JPWO2018181470A1 - Azo compound or salt thereof, and dye-based polarizing film, dye-based polarizing plate, and liquid crystal display device containing the same - Google Patents

Abstract

An object of the present invention is to provide an azo compound useful as a dichroic dye used for a polarizing plate.
The present invention provides the following formula (1):

(Wherein, A ¹ and A ² are each independently a naphthyl group which may have a substituent selected from the group consisting of a hydroxy group, a C1-4 alkoxy group having a sulfo group and a sulfo group, or a substituent A phenyl group which may have
R _{1 to} R ₆ each independently represent a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a C 1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C 1-4 alkyl-substituted acylamino. Group. )
Or a salt thereof.

Description

  The present invention relates to a novel azo compound or a salt thereof, and a dye-based polarizing film, a dye-based polarizing plate, and a liquid crystal display device containing the same.

  A polarizing plate having a light transmission / shielding function is a basic component of a display device such as a liquid crystal display (LCD) together with a liquid crystal having a light switching function. Application fields of this LCD include small devices such as calculators and watches in the early days, notebook computers, word processors, liquid crystal projectors, liquid crystal televisions, car navigation systems, indoor and outdoor measuring devices, and the like. Further, the present invention can be applied to a lens having a polarizing function, and is applied to sunglasses with improved visibility, and in recent years, polarized glasses compatible with 3D televisions and the like. The polarizing plate is used in a wide range of conditions from low temperature to high temperature, low humidity to high humidity, low light amount to high light amount because of the widespread use of the polarizing plate as described above. There is a demand for a polarizing plate having properties.

  At present, a polarizing plate is used for a polarizing film base material such as a stretch-oriented polyvinyl alcohol or a derivative thereof film or a polyene-based film in which a polyene is formed by dehydrochlorination of a polyvinyl chloride film or dehydration of a polyvinyl alcohol-based film to produce and align a polyene. It is manufactured by dyeing or containing iodine or a dichroic dye. These are substances that greatly affect the polarization characteristics and durability of the polarizing plate. An iodine-based polarizing film using iodine has excellent polarizing performance, but is weak to water and heat, and has a problem in durability when used for a long time in a high temperature and high humidity state. In order to improve the durability, a method of treating with an aqueous solution containing formalin or boric acid, or a method of using a polymer film having low moisture permeability as a protective film has been considered, but the effect is not sufficient. On the other hand, a dye-based polarizing film using a dye has better moisture resistance and heat resistance than an iodine-based polarizing film, but generally has insufficient polarizing performance.

  Until recently, an image was displayed with high brightness in order to improve the clarity of the image on the liquid crystal display. In hybrid cars and mobile terminals equipped with such displays, there has been a demand to extend the battery driving time, so even if the LCD manufacturer reduces the brightness to reduce power consumption, the image brightness, There has been a demand for a polarizing plate that can maintain color clarity.

  However, in a polarizing film made by adsorbing and orienting several kinds of dyes on a polymer film, if there is light leakage (color leakage) of a specific wavelength in the visible light wavelength region, the polarizing film is attached to the liquid crystal panel. In the dark state, the hue of the liquid crystal display may change. Therefore, when a polarizing film is mounted on a liquid crystal display device, in order to prevent discoloration of the liquid crystal display due to color leakage of a specific wavelength in a dark state, a neutral color obtained by dyeing or containing several kinds of dyes in a polymer film is used. In the polarizing film described above, the transmittance (orthogonal transmittance) at the orthogonal position in the wavelength region of the visible light region must be uniformly reduced. Further, in a vehicle-mounted liquid crystal display, since a high temperature and high humidity environment occurs in a summer car, a polarizing plate that does not change the degree of polarization even in a severe environment is required. Previously, an iodine-based polarizing plate having good polarization performance and exhibiting a neutral gray was used. However, the iodine-based polarizing plate has a problem that the light resistance, heat resistance, and moist heat resistance are not sufficient as described above. In order to solve this problem, a dye-based neutral gray polarizing plate dyeing or containing several types of dichroic dyes has been used. The dye-based neutral gray polarizing plate generally uses a combination of red, blue and yellow dyes, which are three primary colors of light. However, as described above, the polarization performance of the dye-based neutral gray polarizing plate is not sufficient. Therefore, it was necessary to develop a dichroic dye having good polarization performance for each of the three primary colors.

  A feature of the dye system is that it dyes or contains a corresponding independent dye in order to control the three primary components of light as described above. Light sources used in recent liquid crystal display panels include a cold cathode fluorescent lamp method and an LED method. The light source wavelength emitted from the light source differs depending on the method, and the same method often differs depending on panel manufacturers. Therefore, in developing a dichroic dye having good polarization performance, it is particularly important to design a dichroic dye having an absorption wavelength matching the wavelength of the light source.

  Examples of the dye used in the production of the dye-based polarizing film as described above include water-soluble azo compounds described in Patent Documents 1 to 6 and the like.

JP-A-03-12606 JP 2001-33627 A JP 2009-132794 A JP 2001-240762 A JP 2001-108828 A JP-A-60-156759

Dye Chemistry P139-149; Yutaka Hosoda, published by Gihodo, 1957

An object of the present invention is to provide a novel polarizing plate. Another object of the present invention is to provide a polarizing plate having excellent polarization performance. Another object of the present invention is to provide a polarizing plate having durability (moisture resistance, heat resistance, or light resistance). Still another object of the present invention is to provide a neutral gray polarizing plate obtained by adsorbing and orienting two or more types of dichroic dyes on a polymer film, wherein a color at an orthogonal position in a wavelength region of a visible light region is provided. An object of the present invention is to provide a polarizing plate having no leakage and having excellent polarizing performance.
A further object is to provide a dye-based neutral gray polarizing plate for an in-vehicle liquid crystal display, which provides a high-performance polarizing plate having good brightness, polarization performance, and durability (moisture resistance, heat resistance, or light resistance). It is in.

