxycarbonylamino, or cycloheptoxycarbonylamino; ３ -C ７ Among these, a linear or branched alkoxycarbonylamino group is preferred, and a linear alkoxycarbonylamino group is more preferred.

[0058] The aryloxycarbonylamino group is preferably C ６ -C １２ It is an aryloxycarbonylamino group, and specific examples include phenylcarbonylamino, naphthylcarbonylamino, biphenylcarbonylamino, and the like.

[0059] The alkylamino group may be a linear, branched, or cyclic monoalkylamino group or dialkylamino group.

[0060] The monoalkylamino group is preferably a monoC １ -C １０ Specific examples of the alkylamino group include linear mono-C alkylamino groups such as methylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, n-octylamino, n-nonylamino, and n-decylamino. １ -C １０ Alkylamino groups: branched mono-C alkylamino groups such as isopropylamino, isobutylamino, sec-butylamino, t-butylamino, isoamylamino, t-amylamino, isohexylamino, t-hexylamino, isoheptylamino, t-heptylamino, isooctylamino, t-octylamino, 2-ethylhexylamino, isononylamino, and isodecylamino. ３ -C １０ alkylamino group; or a cyclic mono-C group such as cyclopropylamino, cyclobutylamino, cyclopentylamino, cyclohexylamino, or cycloheptylamino. ３ -C ７ Among these, a linear or branched monoalkylamino group is preferred, and a linear monoalkylamino group is more preferred.

[0061] The dialkylamino group is preferably a diC １ -C １０ Specific examples of the alkylamino group include linear di-C alkylamino groups such as dimethylamino, diethylamino, di-n-propylamino, di-n-butylamino, di-n-pentylamino, di-n-hexylamino, di-n-heptylamino, di-n-octylamino, di-n-nonylamino, and di-n-decylamino. １ -C １０Alkylamino groups: branched di-C alkylamino groups having two branched chains, such as diisopropylamino, diisobutylamino, di-sec-butylamino, di-t-butylamino, diisoamylamino, di-t-amylamino, diisohexylamino, di-t-hexylamino, diisoheptylamino, di-t-heptylamino, diisooctylamino, di-t-octylamino, di-(2-ethylhexyl)amino, diisononylamino, and diisodecylamino; ３ -C １０ an alkylamino group; or a cyclic di-C group having two rings, such as dicyclopropylamino, dicyclobutylamino, dicyclopentylamino, dicyclohexylamino, and dicycloheptylamino; ３ -C ７ Among these, a linear or branched dialkylamino group is preferred, and a linear dialkylamino group is more preferred.

[0062] The arylamino group may be a monoarylamino group or a diarylamino group.

[0063] The monoarylamino group is preferably a mono-C ６ -C １２ It is an arylamino group, and specific examples include phenylamino (anilino), naphthylamino, and biphenylamino.

[0064] The diarylamino group is preferably a diC ６ -C １２ It is an arylamino group, and specific examples include diphenylamino, dinaphthylamino, and di(biphenyl)amino.

[0065] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom, a chlorine atom, or a bromine atom being preferred.

[0066] The protecting group is not particularly limited as long as it is a protecting group that is commonly used for a hydroxy group. Examples of such a protecting group include a tert-butyldimethylsilyl (TBS) group, a trimethylsilyl (TMS) group, and a methyl (Me) group (which, together with the hydroxy moiety, forms a C １a benzyl (Bn) group (which, together with the hydroxy moiety, forms an alkoxy group), a benzyl (Bn) group (which, together with the hydroxy moiety, forms a phenyl-substituted C １ a p-methoxybenzyl (PMB) group (which, together with the hydroxy moiety, forms an alkoxy group), a p-methoxyphenyl substituted C １ alkoxy group), tosyl (Ts) group, allyl group, acetyl (Ac) group (which together with the hydroxy moiety form a C １ a trityl (Tr) group (which, together with the hydroxy moiety, forms a triphenyl-substituted C １ alkoxy group), and benzoyl (Bz) group (together with the alkoxy moiety to form a phenylcarbonyloxy group).

[0067] More preferred R １ ~R ８ Examples of the group include a hydrogen atom and C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Examples include alkoxy groups.

[0068] More preferred Q １ and Q ２ Examples of the hydroxyl group include a hydrogen atom, a chlorine atom, a hydroxyl group, a hydroxyl group having a protecting group, and C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Examples of the group include an alkoxy group, a nitro group, a carboxy group, and a sulfo group.

[0069] More preferred X １ and X ２ Examples of the C alkyl group include unsubstituted or one or two C alkyl groups. １ -C ４ an amino group having an alkyl group; an unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C４ a phenylamino group having one or two substituents selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; an unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ a naphthylamino group having one or two substituents selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; an unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ a benzoylamino group having one or two substituents selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; or an unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ and naphthotriazole groups each having one or two substituents selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group.

[0070] C that the amino group may have １ -C ４ The alkyl group may be unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ may be substituted with a phenyl group having one or two substituents selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group, and １ -C ４ Examples of alkyl groups include benzylamino and aminobenzylamino groups.

[0071] More preferred X１ and X ２ As the alkyl group, unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ A particularly preferred example of X is a phenylamino group having one or two substituents independently selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group. １ and X ２ As for C １ -C ４ Examples include a phenylamino group having an alkoxy group.

[0072] In the above formulas (1) and (2), R ９ represents a hydrogen atom or a methyl group, preferably a methyl group. m and n each independently represent an integer of 1 to 3, preferably 2.

[0073] It is preferable that the azo compound represented by formula (1) or a salt thereof is an azo compound represented by formula (3) below or a salt thereof, and the azo compound represented by formula (2) or a salt thereof is an azo compound represented by formula (4) below or a salt thereof, because a polarizing film with higher transmittance and a higher polarization degree can be provided. (In formula (3), R １ ~R ４ each independently represents an arbitrary substituent, and n represents an integer of 1 to 3. (In formula (4), R ５ ~R ８ each independently represents an arbitrary substituent, R ９ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.

[0074] In formulas (3) and (4), the ring structures drawn with solid and broken lines represent a phenyl (phenylene) group or a naphthyl (naphthylene) group.

[0075] In formulas (3) and (4), R １ ~R ８ each independently represents an optional substituent, and the optional substituent has the same meaning as the optional substituent in formulas (1) and (2).

[0076] In formulas (1) to (4), m and n each independently represent an integer of 1 to 3, preferably 2. In formulas (2) and (4), R ９ represents a hydrogen atom or a methyl group, and is preferably a methyl group.

[0077] In formulas (1) and (3), R １ ~R ４ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ In formulas (2) and (4), R ５ ~R ８ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ In the case where the alkoxy group is one of the above, it is possible to provide a polarizing film with a higher transmittance and / or a higher polarization degree, which is preferable.

[0078] As described in Patent Document 10, an azo compound represented by formula (1) or a salt thereof (compound A) is often represented by the general formula (1). However, when an amine species (Y) is used during synthesis, it is generally believed that the amine species (Y) is coordinated as shown in formula (5). In the present application, the azo compounds represented by formulas (1) and (3) or salts thereof (compound A) include those in which the amine species (Y) is coordinated, and the expected effects can be achieved regardless of the type of amine species (Y). Examples of the amine species (Y) include aqueous ammonia, amino alcohols, hexamethylenetetramine, pyridine, etc. Preferred are monoethanolamine, N-methylethanolamine, diethanolamine, and pyridine, more preferably monoethanolamine and N-methylethanolamine, and even more preferably N-methylethanolamine. (In formula (5), X １ , Q １ , R１ ~R ４ , m has the same meaning as in formula (1).

