Azo compound or salt thereof, and polarizing film, polarizing plate, and liquid crystal display device comprising same

Abstract

The present invention is an azo compound represented by formula (1): # imgabs0 # (in formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent, and A represents an arbitrary substituent) or a salt thereof.

Description

Technical Field

[0001] The present invention relates to novel azo compounds or salts thereof, and polarizing films, polarizing plates and liquid crystal display devices containing the same. Background Art

[0002] Polarizing plates with light transmission / shading functions and liquid crystals with light switching functions are the basic components of display devices such as liquid crystal displays (LCDs). The application field of this LCD has also developed from small devices such as calculators and watches in the early days to notebook computers, word processors, liquid crystal projectors, liquid crystal televisions, car navigation systems, and indoor and outdoor measuring instruments. In addition, it can also be applied to lenses with polarizing functions, and has been applied to sunglasses that improve visibility and polarized glasses corresponding to 3D televisions in recent years. Since the above polarizing plates have a wide range of uses and are used under a wide range of conditions from low temperature to high temperature, low humidity to high humidity, and low light intensity to high light intensity, polarizing plates with high polarization performance and high durability are required.

[0003] At present, polarizing plates are manufactured by dyeing or impregnating, stretching and aligning a film of polyvinyl alcohol or its derivatives with iodine or a dichroic dye, or by removing hydrochloric acid from a polyvinyl chloride film or dehydrating a polyvinyl alcohol film to produce polyene and aligning it. These substances greatly affect the polarization characteristics and durability of the polarizing plate. The iodine-based polarizing film using iodine has excellent polarization performance, but is not resistant to water and heat, and has problems with its durability when used for a long time under high temperature and high humidity. In order to improve durability, methods such as treating with formalin or an aqueous solution containing boric acid and using a polymer film with low moisture permeability as a protective film have been considered, but the effect is not sufficient.

[0004] On the other hand, dye-based polarizing films using dyes have excellent moisture resistance and heat resistance compared to iodine-based polarizing films, but generally have insufficient polarization performance. Dye-based neutral gray polarizing plates are generally manufactured by combining multiple dyes, but the polarization performance of dye-based neutral gray polarizing plates is insufficient, so it is necessary to develop dichroic dyes that have good polarization performance for each color used.

[0005] As the above-mentioned dye-based polarizing film, for example, there are listed: dye-based polarizing films using water-soluble azo compounds described in Patent Documents 1 to 3, and recently, in order to improve the performance of dichroic dyes, 1-naphthol-3-sulfonic acid derivatives described in Patent Document 2 have been developed, but sufficient polarizing properties have not yet been obtained, and further performance improvement is required.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] International Publication No. 2017 / 146212

[0009] [Patent Document 2] International Publication No. 2019 / 117131

[0010] [Patent Document 3] International Publication No. 2020 / 050333

[0011] [Patent Document 4] International Publication No. 2021 / 015188.

[0012] [Non-patent literature]

[0013] [Non-patent document 1] Dye Chemistry; written by Yutaka Hosoda, published by Gihodo, 1957

[0014] [Non-patent document 2] Application of functional pigments (CMC Publishing Co., Ltd., 1st edition, supervised by Masahiro Irie, pages 98 to 100). Summary of the invention

[0015] [Problems to be solved by the invention]

[0016] One of the purposes of the present invention is to provide a dichroic dye, a polarizing film, and a polarizing plate having excellent polarizing performance, and another purpose of the present invention is to provide a neutral gray polarizing plate with less orthogonal color leakage in the wavelength range of the visible light region. Another purpose of the present invention is to provide a high-performance polarizing plate having excellent polarizing performance and durability (heat resistance, moisture resistance, or light resistance). In order to achieve these purposes, a novel dichroic dye (azo compound) is required.

[0017] [Methods for solving the problem]

[0018] As a result of intensive studies to achieve these objects, the present inventors have found that a polarizing film and a polarizing plate containing a specific azo compound or a salt thereof have excellent polarizing performance and durability.

[0019] That is, the present invention relates to the following [1] to [9].

[0020] [1] An azo compound or a salt thereof represented by the following formula (1):

[0021]

[0022] (In formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent, and A represents an arbitrary substituent).

[0023] [2] The azo compound or a salt thereof according to [1], wherein the azo compound represented by the above formula (1) is represented by the following formula (2):

[0024]

[0025] (In formula (2), R 1 To R 8 Each independently represents an arbitrary substituent, m represents an integer of 0 or 1, and n represents 0 or 1).

[0026] [3] The azo compound or a salt thereof according to [1], wherein the azo compound represented by the above formula (1) is represented by the following formula (3):

[0027]

[0028] (In the above formula (3), R 1 To R 6 (a, b, c, e, and d each independently represent an arbitrary substituent, and m represents 0 or 1).

[0029] [4] A polarizing film comprising the azo compound or a salt thereof according to any one of [1] to [3].

[0030] [5] The polarizing film according to [4], comprising a substrate.

[0031] [6] The polarizing film according to [4], comprising one or more organic dyes other than the azo compound or salt thereof according to any one of [1] to [3].

[0032] [7] The polarizing film as described in [4], having a neutral gray color.

[0033] [8] A polarizing plate comprising the polarizing film described in [4] and a transparent protective film provided on one or both sides of the polarizing film.

[0034] [9] A display device comprising the polarizing film described in [4] or the polarizing plate described in [8].

[0035] [Effects of the invention]

[0036] The azo compound or its salt of the present invention can be used as a dye for polarizing film. In one aspect, the polarizing film and polarizing plate of the present invention have excellent polarizing performance. In one aspect, the polarizing plate with neutral gray of the present invention shows achromatic color without orthogonal color leakage and high performance in the wavelength range of the visible light region. In one aspect, the polarizing film and polarizing plate of the present invention have excellent polarizing performance (transmittance, contrast) and durability (moisture resistance, heat resistance, light resistance). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] none.

[0038] Description of Reference Numerals

[0039] none. DETAILED DESCRIPTION

[0040] In the present specification and claims, “azo compound or its salt” is referred to as “azo compound” for short, unless the free form is clearly indicated.

[0041] In this specification and claims, since a "substituent" may include a hydrogen atom, it is also described as a "substituent" for convenience. "May have a substituent" means that it also includes the case of not having a substituent. For example, "phenyl which may have a substituent" includes a simple unsubstituted phenyl and a phenyl with a substituent. In addition, unless otherwise specified, the "lower" of the lower alkyl, lower alkoxy, etc. in this application means that the number of carbon atoms is 1 to 4 (C1-C4), preferably 1 to 3 (C1-C3).

[0042] The azo compound or a salt thereof of the present invention has an isoindole-substituted 1-naphthol-3-sulfonic acid derivative represented by the following formula (1).

[0043]

[0044] (In formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent, and A represents an arbitrary substituent.)

[0045] In the above formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent, and A represents an arbitrary substituent. The substituents which may be possessed by the aforementioned group and the arbitrary substituent represented by A include, for example, a diazenyl group, a heterocyclic amino group, a condensed heterocyclic amino group, an alkyl group, an alkoxy 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 alkylsulfonyl group, an arylsulfonyl group, an alkylsulfonyl group, an arylsulfonyl group, an alkylthio group, an arylthio group, an alkylurea group, an arylurea group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, an alkylamino group, an arylamino group, a hydroxyl group (-OH), a cyano group (-CN), a nitro group (-NO2), a mercapto group (-SH), a halogen atom, a carboxyl group (-CO2H), a sulfonic acid group (-SO3H), an amino group (-NH2), a hydrogen atom, and the like.

[0046] As described later, the "benzene ring which may have a substituent" or "naphthalene ring which may have a substituent" as Ar may be a structure at a corresponding position in formula (2) or (3).

[0047] Examples of the heterocyclic amino group include 5- or 6-membered rings containing 1 to 3 heteroatoms selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms. Specific examples of such heterocyclic amino groups include:

[0048] 5-membered heteroalicyclic amine groups such as pyrrolidinylamine, tetrahydrofuranylamine, tetrahydrothiophen-2-ylamine, and tetrahydrothiophen-3-ylamine;

[0049] Piperidinylamino, piperazinylamino, di Alk-2-ylamino, Linoylamine, thio 6-membered heteroalicyclic amine groups such as linoamino groups;

[0050] Pyrrolylamine, pyrazolylamine, imidazoleamine, triazoleamine, furylamine, thiophene-2-ylamine, thiophene-3-ylamine, A 5-membered aromatic heterocyclic amine group such as azole amine group, thiazolyl amine group, etc.; or

[0051] 6-membered aromatic heterocyclic amine groups such as pyridylamino, pyrazylamino, pyridazinylamino and triazinylamino.

[0052] In the above heterocyclic group, the heterocyclic moiety is preferably an aromatic ring. In addition, as the hetero atom constituting the heterocyclic ring, it is more preferably selected from a nitrogen atom and a sulfur atom.

[0053] Examples of the above-mentioned condensed heterocyclic amino group include heterocyclic amino groups in which one benzene ring is condensed with a condensed 5- or 6-membered ring in a 5- or 6-membered heterocyclic group containing 1 to 3 heteroatoms selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms. Specific examples of such condensed heterocyclic amino groups include:

[0054] The heterocyclic moiety such as isobenzofuranylamine is a 5-membered alicyclic condensed heteroalicyclic amine;

[0055] The heterocyclic moiety such as benzopyranylamine is a 6-membered alicyclic condensed heteroalicyclic amine;

[0056] Benzopyrrolamine, benzopyrazolamine, benzimidazoleamine, benzotriazoleamine, benzofuranamine, benzothiophene-2-ylamine, benzothiophene-3-ylamine, benzo A condensed aromatic heterocyclic amine group whose heterocyclic ring part is an aromatic 5-membered ring, such as azole amine group and benzothiazolyl amine group; or

[0057] Quinolinylamino, cinnamylamino, oxazinylamino, quinazolinylamino, quinoline Examples of the heterocyclic moiety include linoamino and other aromatic heterocyclic amine groups, wherein the heterocyclic moiety is a condensed aromatic heterocyclic amine group having an aromatic 6-membered ring.

[0058] In the above heterocyclic group, the heterocyclic moiety is preferably an aromatic ring. In addition, as the hetero atom constituting the heterocyclic ring, it is more preferably selected from a nitrogen atom and a sulfur atom.

[0059] Examples of the alkyl group include linear, branched or cyclic alkyl groups, and preferably C1-C 10 Alkyl. As C1-C 10 Specific examples of the alkyl group include:

[0060] Straight-chain C1-C2-6-yl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl 10 Alkoxy;

[0061] Branched C3-C4 groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, tert-pentyl, isohexyl, tert-hexyl, isoheptyl, tert-heptyl, isooctyl, tert-octyl, 2-ethylhexyl, isononyl, and isodecyl 10 Alkyl; or

[0062] Cyclic C3-C7 alkoxy groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Among these, linear or branched alkoxy groups are more preferred, and linear or branched C1-C4 alkyl groups are more preferred.

[0063] Examples of the alkoxy group include linear, branched or cyclic alkoxy groups, and preferably C1-C 10 Alkoxy. As C1-C 10 Specific examples of the alkoxy group include:

[0064] methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy straight-chain C1-C 10 Alkoxy;

[0065] branched C3-C4-6 ... 10 alkoxy; or

[0066] Cyclic C3-C7 alkoxy groups such as cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and cycloheptyloxy groups. Among these, linear or branched alkoxy groups are more preferred, and linear or branched C1-C4 alkoxy groups are more preferred.