  The present inventors have conducted intensive studies to achieve such an object, and as a result, have found that a polarizing film and a polarizing plate containing a specific azo compound or a salt thereof have excellent polarizing performance, and completed the present invention. did.

That is, the present invention relates to the following (1) to (26).
(1) The following equation (1):

(Wherein, A ¹ and A ² are each independently a naphthyl group which may have a substituent selected from the group consisting of a hydroxy group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or A phenyl group which may have a group,
R _{1 to} R ₆ each independently represent a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a C 1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C 1-4 alkyl-substituted acylamino. Is the base)
Or an azo compound represented by the formula:
(2) One or both of A ¹ and A ² (if both are independent) are a sulfo group, a carboxy group, a C1-4 alkoxy group having a sulfo group, a C1-4 alkyl group, a C1-4 alkoxy group , Halogen, nitro, amino, N, N-dimethylamino, N, N-diethylamino, methylamino, ethylamino, n-propylamino, n-butylamino, sec-butylamino And a phenyl group having at least one substituent selected from the group consisting of C1-4 alkyl-substituted acylamino groups such as an acetylamino group, a propionamide group, and a butylamide group. The azo compound or a salt thereof according to 1).
(3) One or both of A ¹ and A ² (if both are independent) have at least one substituent selected from a sulfo group, a carboxy group, and a C1-4 alkoxy group having a sulfo group. A hydrogen atom, a sulfo group, a carboxy group, a C1-4 alkoxy group having a sulfo group, a C1-4 alkyl group, a C1-4 alkoxy group, a halogen group, a nitro group, an amino group, a C1-4 alkyl-substituted amino group, Or the azo compound or salt thereof according to (1) or (2), which is a phenyl group further having a C1-4 alkyl-substituted acylamino group.
(4) When one or both of A ¹ and A ² (if both are independent), the following formula (2):

(In the formula, one of R ₇ and R ₈ is a C 1-4 alkoxy group having a sulfo group, a carboxyl group, or a sulfo group, and the other is a C 1-4 alkoxy group having a hydrogen atom, a sulfo group, a carboxy group, or a sulfo group. Group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, C1-4 alkyl-substituted amino group, or C1-4 alkyl-substituted acylamino group)
The azo compound according to any one of (1) to (3), which is a phenyl group represented by: or a salt thereof.
(5) The azo compound or salt thereof according to (4), wherein one of R ₇ and R ₈ is a sulfo group or a carboxyl group, and the other is a hydrogen atom, a sulfo group, a carboxy group, a methyl group, or a methoxy group. .
(6) The azo compound or a salt thereof according to any one of (1) to (5), wherein at least one of A ¹ and A ² is the naphthyl group.
(7) The azo compound or a salt thereof according to any one of (1) to (6), wherein both A ¹ and A ² are the phenyl groups.
(8) When one or both of A ¹ and A ² (if both are independent), the following formula (3):

(In the formula, R ₉ is a hydrogen atom, a hydroxy group, a C1-4 alkoxy group having a sulfo group, or a sulfo group, and n is an integer of 1 to 3.)
The azo compound or a salt thereof according to any one of (1) to (6), which is a naphthyl group represented by:
(9) The azo compound or a salt thereof according to (8), wherein R ₉ is a hydrogen atom and n is 2.
(10) The following equation (4):

(Wherein, R _{1 to} R ₆ are as defined in formula (1))
The azo compound according to any one of (1) to (9), or a salt thereof.
(11) The following equation (5):

(Wherein, at least one of R _{10 to} R ₁₃ is a sulfo group, and the others are a hydrogen atom, a sulfo group, a carboxyl group, a C1-4 alkoxy group having a sulfo group, a methyl group, or a methoxy group; _{1 to} R ₆ are as defined in formula (1))
The azo compound according to any one of (1) to (5), or a salt thereof.
(12) R _{1 to} R ₆ are each independently a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a halogen group, or a C 1-4 alkoxy group having a sulfo group (1) to (11) Or the salt thereof.
(13) Any of (1) to (12), wherein R _{1 to} R ₆ are each independently a C 1-4 alkoxy group having a sulfo group, a hydrogen atom, a methyl group, an ethyl group, a halogen group, or a methoxy group. Or an azo compound or a salt thereof.
(14) The azo compound or a salt thereof according to any one of (1) to (13), wherein at least one of R _{1 to} R ₆ is a C1-4 alkoxy group having a sulfo group.
(15) The azo compound or a salt thereof according to (14), wherein the C1-4 alkoxy group having a sulfo group is a 3-sulfopropoxy group.
(16) A dye-based polarizing film comprising a polarizing film base containing the azo compound or a salt thereof according to any one of (1) to (15).
(17) A dye-based polarizing film comprising a polarizing film substrate containing the azo compound or salt thereof according to any one of (1) to (15) and at least one other organic dye.
(18) The dye-based polarizing film according to (16) or (17), wherein the polarizing film substrate is a film made of a polyvinyl alcohol resin or a derivative thereof.
(19) A dye-based polarizing plate having a transparent protective layer attached to one or both surfaces of the dye-based polarizing film according to any one of (16) to (18).
(20) A polarizing plate for liquid crystal display comprising the dye-based polarizing film according to any one of (16) to (18) or the dye-based polarizing plate according to (19).
(21) A neutral gray polarizing plate comprising the dye-based polarizing film according to any one of (16) to (18) or the dye-based polarizing plate according to (19).
(22) A liquid crystal display device comprising the dye-based polarizing plate according to (19), the liquid crystal display polarizing plate according to (20), or the neutral gray polarizing plate according to (21).