[0079] <Polarizing Film> The polarizing film according to the present invention has an excellent (low) crossed transmittance at a wavelength of 730 nm, and is obtained by incorporating an azo compound represented by formula (1) or a salt thereof (compound A) and an azo compound represented by formula (2) or a salt thereof (compound B) into a substrate. In one aspect, the polarizing film of the present invention exhibits high durability in addition to a high polarization degree and high contrast. In one aspect, the polarizing film of the present invention has a crossed transmittance (Tc) of 0% or more and 4% or less at a wavelength of 730 nm when the single transmittance is 40.5%±1%.

[0080] <Substrate> The substrate contained in the polarizing film of the present invention is preferably a film obtained by forming a hydrophilic polymer that readily adsorbs the present compounds (A) and (B) or dichroic dyes, particularly azo compounds. The hydrophilic polymer is not particularly limited, but examples thereof include polyvinyl alcohol-based resins, amylose-based resins, starch-based resins, cellulose-based resins, and polyacrylate-based resins. Among these resins, polyvinyl alcohol-based resins or derivatives thereof are preferred from the viewpoints of dyeability, processability, and crosslinkability of the dichroic dye. The shape of the substrate is not particularly limited, and it can be prepared in any shape, such as a film, sheet, flat plate, curved plate, or hemisphere. The thickness of the substrate can be appropriately designed depending on the application of the polarizing film, but is preferably in the range of 5 μm to 150 μm, and more preferably in the range of 10 μm to 100 μm. The polarizing film according to the present invention can be produced, for example, by forming the hydrophilic polymer as a base material into a film, then incorporating compound A, compound B, and, if desired, other azo compounds or salts thereof into the film, and then subjecting the obtained film to an orientation treatment such as stretching.

[0081] The azo compound represented by formula (1) or a salt thereof (compound A) can be produced, for example, by the method described in Patent Document 1. Specific examples of compound A are listed below, but are not limited to these. The azo compound is represented in the form of a free acid. In the following formula, the coordination of an amine species (Y) as represented by formula (5) is omitted, but any amine species may be coordinated.

[0082] The azo compound represented by formula (2) or a salt thereof (compound B) can be produced by a general method for synthesizing azo compounds, such as the methods described in Patent Documents 6 and 7. Specific examples of compound B are listed below, but are not limited to these. The azo compound is expressed in the form of a free acid. In addition, in the polarizing film of the present invention, when the number of moles of compound A is taken as 1, the number of moles of compound B is preferably 0.1 times or more, more preferably 0.5 times or more, and even more preferably 1 time or more, that of compound A.

[0083] Compound A is preferably a green dye having a maximum absorption wavelength of more than 640 nm, and compound B is preferably a blue dye having a maximum absorption wavelength of more than 600 nm. The polarizing film of the present invention preferably contains one type each of compound A and compound B.

[0084] The azo compound represented by formula (1) or (3) or a salt thereof (compound A) is preferably a compound A that satisfies the following conditions when the single transmittance of a polarizing film containing compound A is adjusted to Ts = 44.0% ± 0.1%: ｍａｘ The wavelength (λ ) on the longest wavelength side of the wavelength range in which the value of the crossed transmittance Tc in the absorption band including the maximum absorption wavelength is less than 1.0%. １ ) and the shortest wavelength (λ ２) for λ １ and λ ２ The wavelength range of λ is preferably greater than 650 nm to 750 nm, and more preferably greater than 640 nm to 760 nm. By using compound A having the polarizing film properties described above, a polarizing film with good polarization properties in the long wavelength region can be provided. With regard to the azo compound or salt thereof (compound B) represented by formula (2) or (4), it is preferable that compound B satisfies the following conditions when the single transmittance of a polarizing film containing compound B is adjusted to Ts = 44.0% ± 0.1%: λ ｍａｘ The wavelength (λ ) on the longest wavelength side of the wavelength range in which the value of the crossed transmittance Tc in the absorption band including the maximum absorption wavelength is less than 1.0%. １ ) and the shortest wavelength (λ ２ ) for λ １ and λ ２ The wavelength range is preferably greater than 600 nm to 650 nm, and more preferably greater than 590 nm to 660 nm.

[0085] When a polarizing film is prepared by blending multiple dyes, the film exhibits better optical properties when the gaps between the absorption waveforms of the dyes are filled. １ and λ ２ and the λ １ and λ ２ Therefore, by combining Compound A and Compound B, the gap between the absorption waveforms of the dyes is filled, and a polarizing film having high optical properties, namely, sufficient polarization properties at 730 nm, can be provided.

[0086] The polarizing film of the present invention preferably further contains one or more dichroic dyes other than Compound A and Compound B. The dichroic dyes preferably include a dichroic dye (hereinafter referred to as Compound C) that absorbs light in the short wavelength region and is primarily yellow to orange, and a dichroic dye (hereinafter referred to as Compound D) that absorbs light in the short wavelength region. It is preferable to use one type each of Compound C and Compound D. The polarizing film of the present invention has a higher degree of polarization and higher contrast over a wider wavelength range than conventional dye-based polarizing films. Furthermore, a polarizing plate made of this polarizing film exhibits higher durability against heat, humidity, and light than conventional dye-based polarizing plates.

[0087] Compound C, which is a dichroic dye that is primarily yellow to orange and has a maximum absorption wavelength of 400 nm or more and less than 500 nm and can be used in the polarizing film of the present invention, is preferably an azo compound, and commercially available products such as C.I. Direct Yellow 12, C.I. Direct Yellow 28, C.I. Direct Yellow 44, C.I. Direct Orange 26, C.I. Direct Orange 39, C.I. Direct Orange 71, and C.I. Direct Orange 107 can be used. In addition, stilbene-based orange dyes of formula (2) described in Example 1 of WO 2007 / 138980 and ureido-based orange dyes such as those described in WO 2018 / 181470 and WO 2019 / 124161 can also be used appropriately, but are not limited to these.

[0088] Compound D, which is a dichroic dye that is mainly red to purple and has a maximum absorption wavelength of 500 nm or more and less than 600 nm and can be used in the polarizing film of the present invention, is preferably an azo compound, and commercially available products such as C.I. Direct Red 2, C.I. Direct Red 31, C.I. Direct Red 79, C.I. Direct Red 81, C.I. Direct Red 117, and C.I. Direct Red 247 can be used. Furthermore, ureido-based red dyes such as those described in WO 2016 / 186194, WO 2016 / 186195, and WO 2016 / 186196, and 1-naphthol-3-sulfonic acid (J acid)-based red dyes such as those described in JP-A-08-291259, JP-A-2002-275381, and WO 2017 / 135391 can also be used appropriately, but are not limited to these.

[0089] The azo compounds represented by the above formulas (1) to (5) and the dichroic dyes used in combination may each be in the form of a free acid or a salt, and may also be salts of metal ions or ammonium ions. Examples of metal ions include alkali metal ions such as lithium ion, sodium ion, and potassium ion, and alkaline earth metal ions such as calcium ion and magnesium ion. Examples of ammonium ions include ammonium ion, methylammonium ion, dimethylammonium ion, triethylammonium ion, tetraethylammonium ion, tetra-n-propylammonium ion, tetra-n-butylammonium ion, monoethanolammonium ion, diethanolammonium ion, triethanolammonium ion, and N-methyl-N-monoethanolammonium ion. More specifically, in the case of a free acid, for example, sulfonic acid (-SO ３ H) in the case of sodium ions, and sodium sulfonate (-SO ３ Na), and for ammonium ions, ammonium sulfonate (-SO ３ NH ４ ) represents

[0090] In the polarizing film of the present invention, the blending ratio of the azo compounds used is preferably adjusted so that the transmittance falls within the preferred range described below. The polarizing performance of the polarizing film varies not only depending on the blending ratio of the azo compounds in the polarizing film but also on various factors, such as the swelling degree and stretching ratio of the substrate to which the azo compounds are adsorbed, the dyeing time, the dyeing temperature, the pH during dyeing, and the influence of salts. Therefore, such blending ratios can be appropriately adjusted based on the explanation described below.