[0067] The alkoxy group may be an alkoxy group having a substituent, for example, a C1-C4 alkoxy group having a sulfonic acid group. As the "C1-C4 alkoxy group having a sulfonic acid group", a straight chain alkoxy group is more preferred, and the substitution position of the sulfonic acid group is more preferably the end of the alkoxy group. More preferred are 3-sulfonic acid propoxy and 4-sulfonic acid butoxy, and particularly preferred is 3-sulfonic acid propoxy.

[0068] The above aryloxy group is preferably C6-C 12 Specific examples of the aryloxy group include a phenoxy group, a naphthoxy group, and a biphenyloxy group.

[0069] Examples of the alkylcarbonylamino group include linear, branched or cyclic alkylcarbonylamino groups, preferably C1-C 10 Alkylcarbonylamino. As C1-C 10 Specific examples of the alkylcarbonylamino group include:

[0070] methylcarbonylamino (acetylamino), ethylcarbonylamino, n-propylcarbonylamino, n-butylcarbonylamino, n-pentylcarbonylamino, n-hexylcarbonylamino, n-heptylcarbonylamino, n-octylcarbonylamino, n-nonylcarbonylamino, n-decylcarbonylamino, and other linear C1-C 10 Alkylcarbonylamino;

[0071] branched C3-C4 carbonyl amino, such as isopropylcarbonylamino, isobutylcarbonylamino, sec-butylcarbonylamino, tert-butylcarbonylamino, isopentylcarbonylamino, tert-pentylcarbonylamino, isohexylcarbonylamino, tert-hexylcarbonylamino, isoheptylcarbonylamino, tert-heptylcarbonylamino, isooctylcarbonylamino, tert-octylcarbonylamino, 2-ethylhexylcarbonylamino, isononylcarbonylamino, isodecylcarbonylamino, etc. 10 an alkylcarbonylamino group; or

[0072] Cyclic C3-C7 alkylcarbonylamino groups such as cyclopropylcarbonylamino, cyclobutylcarbonylamino, cyclopentylcarbonylamino, cyclohexylcarbonylamino, and cycloheptylcarbonylamino. Among these, linear or branched alkylcarbonylamino groups are more preferred, and linear alkylcarbonylamino groups are more preferred.

[0073] The above arylcarbonylamino group is preferably C6-C 12 Specific examples of the arylcarbonylamino group include a phenylcarbonylamino group (benzoylamino group), a naphthylcarbonylamino group, and a biphenylcarbonylamino group.

[0074] Examples of the alkylcarbonyloxy group include linear, branched or cyclic alkylcarbonyloxy groups, preferably C1-C 10 Alkylcarbonyloxy. As C1-C 10 Specific examples of the alkylcarbonyloxy group include:

[0075] methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, n-butylcarbonyloxy, n-pentylcarbonyloxy, n-hexylcarbonyloxy, n-heptylcarbonyloxy, n-octylcarbonyloxy, n-nonylcarbonyloxy, n-decylcarbonyloxy, 10 Alkylcarbonyloxy;

[0076] branched C3-C4 carbonyl such as isopropylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, isopentylcarbonyloxy, tert-pentylcarbonyloxy, isohexylcarbonyloxy, tert-hexylcarbonyloxy, isoheptylcarbonyloxy, tert-heptylcarbonyloxy, isooctylcarbonyloxy, tert-octylcarbonyloxy, 2-ethylhexylcarbonyloxy, isononylcarbonyloxy, isodecylcarbonyloxy and the like 10 alkylcarbonyloxy; or

[0077] Cyclic C3-C7 alkylcarbonyloxy groups such as cyclopropylcarbonyloxy, cyclobutylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, and cycloheptylcarbonyloxy groups. Among these, linear or branched alkylcarbonyloxy groups are more preferred, and linear alkylcarbonyloxy groups are more preferred.

[0078] The arylcarbonyloxy group is preferably C6-C 12 Specific examples of the arylcarbonyloxy group include a phenylcarbonyloxy group, a naphthylcarbonyloxy group, and a biphenylcarbonyloxy group.

[0079] Examples of the alkylcarbonyl group include linear, branched or cyclic alkylcarbonyl groups, preferably C1-C 10 Alkylcarbonyl. As C1-C 10 Specific examples of the alkylcarbonyl group include:

[0080] Straight-chain C1-C2-6-carbonyl radicals of methylcarbonyl, ethylcarbonyl, n-propylcarbonyl, n-butylcarbonyl, n-pentylcarbonyl, n-hexylcarbonyl, n-heptylcarbonyl, n-octylcarbonyl, n-nonylcarbonyl, and n-decylcarbonyl 10 Alkylcarbonyl;

[0081] branched C3-C4 carbonyl such as isopropylcarbonyl, isobutylcarbonyl, sec-butylcarbonyl, tert-butylcarbonyl, isopentylcarbonyl, tert-pentylcarbonyl, isohexylcarbonyl, tert-hexylcarbonyl, isoheptylcarbonyl, tert-heptylcarbonyl, isooctylcarbonyl, tert-octylcarbonyl, 2-ethylhexylcarbonyl, isononylcarbonyl, isodecylcarbonyl 10 alkylcarbonyl; or

[0082] Cyclic C3-C7 alkylcarbonyl groups such as cyclopropylcarbonyl, cyclobutylcarbonyl, cyclopentylcarbonyl, cyclohexylcarbonyl, and cycloheptylcarbonyl. Among these, linear or branched alkylcarbonyl groups are more preferred, and linear alkylcarbonyl groups are more preferred.

[0083] As the arylcarbonyl group, a C6-C 12 Specific examples of the arylcarbonyl group include phenylcarbonyl (benzoyl), naphthylcarbonyl, and biphenylcarbonyl.

[0084] Examples of the alkylcarbamoyl group include linear, branched or cyclic monoalkylcarbamoyl groups or dialkylcarbamoyl groups.

[0085] As the monoalkylcarbamoyl group, a mono-C1-C 10 Specific examples of alkylcarbamoyl groups include:

[0086] methylcarbamoyl, ethylcarbamoyl, n-propylcarbamoyl, n-butylcarbamoyl, n-pentylcarbamoyl, n-hexylcarbamoyl, n-heptylcarbamoyl, n-octylcarbamoyl, n-nonylcarbamoyl, n-decylcarbamoyl, straight-chain mono C1-C 10 Alkylcarbamoyl;

[0087] Branched mono-C3-C4 carboxylic acids such as isopropylcarbamoyl, isobutylcarbamoyl, sec-butylcarbamoyl, tert-butylcarbamoyl, isopentylcarbamoyl, tert-amylcarbamoyl, isohexylcarbamoyl, tert-hexylcarbamoyl, isoheptylcarbamoyl, tert-heptylcarbamoyl, isooctylcarbamoyl, tert-octylcarbamoyl, 2-ethylhexylcarbamoyl, isononylcarbamoyl, and isodecylcarbamoyl 10 Alkylcarbamoyl; or

[0088] Cyclic mono C3-C7 alkylcarbamoyl groups such as cyclopropylcarbamoyl, cyclobutylcarbamoyl, cyclopentylcarbamoyl, cyclohexylcarbamoyl, and cycloheptylcarbamoyl. Among these, linear or branched monoalkylcarbamoyl groups are more preferred, and linear monoalkylcarbamoyl groups are more preferred.

[0089] As the dialkylcarbamoyl group, di-C1-C 10 Specific examples of alkylcarbamoyl groups include:

[0090] Straight-chain di-C1-C2-dinitro-1,1-dimethylcarbamoyl, diethylcarbamoyl, di-n-propylcarbamoyl, di-n-butylcarbamoyl, di-n-pentylcarbamoyl, di-n-hexylcarbamoyl, di-n-heptylcarbamoyl, di-n-octylcarbamoyl, di-n-nonylcarbamoyl, di-n-decylcarbamoyl 10 Alkylcarbamoyl;

[0091] Branched di-C3-C4-dinitrocarbamoyl having two branches, such as diisopropylcarbamoyl, diisobutylcarbamoyl, di-sec-butylcarbamoyl, di-tert-butylcarbamoyl, diisoamylcarbamoyl, di-tert-amylcarbamoyl, diisohexylcarbamoyl, di-tert-hexylcarbamoyl, diisoheptylcarbamoyl, di-tert-heptylcarbamoyl, diisooctylcarbamoyl, di-tert-octylcarbamoyl, di-(2-ethylhexyl)carbamoyl, diisononylcarbamoyl, and diisodecylcarbamoyl 10 Alkylcarbamoyl; or

[0092] Cyclic di-C3-C7 alkylcarbamoyl groups having two rings, such as dicyclopropylcarbamoyl, dicyclobutylcarbamoyl, dicyclopentylcarbamoyl, dicyclohexylcarbamoyl, and dicycloheptylcarbamoyl groups. Among these, linear or branched dialkylcarbamoyl groups are more preferred, and linear dialkylcarbamoyl groups are more preferred.

[0093] Examples of the arylcarbamoyl group include a monoarylcarbamoyl group and a diarylcarbamoyl group.

[0094] Monoarylcarbamoyl, preferably mono C6-C 12 Specific examples of the arylcarbamoyl group include a phenylcarbamoyl group, a naphthylcarbamoyl group, a biphenylcarbamoyl group, and the like.

[0095] As the diarylcarbamoyl group, di-C6-C 12 Specific examples of the arylcarbamoyl group include a diphenylcarbamoyl group, a dinaphthylcarbamoyl group, a di(biphenyl)carbamoyl group, and the like.

[0096] Examples of the alkoxycarbonyl group include linear, branched or cyclic alkoxycarbonyl groups, and preferably C1-C 10 Alkoxycarbonyl. As C1-C 10 Specific examples of the alkoxycarbonyl group include:

[0097] Methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butoxycarbonyl, n-pentyloxycarbonyl, n-hexyloxycarbonyl, n-heptyloxycarbonyl, n-octyloxycarbonyl, n-nonyloxycarbonyl, n-decyloxycarbonyl, straight-chain C1-C 10 Alkoxycarbonyl;

[0098] branched C3-C4 carbonyl such as isopropoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, isopentyloxycarbonyl, tert-pentyloxycarbonyl, isohexyloxycarbonyl, tert-hexyloxycarbonyl, isoheptyloxycarbonyl, tert-heptyloxycarbonyl, isooctyloxycarbonyl, tert-octyloxycarbonyl, 2-ethylhexyloxycarbonyl, isononyloxycarbonyl, isodecyloxycarbonyl and the like 10 alkoxycarbonyl; or

[0099] Cyclic C3-C7 alkoxycarbonyl groups such as cyclopropyloxycarbonyl, cyclobutyloxycarbonyl, cyclopentyloxycarbonyl, cyclohexyloxycarbonyl and cycloheptyloxycarbonyl. Among these, linear or branched alkoxycarbonyl groups are more preferred, and linear alkoxycarbonyl groups are more preferred.

[0100] The above aryloxycarbonyl group is preferably C6-C 12 Specific examples of the aryloxycarbonyl group include a phenoxycarbonyl group, a naphthoxycarbonyl group, a biphenyloxycarbonyl group, and the like.