  The azo compound of the present invention or a salt thereof is useful as a dye for a polarizing film. The polarizing film of the present invention containing the azo compound or a salt thereof has high polarizing performance comparable to a polarizing film using iodine. In one embodiment, the polarizing film of the present invention is also excellent in durability (constitution, heat resistance, or light resistance). Therefore, it is suitable for various liquid crystal displays and liquid crystal projectors, for in-vehicle applications requiring high polarization performance and durability, and for display applications of industrial instruments used in various environments.

<Azo compound>
The azo compound of the present invention is represented by the following formula (1).

A ¹ and A ² are each independently a naphthyl group which may have a substituent, or a phenyl group which has a substituent. In one aspect, both A ¹ and A ² are phenyl groups. In another aspect, at least one of A ¹ and A ² is a naphthyl group which may have a substituent. When both A ¹ and A ² are a naphthyl group which may have a substituent, the substituents of the naphthyl group may be the same or different. When both A ¹ and A ² are phenyl groups which may have a substituent, the substituents of the phenyl group may be the same or different. Here, in the specification and the claims of the present application, “lower” in “lower alkyl” and “lower alkoxy” means having 1 to 4 carbon atoms. It is also referred to as “C1-4”.

  The phenyl group having a substituent is preferably a sulfo group, a carboxy group, a lower alkoxy group having a sulfo group, a lower alkyl group, a lower alkoxy group, a halogen group, a nitro group, an amino group, a lower alkyl-substituted amino group, and a lower alkyl group. An alkyl-substituted acylamino group is a phenyl group having at least one substituent selected from the group consisting of a phenyl group. When the phenyl group has two or more substituents, at least one of the substituents is preferably a sulfo group, a carboxy group, or a lower alkoxy group having a sulfo group. Other substituents are a sulfo group, a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxy group having a sulfo group, a carboxy group, a chloro group, a bromo group, a nitro group, an amino group, a lower alkyl-substituted amino group, or It is preferably a lower alkyl-substituted acylamino group. Other substituents are more preferably sulfo group, hydrogen atom, methyl group, ethyl group, methoxy group, ethoxy group, carboxy group, sulfoethoxy group, sulfopropoxy group, sulfobutoxy group, chloro group, nitro group, amino Group, N, N-dimethylamino group, N, N-diethylamino group, methylamino group, ethylamino group, n-propylamino group, n-butylamino group, sec-butylamino group, acetylamino group, propionamide group And a butylamide group, and particularly preferably a sulfo group, a carboxy group, a hydrogen atom, a methyl group, a methoxy group, a sulfoethoxy group, a sulfopropoxy group, or a sulfobutoxy group. The substitution position is not particularly limited, but is preferably 2-position only, 4-position only, combination of 2-position and 6-position, combination of 2-position and 4-position, combination of 3-position and 5-position And particularly preferably 2-position only, 4-position only, combination of 2-position and 4-position, or combination of 3-position and 5-position. In addition, only the 2-position and only the 4-position indicate that the compound has one substituent other than a hydrogen atom only at the 2- or 4-position.

The phenyl group having a substituent is preferably represented by the following formula (2).

One of R ₇ and R ₈ is a sulfo group, a carboxyl group, or a lower alkoxy group having a sulfo group, and the other is a hydrogen atom, a sulfo group, a carboxy group, a lower alkoxy group having a sulfo group, a lower alkyl group, a lower alkoxy group. Group, halogen group, nitro group, amino group, lower alkyl-substituted amino group, or lower alkyl-substituted acylamino group. Preferably, one of R ₇ and R ₈ is a sulfo group or a carboxy group, and the other is a hydrogen atom, a sulfo group, a carboxy group, a methyl group, or a methoxy group.

  The naphthyl group which may have a substituent is preferably a naphthyl group which may have one or more substituents selected from the group consisting of a hydroxy group, a lower alkoxy group having a sulfo group and a sulfo group. .

The naphthyl group which may have a substituent is preferably a naphthyl group represented by the following formula (3).

R ₉ is a hydrogen atom, a hydroxy group, a lower alkoxy group having a sulfo group, or a sulfo group. n is an integer of 1 to 3. The position of the sulfo group may be present on any benzene nucleus of the naphthalene ring. Preferably, R ₉ is a hydrogen atom and n is 2. The lower alkoxy group having a sulfo group is preferably a straight-chain alkoxy group, and the substitution position of the sulfo group is preferably at the alkoxy group terminal. The lower alkoxy group having a sulfo group is more preferably a 3-sulfopropoxy group and a 4-sulfobutoxy group. Although the position of the substituent of the naphthyl group is not particularly limited, it is explained by the number shown in the formula (3). Combinations are preferred, and when there are three substituents, 3-, 5- and 7-positions, 3-, 6- and 8-positions are preferred.

R _{1 to} R ₆ are not particularly limited, but preferably each independently represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a lower alkyl-substituted acylamino. Group. R _{1 to} R ₆ are each independently preferably a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxy group having a sulfo group, or a halogen group, more preferably a hydrogen atom, a methyl group, an ethyl group, A methoxy group, an ethoxy group, a chloro group, a fluorine group, a 3-sulfopropoxy group, or a 4-sulfobutoxy group, and more preferably a hydrogen atom, a methyl group, an ethyl group, a methoxy group, or a 3-sulfopropoxy group. is there.