[0091] (Luminous Efficiency Corrected Transmittance) The transmittance of the polarizing film and polarizing plate according to the present invention is measured in accordance with JIS Z 8722:2009.

[0092] (Luminous Efficiency-Corrected Single-Phase Transmittance) The polarizing film and polarizing plate according to the present invention preferably have a single-plate transmittance of 35% to 70% in the wavelength range of 380 nm to 780 nm. The single-plate transmittance is the transmittance corrected for luminous efficiency according to JIS Z 8722:2009 for one measurement sample (e.g., polarizing film or polarizing plate). Although higher transmittance is required for polarizing plate performance, a single-plate transmittance of 35% to 70% ensures that a polarizing film having such a single-plate transmittance can be used in a display device to display brightness without creating an unnatural feeling. A single-plate transmittance exceeding 70% is not preferable because it may significantly reduce the degree of polarization. On the other hand, since the degree of polarization tends to decrease as the transmittance increases, from the viewpoint of a balance with the degree of polarization, the single-plate transmittance is more preferably 35% to 60%, even more preferably 37% to 55%, and particularly preferably 39% to 50%.

[0093] The degree of polarization of the polarizing film or polarizing plate is preferably 50% to 100%, more preferably 80% to 100%, still more preferably 95% to 100%, and particularly preferably 99% to 100%. A higher degree of polarization is preferable, but in terms of the relationship between the degree of polarization and the transmittance, the transmittance and degree of polarization can be adjusted to an appropriate value depending on whether brightness or the degree of polarization (or contrast) is prioritized, and the polarizing film or polarizing plate can be applied to a display device or the like.

[0094] Regarding the absorption band, adjusting the transmittance between 400 and 700 nm causes light leakage on the long wavelength side, resulting in a decrease in actual contrast (deterioration in display quality). To suppress this, it is preferable to have a uniform absorption band in the range of 380 to 780 nm. For example, to effectively suppress light leakage on the long wavelength side of 700 nm or longer, it is preferable to adjust the cross-phase transmittance at 700 nm or longer, specifically the cross-phase transmittance at 730 nm. The transmittance is preferably adjusted to 0 to 20%, more preferably 0 to 4%, and even more preferably 0 to 1%.

[0095] Next, a specific method for producing a polarizing film will be described using as an example a case in which a polarizing film is produced by adsorbing an azo compound onto a substrate made of a polyvinyl alcohol-based resin. Note that the method for producing a polarizing film according to the present invention is not limited to the following method.

[0096] (Preparation of Raw Film) The film that will become the base film (hereinafter referred to as raw film or film) can be produced by film-forming a polyvinyl alcohol resin. The polyvinyl alcohol resin is not particularly limited, and commercially available products or those synthesized by known methods may be used. Polyvinyl alcohol resins can be obtained, for example, by saponifying a polyvinyl acetate resin. Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids. The degree of saponification of the polyvinyl alcohol resin is typically approximately 85 to 100 mol%, and more preferably 95 mol% or higher. The polyvinyl alcohol resin may be further modified; for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may also be used. The degree of polymerization of the polyvinyl alcohol resin means the viscosity-average degree of polymerization, which can be determined by a method well known in the art, and is usually preferably about 1,000 to 10,000, more preferably about 1,500 to 6,000.

[0097] The method for forming a polyvinyl alcohol resin film is not particularly limited, and film formation can be carried out by a known method. In this case, the polyvinyl alcohol resin film may contain a plasticizer such as glycerin, ethylene glycol, propylene glycol, or low-molecular-weight polyethylene glycol. The content of the plasticizer is preferably 5 to 20 wt %, more preferably 8 to 15 wt %, based on the entire film. The thickness of the raw film is not particularly limited, but is, for example, about 5 μm to 150 μm, preferably about 10 μm to 100 μm.

[0098] (Swelling Step) The obtained raw film is subjected to a swelling treatment. The swelling treatment is preferably carried out by immersing the raw film in a solution at 20 to 50°C for 30 seconds to 10 minutes, and the solution is preferably water. The stretching ratio of the raw film due to swelling is preferably adjusted to 1.00 to 1.50 times, and more preferably adjusted to 1.10 to 1.35 times. When the time required to produce a polarizing film is to be shortened, the swelling treatment can be omitted because the raw film also swells during the dyeing treatment described below.

[0099] (Dyeing Step) Subsequently, the film obtained after the swelling treatment is subjected to a dyeing step in which the azo compound or dichroic dye of the present invention is adsorbed and impregnated therein. If the swelling step is omitted, the swelling treatment of the raw film can be carried out simultaneously with the dyeing step. In the dyeing step, for example, an azo compound which is a dichroic dye exemplified in "Application of Functional Dyes" edited by Irie Masahiro, First Edition, CMC Co., Ltd., June 2002, pp. 98-100, may be used to adjust the color of the resin film to be colored, to an extent that does not impair the performance of the polarizing film of the present invention.

[0100] The dyeing step is not particularly limited as long as it is a method of adsorbing and impregnating an azo compound as a dichroic dye into a film, but for example, it is preferable to color the film by immersing it in a dyeing solution, or it can also be colored by applying the dyeing solution to the film. The concentration of each azo compound in the dyeing solution is not particularly limited as long as the film is sufficiently colored, but can be adjusted, for example, within the range of 0.05 g / L to 100 g / L.

[0101] The temperature of the dyeing solution in the dyeing step is preferably 5 to 60° C., more preferably 20 to 50° C., and particularly preferably 35 to 50° C. The time for immersing the film in the dyeing solution can be appropriately adjusted, and is preferably adjusted between 30 seconds and 20 minutes, and more preferably between 1 and 10 minutes.

[0102] The dyeing solution may further contain a dyeing assistant, if necessary, in addition to the azo compound used in the present invention. Examples of dyeing assistants include sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate, anhydrous sodium sulfate, and sodium tripolyphosphate. The content of the dyeing assistant can be adjusted as desired by the immersion time and the temperature of the dyeing solution based on the dyeing properties of the dye used, but is preferably 0.01 to 5 wt %, more preferably 0.1 to 2 wt %, in the dyeing solution.

[0103] (Cleaning Step 1) After the dyeing step, a cleaning step (hereinafter also referred to as "cleaning step 1") can be performed to remove the dye solution adhering to the surface of the resin film. Performing cleaning step 1 can prevent the dye remaining on the surface of the resin film from migrating into the subsequent treatment solution. In cleaning step 1, water is generally used as the cleaning solution. The cleaning method preferably involves immersing the dyed resin film in the cleaning solution. Alternatively, the resin film can also be cleaned by applying the cleaning solution to it. The cleaning time is not particularly limited, but is preferably 1 to 300 seconds, and more preferably 1 to 60 seconds. The temperature of the cleaning solution in cleaning step 1 must be such that the material constituting the resin film (e.g., a hydrophilic polymer, in this case, a polyvinyl alcohol-based resin) does not dissolve. Therefore, the cleaning treatment is generally performed at 5 to 40°C. However, cleaning step 1 can be omitted because the performance of the polarizing film is not affected without the step.

[0104] (Step of incorporating a crosslinking agent and / or a water-resistant agent into a film) After the dyeing step or washing step 1, a crosslinking agent and / or a water-resistant agent can be incorporated into the resin film. The method of incorporating a crosslinking agent and / or a water-resistant agent into the resin film preferably involves immersing the resin film in a treatment solution containing the crosslinking agent and / or the water-resistant agent. Alternatively, the treatment solution may be applied or coated onto the resin film. The treatment solution contains at least one crosslinking agent and / or water-resistant agent and a solvent. The temperature of the treatment solution is preferably 5 to 70°C, more preferably 5 to 50°C. The treatment time in this step is preferably 30 seconds to 6 minutes, more preferably 1 to 5 minutes.