[0101] Examples of the alkylsulfonylamino group include linear, branched or cyclic alkylsulfonylamino groups, preferably C1-C 10 Alkylsulfonylamino. As C1-C 10 Specific examples of the alkylsulfonylamino group include:

[0102] a linear C1-C12 amino group of methylsulfonylamino, ethylsulfonylamino, n-propylsulfonylamino, n-butylsulfonylamino, n-pentylsulfonylamino, n-hexylsulfonylamino, n-heptylsulfonylamino, n-octylsulfonylamino, n-nonylsulfonylamino, or n-decylsulfonylamino; 10 Alkylsulfonylamino;

[0103] branched C3-C 2-amino-3-amino-2-nitropropanesulfonylamino, isopropylsulfonylamino, isobutylsulfonylamino, sec-butylsulfonylamino, tert-butylsulfonylamino, isopentylsulfonylamino, tert-pentylsulfonylamino, isohexylsulfonylamino, tert-hexylsulfonylamino, isoheptylsulfonylamino, tert-heptylsulfonylamino, isooctylsulfonylamino, tert-octylsulfonylamino, 2-ethylhexylsulfonylamino, isononylsulfonylamino, isodecylsulfonylamino, etc. 10 Alkylsulfonylamino; or

[0104] Cyclic C3-C7 alkylsulfonylamino groups such as cyclopropylsulfonylamino, cyclobutylsulfonylamino, cyclopentylsulfonylamino, cyclohexylsulfonylamino, and cycloheptylsulfonylamino. Among these, linear or branched alkylsulfonylamino groups are more preferred, and linear alkylsulfonylamino groups are more preferred.

[0105] The above arylsulfonylamino group is preferably C6-C 12 Specific examples of the arylsulfonylamino group include a phenylsulfonylamino group, a toluenesulfonylamino group, a naphthylsulfonylamino group, and a biphenylsulfonylamino group.

[0106] Examples of the alkylamide sulfonyl group include linear, branched or cyclic monoalkylamide sulfonyl groups or dialkylamide sulfonyl groups.

[0107] As the monoalkylaminosulfonyl group, a mono-C1-C10 Specific examples of alkylsulfonyl groups include:

[0108] Straight chain mono C1-C1 sulfonyl of methylsulfamoyl, ethylsulfamoyl, n-propylsulfamoyl, n-butylsulfamoyl, n-pentylsulfamoyl, n-hexylsulfamoyl, n-heptylsulfamoyl, n-octylsulfamoyl, n-nonylsulfamoyl, n-decylsulfamoyl 10 Alkylsulfonylamine;

[0109] Branched mono-C3-C4 sulfonyl groups such as isopropylsulfonylamine, isobutylsulfonylamine, sec-butylsulfonylamine, tert-butylsulfonylamine, isopentylsulfonylamine, tert-pentylsulfonylamine, isohexylsulfonylamine, tert-hexylsulfonylamine, isoheptylsulfonylamine, tert-heptylsulfonylamine, isooctylsulfonylamine, tert-octylsulfonylamine, 2-ethylhexylsulfonylamine, isononylsulfonylamine, and isodecylsulfonylamine 10 Alkylsulfonylamine; or

[0110] Cyclic mono C3-C7 alkylsulfonylamine groups such as cyclopropylsulfonylamine, cyclobutylsulfonylamine, cyclopentylsulfonylamine, cyclohexylsulfonylamine, and cycloheptylsulfonylamine. Among these, linear or branched monoalkylsulfonylamine groups are more preferred, and linear monoalkylsulfonylamine groups are more preferred.

[0111] Dialkylaminosulfonyl, preferably di-C1-C 10 Specific examples of alkylsulfonyl groups include:

[0112] dimethylsulfonylamine, diethylsulfonylamine, di-n-propylsulfonylamine, di-n-butylsulfonylamine, di-n-pentylsulfonylamine, di-n-hexylsulfonylamine, di-n-heptylsulfonylamine, di-n-octylsulfonylamine, di-n-nonylsulfonylamine, di-n-decylsulfonylamine 10 Alkylsulfonylamine;

[0113] A branched di-C3-C4-sulfonyl group having two branches, such as diisopropylsulfonylamine, diisobutylsulfonylamine, di-sec-butylsulfonylamine, di-tert-butylsulfonylamine, diisoamylsulfonylamine, di-tert-amylsulfonylamine, diisohexylsulfonylamine, di-tert-hexylsulfonylamine, diisoheptylsulfonylamine, di-tert-heptylsulfonylamine, diisooctylsulfonylamine, di-tert-octylsulfonylamine, di-(2-ethylhexyl)sulfonylamine, diisononylsulfonylamine, and diisodecylsulfonylamine 10 Alkylsulfonylamine; or

[0114] Cyclic di-C3-C7 alkyl sulfonylamine groups having two rings, such as dicyclopropylsulfonylamine, dicyclobutylsulfonylamine, dicyclopentylsulfonylamine, dicyclohexylsulfonylamine, and dicycloheptylsulfonylamine. Among these, linear or branched dialkylsulfonylamine groups are more preferred, and linear dialkylsulfonylamine groups are more preferred.

[0115] Examples of the arylamine sulfonyl group include a monoarylamine sulfonyl group and a diarylamine sulfonyl group.

[0116] Monoarylsulfonylamine, preferably monoC6-C 12 Specific examples of the arylsulfonylamine group include a phenylsulfonylamine group, a naphthylsulfonylamine group, a biphenylsulfonylamine group, and the like.

[0117] Diarylamine sulfonyl, preferably di-C6-C 12 Specific examples of the arylsulfonylamine group include a diphenylsulfonylamine group, a dinaphthylsulfonylamine group, and a di(biphenyl)sulfonylamine group.

[0118] Examples of the alkylsulfonyl group include linear, branched or cyclic alkylsulfonyl groups, and preferably C1-C 12 Alkylsulfonyl. As C1-C 12 Specific examples of the alkylsulfonyl group include:

[0119] methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, n-butylsulfonyl, n-pentylsulfonyl, n-hexylsulfonyl, n-heptylsulfonyl, n-octylsulfonyl, n-nonylsulfonyl, n-decylsulfonyl, n-undecylsulfonyl, n-dodecylsulfonyl, straight-chain C1-C2 12 Alkylsulfonyl;

[0120] branched C3-C4 sulfonyl groups such as isopropylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl, tert-butylsulfonyl, isopentylsulfonyl, tert-pentylsulfonyl, isohexylsulfonyl, tert-hexylsulfonyl, isoheptylsulfonyl, tert-heptylsulfonyl, isooctylsulfonyl, tert-octylsulfonyl, 2-ethylhexylsulfonyl, isononylsulfonyl, isodecylsulfonyl, isundecylsulfonyl, 31-undecylsulfonyl, isododecylsulfonyl, and 31-dodecylsulfonyl. 12 Alkylsulfonyl; or

[0121] Cyclic C3-C7 alkylsulfonyl groups such as cyclopropylsulfonyl, cyclobutylsulfonyl, cyclopentylsulfonyl, cyclohexylsulfonyl and cycloheptylsulfonyl. Among these, linear or branched alkylsulfonyl groups are more preferred, and linear alkylsulfonyl groups are more preferred.

[0122] The above arylsulfonyl group is preferably C6-C 12Specific examples of the arylsulfonyl group include a phenylsulfonyl group, a naphthylsulfonyl group, a biphenylsulfonyl group, and the like.

[0123] Examples of the alkylthio group include linear, branched or cyclic alkylthio groups, and preferably C1-C 10 Alkylthio. As C1-C 10 Specific examples of the alkylthio group include:

[0124] methylthio, ethylthio, n-propylthio, n-butylthio, n-pentylthio, n-hexylthio, n-heptylthio, n-octylthio, n-nonylthio, n-decylthio, straight-chain C1-C 10 Alkylthio;

[0125] branched C3-C4 thiols such as isopropylthio, isobutylthio, sec-butylthio, tert-butylthio, isopentylthio, tert-pentylthio, isohexylthio, tert-hexylthio, isoheptylthio, tert-heptylthio, isooctylthio, tert-octylthio, 2-ethylhexylthio, isononylthio, isodecylthio and the like 10 alkylthio; or

[0126] Cyclic C3-C7 alkylthio groups such as cyclopropylthio, cyclobutylthio, cyclopentylthio, cyclohexylthio, and cycloheptylthio. Among these, linear or branched alkylthio groups are more preferred, and linear alkylthio groups are more preferred.

[0127] The above arylthio group is preferably C6-C 12 Specific examples of the arylthio group include a phenylthio group, a naphthylthio group, a biphenylthio group, and the like.

[0128] Examples of the alkyl urea group include linear, branched or cyclic monoalkyl urea groups or dialkyl urea groups.

[0129] As the monoalkylurea group, a mono-C1-C 10 Specific examples of the alkylurea group include:

[0130] methylurea, ethylurea, n-propylurea, n-butylurea, n-pentylurea, n-hexylurea, n-heptylurea, n-octylurea, n-nonylurea, n-decylurea, straight-chain mono-C1-C 10 Alkylurea group;

[0131] Branched mono-C3-C urea groups such as isopropyl urea, isobutyl urea, sec-butyl urea, tert-butyl urea, isopentyl urea, tert-pentyl urea, isohexyl urea, tert-hexyl urea, isoheptyl urea, tert-heptyl urea, isooctyl urea, tert-octyl urea, 2-ethylhexyl urea, isononyl urea, isodecyl urea, etc. 10 Alkylurea; or

[0132] Cyclic mono C3-C7 alkylurea groups such as cyclopropylurea, cyclobutylurea, cyclopentylurea, cyclohexylurea, and cycloheptylurea. Among these, linear or branched alkylurea groups are exemplified, and linear alkylurea groups are more preferred.

[0133] Dialkylurea, preferably di-C1-C 10 Specific examples of the alkylurea group include:

[0134] A straight-chain di-C1-C2-dinitro-urea group, such as a dimethylurea group, a diethylurea group, a di-n-propylurea group, a di-n-butylurea group, a di-n-pentylurea group, a di-n-hexylurea group, a di-n-heptylurea group, a di-n-octylurea group, a di-n-nonylurea group, or a di-n-decylurea group. 10 Alkylurea group;

[0135] A branched di-C3-C4-urea group having two branches, such as a diisopropylurea group, a diisobutylurea group, a di-sec-butylurea group, a di-tert-butylurea group, a diisopentylurea group, a di-tert-pentylurea group, a diisohexylurea group, a di-tert-hexylurea group, a diisoheptylurea group, a di-tert-heptylurea group, a diisooctylurea group, a di-tert-octylurea group, a di-(2-ethylhexyl)urea group, a diisononylurea group, a diisodecylurea group, etc. 10 Alkylurea; or

[0136] Cyclic di-C3-C7 alkylurea groups having two rings, such as dicyclopropylurea groups, dicyclobutylurea groups, dicyclopentylurea groups, dicyclohexylurea groups, and dicycloheptylurea groups. Among these, linear or branched dialkylurea groups are more preferred, and linear dialkylurea groups are more preferred.

[0137] Examples of the aryl urea group include a monoaryl urea group and a diaryl urea group.

[0138] As the monoaryl urea group, a mono C6-C 12 Specific examples of the aryl ureido group include a phenyl ureido group, a naphthyl ureido group, and a biphenyl ureido group.

[0139] Diaryl urea group, preferably di-C6-C 12 Specific examples of the aryl ureido group include a diphenyl ureido group, a dinaphthyl ureido group, and a di(biphenyl)ureido group.