In one embodiment, at least one of R _{1 to} R ₆ is a lower alkoxy group having a sulfo group.
The lower alkoxy group having a sulfo group is preferably a C2-4 alkoxy group, more preferably a C3-4 alkoxy group, and particularly preferably a C3 alkoxy group. The substitution position of the sulfo group is not particularly limited, but is preferably a terminal of the alkoxy group. Particularly preferred C1-4 alkoxy groups having a sulfo group are a 3-sulfopropoxy group and a 4-sulfobutoxy group, most preferably a 3-sulfopropoxy group.

R ₁ may be a lower alkoxy group having a sulfo group, R ₃ may be a lower alkoxy group having a sulfo group, R ₅ may be a lower alkoxy group having a sulfo group, R ₁ and R ₃ may each independently be a lower alkoxy group having a sulfo group, R ₁ and R ₅ may each independently be a lower alkoxy group having a sulfo group, and R ₃ and R ₅ each independently _May be a lower alkoxy group having a sulfo group, and R _1, R ₃ and R ₅ may each independently be a lower alkoxy group having a sulfo group.

In one embodiment, none of R _{1 to} R ₆ is a C 1-4 alkoxy group having a sulfo group.

As the positions of R _{1 to} R ₆ , preferably, only the 2-position, only the 5-position, a combination of the 2-position and the 6-position, a combination of the 2-position and the 5-position, and the 3-position and the 5-position Are more preferable, and more preferably, only the 2-position, only the 5-position, or a combination of the 2-position and the 5-position. In addition, only the 2-position and only the 5-position indicate that only the 2- or 5-position has one substituent other than a hydrogen atom.

In one embodiment, A ¹ and A ² are each independently a naphthyl group which may have a substituent selected from the group consisting of a hydroxy group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or A phenyl group which may have a group, provided that both A ¹ and A ² are a phenyl group having a substituent,
R _{1 to} R ₆ each independently represent a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a C 1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C 1-4 alkyl-substituted acylamino. Group.

In one embodiment, A ¹ and A ² are each independently a phenyl group which may have a substituent,
R _{1 to} R ₆ are each independently a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a hydroxy group, a carboxy group, a halogen group, or a C 1-4 alkyl-substituted acylamino group.

In one embodiment, A ¹ and A ² are each independently a phenyl group which may have a substituent,
At least one of R _{1 to} R ₆ is a C1-4 alkoxy group having a sulfo group, and the rest are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a carboxy group, a hydroxy group, a halogen group. Or a C1-4 alkyl-substituted acylamino group.

The azo compound represented by the formula (1) is preferably represented by the following formula (4).

In one aspect, the azo compound represented by the formula (1) is preferably represented by the formula (5).

At least one of R _{10 to} R ₁₃ is a sulfo group, and the others represent a hydrogen atom, a sulfo group, a carboxyl group, a C1-4 alkoxy group having a sulfo group, a methyl group, or a methoxy group.
R _{1 to} R ₆ are as defined in formula (1).

  Next, specific examples of the azo compound represented by the formula (1) are shown below. The sulfo group, carboxy group, and hydroxy group in the formula are represented in the form of a free acid.

Specific examples in which at least one of A ¹ and A ² is a naphthyl group are shown below.

Specific examples in which both A ¹ and A ² are phenyl groups and none of R _{1 to} R ₆ is a lower alkoxy group having a sulfo group are shown below.

Specific examples in which both A ¹ and A ² are phenyl groups and at least one of R _{1 to} R ₆ is a lower alkoxy group having a sulfo group are shown below.

  The azo compound represented by the formula (1) may be in the form of a free acid or in the form of a salt. Such salts include alkali metal salts such as lithium, sodium and potassium salts, ammonium salts, and organic salts such as amine salts, with sodium salts being preferred.

  The azo compound represented by the formula (1) or a salt thereof is subjected to diazotization and coupling in accordance with a general azo dye production method as described in Non-Patent Document 1, and as described in Patent Document 3. It can be produced by reacting with a ureiding agent.

  As an example of a specific production method, an aniline having a substituent represented by the following formula (i) is diazotized by the same production method as in Non-Patent Document 1, and is coupled with an aniline of the following formula (ii). Thus, a monoazoamino compound represented by the following formula (iii) is obtained.

(In the formula, A ¹ represents the same meaning as in the above formula (1).)

(In the formula, R ₁ and R ₂ represent the same meaning as in the above formula (1).)

(In the formula, A ¹ , R ₁ , and R ₂ represent the same meaning as in the above formula (1).)

  Next, the monoazoamino compound (iii) is diazotized and subjected to secondary coupling with an aniline represented by the following formula (iv) to obtain a disazoamino compound represented by the following formula (v).

(In the formula, R ₃ and R ₄ represent the same meaning as in the above formula (1).)

(In the formula, A ¹ and R _{1 to} R ₄ represent the same meaning as in the above formula (1).)

Similarly, an aniline having a substituent represented by the following formula (vi) is diazotized by the same method as in Non-Patent Document 1, coupled with an aniline of the following formula (vii), and represented by the following formula (viii). To obtain a monoazoamino compound.

(In the formula, A ² represents the same meaning as in the above formula (1).)

(In the formula, R ₅ and R ₆ represent the same meaning as in the above formula (1).)

(In the formula, A ² , R ₅ and R ₆ represent the same meaning as in the above formula (1).)

  The azo compound of the formula (1) is obtained by reacting the disazoamino compound (v) and the monoazoamino compound (viii) with a ureating agent such as phenyl chloroformate.