[0105] Examples of crosslinking agents that can be used include boron compounds such as boric acid, borax, and ammonium borate; polyaldehydes such as glyoxal and glutaraldehyde; polyisocyanate compounds such as biuret, isocyanurate, and block types; and titanium compounds such as titanium oxysulfate. Other examples include ethylene glycol glycidyl ether and polyamide epichlorohydrin. Examples of water-resistant agents include succinic peroxide, ammonium persulfate, calcium perchlorate, benzoin ethyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, ammonium chloride, and magnesium chloride. Preferably, boric acid is used. The solvent for the crosslinking agent and / or water-resistant agent is not particularly limited, but water is preferred. The concentrations of the crosslinking agent and / or water-resistant agent in the treatment solution can be appropriately determined depending on the types thereof, but when boric acid is used, for example, the concentration of boric acid in the treatment solution is preferably 0.1 to 6.0 wt %, more preferably 1.0 to 4.0 wt %. When it is desired to shorten the time required to produce a polarizing film or when the crosslinking treatment or water-resistant treatment is not necessary, it is possible to omit the treatment step.

[0106] (Stretching step) After the dyeing step, or optionally after the washing step 1 or the step of incorporating a crosslinking agent and / or a water-resistant agent, the stretching step is carried out. The stretching step is carried out by uniaxially stretching the resin film. The stretching method may be either a dry stretching method or a wet stretching method. The stretching ratio is preferably 3 times or more, more preferably 5 to 8 times.

[0107] In the dry stretching method, when the stretching heating medium is air, the resin film is preferably stretched at a temperature of the air medium ranging from room temperature to 180°C. The humidity is preferably 20 to 95% RH in the atmosphere. Examples of methods for heating the resin film include inter-roll zone stretching, roll heating stretching, hot rolling stretching, and infrared heating stretching, but the method is not limited to these stretching methods. The dry stretching step may be performed in one stretching stage or in two or more multi-stage stretching stages.

[0108] In the wet stretching method, the resin film is preferably stretched in water, a water-soluble organic solvent, or a mixture thereof. More preferably, the resin film is stretched while immersed in a solution containing at least one crosslinking agent and / or water-resistant agent. The crosslinking agent and water-resistant agent may be the same as those described above in the step of incorporating the crosslinking agent and / or water-resistant agent. The concentration of the crosslinking agent and / or water-resistant agent in the solution used in the stretching step is preferably 0.5 to 15% by weight, more preferably 2.0 to 8.0% by weight. The stretching temperature is preferably 40 to 60°C, more preferably 45 to 58°C. The stretching time is typically 30 seconds to 20 minutes, preferably 2 to 5 minutes. The wet stretching step may be performed in a single stretching step or in a multi-stage stretching step of two or more stages.

[0109] (Washing Step 2) After the stretching step, precipitation of the crosslinking agent and / or water-resistant agent or adhesion of foreign matter to the surface of the resin film may occur. Therefore, a washing step (hereinafter also referred to as "washing step 2") for washing the surface of the resin film may be optionally performed. The washing time is preferably 1 second to 5 minutes. The washing method is preferably to immerse the resin film in a washing solution, but washing can also be performed by applying or coating the washing solution to the resin film. Water is preferred as the washing solution. The washing treatment may be performed in one stage or in a multi-stage treatment of two or more stages. The temperature of the washing solution in the washing step is not particularly limited, but is usually 5 to 50°C, preferably 10 to 40°C.

[0110] In addition to water, examples of the treatment liquid or solvent used in each of the above-mentioned treatment steps include alcohols such as dimethyl sulfoxide, N-methylpyrrolidone, methanol, ethanol, propanol, isopropyl alcohol, glycerin, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. The treatment liquid or solvent is not limited to these, but water is most preferred. These treatment liquids or solvents may be used alone or as a mixture of two or more.

[0111] (Drying Step) After the stretching step or washing step 2, the resin film is subjected to a drying step. The drying treatment can be carried out by natural drying, but to improve drying efficiency, it can also be carried out by compressing with a roll or removing surface moisture with an air knife or water-absorbing roll, or it can also be carried out by blowing air. The temperature for the drying treatment is preferably 20 to 100°C, more preferably 60 to 100°C. The drying time is preferably 30 seconds to 20 minutes, more preferably 5 to 10 minutes.

[0112] The polarizing plate according to the present invention comprises a polarizing film containing the above-described azo compound in a raw film, and a transparent protective layer provided on one or both sides of the polarizing film. The transparent protective layer is used to improve the water resistance and handling properties of the polarizing film.

[0113] The transparent protective layer is a protective film formed using a transparent material. The protective film has a layer shape that can maintain the shape of the polarizing film and is preferably made of a plastic or the like that is excellent in transparency, mechanical strength, thermal stability, moisture-blocking properties, etc. However, a protective film made of another material that can have equivalent functions to such a plastic may also be used. Examples of plastics that can constitute the protective film include films obtained from thermoplastic resins such as polyester-based resins, acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, and acrylic-based resins, thermosetting resins such as acrylic-based, urethane-based, acrylic urethane-based, epoxy-based, and silicone-based resins, and ultraviolet-curable resins. Among these, polyolefin-based resins include amorphous polyolefin-based resins that have polymerization units of cyclic polyolefins such as norbornene-based monomers or polycyclic norbornene-based monomers. In general, it is preferable to select a protective film that does not impair the performance of the polarizing film, and triacetyl cellulose (TAC) made of a cellulose acetate resin or a norbornene resin is particularly preferable as such a protective film. Furthermore, the protective film may be subjected to a hard coat treatment, an anti-reflection treatment, or a treatment for the purposes of preventing sticking, diffusing light, anti-glare, or the like, as long as the effects of the present invention are not impaired. The thickness of the transparent protective layer can be appropriately designed depending on the application of the polarizing film, but is preferably in the range of 1 μm to 200 μm, more preferably in the range of 5 μm to 150 μm, and particularly preferably in the range of 10 μm to 100 μm.

[0114] The polarizing plate preferably further includes an adhesive layer between the transparent protective layer and the polarizing film for bonding the transparent protective layer to the polarizing film. The adhesive constituting the adhesive layer is not particularly limited, but a polyvinyl alcohol-based adhesive is preferred. Examples of polyvinyl alcohol-based adhesives include, but are not limited to, Exeval RS-2117 (manufactured by Kuraray Co., Ltd.). A crosslinking agent and / or a water-resistant agent can also be added to the adhesive. A maleic anhydride-isobutylene copolymer is preferably used as the polymer constituting the polyvinyl alcohol-based adhesive, and an adhesive containing a crosslinking agent can also be used if necessary. Examples of maleic anhydride-isobutylene copolymers include ISOBAM #18 (manufactured by Kuraray Co., Ltd.), ISOBAM #04 (manufactured by Kuraray Co., Ltd.), ammonia-modified ISOBAM #104 (manufactured by Kuraray Co., Ltd.), ammonia-modified ISOBAM #110 (manufactured by Kuraray Co., Ltd.), imidized ISOBAM #304 (manufactured by Kuraray Co., Ltd.), and imidized ISOBAM #310 (manufactured by Kuraray Co., Ltd.). A water-soluble polyfunctional epoxy compound can be used as the crosslinking agent. Examples of water-soluble polyfunctional epoxy compounds include Denacol EX-521 (manufactured by Nagase Chemtec Corporation) and Tetrad-C (manufactured by Mitsubishi Gas Chemical Company, Inc.). In addition to polyvinyl alcohol-based resins, known adhesives such as urethane-based, acrylic-based, and epoxy-based adhesives can also be used. Acetoacetyl-modified polyvinyl alcohol is particularly preferred, and polyaldehydes are also preferred as the crosslinking agent. To improve the adhesive strength or water resistance of the adhesive, additives such as zinc compounds, chlorides, or iodides can be added to the adhesive alone or in combination at a concentration of approximately 0.1 to 10 wt %. The additives that can be added to the adhesive are not particularly limited and can be selected appropriately. A polarizing plate can be produced by bonding the transparent protective layer and the polarizing film together with the adhesive and then drying or heat-treating them at an appropriate temperature.