[0140] Examples of the alkoxycarbonylamino group include linear, branched or cyclic alkoxycarbonylamino groups, and preferably C1-C 10 Alkoxycarbonylamino. As C1-C 10 Specific examples of the alkoxycarbonylamino group include:

[0141] methoxycarbonylamino, ethoxycarbonylamino, n-propoxycarbonylamino, n-butoxycarbonylamino, n-pentyloxycarbonylamino, n-hexyloxycarbonylamino, n-heptyloxycarbonylamino, n-octyloxycarbonylamino, n-nonyloxycarbonylamino, n-decyloxycarbonylamino, etc. 10 Alkoxycarbonylamino group;

[0142] branched C3-C4 amino groups such as isopropoxycarbonylamino, isobutoxycarbonylamino, sec-butoxycarbonylamino, tert-butoxycarbonylamino, isopentyloxycarbonylamino, tert-pentyloxycarbonylamino, isohexyloxycarbonylamino, tert-hexyloxycarbonylamino, isoheptyloxycarbonylamino, tert-heptyloxycarbonylamino, isooctyloxycarbonylamino, tert-octyloxycarbonylamino, 2-ethylhexyloxycarbonylamino, isononyloxycarbonylamino, and isodecyloxycarbonylamino 10 an alkoxycarbonylamino group; or

[0143] Cyclic C3-C7 alkoxycarbonylamino groups such as cyclopropyloxycarbonylamino, cyclobutyloxycarbonylamino, cyclopentyloxycarbonylamino, cyclohexyloxycarbonylamino, and cycloheptyloxycarbonylamino. Among these, linear or branched alkoxycarbonylamino groups are more preferred, and linear alkoxycarbonylamino groups are more preferred.

[0144] The aryloxycarbonylamino group is preferably a C6-C 12 Specific examples of the aryloxycarbonylamino group include a phenylcarbonylamino group, a naphthylcarbonylamino group, and a biphenylcarbonylamino group.

[0145] Examples of the alkylamino group include linear, branched or cyclic monoalkylamino groups or dialkylamino groups.

[0146] Monoalkylamino, preferably mono-C1-C 10 Specific examples of alkylamino groups include:

[0147] Straight-chain mono C1-C1 amino groups such as methylamino, ethylamino, n-propylamino, n-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, n-octylamino, n-nonylamino, and n-decylamino 10 Alkylamine;

[0148] Branched mono-C3-C4 amino groups such as isopropylamino, isobutylamino, sec-butylamino, tert-butylamino, isopentylamino, tert-pentylamino, isohexylamino, tert-hexylamino, isoheptylamino, tert-heptylamino, isooctylamino, tert-octylamino, 2-ethylhexylamino, isononylamino, isodecylamino, etc. 10 Alkylamino; or

[0149] Cyclic mono C3-C7 alkylamino groups such as cyclopropylamino, cyclobutylamino, cyclopentylamino, cyclohexylamino, and cycloheptylamino. Among these, linear or branched monoalkylamino groups are more preferred, and linear monoalkylamino groups are more preferred.

[0150] The dialkylamino group is preferably a C1-C 10 As a specific example, alkylamino groups are

[0151] dimethylamino, diethylamino, di-n-propylamino, di-n-butylamino, di-n-pentylamino, di-n-hexylamino, di-n-heptylamino, di-n-octylamino, di-n-nonylamino, di-n-decylamino, di-C1-C2-6-amino 10 Alkylamine;

[0152] Branched di-C3-C4 amino groups having two branches, such as diisopropylamino, diisobutylamino, di-sec-butylamino, di-tert-butylamino, diisopentylamino, di-tert-pentylamino, diisohexylamino, di-tert-hexylamino, diisoheptylamino, di-tert-heptylamino, diisooctylamino, di-tert-octylamino, di-(2-ethylhexyl)amino, diisononylamino, and diisodecylamino 10 Alkylamino; or

[0153] Cyclic di-C3-C7 alkylamino groups having two rings such as dicyclopropylamino, dicyclobutylamino, dicyclopentylamino, dicyclohexylamino, dicycloheptylamino, etc. Among these, linear or branched dialkylamino groups are more preferred, and linear dialkylamino groups are more preferred.

[0154] Examples of the arylamine group include a monoarylamine group and a diarylamine group.

[0155] As the monoarylamine group, a mono C6-C 12 Specific examples of the arylamino group include a phenylamino group (anilino group), a naphthylamino group, a biphenylamino group, and the like.

[0156] Diarylamine, preferably di-C6-C 12 Specific examples of the arylamino group include a diphenylamino group, a dinaphthylamino group, and a di(biphenyl)amino group.

[0157] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom, a chlorine atom or a bromine atom is more preferred.

[0158] Preferred examples of A include a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group, a C1-C4 alkoxy group having a sulfonic acid group, a nitro group, and a sulfonic acid group.

[0159] In the above formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent. When Ar is a heterocyclic ring, for example, a 5- or 6-membered heterocyclic ring containing 1 to 3 heteroatoms selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms is listed. Specific examples of such a heterocyclic ring include, for example:

[0160] Alicyclic heterocyclic 5-membered rings such as pyrrolidine, tetrahydrofuran, and tetrahydrothiophene;

[0161] Piperidine, piperazine, di Alicyclic hetero 6-membered rings such as alkanes, oxazine, and thiooxazine;

[0162] Pyrrole, pyrazole, imidazole, triazole, furan, thiophene, Aromatic heterocyclic 5-membered rings such as azole and thiazole;

[0163] Aromatic heterocyclic 6-membered rings such as pyridine, pyrazine, pyridazine, triazine, etc.

[0164] The heterocyclic ring part of dihydroisobenzofuran (phthalane), indoline, isoindoline, etc. is a 5-membered alicyclic condensed aliphatic heterocyclic ring;

[0165] Benzopyrrole, benzopyrazole, benzimidazole, benzotriazole, benzofuran, benzothiophene, benzo The heterocyclic ring part of oxazole, benzothiazole, naphthiazole, etc. is a condensed aromatic heterocyclic ring of an aromatic 5-membered ring; or

[0166] Quinoline, Cinnoline, cinnoline, quinazoline, quinolone The heterocyclic ring part of phenoxyl group or the like is a condensed aromatic heterocyclic ring of an aromatic 6-membered ring.

[0167] In the above heterocyclic group, the heterocyclic moiety is preferably an aromatic ring. In addition, as the hetero atom constituting the heterocyclic ring, it is more preferably selected from a nitrogen atom and a sulfur atom.

[0168] When the azo compound represented by formula (1) is represented by the following formula (2), it is more preferable because a polarizing film having higher transmittance and higher polarization degree can be provided.

[0169]

[0170] In formula (2), R 1 To R 8 Each independently represents an arbitrary substituent, m represents 0 or 1, and n represents 0 or 1.

[0171] In formula (2), the ring structure drawn by the solid line and the dotted line represents a phenyl (phenylene) group or a naphthyl (naphthylene) group.

[0172] In the above formula (2), R 1 To R 8 Each independently represents an arbitrary substituent. Examples of the arbitrary substituent include the same substituents as the substituents that may be present in formula (1), but the substituents are selected independently of the substituents that may be present in formula (1). In addition, m represents 0 or 1, and n represents 0 or 1, and n is preferably 0. More preferably, R 1 To R 8 , each independently represents a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, a carboxyl group, a sulfonic acid group, a C1-C4 alkoxy group having a sulfonic acid group, an amino group, an acetylamino group, or a benzoylamino group which may have a substituent.

[0173] The azo compound represented by formula (2) is more preferably represented by the following formula (3).

[0174]

[0175] In the above formula (3), R 1 To R 6 Each independently represents an arbitrary substituent, and m represents 0 or 1.

[0176] In the above formula (3), R 1 To R 6 Each of them has the same meaning as in formula (2). In addition, m represents 0 or 1. More preferably, m is 0, R 1 To R 6 (R 1 To R 4 ) are each independently a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group, a halogen atom, a carboxyl group, a sulfonic acid group, a C1-C4 alkoxy group having a sulfonic acid group, an amino group, an acetylamino group, or a benzoylamino group which may have a substituent.

[0177] In formula (2) and formula (3), examples of the "C1-C4 alkyl group" include straight-chain alkyl groups such as methyl, ethyl, n-propyl, and n-butyl, branched-chain alkyl groups such as sec-butyl and tert-butyl, and unsaturated hydrocarbon groups such as vinyl.

[0178] In formula (2) and formula (3), examples of the "C1-C4 alkoxy group" include methoxy, ethoxy, propoxy, n-butoxy, sec-butoxy, tert-butoxy and the like.

[0179] In formula (2) and formula (3), the "C1-C4 alkoxy group having a sulfonic acid group" is preferably a straight chain alkoxy group, and the substitution position of the sulfonic acid group is preferably the terminal of the alkoxy group. More preferred are 3-sulfonic acid propoxy and 4-sulfonic acid butoxy, and particularly preferred is 3-sulfonic acid propoxy.

[0180] In formula (2) and formula (3), the substituent of the "benzoylamino group which may have a substituent" is not particularly limited, but is preferably a water-soluble group, and more preferably a carboxyl group or a sulfonic acid group.

[0181] The azo compound or its salt represented by the above formula (1) can be easily produced by performing the well-known diazotization and coupling according to the conventional azo dye production method described in Non-Patent Document 1. The synthesis method is described by taking the azo compound represented by formula (2) with m=1 and n=0 as an example.

[0182] First, an aromatic amine represented by the following formula (A) is diazotized by a known method described in Non-Patent Document 1 and coupled once with an aromatic amine represented by the following formula (B) to obtain a monoazoamine compound represented by the following formula (C).

[0183]

[0184] (In formula (A) to formula (C), R 1 To R 4 Each has the same meaning as in formula (1).

[0185] Next, the monoazoamine compound (C) is diazotized by a known method described in Non-Patent Document 1 and secondarily coupled with an aromatic amine of the following formula (D) to obtain a disazoamine compound represented by the following formula (E).

[0186]

[0187] (In formula (D) and formula (E), R 1 To R 6 Each has the same meaning as in formula (1).

[0188] Next, the compound of formula (E) is diazotized by a known method described in Non-Patent Document 1 and coupled with an isoindole-substituted 1-naphthol-3-sulfonic acid derivative represented by the following formula (F) to obtain an azo compound of formula (2).

[0189]

[0190] In the above reaction, the diazotization step can be carried out by a standard method of mixing an aqueous solution or suspension of a mineral acid such as hydrochloric acid or sulfuric acid of the diazo component with a nitrite such as sodium nitrite, or by a reverse method of first adding the nitrite to a neutral or weakly alkaline aqueous solution of the diazo component and then mixing it with the mineral acid. The suitable temperature for diazotization is -10 to 40°C. In addition, the coupling step with aromatic amines is carried out by mixing an acidic aqueous solution such as hydrochloric acid or acetic acid with the above diazo solutions under acidic conditions of a temperature of -10 to 40°C and a pH of 2 to 7.

[0191] The monoazo compound or disazo compound obtained by coupling can be used directly, or can be filtered out after being precipitated by acid precipitation or salt precipitation, or can be directly used in the subsequent steps in the form of a solution or suspension. The monoazo compound or disazo compound obtained by coupling is poorly soluble. In the case of forming a suspension, it can be filtered and used as a filter cake in the subsequent coupling step.