  The diazotization step is performed, for example, by a conventional method of mixing a nitric acid such as sodium nitrite with an aqueous solution of a mineral acid such as hydrochloric acid or sulfuric acid of the diazo component, or a neutral or weakly alkaline aqueous solution of the diazo component. Is carried out by the reverse method of adding nitrite to the mixture and then mixing it with a mineral acid. The temperature for the diazotization is suitably from -10 to 40C. Further, the coupling step with anilines is preferably performed by mixing an acidic aqueous solution such as hydrochloric acid or acetic acid with each of the above diazo liquids, at a temperature of -10 to 40 ° C, and at pH 2 to 7 under acidic conditions.

  The disazoamino compound (v) and the monoazoamino compound (viii) obtained by the coupling can be precipitated by acid precipitation or salting out and taken out by filtration, or can proceed to the next step as a solution or suspension. . If the diazonium salt is hardly soluble and is in a suspension, it can be filtered and used as a press cake in the next coupling step.

  Specific conditions for the ureidation reaction of the disazoamino compound (v) with the monoazoamino compound (viii) using a ureating agent include, for example, a method in which the temperature is 10 to 10 according to the production method shown on page 57 of Patent Document 3. 90 ° C. and pH 3 to 11 are preferred, more preferably 20 to 80 ° C. and pH 4 to 10, particularly preferably 20 to 70 ° C. and pH 6 to 9. Examples of the ureating agent include phenyl chloroformate, phosgene, triphosgene, ethyl chloroformate, butyl chloroformate, isobutyl chloroformate, 4-nitrophenyl chloroformate, 4-fluorophenyl chloroformate, 4-chlorophenyl chloroformate, and chloroformate. 4-bromophenyl, diphenyl carbonate, bis (2-methoxyphenyl) carbonate, bis (pentafluorophenyl) carbonate, bis (4-nitrophenyl) carbonate, and 1,1′-carbonyldiimidazole can be used. It is not limited to. The ureiding agent is preferably phenyl chloroformate, 4-nitrophenyl chloroformate, 4-chlorophenyl chloroformate, diphenyl carbonate, bis (4-nitrophenyl) carbonate, more preferably phenyl chloroformate, chloroformate 4 -Nitrophenyl.

  After completion of the ureidation reaction, the obtained azo compound of the formula (1) is precipitated by salting out and filtered out. When purification is necessary, salting out may be repeated or precipitation may be performed from water using an organic solvent. Examples of the organic solvent used for purification include water-soluble organic solvents such as alcohols such as methanol and ethanol, and ketones such as acetone.

Aromatic amines represented by A ₁ -NH ₂ and A ₂ -NH ₂ which are starting materials for synthesizing the azo compound represented by the formula (1) are naphthylamines or anilines.

As the naphthylamines, it is preferable to use naphthylamines having at least one selected from the group consisting of a hydrogen atom, a hydroxy group, a lower alkoxy group having a sulfo group, and a sulfo group. Examples of naphthylamines include 4-aminonaphthalenesulfonic acid, 7-aminonaphthalene-3-sulfonic acid, 1-aminonaphthalene-6-sulfonic acid, 1-aminonaphthalene-7-sulfonic acid, and 7-aminonaphthalene-1 , 3-disulfonic acid, 6-aminonaphthalene-1,3-disulfonic acid, 7-aminonaphthalene-1,5-disulfonic acid, 7-aminonaphthalene-1,3,6-trisulfonic acid and the like. 7-aminonaphthalene-3-sulfonic acid, 6-aminonaphthalene-1,3-disulfonic acid, 7-aminonaphthalene-1,4-disulfonic acid, 7-aminonaphthalene-1,5-disulfonic acid, 2-amino- 8-hydroxy-naphthalene-6-sulfonic acid, 3-amino-8-hydroxynaphthalene-6-sulfonic acid, 1-aminonaphthalene-3,6,8-trisulfonic acid, 2-amino-5-hydroxynaphthalene-1 , 7-Disulfonic acid, 1-aminonaphthalene-3,8-disulfonic acid and the like are preferred.
Examples of the naphthylamines having a sulfo group and a lower alkoxy group having a sulfo group include 7-amino-3- (3-sulfopropoxy) naphthalene-1-sulfonic acid and 7-amino-3- (4-sulfbutoxy). Naphthalene-1-sulfonic acid, 7-amino-4- (3-sulfopropoxy) naphthalene-2-sulfonic acid, 7-amino-4- (4-sulfobutoxy) naphthalene-2-sulfonic acid, 6-amino-4 -(3-Sulfopropoxy) naphthalene-2-sulfonic acid, 6-amino-4- (4-sulfobutoxy) naphthalene-2-sulfonic acid, 2-amino-5- (3-sulfopropoxy) naphthalene-1,7 -Disulfonic acid, 6-amino-4- (3-sulfopropoxy) naphthalene-2,7-disulfonic acid, 7-amino-3- (3-sulfop Epoxy), and naphthalene-1,5-disulfonic acid.