[0115] When a polarizing plate is attached to a display device such as a liquid crystal display or an organic electroluminescence display (commonly known as an OLED), various functional layers for improving the viewing angle and / or contrast, or a layer or film having brightness-enhancing properties may be provided on the surface of the transparent protective layer or transparent protective film, which will subsequently become the unexposed surface. The various functional layers are, for example, layers or films for controlling retardation. The polarizing plate is preferably attached to these films or display devices with an adhesive.

[0116] Furthermore, the polarizing plate may be provided with various known functional layers, such as an antireflection layer, an antiglare layer, or a hard coat layer, on the exposed surface of the protective layer or protective film. When preparing such layers having various functions, a method of coating a material having various functions on the exposed surface of the protective layer or protective film is preferred, but it is also possible to attach a layer or film having such functions to the exposed surface of the protective layer or protective film via an adhesive or pressure-sensitive adhesive.

[0117] The polarizing film or polarizing plate according to the present invention may be provided with a protective layer and / or a functional layer, as well as a transparent support such as glass, quartz, or sapphire, as necessary, and is used in liquid crystal projectors, calculators, clocks, notebook computers, word processors, liquid crystal televisions, polarized lenses, polarized glasses, car navigation systems, and indoor and outdoor measuring instruments and displays. In particular, the polarizing film or polarizing plate according to the present invention is suitable for use in display devices such as reflective liquid crystal display devices, semi-transmissive liquid crystal display devices, and organic electroluminescence devices. A display device using the polarizing film or polarizing plate according to the present invention can produce high-quality paper-like white and neutral black. Furthermore, a display device using the polarizing film or polarizing plate according to the present invention has high durability, high reliability, long-term high contrast, and high color reproducibility.

[0118] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Percentages and parts in the examples are by weight unless otherwise specified.

[0119] Example 1 Synthesis Example (Step 1) A tetrakisazo compound represented by formula (6) was obtained according to the method described in WO 2012 / 108169.

[0120] (Step 2) 38.2 parts of the tetrakis azo compound obtained in Step 1 was added to 900 parts of water and stirred to form a suspension. 28.4 parts of monoethanolamine and 11.3 parts of copper sulfate pentahydrate were added thereto and reacted at 90 to 98°C for 10 hours to complete the copperation reaction. After salting out with sodium chloride, the mixture was filtered and dried to obtain 7.0 parts of a compound in which an amine is coordinated to an azo compound represented by Compound Example A-1. The form in which the amine is coordinated to the azo compound is represented by formula (7).

[0121] <Preparation of Polarizing Film and Polarizing Plate> A polyvinyl alcohol resin film ("VF-PE#6000" manufactured by Kuraray Co., Ltd.; hereinafter simply referred to as "film") having a saponification degree of 99 mol% or more and a thickness of 60 μm was immersed in warm water at 35° C. for 3 minutes to undergo a swelling treatment. The swelled film was then immersed for 10 minutes in a 48° C. aqueous solution containing 1.1 parts by weight of an azo compound represented by Compound Example A-1 (represented by Formula (7) in the amine-coordinated form) as Compound A, 1.5 parts by weight of an azo compound represented by Compound Example B-1 as Compound B, 0.1 parts by weight of an azo compound represented by Compound Example C-1 as Compound C, 0.8 parts by weight of an azo compound represented by Compound Example D-1 as Compound D, 1.5 parts by weight of sodium tripolyphosphate, 1.5 parts by weight of anhydrous sodium sulfate, and 1,500 parts by weight of water, to incorporate the azo compounds. The azo compound-containing film was washed with water and, after washing, subjected to a crosslinking treatment with boric acid for 1 minute in an aqueous solution containing 2.7 wt % boric acid at 40°C. The crosslinked film was stretched 6.0 times while undergoing crosslinking treatment for 5 minutes in an aqueous solution containing 3.0 wt % boric acid at 58°C. While maintaining the stretched film in a tensed state, it was washed with water at room temperature for 10 seconds. The washed film was immediately dried at 70°C for 3 minutes to obtain a polarizing film. Using the above method, a polarizing film according to the present invention containing an azo compound having a structure of formula (1) and an azo compound having a structure of formula (2) was prepared. A 60 μm-thick alkali-treated triacetyl cellulose film (TG-60UL, manufactured by Fujifilm Corporation; hereinafter abbreviated as "TAC") was laminated on both sides of the polarizing film using a polyvinyl alcohol adhesive, thereby preparing a polarizing plate according to the present invention having a TAC / adhesive layer / polarizing film / adhesive layer / TAC structure. The obtained polarizing plate maintained the optical properties of the polarizing film, particularly the single transmittance, hue, degree of polarization, etc. This polarizing plate was used as the measurement sample of Example 1.

[0122] Example 2 Synthesis Example 8.7 parts of an azo compound represented by Compound Example A-1 was obtained in the same manner as in Example 1, except that 28.4 parts of N-methylethanolamine was used instead of 28.4 parts of monoethanolamine in Step 2 of the Synthesis Example of Example 1. The form in which the amine is coordinated to the azo compound is represented by formula (8).

[0123] <Preparation of Polarizing Film and Polarizing Plate> A polarizing plate was prepared in the same manner as in the preparation of the polarizing film and polarizing plate of Example 1, except that the four types of compounds used in the preparation of the polarizing film of Example 1 were replaced with "0.7 parts by weight of an azo compound represented by [Example Compound A-1] (formula (8) in the form in which the amine is coordinated) as Compound A, 0.9 parts by weight of an azo compound represented by [Example Compound B-55] as Compound B, 0.1 parts by weight of an azo compound represented by [Example Compound C-1] as Compound C, and 0.7 parts by weight of an azo compound represented by [Example Compound D-1] as Compound D."

[0124] Example 3 Preparation of Polarizing Film and Polarizing Plate A polarizing plate was prepared in the same manner as in the preparation of the polarizing film and polarizing plate of Example 1, except that the four types of compounds used in the preparation of the polarizing film of Example 1 were replaced with "1.5 parts by weight of an azo compound represented by [Example Compound A-1] (formula (7) in the form in which the amine is coordinated) as Compound A, 1.8 parts by weight of an azo compound represented by [Example Compound B-1] as Compound B, 0.1 parts by weight of an azo compound represented by [Example Compound C-3] as Compound C, and 0.8 parts by weight of an azo compound represented by [Example Compound D-1] as Compound D."

[0125] Example 4 Preparation of Polarizing Film and Polarizing Plate A polarizing plate was prepared in the same manner as in the preparation of the polarizing film and polarizing plate of Example 1, except that the four types of compounds used in the preparation of the polarizing film of Example 1 were replaced with "1.5 parts by weight of an azo compound represented by [Example Compound A-1] (formula (8) in the form in which the amine is coordinated) as Compound A, 2.4 parts by weight of an azo compound represented by [Example Compound B-1] as Compound B, 0.1 part by weight of an azo compound represented by [Example Compound C-1] as Compound C, and 0.6 parts by weight of an azo compound represented by [Example Compound D-1] as Compound D."