[0192] The coupling reaction of the diazo compound of the disazo compound and the naphthols represented by formula (F) is carried out under neutral to alkaline conditions of a temperature of -10 to 40°C and a pH of 7 to 10. After the reaction is completed, the product is precipitated by salting out and filtered out. In addition, if purification is required, the product may be repeatedly salted out or precipitated from water using an organic solvent. Examples of the organic solvent used in purification include water-soluble organic solvents such as alcohols such as methanol and ethanol, and ketones such as acetone.

[0193] When the aromatic amine represented by the formula (A) as a starting material for synthesizing the azo compound represented by the formula (2) or a salt thereof is a substituted naphthylamine compound, examples thereof include 2-aminonaphthalene-6-sulfonic acid, 2-aminonaphthalene-6,8-disulfonic acid, 2-aminonaphthalene-5,7-disulfonic acid, 2-aminonaphthalene-4,8-disulfonic acid, 2-aminonaphthalene-4,6,8-trisulfonic acid, 2-aminonaphthalene-3,6,8-trisulfonic acid, 2-amino-1-hydroxy-naphthalene-6-sulfonic acid, 3-amino-1-hydroxy-naphthalene-6-sulfonic acid, 2-amino-8-hydroxy-naphthalene-6-sulfonic acid, 3-amino-8-hydroxy-naphthalene-6-sulfonic acid, 2-amino-1,8-dihydroxy-naphthalene-6-sulfonic acid, 3-amino-1,8-dihydroxy-naphthalene-6-sulfonic acid, 2-amino-1,8-dihydroxy-naphthalene-3-sulfonic acid, -amino-1,8-dihydroxy-naphthalene-3,6-disulfonic acid, 2-amino-1-methoxy-8-hydroxy-naphthalene-6-sulfonic acid, 3-amino-1-methoxy-8-hydroxy-naphthalene-6-sulfonic acid, 2-amino-1-hydroxy-8-methoxy-naphthalene-6-sulfonic acid, 3-amino-1-hydroxy-8-methoxy-naphthalene-6-sulfonic acid, 2-amino-1-hydroxy-8-(3-sulfonic acid propoxy) -naphthalene-3-sulfonic acid, 2-amino-1-hydroxy-8-(4-sulfonic acid butoxy)-naphthalene-3-sulfonic acid, 2-amino-1-(3-sulfonic acid propoxy)-8-hydroxy-naphthalene-3-sulfonic acid, 2-amino-1-(4-sulfonic acid butoxy)-8-hydroxy-naphthalene-3-sulfonic acid, 2-amino-1,8-dihydroxy-naphthalene-6-aminomethyl-3-disulfonic acid, etc., but not limited to these. More preferred are 2-aminonaphthalene-6,8-disulfonic acid, 2-aminonaphthalene-5,7-disulfonic acid, 2-aminonaphthalene-4,8-disulfonic acid, and 2-aminonaphthalene-3,6,8-trisulfonic acid.

[0194] When the aromatic amine represented by formula (A) as a starting material for synthesizing the azo compound represented by formula (2) or its salt is a substituted phenylamine compound, for example, 4-sulfonic acid aniline, 3-sulfonic acid aniline, 2-sulfonic acid aniline, 2,4-disulfonic acid aniline, 2,5-disulfonic acid aniline, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 5-aminoisophthalic acid, 2-aminoterephthalic acid, 4-amino The aniline of the present invention is preferably phthalic acid, 4-nitro-2-sulfonic acid aniline, 2-nitro-4-sulfonic acid aniline, 4-methoxy-2-sulfonic acid aniline, 2-methoxy-4-sulfonic acid aniline, 4-chloro-3-sulfonic acid aniline, 4-chloro-3-carboxylic acid aniline, 4-(3-sulfonic acid propoxy) aniline, 4-(4-aminobenzamide) benzene-1,3-disulfonic acid, 5-(4-aminobenzamide) benzene-1,3-dicarboxylic acid, but is not limited thereto. More preferably, 4-sulfonic acid aniline, 4-aminobenzoic acid, 2,4-disulfonic acid aniline, 4-(4-aminobenzamide) benzene-1,3-disulfonic acid, 5-(4-aminobenzamide) benzene-1,3-dicarboxylic acid are used.

[0195] When the aromatic amines represented by formula (B) and formula (D) as starting materials for synthesizing the azo compound represented by formula (2) or its salt are substituted phenylamine compounds, examples thereof include aniline, 2-methylaniline, 2-ethylaniline, 2-propylaniline, 2-butylaniline, 3-methylaniline, 3-ethylaniline, 3-propylaniline, 3-butylaniline, 2,5-dimethylaniline, 2,5-diethylaniline, 2-methoxyaniline, 2-ethoxyaniline, 2-propoxyaniline, 2-butoxyaniline, 3-methoxyaniline, 3-ethoxyaniline, 3-propoxyaniline, 3-butoxyaniline, 2-methylaniline, 2-ethylaniline, 2-propylaniline, 2-butyl ... Oxy-5-methylaniline, 2,5-dimethoxyaniline, 3,5-dimethylaniline, 2,6-dimethylaniline, 3,5-dimethoxyaniline, 2-chloroaniline, 3-chloroaniline, 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid, 3-(2-aminophenoxy)propane-1-sulfonic acid, 4-(2-amino-4-methylphenoxy)butane-1-sulfonic acid, 4-(2-aminophenoxy)butane-1-sulfonic acid, 2-(2-aminophenoxy)ethane-1-sulfonic acid, 2-(2-aminophenoxy)ethane-1-sulfonic acid, 3-(3-amino-4-methylphenoxy)propane -1-sulfonic acid, 3-(3-aminophenoxy)propane-1-sulfonic acid, 4-(3-amino-4-methylphenoxy)butane-1-sulfonic acid, 4-(3-aminophenoxy)butane-1-sulfonic acid, 2-(3-amino-4-methylphenoxy)ethane-1-sulfonic acid, 2-(3-aminophenoxy)ethane-1-sulfonic acid, 3-(2-amino-4-methoxyphenoxy)propane-1-sulfonic acid, 4-(2-amino-4-methoxyphenoxy)butane-1-sulfonic acid, 2-(2-amino-4-methoxyphenoxy)ethane-1-sulfonic acid, 3-(3-amino-4-methoxyphenoxy)propane-1-sulfonic acid , 4-(3-amino-4-methoxyphenoxy) butane-1-sulfonic acid, 2-(3-amino-4-methoxyphenoxy) ethane-1-sulfonic acid, 3-(2-amino-4-ethoxyphenoxy) propane-1-sulfonic acid, 4-(2-amino-4-ethoxyphenoxy) butane-1-sulfonic acid, 2-(2-amino-4-ethoxyphenoxy) ethane-1-sulfonic acid, 3-(3-amino-4-ethoxyphenoxy) propane-1-sulfonic acid, 4-(3-amino-4-ethoxyphenoxy) butane-1-sulfonic acid, 2-(3-amino-4-ethoxyphenoxy) ethane-1-sulfonic acid, but are not limited to these. In addition, the amine groups of these aromatic amines may be protected. As a protecting group, for example, ω-methanesulfonic acid group is listed.

[0196] When the aromatic amines represented by formula (B) and formula (D) as starting materials for synthesizing the azo compound represented by the aforementioned formula (2) or its salt are substituted naphthylamine compounds, examples thereof include: 1-amino-6-naphthalenesulfonic acid, 1-amino-7-naphthalenesulfonic acid, 1-amino-2-methoxy-6-naphthalenesulfonic acid, 1-amino-2-methoxy-7-naphthalenesulfonic acid, 1-amino-2-ethoxy-6-naphthalenesulfonic acid, 1-amino-2-ethoxy-7-naphthalenesulfonic acid, 1-amino-5-hydroxy-7-naphthalenesulfonic acid, but are not limited to these.

[0197] Specific examples of the azo compound represented by the above formula (1) or a salt thereof are listed below. In addition, the azo compound is represented in the form of a free acid.

[0198] [Compound Example 1-1]

[0199]

[0200] [Compound Example 11-2]

[0201]

[0202] [Compound Examples 1-3]

[0203]

[0204] [Compound Examples 1-4]

[0205]

[0206] [Compound Example 1-5]

[0207]

[0208] [Compound Example 1-6]

[0209]

[0210] [Compound Example 1-7]

[0211]

[0212] [Compound Example 1-8]

[0213]

[0214] [Compound Example 1-9]

[0215]

[0216] [Compound Example 1-10]

[0217]

[0218] [Compound Example 1-11]

[0219]

[0220] [Compound Example 1-12]

[0221]

[0222] [Compound Example 1-13]

[0223]

[0224] [Compound Example 1-14]

[0225]

[0226] [Compound Example 1-15]

[0227]

[0228] [Compound Example 1-16]

[0229]

[0230] [Compound Example 1-117]

[0231]

[0232] [Compound Example 1-18]

[0233]

[0234] [Compound Example 1-19]

[0235]

[0236] [Compound Example 1-20]

[0237]

[0238] [Compound Example 1-21

[0239]

[0240] [Compound Example 1-22]

[0241]

[0242] [Compound Example 1-23]

[0243]

[0244] [Compound Example 1-24]

[0245]

[0246] [Compound Example 1-25]

[0247]

[0248] [Compound Example 1-26]

[0249]

[0250] [Compound Example 1-27]

[0251]

[0252] [Compound Example 1-28]

[0253]

[0254] [Compound Example 1-29]

[0255]

[0256] [Compound Example 1-30]

[0257]

[0258] [Compound Example 1-31]

[0259]

[0260] [Compound Example 1-32]

[0261]

[0262]

[0263] [Compound Example 1-34]

[0264]

[0265] [Compound Example 1-35]

[0266]

[0267] [Compound Example 1-36]

[0268]

[0269] [Compound Example 1-37]

[0270]

[0271] [Compound Example 1-38]

[0272]

[0273] [Compound Example 1-39]

[0274]

[0275] [Compound Example 1-40]

[0276]

[0277] [Compound Example 1-41]

[0278]

[0279] [Compound Example 1-42]

[0280]

[0281] Compound Example 1-43

[0282]

[0283] Compound Example 1-44

[0284]

[0285] Compound Example 1-45]

[0286]

[0287] Compound Example 1-46]

[0288]

[0289] [Compound Example 1-47]

[0290]

[0291] [Compound Example 1-48]

[0292]

[0293] [Compound Example 1-49]

[0294]

[0295] Compound Example 1-50]

[0296]

[0297] [Compound Example 1-51]

[0298]

[0299] [Compound Example 1-52]

[0300]

[0301] The azo compound represented by the above formula (1) may be in the form of a free acid or a salt, or may be a salt of a metal ion or an ammonium ion. Examples of metal ions include alkali metal ions such as lithium ions, sodium ions, and potassium ions, and alkaline earth metal ions such as calcium ions and magnesium ions. Examples of ammonium ions include ammonium ions, methylammonium ions, dimethylammonium ions, triethylammonium ions, tetraethylammonium ions, tetra-n-propylammonium ions, tetra-n-butylammonium ions, and triethanolammonium ions. More specifically, for example, in the case of a free acid, sulfonic acid (-SO3H) is represented, in the case of a sodium ion, sodium sulfonate (-SO3Na) is represented, and in the case of an ammonium ion, ammonium sulfonate (-SO3NH4) is represented.