  Examples of anilines include 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 4-aminobenzoic acid, 2-amino-5-methylbenzenesulfonic acid, and 2-amino-5-ethylbenzene. Sulfonic acid, 2-amino-5-propylbenzenesulfonic acid, 2-amino-5-butylbenzenesulfonic acid, 4-amino-3-methylbenzenesulfonic acid, 4-amino-3-ethylbenzenesulfonic acid, 4-amino- 3-propylbenzenesulfonic acid, 4-amino-3-butylbenzenesulfonic acid, 2-amino-5-methoxybenzenesulfonic acid, 2-amino-5-ethoxybenzenesulfonic acid, 2-amino-5-propoxybenzenesulfonic acid , 2-amino-5-butoxybenzenesulfonic acid, 4-amino-3-meth Xybenzenesulfonic acid, 4-amino-3-ethoxybenzenesulfonic acid, 4-amino-3-propoxybenzenesulfonic acid, 4-amino-3-butoxybenzenesulfonic acid, 2-amino-4-sulfobenzoic acid, 2- Amino-5-sulfobenzoic acid, 4-amino-3-sulfobenzoic acid, 5-amino-2-chlorobenzoic acid, 5-aminoisophthalic acid, 2-amino-5-chlorobenzenesulfonic acid, 2-amino-5- Bromobenzenesulfonic acid, 2-amino-5-nitrobenzenesulfonic acid, 2,5-diaminobenzenesulfonic acid, 2-amino-5-dimethylaminobenzenesulfonic acid, 2-amino-5-diethylaminobenzenesulfonic acid, 5-acetamide -2-aminobenzenesulfonic acid, 4-aminobenzene-1,3-disulfonic acid, 2 Aminobenzene-1,4-disulfonic acid, 4-amino-2-methylbenzenesulfonic acid, 2- (4-aminophenoxy) ethane-1-sulfonic acid, 3- (4-aminophenoxy) propane-1-sulfonic acid 4- (4-aminophenoxy) butane-1-sulfonic acid, 2- (3-aminophenoxy) ethane-1-sulfonic acid, 3- (3-aminophenoxy) propane-1-sulfonic acid, 4- (3 -Aminophenoxy) butane-1-sulfonic acid, 2-amino-5- (2-sulfoethoxy) benzenesulfonic acid, 2-amino-5- (3-sulfopropoxy) benzenesulfonic acid, 2-amino-5- ( 4-sulfobutoxy) benzenesulfonic acid, 2-amino-5- (2-sulfoethoxy) benzoic acid, 2-amino-5- (3-sulfopropoxy) benzoic acid Acid, 2-amino-5- (4-sulfobutoxy) benzoic acid, 4-amino-3- (2-sulfoethoxy) benzenesulfonic acid, 4-amino-3- (3-sulfopropoxy) benzenesulfonic acid, 4 -Amino-3- (4-sulfobutoxy) benzenesulfonic acid, 4-amino-3- (2-sulfoethoxy) benzoic acid, 4-amino-3- (3-sulfopropoxy) benzoic acid, 4-amino-3 -(4-sulfobutoxy) benzoic acid, 2- (4-amino-3-methylphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-methylphenoxy) propane-1-sulfonic acid, 4- (4-amino-3-methylphenoxy) butane-1-sulfonic acid, 2- (4-amino-3-ethylphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-ethylpheno) B) propane-1-sulfonic acid, 4- (4-amino-3-ethylphenoxy) butane-1-sulfonic acid, 2- (4-amino-3-propylphenoxy) ethane-1-sulfonic acid, 3- ( 4-amino-3-propylphenoxy) propane-1-sulfonic acid, 4- (4-amino-3-propylphenoxy) butane-1-sulfonic acid, 2- (4-amino-3-butylphenoxy) ethane-1 -Sulfonic acid, 3- (4-amino-3-butylphenoxy) propane-1-sulfonic acid, 4- (4-amino-3-butylphenoxy) butane-1-sulfonic acid, 2- (4-amino-3 -Methoxyphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-methoxyphenoxy) propane-1-sulfonic acid, 4- (4-amino-3-methoxyphenoxy) Tan-1-sulfonic acid, 2- (4-amino-3-ethoxyphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-ethoxyphenoxy) propane-1-sulfonic acid, 4- (4- Amino-3-ethoxyphenoxy) butane-1-sulfonic acid, 2- (4-amino-3-propoxyphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-propoxyphenoxy) propane-1-sulfone Acid, 4- (4-amino-3-propoxyphenoxy) butane-1-sulfonic acid, 2- (4-amino-3-butoxyphenoxy) ethane-1-sulfonic acid, 3- (4-amino-3-butoxy) Phenoxy) propane-1-sulfonic acid, 4- (4-amino-3-butoxyphenoxy) butane-1-sulfonic acid, and the like. These aromatic amines may have an amino group protected. Examples of the protecting group include an ω-methanesulfone group.

  The aromatic amines (ii), (iv) and (vii) which are the primary and secondary couplers 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-methoxy-5-methylaniline, 2,5-dimethoxyaniline, 3,5-dimethylaniline, 2,6- Dimethylaniline, 3,5-dimethoxyaniline, 5-chloro-2-methoxyaniline, 5-chloro -2-ethoxyaniline, 5-chloro-2-propoxyaniline, 5-chloro-2-butoxyaniline, 5-fluoro-2-methoxyaniline, 5-fluoro-2-ethoxyaniline, 5-fluoro-2-propoxyaniline , 5-fluoro-2-butoxyaniline, 3-amino-4-methoxybenzoic acid, 3-amino-4-ethoxybenzoic acid, 3-amino-4-propoxybenzoic acid, 3-amino-4-butoxybenzoic acid, 2-aminophenol, 2-amino-4-methylphenol, 3-amino-4-methoxy-acetanilide, 3-amino-4-ethoxy-acetanilide, 3-amino-4-propoxy-acetanilide, 3-amino-4- Butoxy-acetanilide, 3- (2-amino-4-methylphenoxy) propane-1-sulfone 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-amino-4-methylphenoxy) 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-sulfone Acid, 2- (3-amino-4-methylphenoxy) ethane-1-sulfonic acid, 2- (3-aminophenoxy) ethane-1-sulfonic acid, 3- (2-amino-4-me (Xyphenoxy) 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-e Toxiphenoxy) butane-1-sulfonic acid, 2- (3-amino-4-ethoxyphenoxy) ethane-1-sulfonic acid, 3- (2-amino-4-chlorophenoxy) propane-1-sulfonic acid, 3- (2-amino-4-fluorophenoxy) propane-1-sulfonic acid, 4- (2-amino-4-chlorophenoxy) butane-1-sulfonic acid, 4- (2-amino-4-fluorophenoxy) butane- Examples thereof include 1-sulfonic acid, 2- (2-amino-4-chlorophenoxy) ethane-1-sulfonic acid, and 2- (2-amino-4-fluorophenoxy) ethane-1-sulfonic acid. These aromatic amines may have an amino group protected. Examples of the protecting group include an ω-methanesulfone group.