[0126] Comparative Example 1 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to compounds represented by the following formulas (9) and (10), C.I. Direct Orange 39, and C.I. Direct Red 117, which are described in Example 8 of Patent Document 1. That is, four types of dichroic dyes were used, and this polarizing plate was composed of compounds represented by the following formulas (9) and (10) as dyes replacing Compound A and Compound B, C.I. Direct Orange 39 as Compound C, and C.I. Direct Red 117 as Compound D.

[0127] Comparative Example 2 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to the compounds represented by the following formulas (11) and (12) and the compounds described in [Example Compound C-1] and [Example Compound D-1], which are described in Example 87 of Patent Document 2. That is, this polarizing plate was composed of the compounds represented by the following formulas (11) and (12) as dyes instead of Compound A and Compound B, [Example Compound C-1] as Compound C, and [Example Compound D-1] as Compound D.

[0128] Comparative Example 3 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to the compounds represented by the following formulas (9) and (13) and the compounds described in [Example Compound C-1] and [Example Compound D-2], which are described in Example 19 of Patent Document 3. That is, this polarizing plate was composed of the compounds represented by the following formulas (9) and (13) as dyes instead of Compound A and Compound B, [Example Compound C-1] as Compound C, and [Example Compound D-1] as Compound D.

[0129] Comparative Example 4 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to compounds represented by the following formulas (11) and (13), Example Compound C-1, and C.I. Direct Red 117, which are described in Example 13 of Patent Document 3. That is, this polarizing plate was composed of compounds represented by the following formulas (11) and (13) as dyes instead of Compound A and Compound B, Example Compound C-1 as Compound C, and Example Compound D-1 as Compound D.

[0130] Comparative Example 5 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to compounds represented by the following formulas (6) and (14), C.I. Direct Orange 39, and [Example Compound D-3], which are described in Example B1 of Patent Document 4. That is, this polarizing plate was composed of compounds represented by the following formulas (6) and (14) as dyes instead of Compound A and Compound B, C.I. Direct Orange 39 as Compound C, and [Example Compound D-3] as Compound D.

[0131] Comparative Example 6 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (6), [Example Compound C-1], and [Example Compound D-1], which are described in Example 18 of Patent Document 2. That is, this polarizing plate did not use Compound A, but contained a compound represented by the following formula (6) as a dye in place of Compound B, [Example Compound C-1] as Compound C, and [Example Compound D-3] as Compound D.

[0132] Comparative Example 7 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (15) described in Example 4 of Patent Document 1, [Example Compound C-1], and C.I. Direct Red 117. That is, this polarizing plate was composed of a compound represented by the following formula (15) as a dye replacing Compound A, no Compound B, [Example Compound C-1] as Compound C, and C.I. Direct Red 117 as Compound D.

[0133] Comparative Example 8 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (16), [Example Compound C-1], and [Example Compound D-4], which are described in Example 6 of Patent Document 5. That is, this polarizing plate did not use Compound A, but contained a compound represented by the following formula (16) as a dye in place of Compound B, [Example Compound C-1] as Compound C, and [Example Compound D-4] as Compound D.

[0134] Comparative Example 9 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (17) described in Example 3 of Patent Document 9, C.I. Direct Orange 39, and [Example Compound D-5]. That is, this polarizing plate did not use Compound A, but contained a compound represented by the following formula (17) as a dye replacing Compound B, C.I. Direct Orange 39 as Compound C, and [Example Compound D-5] as Compound D.

[0135] Comparative Example 10 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (18), [Example Compound C-2], and [Example Compound D-6], which are described in Example 22 of Patent Document 10. That is, this polarizing plate did not use Compound A, but contained a compound represented by the following formula (18) as a dye in place of Compound B, [Example Compound C-2] as Compound C, and [Example Compound D-6] as Compound D.

[0136] Comparative Example 11 A polarizing plate was produced in the same manner as in Example 1, except that the four compounds used in producing the polarizing film in Example 1 were changed to three compounds: a compound represented by the following formula (19) described in Example 3 of Patent Document 11, C.I. Direct Orange 39, and [Example Compound D-7]. That is, this polarizing plate did not use Compound A, but contained a compound represented by the following formula (19) as a dye replacing Compound B, C.I. Direct Orange 39 as Compound C, and [Example Compound D-7] as Compound D.

[0137] [Comparative Example 12] A polarizing plate was prepared in the same manner as in Comparative Example 6, except that the parts by weight of the dye used were changed. Specifically, the amount of the azo compound represented by formula (6) was changed to 2.0 parts by weight, the amount of the azo compound represented by [Example Compound C-1] was changed to 0.1 parts by weight, and the amount of the azo compound represented by [Example Compound D-1] was changed to 0.3 parts by weight. By changing the parts by weight, a polarizing plate with a single transmittance of 40.1% was obtained.

[0138] [Comparative Example 13] A polarizing plate was produced in the same manner as in Comparative Example 10, except that the parts by weight of the dye used were changed. Specifically, the amount of the azo compound represented by the above formula (18) was changed to 1.5 parts by weight, the amount of the azo compound represented by [Example Compound C-2] was changed to 1.5 parts by weight, and the amount of the azo compound represented by [Example Compound D-6] was changed to 0.9 parts by weight. By changing the parts by weight, a polarizing plate with a single transmittance of 40.1% was obtained.

[0139] Reference Example 1A Preparation of Polarizing Film A polyvinyl alcohol resin film ("VF-PE#6000" manufactured by Kuraray Co., Ltd.; hereinafter simply referred to as "film") having a saponification degree of 99 mol% or more and a thickness of 60 μm was immersed in warm water at 35°C for 3 minutes to undergo a swelling treatment. The swelled film was then immersed in a 48°C aqueous solution containing 0.45 parts by weight of an azo compound represented by Formula (7) in the amine-coordinated form, 1.5 parts by weight of sodium tripolyphosphate, 1.5 parts by weight of anhydrous sodium sulfate, and 1,500 parts by weight of water for 2 to 5 minutes so as to incorporate the azo compound into the film, resulting in a single-substance transmittance Ts of 44.0%±0.1%. The azo compound-incorporated film was then washed with water, and after washing, crosslinked with boric acid for 1 minute in a 40°C aqueous solution containing 2.7 wt% boric acid. The film obtained after the crosslinking treatment was stretched 5.0 times while undergoing crosslinking treatment for 5 minutes in an aqueous solution containing 3.0 wt% boric acid at 55°C. While maintaining the tension of the stretched film, the film was washed with water at room temperature for 10 seconds. The washed film was immediately dried at 70°C for 3 minutes to obtain a polarizing film.

[0140] Reference Example 2A Preparation of Polarizing Film A polarizing film was prepared in the same manner as in the preparation of the polarizing film of Reference Example 1A, except that the azo compound used in the preparation of the polarizing film of Reference Example 1A was replaced with 0.45 parts by weight of an azo compound represented by [Example Compound A-1] (represented by Formula (8) when the amine is coordinated).

[0141] Reference Example 1B Preparation of Polarizing Film A polarizing film was prepared in the same manner as in the preparation of the polarizing film of Reference Example 1A, except that the azo compound used in the preparation of the polarizing film of Reference Example 1A was replaced with 0.45 parts by weight of the azo compound represented by [Compound Example B-1].

[0142] Reference Example 2B Preparation of Polarizing Film A polarizing film was prepared in the same manner as in the preparation of the polarizing film of Reference Example 1A, except that the azo compound used in the preparation of the polarizing film of Reference Example 1A was replaced with 0.45 parts by weight of an azo compound represented by [Compound Example B-55].