[0302] <Polarizing film>

[0303] The polarizing film of the present invention contains the azo compound or its salt represented by the above formula (1) as a dichroic dye. The polarizing film has a neutral gray polarizing film and a color polarizing film, and is preferably a neutral gray polarizing film. Here, "neutral gray" means that when two polarizing films are overlapped in a manner in which their orientation directions are perpendicular to each other (hereinafter also referred to as "orthogonal position"), there is less light leakage (color leakage) at a specific wavelength in the wavelength range of the visible light region.

[0304] The polarizing film of the present invention comprises azo compounds or salts thereof represented by the above formula (1) alone or in combination of multiple types as dichroic dyes, and may further contain one or more other organic dyes other than the azo compounds represented by the above formula (1) as needed. The other organic dyes are not particularly limited, but dyes having high dichroism and having absorption characteristics in a wavelength region different from the absorption wavelength region of the azo compounds or salts represented by the above formula (1) are more preferred. As other organic dyes, for example, CIDirect Yellow 12, CIDirect Yellow 28, CIDirect Yellow 44, CIDirect Orange 26, CIDirect Orange 39, CIDirect Orange 71, CIDirect Orange 107, CIDirect Red 2, CIDirect Red 31, CIDirect Red 79, CIDirect Red 81, CIDirect Red 247, CIDirect Blue 69, CIDirect Green 80, and CIDirect Green 59, and dyes described in Non-Patent Document 2 are listed as representative examples, but it is more preferred to use the dyes developed for polarizing plates described in Patent Documents 1 to 4 according to the purpose. These organic dyes are used as free acids, alkali metal salts (such as Na salts, K salts, Li salts), ammonium salts, or amine salts.

[0305] When other organic dyes are used in combination, the types of organic dyes to be prepared are different depending on whether the target polarizing film is a neutral gray polarizing film, a color polarizing film for a liquid crystal projector, or other color polarizing films. The preparation ratio is not particularly limited, but generally, the total amount of at least one other organic dye is preferably used in the range of 0.01 to 100 parts by mass, and more preferably in the range of 0.1 to 10 parts by mass, relative to 1 part by mass of the azo compound or its salt of formula (1).

[0306] When the target polarizing film is a neutral gray polarizing film, the type and blending ratio of other organic dyes used in combination are adjusted so that the color leakage in the wavelength range of the visible light region of the obtained polarizing film is reduced.

[0307] When the target polarizing film is a color polarizing film, the types and blending ratios of other organic dyes used in combination are adjusted so that the obtained polarizing film has a high single-plate average transmittance in a specific wavelength domain and a lower average transmittance at the orthogonal position, for example, a single-plate average transmittance of more than 39% and an average transmittance at the orthogonal position of less than 0.4% in the specific wavelength domain.

[0308] The polarizing film of the present invention can be produced by doping a dichroic dye comprising the azo compound represented by formula (1) or a salt thereof and other dyes as required into a polarizing film substrate (hereinafter referred to as "substrate") and aligning the dye by a known method.

[0309] The polarizing film substrate is preferably a polymer film, and more preferably a film composed of a polyvinyl alcohol resin or a derivative thereof. As a specific example of the polarizing film substrate, polyvinyl alcohol resin is listed, or it is modified with olefins such as ethylene and propylene, or unsaturated carboxylic acids such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid. In terms of the adsorption and orientation of the dye, it is more preferred to use a film composed of a polyvinyl alcohol resin or a derivative thereof as the polarizing film substrate. The thickness of the polarizing film base material is usually 10 to 100 μm, and preferably about 20 to 80 μm.

[0310] In the case where the polarizing film substrate is a polymer film, in order to incorporate the azo compound or its salt of the above formula (1), a method of dyeing the polymer film is usually adopted. Dyeing is performed as follows. First, the azo compound or its salt represented by the above formula (1), and other organic dyes as needed are dissolved in water to prepare a dye bath. The dye concentration in the dye bath is not particularly limited, but is usually selected from the range of about 0.001 to 10% by mass. In addition, a dyeing auxiliary can be used as needed, for example, it is more preferred to use sodium sulfate at a concentration of about 0.1 to 10% by mass. The polymer film can be immersed in the dye bath prepared in this way, for example, for 1 to 10 minutes to be dyed. The dyeing temperature is preferably about 30 to 80°C.

[0311] The alignment of the azo compound or its salt represented by the above formula (1) is carried out by stretching the polymer film dyed with a dichroic dye. The stretching ratio is generally applicable to 2 to 9 times, preferably 3 to 8 times, and more preferably 4 to 7 times. As a stretching method, any well-known method such as a wet method and a dry method can be used. The stretching of the polymer film can also be carried out before dyeing according to the situation. In this case, the water-soluble dye is aligned during dyeing. The aligned polymer film containing the water-soluble dye is post-treated with boric acid treatment using a well-known method as needed. The purpose of such post-treatment is to improve the light transmittance and polarization degree of the polarizing film. The conditions of the boric acid treatment vary depending on the type of polymer film used and the type of dye used, but in general, the boric acid concentration of the boric acid aqueous solution is, for example, 0.1 to 15% by mass, preferably in the range of 1 to 10% by mass, the treatment temperature is 30 to 80°C, preferably 40 to 75°C, and the immersion is 0.5 to 10 minutes. Furthermore, if necessary, the fixing treatment may be performed together in an aqueous solution containing a cationic polymer compound.

[0312] As the use of the polarizing film of the present invention, for example, liquid crystal projectors, calculators, watches, laptop computers, word processors, liquid crystal televisions, car navigation systems, indoor and outdoor measuring instruments and displays, and lenses and glasses are listed. The polarizing film made using the dye of the present invention (hereinafter also referred to as "dye-based polarizing film") has high polarization performance comparable to that of the polarizing film made using iodine (hereinafter also referred to as "iodine-based polarizing film"), and the durability is also excellent. Therefore, it is particularly suitable for use in applications requiring high polarization performance and durability, such as various liquid crystal displays for vehicle-mounted use and outdoor display (such as display applications and wearable applications of industrial instruments), and liquid crystal projectors.

[0313] <Polarizing plate>

[0314] The polarizing plate of the present invention (hereinafter also referred to as "dye-based polarizing plate") can be obtained by laminating a transparent protective film on one or both sides of the polarizing film of the present invention. The polarizing plate of the present invention has excellent polarization performance and durability (moisture resistance, heat resistance, light resistance). As a material for forming the transparent protective film, it is more preferred to use a material with excellent optical transparency and mechanical strength, for example: cellulose acetate film, acrylic film, tetrafluoroethylene / hexafluoropropylene copolymer and other fluorine-based films, films composed of polyester resins, polyolefin resins or polyamide resins, etc. The transparent protective film is more preferably a triacetyl cellulose (TAC) film or a cycloolefin film. The thickness of the protective film is usually more preferably 40 to 200 μm.

[0315] An adhesive may be used to bond the polarizing film of the present invention to the protective film. Examples of the adhesive include polyvinyl alcohol adhesives, urethane emulsion adhesives, acrylic adhesives, and polyester isocyanate adhesives, and polyvinyl alcohol adhesives are more preferred.

[0316] A transparent protective layer may be further provided on the surface of the polarizing plate of the present invention. As the transparent protective layer, for example, an acrylic or polysiloxane hard coating or an urethane protective layer is cited. In addition, in order to further improve the light transmittance of the single plate, it is preferred to provide an anti-reflection layer (AR layer) on top of this transparent protective layer. The AR layer can be formed by, for example, evaporating or sputtering materials such as silicon dioxide and titanium oxide, or by coating a thin fluorine-based material. The dye-based polarizing plate is preferably further provided with a support. The dye-based polarizing plate can also be used as an elliptically polarizing plate by attaching a phase difference plate to the surface.

[0317] The polarizing plate of the present invention may be either a neutral gray polarizing plate or a color polarizing plate depending on the application.

[0318] The neutral gray polarizing plate of the present invention has a neutral color, less color leakage in the orthogonal position in the polarization area of ​​the visible light region, excellent polarization performance, and high durability by suppressing discoloration and reduction of polarization performance even under high temperature and high humidity conditions. Therefore, it is suitable for use in vehicles or outdoor displays.

[0319] The neutral gray polarizing plate for vehicle use or outdoor display is preferably a polarizing plate with an AR layer provided on the polarizing plate composed of the polarizing film of the present invention and a transparent protective film to further improve the single body transmittance, and more preferably a polarizing plate with an AR layer and a support body attached to both the AR layer and a support body such as a transparent resin. The AR layer can be provided on one side or both sides of the polarizing plate. The support body is preferably provided on one side of the polarizing plate, and can be directly provided on the polarizing plate, or the polarizing plate with an AR layer (AR layer / polarizing plate / AR layer) can be provided on the support body. The AR layer and the polarizing plate with a support body preferably have AR layer / polarizing plate / AR layer / support body in sequence. The support body preferably has a planar portion for attaching the polarizing plate, and is preferably a transparent substrate because it is used for optical purposes. As a transparent substrate, it is roughly divided into an inorganic substrate and an organic substrate, and examples thereof include inorganic substrates such as soda glass, borosilicate glass, crystal substrate, sapphire substrate, and spinel substrate, and organic substrates such as acrylate, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, and cycloolefin polymer, but organic substrates are more preferred. The thickness and size of the transparent substrate can be a desired size.

[0320] Color polarizing plates have excellent polarizing properties and do not cause discoloration or decrease in polarizing properties even under high temperature and high humidity conditions. Therefore, they are suitable for use in display devices such as liquid crystal projectors, vehicles, and outdoor displays.

[0321] The color polarizing plate for liquid crystal projector has brightness and excellent polarization performance. In the required wavelength range of the polarizing plate (A. When using an ultra-high pressure mercury lamp; 420 to 500nm for the blue channel, 500 to 580nm for the green channel, and 600 to 680nm for the red channel, B.3 The peak wavelength when using a primary color LED lamp; 430 to 450nm for the blue channel, 520 to 535nm for the green channel, and 620 to 635nm for the red channel), the average light transmittance of the single plate is 39% or more, and the average light transmittance of the orthogonal position is 0.4% or less. It is more preferred that in the required wavelength range of the polarizing plate, the average light transmittance of the single plate is 41% or more, and the average light transmittance of the orthogonal position is 0.3% or less, and more preferably 0.2% or less. It is even more preferred that in the required wavelength range of the polarizing plate, the average light transmittance of the single plate is 42% or more, and the average light transmittance of the orthogonal position is 0.1% or less.

[0322] In addition, the single plate average transmittance is the average value of the light transmittance in a specific wavelength region when natural light is incident on a single polarizing plate (hereinafter also referred to as a "polarizing plate") that is not provided with a support such as an AR layer and a transparent glass plate. The average transmittance in the orthogonal position is the average value of the light transmittance in a specific wavelength region when natural light is incident on two overlapping polarizing plates so that their isoalignment directions are orthogonal to each other.

[0323] The polarizing film of the color polarizing plate used for vehicle-mounted or outdoor display is the same as the neutral gray polarizing plate, and a protective layer or AR layer and a support body can be set on the dye-based polarizing plate as needed. The color polarizing plate with a support body can be obtained by, for example, coating a transparent adhesive (adhesive) agent on the flat portion of the support body, and then attaching the dye-based polarizing plate to this coated surface. Alternatively, a transparent adhesive (adhesive) agent can be applied to the dye-based polarizing plate, and then the support body is attached to this coated surface. The adhesive (adhesive) agent is preferably, for example, an acrylate system. In addition, when this dye-based polarizing plate is used as an elliptically polarizing plate, the phase difference plate side is usually attached to the support body to form a stacking order of a dye-based polarizing plate / phase difference plate / support body, but the polarizing plate side can also be attached to the support body to form a stacking order of a phase difference plate / polarizing plate / support body.