<Dye-based polarizing film>
The dye-based polarizing film includes a polarizing film substrate containing an azo compound represented by the formula (1) or a salt thereof as a dichroic dye. The dye-based polarizing film may be any of a neutral gray polarizing film and a color polarizing film, and is preferably a neutral gray polarizing film. Here, "neutral gray" refers to a state in which two polarizing films are overlapped so that their orientation directions are orthogonal to each other (hereinafter, also referred to as "orthogonal position"), and a specific wavelength in the wavelength region of the visible light region. Means less light leakage (color leakage).

  The dye-based polarizing film contains an azo compound represented by the formula (1) or a salt thereof as a dichroic dye singly or in combination of plural kinds, and further contains one or more other organic dyes as necessary. be able to. The other organic dye is not particularly limited, but is preferably a dye having an absorption characteristic in a wavelength region different from the absorption wavelength region of the azo compound represented by the formula (1) or a salt thereof and having high dichroism. Other organic dyes include, for example, C.I. Eye. direct. Yellow 12, sea. Eye. direct. Yellow 28, sea. Eye. direct. Yellow 44, sea. Eye. direct. Orange 26, sea. Eye. direct. Orange 39, sea. Eye. direct. Orange 71, sea. Eye. direct. Orange 107, sea. Eye. direct. Red 2, Sea. Eye. direct. Red 31, Sea. Eye. direct. Red 79, Sea. Eye. direct. Red 81, Sea. Eye. direct. Red 247, Sea. Eye. direct. Green 80 and Sea. Eye. direct. Green 59, and the dyes described in Patent Documents 1 to 6 and the like are typical examples. According to the purpose, a dye developed for a polarizing plate as described in Patent Documents 1 to 6 is used. Is preferred. These organic dyes are used as a free acid, an alkali metal salt (for example, a Na salt, a K salt, a Li salt), an ammonium salt, or a salt of an amine.

  When another organic dye is used in combination, the type of the organic dye to be mixed differs depending on whether the intended polarizing film is a neutral gray polarizing film, a color polarizing film for a liquid crystal projector, or another color polarizing film. The mixing ratio is not particularly limited, but generally, the total of at least one or more other organic dyes is 0.01 to 1 part by mass of the azo compound of the formula (1) or a salt thereof. It is preferably used in the range of 100 to 100 parts by mass, more preferably 0.1 to 10 parts by mass.

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

  When the intended polarizing film is a color polarizing film, the obtained polarizing film has a high single-plate average light transmittance in a specific wavelength region, and the average light transmittance in the orthogonal position is low, for example, a specific The kind and the mixing ratio of the other organic dyes to be used together are adjusted so that the single plate average light transmittance of 39% or more and the orthogonal position average light transmittance of 0.4% or less in the wavelength region. .

  Dye-based polarizing films are known in the art. A dichroic dye containing an azo compound represented by the formula (1) or a salt thereof and, if necessary, another dye is known to a polarizing film substrate (for example, a polymer film). The compound can be manufactured by containing and orienting by the method described above, mixing with liquid crystal, or orienting by a coating method.

  The polarizing film substrate is preferably a polymer film, and more preferably a film made of a polyvinyl alcohol resin or a derivative thereof. Specific examples of the polarizing film substrate include a polyvinyl alcohol resin or a derivative thereof, and an ethylene or olefin such as propylene, or a modified carboxylic acid such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid. And the like. As the polarizing film substrate, a film made of a polyvinyl alcohol resin or a derivative thereof is preferably used from the viewpoints of dye adsorption and orientation. The thickness of the polarizing film substrate is usually 10 to 100 μm, preferably about 20 to 80 μm.

  When the polarizing film substrate is a polymer film, a method of dyeing the polymer film is usually employed to contain the azo compound of the formula (1) or a salt thereof. Staining is performed, for example, as follows. First, a dye bath is prepared by dissolving the azo compound represented by the formula (1) or a salt thereof and, if necessary, other organic dyes in water. 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. If necessary, a dyeing assistant may be used. For example, it is preferable to use sodium sulfate in a concentration of, for example, about 0.1 to 10% by mass. For example, the polymer film is immersed in the dyeing bath prepared in this manner for 1 to 10 minutes to perform dyeing. The dyeing temperature is preferably about 30 to 80 ° C.

  The orientation of the azo compound represented by the formula (1) or a salt thereof is performed by stretching a polymer film dyed with a dichroic dye. The stretching ratio is generally 2 to 8 times, but is not limited, and is preferably 3 to 7.5 times, more preferably 4 to 7 times. As a stretching method, any known method such as a wet method and a dry method may be used. Stretching of the polymer film may optionally be performed before dyeing. In this case, the orientation of the water-soluble dye is performed at the time of dyeing. The polymer film containing and orienting the water-soluble dye is subjected to post-treatment such as boric acid treatment by a known method, if necessary. Such a post-treatment is performed for the purpose of improving the light transmittance and the degree of polarization of the polarizing film. The conditions of the boric acid treatment vary depending on the type of the polymer film to be used and the type of the dye to be used. In general, the boric acid concentration of the aqueous boric acid solution is, for example, 0.1 to 15% by mass, preferably 1 to 10% by mass. The treatment is carried out by immersing in a temperature range of 30 to 80 ° C., preferably 40 to 75 ° C. for 0.5 to 10 minutes. Further, if necessary, the fix treatment may be performed together with an aqueous solution containing a cationic polymer compound.