[0143] Comparative Example 1A Preparation of Polarizing Film A polarizing film was prepared in the same manner as in the preparation of the polarizing film of Reference Example 1A, except that the azo compound used in the preparation of the polarizing film of Reference Example 1A was replaced with 0.45 parts by weight of the azo compound represented by formula (10) above.

[0144] [Comparative Example 1B] <Preparation of Polarizing Film> A polarizing film was prepared in the same manner as in the preparation of the polarizing film of Reference Example 1A, except that the azo compound used in the preparation of the polarizing film of Reference Example 1A was replaced with 0.45 parts by weight of the azo compound represented by formula (9) above.

[0145] <Evaluation> The measurement samples obtained in Reference Examples 1A to 2A, 1B and 2B, Examples 1 to 4, and Comparative Examples 1A, 1B, and 1 to 13 were evaluated as follows.

[0146] <Parallel Polarized Transmittance Ky, Orthogonal Polarized Transmittance Kz> The parallel polarized transmittance (Ky) and orthogonal polarized transmittance (Kz) of each measurement sample were measured using a spectrophotometer (Hitachi High-Tech UH-4150). Here, Ky refers to the transmittance when the absorption axis of the absolute polarizer and the absorption axis of the polarizing film or polarizing plate are superimposed parallel to each other, and Kz refers to the transmittance when the absorption axis of the absolute polarizer and the absorption axis of the polarizing plate or polarizing film are superimposed perpendicular to each other. Ky and Kz were measured at wavelength intervals of 1 nm in the range of 380 to 780 nm (or 400 to 700 nm, or 730 nm).

[0147] <Single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc> The single transmittance Ts is the spectral transmittance at each wavelength when a single measurement sample is measured. The parallel transmittance Tp is the spectral transmittance at each wavelength when two measurement samples are superimposed so that the absorption axes of the samples are parallel. The crossed transmittance Tc is the spectral transmittance measured when two polarizing plates are superimposed so that the absorption axes of the polarizing plates are perpendicular to each other. Using the Ky and Kz values ​​at 380 to 780 nm obtained by the measurement, various transmittances at 380 to 780 nm (or 400 to 700 nm, or 730 nm) were calculated using the following calculation formulas (i) to (iii).

[0148] <Luminous efficiency corrected single transmittance Ys ３８０～７８０ or Ys ４００～７００ , visibility correction parallel transmittance Yp３８０～７８０ or Yp ４００～７００ , and luminosity-corrected orthogonal transmittance Yc ３８０～７８０ or Yc ４００～７００ > Visibility corrected single transmittance Ys ３８０～７８０ , visibility correction parallel transmittance Yp ３８０～７８０ and luminosity-corrected orthogonal transmittance Yc ３８０～７８０ is the transmittance corrected for luminosity in accordance with JIS Z 8722:2009 for each of the single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc obtained at predetermined wavelength intervals dλ in the wavelength range of 380 to 780 nm. Specifically, the single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc were each calculated by substituting them into the following formula. In the formula, Pλ represents the spectral distribution of the standard light (light source C), and yλ represents the 2-degree visual field color matching function. When setting the wavelength range, the spectral distribution and color matching function of the standard light used must also be set to the same wavelength range.

[0149] Formulas (1) to (3) are the various transmittances (Ys) when the wavelength range is set to 380 to 780 nm. ３８０～７８０ , Yp ３８０～７８０ , Yc ３８０～７８０ ) is the calculation formula.

[0150] As in Patent Documents 2, 4, and 9, the wavelength range was set to 400 to 700 nm and evaluation was performed. Note that calculation formulas (4) to (6) are calculated based on calculation formulas (1) to (3) to calculate various transmittances (Ys ４００～７００ , Yp ４００～７００ , Yc ４００～７００ ) is the calculation formula.

[0151] <Degree of polarization ρy ３８０～７８０ or ρy ４００～７００ For each measurement sample, the degree of polarization ρy ３８０～７８０ or ρy ４００～７００ The degree of polarization ρy was calculated. ３８０～７８０ is calculated by the formula (7), and the degree of polarization ρy ４００～７００ is shown in the formula (8). The polarization degree is the luminosity-corrected parallel transmittance Yp ３８０～７８０ or Yp ４００～７００ and luminous efficiency corrected orthogonal transmittance Yc ３８０～７８０ or Yc４００～７００ was substituted and calculated.

[0152] <Contrast> The luminosity-corrected parallel transmittance Yp is calculated using the formula (9) or (10). ３８０～７８０ or Yp ４００～７００ and luminous efficiency corrected orthogonal transmittance Yc ３８０～７８０ or Yc ４００～７００ Substituting the above, the contrast (CR ３８０～７８０ or CR ４００～７００ ) was obtained.

[0153] Table 1A shows the λ values ​​at a single transmittance Ts of 44.0%±0.1% for each of the measurement samples prepared in Reference Examples 1A to 2A and Comparative Example 1A. ｍａｘ The wavelength (λ ) on the longest wavelength side of the wavelength range in which the value of the crossed transmittance Tc in the absorption band including the maximum absorption wavelength is less than 1.0%. １ ) and the shortest wavelength (λ ２ ) is shown.

[0154] As shown in Table 1A, Comparative Example 1A has sufficient absorption over a narrow wavelength range, from 597 nm to 694 nm, where Tc is less than 1.0%. In contrast, Reference Example 1A has sufficient absorption over a wide wavelength range, from 638 nm to 760 nm, where Tc is less than 1.0%, and Reference Example 2A has sufficient absorption over a wide wavelength range, from 637 nm to 761 nm, where Tc is less than 1.0%. Additionally, Comparative Example 1A does not have sufficient absorption at a wavelength of 730 nm, because Tc is greater than 1.0% on the wavelength side longer than 694 nm. In contrast, Reference Examples 1A and 2A have sufficient absorption at a wavelength of 730 nm, because 730 nm is included in the wavelength range where Tc is less than 1.0%. Thus, Reference Examples 1A and 2A are shown to be suitable compounds for providing polarizing films and the like having excellent cross transmittance at a wavelength of 730 nm.

[0155] Table 1B shows the λ values ​​at a single transmittance Ts of 44.0%±0.1% for each of the measurement samples prepared in Reference Examples 1B to 2B and Comparative Example 1B. ｍａｘ The wavelength (λ ) on the longest wavelength side of the wavelength range in which the value of the crossed transmittance Tc in the absorption band including the maximum absorption wavelength is less than 1.0%.１ ) and the shortest wavelength (λ ２ ) is shown.

[0156] As shown in Table 1B, Comparative Example 1B has a λ ｍａｘ is 581 nm, while Reference Example 1B has a λ ｍａｘ is 629 nm, and Reference Example 2B is λ ｍａｘ λ is on the longer wavelength side of 628 nm. ｍａｘ When a polarizing film is prepared by blending a plurality of dyes, the film exhibits better optical properties when the gaps between the absorption waveforms of the dyes are filled. As shown in Tables 1A and 1B, the λ ２ is 597 nm, and the λ of Comparative Example 1B １ Since the λ of Reference Example 1A is 617 nm, it is possible to fill in the gap between the absorption waveforms by combining the azo compounds used in Comparative Example 1A and Comparative Example 1B. However, with these combinations, it is not possible to prepare a polarizing plate having sufficient polarization performance at 730 nm. ２ is 638 nm, and the λ of Reference Example 2A ２ is 637 nm, and the λ １ Since the λ of Reference Example 1B is 617 nm, it is difficult to fill the gap between the absorption waveforms of the azo compounds even when the azo compound used in Comparative Example 1B is combined with the azo compound used in Reference Example 1A or 2A. １ is 667 nm, and λ of Reference Example 2B １ Since the wavelength of absorption peaks is 666 nm, when the azo compound used in Reference Example 1B is combined with the azo compound used in Reference Example 1A or 2A, it is possible to fill in the gap between the absorption peaks, thereby providing a polarizing film or the like having superior optical properties. Therefore, a combination of azo compounds represented by the above formulas (1) and (2) is preferred.