[0324] <Display device>

[0325] The display device of the present invention is provided with the polarizing film or polarizing plate of the present invention. As the display device, a liquid crystal display device or an organic electronic product display device is listed, such as a calculator, a watch, a notebook computer, a word processor, a liquid crystal television, a car navigation system, and a display such as an indoor and outdoor measuring instrument and a display, and is particularly suitable for use in various display bodies requiring high polarization performance and durability, such as vehicle-mounted or outdoor display (such as industrial instrument display use and wearable use). The dye-based polarizing film or dye-based polarizing plate provided in the display device is preferably neutral gray.

[0326] In the liquid crystal display device, the dye-based polarizing plate is arranged on either or both sides of the incident side or the exit side of the liquid crystal cell. The dye-based polarizing plate may be in contact with the liquid crystal cell or not, but from the viewpoint of durability, it is more preferred not to be in contact. In the case where the dye-based polarizing plate is in contact with the liquid crystal cell on the exit side of the liquid crystal cell, the liquid crystal cell can be used as a support for the dye-based polarizing plate. In the case where the dye-based polarizing plate is not in contact with the liquid crystal cell, it is more preferred to use a dye-based polarizing plate provided with a support other than the liquid crystal cell. In addition, from the viewpoint of durability, it is more preferred that the dye-based polarizing plate is arranged on both sides of the incident side and the exit side of the liquid crystal cell, and it is more preferred that the polarizing plate surface of the dye-based polarizing plate is arranged on the liquid crystal cell side, and the support surface is arranged on the light source side. In addition, the incident side of the liquid crystal cell means the light source side, and the opposite side means the exit side.

[0327] The liquid crystal cell of the liquid crystal display device is, for example, an active matrix type, preferably formed by sealing liquid crystal between a transparent substrate formed with electrodes and TFTs and a transparent substrate formed with a counter electrode. Light irradiated from a light source such as a cold cathode tube lamp or a white LED passes through a dye-based polarizing plate, and then passes through the liquid crystal cell, a color filter, and a dye-based polarizing plate, and is projected onto a display screen.

[0328] Since dye-based polarizing plates have brightness and excellent polarizing performance as well as polarization and light resistance, liquid crystal display devices are less likely to discolor or degrade in polarization performance even under high temperature and high humidity conditions such as in a car or outdoors, and have high reliability.

[0329] [Example]

[0330] The present invention is described in more detail below by way of examples, but these are merely examples and the present invention is not limited thereto. % and parts in the examples are based on mass unless otherwise specified.

[0331] [Example 1]

[0332] (Step 1)

[0333] 71.7 parts of commercially available 6-amino-1-naphthol-3-sulfonic acid and 52.5 parts of α,α'-dichloro-o-xylene were added to a mixed solution of 900 parts of water and 150 parts of N-methyl-2-pyrrolidone, and the mixture was reacted at 50° C. for 8 hours while maintaining the pH at 3.0 to 7.5 using a 25% aqueous sodium hydroxide solution. 180 parts of sodium chloride was added to the obtained reaction solution, and the precipitated solid was filtered out and dried to obtain 34.1 parts of 6-(isoindolin-2-yl)-1-naphthol-3-sulfonic acid represented by the following formula (10).

[0334]

[0335] (Step 2)

[0336] 27.7 parts of commercially available 4-(4-aminophenylazo)benzenesulfonic acid are added to 300 parts of water and stirred to suspend, and the pH is adjusted to 9.0 using 25% sodium hydroxide, and 17.3 parts of a 40% sodium nitrite aqueous solution are added thereto. The obtained solution is dripped into a mixed solution of 100 parts of water and 42 parts of 35% hydrochloric acid to prepare a diazo liquid. Next, 34.1 parts of 6-(isoindolin-2-yl)-1-naphthol-3-sulfonic acid represented by formula (10) obtained in step 1 are added to 300 parts of water, adjusted to a weak alkalinity with a 25% sodium hydroxide aqueous solution and dissolved. The previously obtained diazo liquid is dripped into the liquid while maintaining the pH at 6.5 to 9.0, and stirred to complete the coupling reaction. Thereafter, it is salted out with sodium chloride, filtered and dried, thereby obtaining 25.0 parts of an azo compound represented by formula (11) (Compound Example 1-1).

[0337]

[0338] [Example 2]

[0339] 26.0 parts of the azo compound (Compound Example 1-38) represented by formula (12) was obtained in the same manner as in Example 1, except that 41.8 parts of 5-{4-[(4-amino-2-methylphenyl)diazenyl]benzoylamino}benzene-1,3-dicarboxylic acid, which is an azo compound synthesized according to Example (n2) of Reference International Publication No. 2021 / 015188, was used to replace 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0340]

[0341] [Example 3]

[0342] 32.5 parts of an azo compound represented by formula (13) (Compound Example 1-47) was obtained in the same manner as in Example 1, except that 65.0 parts of 5-({4-[(4-amino-6-sulfonanaphthalene-1-yl)diazenyl]-6-sulfonanaphthalene-1-yl}diazenyl)benzene-1,3-dicarboxylic acid, which is an azo compound synthesized in Example 6 of Reference WO 2017 / 146212, was used to replace 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0343]

[0344] [Example 4]

[0345] 31.0 parts of the azo compound (Compound Example 1-49) represented by formula (14) was obtained in the same manner as in Example 1, except that 60.6 parts of 4-({4-[(4-amino-6-sulfonanaphthalene-1-yl)diazenyl]-6-sulfonanaphthalene-1-yl}diazenyl)benzoic acid, which is an azo compound synthesized in Example 1 of Reference International Publication No. 2021 / 015188, was used to replace 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0346]

[0347] [Example 5]

[0348] 27.0 parts of an azo compound represented by formula (15) (Compound Example 1-24) was obtained in the same manner as in Example 1, except that 37.5 parts of 7-(4-amino-3-methoxyphenylazo)naphthalene-1,3-disulfonic acid, which is an azo compound synthesized with reference to U.S. Publication No. 2004 / 022805, was used instead of 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0349]

[0350] [Example 6]

[0351] 29.0 parts of the azo compound represented by formula (16) (Compound Example 1-42) were obtained in the same manner as in Example 1, except that 62.1 parts of 4-{(4-{[4-(4-amino-2,5-dimethylphenyl)diazenyl]-2-methylphenyl}diazenyl)benzoylamino}benzene-1,3-disulfonic acid, which is an azo compound synthesized by using Examples (n2) and (n4) of Reference International Publication No. 2021 / 015188, was used to replace 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0352]

[0353] [Example 7]

[0354] 28.0 parts of an azo compound represented by formula (17) (Compound Example 1-53) was obtained in the same manner as in Example 1, except that 71.2 parts of 7-({4-[(4-amino-2,5-dimethylphenyl)diazenyl]-2-chloro-5-(3-sulfonic acidpropoxy)phenyl}diazenyl)naphthalene-1,3-disulfonic acid, which is an azo compound synthesized by formula (8) of Example 1 of Reference International Publication No. 2010 / 038379, was used instead of 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0355]

[0356] [Example 8]

[0357] 22.5 parts of an azo compound represented by formula (18) (Compound Example 1-45) was obtained in the same manner as in Example 1, except that 62.2 parts of 4-{[4-({4-[(4-amino-2,5-dimethylphenyl)diazenyl]-2-methylphenyl}diazenyl)-2-methylphenyl]diazenyl}benzene-1,3-disulfonic acid, which is an azo compound synthesized in Example 1 with reference to International Publication No. 2012 / 108169, was used instead of 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0358]

[0359] [Example 9]

[0360] 26.0 parts of the azo compound (Compound Example 1-52) represented by formula (19) was obtained in the same manner as in Example 1, except that 30.0 parts of 5-[(4-aminobenzoyl)amino]benzene-1,3-dicarboxylic acid, an intermediate synthesized according to Example (n2) of Reference International Publication No. 2021 / 015188, was used to replace 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid used in Step 2 of Example 1.

[0361]

[0362] [Comparative Example 1]

[0363] 27.7 parts of commercially available 4-(4-aminophenylazo)benzenesulfonic acid are added to 300 parts of water and stirred to suspend, and the pH is adjusted to 9.0 using 25% sodium hydroxide, and 17.3 parts of a 40% sodium nitrite aqueous solution are added thereto. The obtained solution is dripped into a mixed solution of 100 parts of water and 42 parts of 35% hydrochloric acid to prepare a diazo liquid. Next, 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid are added to 300 parts of water, adjusted to a weak alkalinity with a 25% sodium hydroxide aqueous solution and dissolved. The previously obtained diazo liquid is dripped into the liquid while maintaining the pH at 6.5 to 9.0, and stirred to complete the coupling reaction. Thereafter, it is salted out with sodium chloride, filtered and dried, thereby obtaining 30.0 parts of an azo compound represented by the following formula (101).

[0364]

[0365] [Comparative Example 2]

[0366] 29.0 parts of an azo compound represented by formula (102) (CIDirect Red 81) was obtained in the same manner as in Comparative Example 1 except that 34.3 parts of 6-benzoylamino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0367]

[0368] [Comparative Example 3]

[0369] 29.5 parts of an azo compound represented by formula (103) was obtained in the same manner as in Comparative Example 1 except that 35.8 parts of 6-(4-aminobenzoyl)amino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid in Comparative Example 1.

[0370]

[0371] [Comparative Example 4]

[0372] 28.5 parts of an azo compound represented by formula (104) was obtained in the same manner as in Comparative Example 1 except that 32.9 parts of 7-benzylamino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0373]

[0374] [Comparative Example 5]

[0375] 19.5 parts of an azo compound represented by formula (105) was obtained in the same manner as in Comparative Example 1 except that 23.9 parts of 6-amino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0376]

[0377] [Comparative Example 6]

[0378] 20.0 parts of an azo compound represented by formula (106) was obtained in the same manner as in Comparative Example 1 except that 25.3 parts of 6-methylamino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0379]

[0380] [Comparative Example 7]

[0381] 20.3 parts of an azo compound represented by formula (107) was obtained in the same manner as in Comparative Example 1 except that 26.7 parts of 6-dimethylamino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0382]

[0383] [Comparative Example 8]

[0384] 20.5 parts of an azo compound represented by formula (108) was obtained in the same manner as in Comparative Example 1 except that 28.3 parts of 6-(pyrrolidin-1-yl)-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid.

[0385]

[0386] [Comparative Example 9]

[0387] 33.0 parts of an azo compound represented by formula (109) was obtained in the same manner as in Comparative Example 1 except that 55.1 parts of 6-(6,8-disulfonic acid-2H-naphtho[1,2-d][1,2,3]triazol-2-yl)-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid in Comparative Example 1.

[0388]

[0389] [Comparative Example 10]

[0390] 31.2 parts of an azo compound represented by formula (110) was obtained in the same manner as in Comparative Example 1 except that 34.4 parts of 6-[4-hydroxyphenyl)diazenyl]-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid in Comparative Example 1.

[0391]

[0392] [Comparative Example 11]

[0393] In addition to replacing 27.7 parts of 4-(4-aminophenylazo)benzenesulfonic acid in Comparative Example 1 with 41.8 parts of 5-{4-[(4-amino-2-methylphenyl)diazenyl]benzoylamino}benzene-1,3-dicarboxylic acid, which is an azo compound synthesized with reference to Example (n2) of International Publication No. 2021 / 015188, 25.0 parts of the azo compound represented by the following formula (111) were obtained in the same manner as in Comparative Example 1.

[0394]

[0395] [Comparative Example 12]

[0396] 22.5 parts of an azo compound represented by the following formula (112) was obtained in the same manner as in Comparative Example 11 except that 32.9 parts of 6-benzylamino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid used in Comparative Example 11.

[0397]

[0398] [Comparative Example 13]

[0399] 28.0 parts of an azo compound represented by formula (113) was obtained in the same manner as in Comparative Example 11 except that 35.8 parts of 6-(4-aminobenzoyl)amino-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid used in Comparative Example 11.

[0400]

[0401] [Comparative Example 14]

[0402] 34.5 parts of an azo compound represented by formula (114) was obtained in the same manner as in Comparative Example 11 except that 34.4 parts of 6-[4-hydroxyphenyl)diazenyl]-1-naphthol-3-sulfonic acid was used instead of 31.5 parts of 6-anilino-1-naphthol-3-sulfonic acid used in Comparative Example 11.

[0403]

[0404] [Comparative Example 15]

[0405] The compound of formula (1-A14) described in International Publication No. 2017 / 146212 was synthesized according to Example 6. The structure is shown in formula (115).

[0406]

[0407] [Comparative Example 16]

[0408] The compound represented by formula (2-9) in International Publication No. 2019 / 117131 was synthesized with reference to Example 6 of International Publication No. 2017 / 146212. The structure is shown in formula (116).

[0409]

[0410] (Examples 1 to 9 and Comparative Examples 1 to 16: Preparation of Polarizing Film)

[0411] A polyvinyl alcohol film having a thickness of 75 μm was immersed in a 45° C. aqueous solution (dye bath) containing 0.03% of each azo compound and 0.1% of sodium sulfate obtained in Examples 1 to 9 and Comparative Examples 1 to 16 for 4 minutes. The film was stretched to 5 times in a 3% boric acid aqueous solution at 50° C., washed with water and dried while being stretched to obtain a polarizing film.

[0412] Evaluation of the polarizing films obtained in Examples 1 to 9 and Comparative Examples 1 to 16 was performed as follows.

[0413] (a) Polarized light transmittance (Ky) and polarized light transmittance (Kz)

[0414] The maximum absorption wavelength, polarized light parallel transmittance (Ky) and polarized light orthogonal transmittance (Kz) of the polarizing film were measured using a spectrophotometer (UH-4150 manufactured by Hitachi, Ltd.). Here, Ky represents the transmittance when the absorption axis of the absolute polarizer is parallel to the absorption axis of the polarizing film, and Kz represents the transmittance when the absorption axis of the absolute polarizer is orthogonally overlapped with the absorption axis of the polarizing film. In the range of 380nm to 780nm, the polarized light parallel transmittance Ky and Kz of each wavelength are measured at a wavelength interval of 1 to 10nm.

[0415] (b) Single penetration (Ts), parallel penetration (Tp), orthogonal penetration (Tc)

[0416] The single transmittance (Ts) indicates the spectral transmittance when there is one polarizing film, the parallel transmittance (Tp) indicates the spectral transmittance when the absorption axes of two polarizing films are arranged in parallel and overlapped, and the orthogonal transmittance (Tc) indicates the spectral transmittance when the absorption axes of two polarizing films are arranged in orthogonal overlap. It is calculated from Ky and Kz at the maximum absorption wavelength obtained by measuring and using the following calculation formulas (I) to (III).

[0417] Ts(%)=(Ky+Kz) / 2 Calculation formula (I)

[0418] Tp(%)=(Ky 2 +Kz 2 ) / 200 Calculation formula (II)

[0419] Tc(%)=(Ky×Kz) / 100 Calculation formula (III)

[0420] (c) Polarization ratio (ρ), dichroic ratio

[0421] The polarization rate (ρ) and the dichroic ratio at the maximum absorption wavelength of each measurement sample were calculated by the following calculation formulas (IV) and (V).

[0422] ρ(%)=[(Ky-Kz) / (Ky+Kz)]×100 Calculation formula (IV)

[0423] Dichroic ratio = log(Kz / 100) / log(Ky / 100) Calculation formula (V)

[0424] Table 1 shows the values ​​obtained by measurement and calculation of the polarizing films of Example 1 and Comparative Examples 1 to 10.

[0425] [Table 1]

[0426]

[0427] As shown in Table 1, the polarizing film produced using the azo compound of Example 1 has a high dichroic ratio. Specifically, the polarizing film of Example 1 has a higher dichroic ratio than any of the polarizing films of Comparative Examples 1 to 10. Moreover, even compared with Comparative Examples 6 and 4, it shows sufficient superiority.

[0428] Furthermore, since the compounds are superior to the azo compounds of Comparative Examples 8 and 9, it is shown that the isoindole group of the present invention contributes to the improvement of performance.

[0429] Table 2 shows the values ​​obtained by measurement and calculation of the polarizing films of Example 2 and Comparative Examples 11 to 14.

[0430] [Table 2]

[0431]

[0432] Similar to Table 1, in Table 2, the polarizing film produced using the azo compound of the present invention in Example 2 has a high dichroic ratio. Specifically, the polarizing film of Example 2 shows a dichroic ratio of more than 45 at a monomer transmittance of about 44%, while the dichroic ratios of Comparative Examples 11, 12, 13, and 14 are all less than 45, and the performance of the compounds of the present application cannot be obtained.

[0433] Table 3 shows the values ​​obtained by measurement and calculation of the polarizing films of Example 3 and Comparative Example 15. Table 4 shows the values ​​obtained by measurement and calculation of the polarizing films of Example 4 and Comparative Example 16.

[0434] [Table 3]

[0435]

[0436] [Table 4]

[0437]

[0438] Tables 3 and 4 show the comparison between the compounds of the present invention and the compounds of the present invention, which are blue dyes with a maximum absorption wavelength exceeding 600 nm. In any case, the examples of the present invention have a higher dichroic ratio than the comparative examples, and the compounds of the present invention have a 1-naphthol-3-sulfonic acid derivative substituted with an isoindole group, so they show that a blue dichroic dye with better performance is obtained.

[0439] Table 5 shows the values ​​obtained by measurement and calculation of the polarizing films of Examples 5 to 9 and Comparative Examples 1 to 2.

[0440] [Table 5]

[0441]

[0442] As shown in Table 5, the polarizing films made using the azo compounds of Examples 5 to 9 all have high polarization rates and dichroic ratios. Specifically, the polarizing films of Examples 5 to 9 show a polarization rate of 98% or more and a high dichroic ratio at a single transmittance of about 44%. In contrast, the polarizing films of Comparative Examples 1 to 2, which are known as general red water-soluble dichroic dyes with a maximum absorption wavelength of 500nm to 580nm, cannot achieve a polarization rate of 98%. In other words, as can be seen from Table 5, even if the number of azo groups and the substituents are changed, as long as the azo compound of the present invention is an azo compound having a 1-naphthol-3-sulfonic acid derivative substituted with an isoindole group, a dichroic dye with high performance is obtained.

[0443] (Example 10: Preparation of Neutral Gray Polarizing Plate)

[0444] A polyvinyl alcohol film having a thickness of 75 μm was immersed in a 45°C aqueous solution (dye bath) containing 0.2% of the compound represented by formula (13) of Example 3 as a red dye, 0.3% of the compound represented by formula (1-A14) of Example 6 of International Publication No. 2017 / 146212 as a blue dye, 0.2% of CIDirect Orange 39 as an orange dye, and 0.1% of Glauber's salt for 4 minutes. The film was stretched to 5 times in a 3% boric acid aqueous solution at 50°C, and washed and dried while maintaining the tension to obtain a polarizing film. The obtained polarizing film had a monomer average transmittance of 42% from 380nm to 780nm, an average transmittance of 0.1% at the orthogonal position, and had a high degree of polarization. Triacetyl cellulose films (TAC films: manufactured by Fujifilm Corporation: trade name TD-80U) were laminated on both sides of the polarizing film via an adhesive of a polyvinyl alcohol aqueous solution to obtain a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC / polarizing film / TAC. One side of the obtained neutral gray polarizing plate was attached to glass using an adhesive to prepare a neutral gray polarizing plate measurement sample laminated in the order of TAC / polarizing film / TAC / glass.

[0445] The neutral gray polarizing plate obtained in Example 10 has no change in average monomer transmittance after being placed under an ambient temperature of 105°C for 500 hours and under an ambient temperature of 80°C and a relative humidity of 90% for 500 hours, and shows long-term durability even under high temperature and high humidity conditions. Moreover, in a xenon light resistance test (SX-75 manufactured by Suga Testing Machine Co., Ltd.), the average monomer transmittance of the neutral gray polarizing plate of Example 10 has no change even after being placed under an ambient temperature of 50°C at 60W for 200 hours, and has excellent light resistance even when exposed to light for a long time.

[0446] These results show that the neutral gray polarizing plate of Example 10 produced using the compound of the present application is a high-performance dye-based polarizing plate having excellent polarizing performance and durability (moisture resistance, heat resistance, and light resistance).

[0447] [Industrial Applicability]

[0448] The polarizing film or polarizing plate made of the azo compound of the present invention can be provided with a protective layer or a functional layer and a transparent support such as glass, crystal, sapphire, etc. as needed, and is suitable for liquid crystal projectors, calculators, watches, notebook computers, word processors, liquid crystal televisions, polarizing lenses, polarizing glasses, car navigation systems, and indoor and outdoor measuring instruments and displays, etc. In particular, the polarizing film or polarizing plate of the present invention can be suitably used in liquid crystal display devices, such as reflective liquid crystal display devices, semi-transmissive liquid crystal display devices, and organic electroluminescent devices other than liquid crystal display devices, etc.

Claims

1. An azo compound or a salt thereof, represented by the following formula (1): In the formula (1), Ar represents a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, or a heterocyclic ring which may have a substituent, and A represents an arbitrary substituent.

2. The azo compound or a salt thereof according to claim 1, wherein The azo compound represented by the above formula (1) is represented by the following formula (2): In formula (2), R 1 To R 8 Each independently represents an arbitrary substituent, m represents an integer of 0 or 1, and n represents 0 or 1.

3. The azo compound or a salt thereof according to claim 1, wherein The azo compound represented by the above formula (1) is represented by the following formula (3): In the above formula (3), R 1 To R 6 Each independently represents an arbitrary substituent, and m represents 0 or 1. 4 . A polarizing film comprising the azo compound or a salt thereof according to claim 1 . The polarizing film according to claim 4 , comprising a substrate. 6 . The polarizing film according to claim 4 , comprising one or more organic dyes other than the azo compound or the salt thereof according to claim 1 . The polarizing film according to claim 4 , having a neutral gray color. 8 . A polarizing plate comprising the polarizing film according to claim 4 and a transparent protective film provided on one or both sides thereof. 9 . A display device comprising the polarizing film according to claim 4 or the polarizing plate according to claim 8 .

Images