[0157] Table 1 shows the results of various transmittances and polarization performances corrected for visibility in the wavelength range of 400 to 700 nm for each of the measurement samples prepared in Examples 1 to 4 and Comparative Examples 1 to 9.

[0158] The polarizing plates of Examples 1 to 4 of the present invention shown in Table 1 exhibited higher performance than any of the polarizing plates of Comparative Examples 1 to 9. Specifically, in both Comparative Examples 1 to 5, which had four-color blends (four types of compounds blended), and Comparative Examples 6 to 9, which had three-color blends (three types of compounds blended), the Examples of the present invention exhibited higher contrast in the wavelength range of 400 to 700 nm.

[0159] Table 2 shows the results of various transmittances and polarization performances corrected for visibility in the wavelength range of 380 nm to 780 nm for each of the measurement samples prepared in Examples 1 to 4 and Comparative Examples 10 and 11.

[0160] As can be seen from Table 2, the polarizing plates of Examples 1 to 4 of the present invention exhibited higher performance than the polarizing plates of Comparative Examples 10 and 11. Specifically, in the wavelength range of 380 to 780 nm, the polarizing plates of Comparative Examples 10 and 11, which are three-color combinations, exhibited higher contrast in each of the Examples of the present invention.

[0161] Comparing the contrast of Examples 1 to 4, it can be seen that the values ​​shown in Table 2 are lower by approximately 1000 to 4000 than those in Table 1. This result is due to the influence of the visibility correction range as shown in formulas (1) to (10). Furthermore, it is thought that if visibility correction is performed in the range of 380 to 780 nm for Comparative Examples 1 to 9, the contrast will similarly decrease.

[0162] Table 3 shows the results of polarization performance when the single transmittance (Ys) after luminosity correction in the wavelength range of 380 to 780 nm of each measurement sample in each of Examples 1 to 4 and Comparative Examples 12 and 13 was made uniform.

[0163] As can be seen from Table 3, the polarizing plates of Examples 1 to 4 of the present invention exhibited higher polarization performance than the polarizing plates of Comparative Examples 12 and 13. Even when compared with Comparative Example 6, which has a Ys close to that of each Example, the highest degree of polarization, and good contrast among the comparative examples listed in Table 1, each Example was found to have higher contrast. Even when compared with Comparative Example 10, which has the highest degree of polarization and good contrast among the comparative examples listed in Table 2, each Example was found to have higher contrast. Even when compared with Comparative Examples 12 and 13, which were prepared with approximately the same luminosity-corrected single transmittance (Ys) as each Example, each Example was found to have higher contrast. Furthermore, by using Compound A and Compound B in combination, the polarizing plates of Examples 1 to 4 had crossed transmittance values ​​at 700 nm or more, particularly crossed transmittance at 730 nm of 0 to 4% or less, which are lower than those of Comparative Examples 12 and 13, indicating improved polarization performance on the long wavelength side. In other words, it was revealed that the polarizing plates of each Example had polarization performance, particularly high polarization degree and high contrast over a wide range from 380 nm to 780 nm, and were polarizing plates with almost no light leakage in the long wavelength range.

[0164] Furthermore, the polarizing plates of Examples 1 to 3 showed almost no deterioration in contrast or polarization even after 500 hours at an ambient temperature of 105°C or after 500 hours at an ambient temperature of 85°C and a relative humidity of 85%, demonstrating long-term durability even under high temperature and high humidity conditions (these observation results are the consensus of the three experts).

[0165] The present invention can provide polarizing films, polarizing plates, and optical components, etc., having optical properties equivalent to or superior to those of conventional polarizing films. The polarizing films or polarizing plates of the present invention can be used in liquid crystal projectors, calculators, clocks, notebook computers, word processors, liquid crystal televisions, polarized lenses, polarized glasses, head-up displays, car navigation systems, organic electroluminescence displays (commonly known as OLEDs), and display devices used in indoor and outdoor measuring instruments and indicators, or similar optical devices. A display device comprising the polarizing film or polarizing plate of the present invention is one aspect of the present invention. Furthermore, as a particularly preferred application of the polarizing plate of the present invention, a display device comprising the polarizing film or polarizing plate of the present invention not only provides a high degree of polarization, i.e., contrast, in the visible light region, particularly in the wavelength region of 380 to 780 nm, but also provides high durability. This durability means that the display device does not lose its polarization degree or contrast even in an environmental temperature of 105°C or 85°C with a relative humidity of 85%. Particularly preferred applications include in-vehicle displays, liquid crystal projectors, head-up displays, and outdoor displays, which are suitable for use in fields requiring not only high contrast but also heat resistance, moist heat resistance, and light resistance.

Claims

1. A polarizing film containing a substrate, wherein the substrate contains an azo compound represented by the following formula (1) or a salt thereof (compound A) and an azo compound represented by the following formula (2) or a salt thereof (compound B): (In formula (1), X １ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q １ and R １ ~R ４ each independently represents an arbitrary substituent, and m represents an integer of 1 to 3. (In formula (2), X ２ represents an amino group which may have a substituent, a phenylamino group which may have a substituent, a naphthylamino group which may have a substituent, a benzoylamino group which may have a substituent, or a naphthotriazole group which may have a substituent, and Q ２ and R ５ ~R ８ each independently represents an arbitrary substituent, R ９ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 3.

2. In formula (1), R １ ~R ４ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ X is an alkoxy group of the formula １ is unsubstituted or one or two C １ -C ４ Alkyl or phenyl substituted C １ -C ４ Amino group having an alkyl group, or unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ Q is a phenylamino group, a naphthylamino group, a benzoylamino group, or a naphthotriazole group each having one or two substituents independently selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; １ is a hydrogen atom, a chlorine atom, a hydroxy group, a hydroxy group having a protecting group, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ an alkoxy group, a nitro group, a carboxy group, or a sulfo group, and in formula (2), R ５ ~R ８ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ X is an alkoxy group of the formula ２ is unsubstituted or one or two C １ -C ４ Alkyl or phenyl substituted C １ -C ４ Amino group having an alkyl group, or unsubstituted or C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ Alkoxy group, C １ -C ４ Q is a phenylamino group, a naphthylamino group, a benzoylamino group, or a naphthotriazole group, each having one or two substituents independently selected from the group consisting of an alkyl group, a carboxy group, a hydroxy group, a sulfo group, and an amino group; ２ is a hydrogen atom, a chlorine atom, a hydroxy group, a hydroxy group having a protecting group, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ The polarizing film according to claim 1 , wherein the group is an alkoxy group, a nitro group, a carboxy group, or a sulfo group.

3. The polarizing film according to claim 1, wherein the azo compound represented by formula (1) or the salt thereof is an azo compound represented by formula (3) below or a salt thereof, and the azo compound represented by formula (2) or the salt thereof is an azo compound represented by formula (4) below or a salt thereof: (In formula (3), R １ ~R ４ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ and m represents an integer of 1 to 3. (In formula (4), R ５ ~R ８ are each independently a hydrogen atom, C １ -C ４ Alkyl group, C １ -C ４ C having an alkoxy group or a sulfo group １ -C ４ R ９ represents a methyl group, and n represents an integer of 1 to 3.

4. The polarizing film according to claim 1, which contains one or more dichroic dyes other than compounds A and B.

5. The polarizing film according to claim 1, wherein the substrate comprises a polyvinyl alcohol-based resin.

6. A polarizing plate comprising a transparent protective film provided on one or both sides of the polarizing film according to any one of claims 1 to 5.

7. A display device comprising the polarizing plate according to claim 6.

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