  Applications of the dye-based polarizing film include, for example, liquid crystal projectors, calculators, watches, notebook computers, word processors, liquid crystal televisions, car navigation systems, indoor and outdoor measuring instruments and displays, lenses, glasses, and the like. The dye-based polarizing film has high polarizing performance comparable to a polarizing film using iodine, and also has excellent durability. Therefore, it is particularly suitable for applications requiring high polarization performance and durability, for example, various liquid crystal displays such as for in-vehicle use and for outdoor display (for example, display use for industrial instruments and wearable use), and liquid crystal projectors. is there.

<Dye-based polarizing plate>
The dye-based polarizing plate can be obtained by laminating a transparent protective film on one or both sides of the dye-based polarizing film. Since the dye-based polarizing plate includes the above-described dye-based polarizing film, the dye-based polarizing plate has excellent polarization performance and moisture resistance, heat resistance, and light resistance. As a material for forming the transparent protective film, a material having excellent optical transparency and mechanical strength is preferable. A film made of a fluorine-based film, a polyester resin, a polyolefin resin, or a polyamide-based resin is used. The transparent protective film is preferably a triacetyl cellulose (TAC) film or a cycloolefin-based film. The thickness of the protective film is usually preferably from 40 to 200 μm.

  Examples of the adhesive that can be used for bonding the dye-based polarizing film and the protective film include a polyvinyl alcohol-based adhesive, a urethane emulsion-based adhesive, an acrylic-based adhesive, and a polyester-isocyanate-based adhesive. A system adhesive is preferred.

  A transparent protective layer may be further provided on the surface of the dye-based polarizing plate. Examples of the further transparent protective layer include, for example, an acrylic or polysiloxane-based hard coat layer and a urethane-based protective layer. In order to further improve the single-plate light transmittance, it is preferable to provide an AR layer (anti-reflection layer) on the transparent protective layer. The AR layer can be formed by vapor deposition or sputtering of a substance such as silicon dioxide or titanium oxide, or can be formed by applying a thin fluorine-based substance. It is preferable that the dye-based polarizing plate further includes a support. The dye-based polarizing plate can be used as an elliptically polarizing plate by attaching a retardation plate to the surface.

  The dye-based polarizing plate may be either a neutral gray polarizing plate or a color polarizing plate depending on the application.

  Neutral gray polarizers have neutral colors, have less orthogonal color leakage in the visible light polarization region, have excellent polarization performance, and are resistant to discoloration and deterioration in polarization performance even in high-temperature, high-humidity conditions. It is suitable for in-vehicle use or outdoor display because of its high performance.

  A neutral gray polarizer for in-vehicle or outdoor display is a polarizer composed of a dye-based polarizer and a transparent protective film, provided with an AR layer in order to further improve the unitary light transmittance, and a polarizer with an AR layer. It is more preferable that the AR layer and the polarizing plate with a support to which both the AR layer and a support such as a transparent resin are adhered are attached. The AR layer can be provided on one side or both sides of the polarizing plate. The support is preferably provided on one side of the polarizing plate, and may be provided directly on the polarizing plate, or a polarizing plate with an AR layer (AR layer / polarizing plate / AR layer) may be provided on the support. . The AR layer and the polarizing plate with a support are preferably provided with an AR layer / a polarizing plate / AR layer / a support in this order. The support preferably has a flat portion for attaching a polarizing plate, and is preferably a transparent substrate for optical use. As a transparent substrate, there are roughly divided into an inorganic substrate and an organic substrate, soda glass, borosilicate glass, a quartz substrate, a sapphire substrate, an inorganic substrate such as a spinel substrate, and acrylic, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, and An organic substrate such as a cycloolefin polymer may be used, but an organic substrate is preferred. The thickness and size of the transparent substrate may be any desired size.

  A color polarizing plate is excellent in polarization performance and does not cause discoloration or deterioration in polarization performance even in a high-temperature and high-humidity state, and thus is suitable for a liquid crystal projector and a display device such as a vehicle-mounted or outdoor display.

  The color polarizing plate for a liquid crystal projector has brightness and excellent polarization performance, and the required wavelength range of the polarizing plate (A. When using an ultra-high pressure mercury lamp; 420 to 500 nm for a blue channel, 500 to 500 nm for a green channel) 580 nm, red channel 600 to 680 nm, peak wavelength when using a B.3 primary color LED lamp; single plate average light transmittance in blue channel 430 to 450 nm, green channel 520 to 535 nm, red channel 620 to 635 nm) The average light transmittance at the orthogonal position is 39% or more, the average light transmittance at the orthogonal position is 0.4% or less, more preferably the average light transmittance of the single plate in the required wavelength region is 41% or more, and the average light transmittance at the orthogonal position is 0%. 0.3% or less, more preferably 0.2% or less. More preferably, the single plate average light transmittance in the required wavelength region of the polarizing plate is 42% or more, and the average light transmittance in the orthogonal position is 0.1% or less.

  The single-plate average light transmittance is defined as a specific wavelength region when natural light is incident on one polarizing plate (hereinafter, also simply referred to as “polarizing plate”) on which no support such as an AR layer and a transparent glass plate is provided. Is the average value of the light transmittance at The average light transmittance in the orthogonal position is the average value of the light transmittance in a specific wavelength region when natural light is incident in a state where two polarizing plates are superposed so that their orientation directions are orthogonal to each other.

  The polarizing film used for the in-vehicle or outdoor display color polarizing plate may be provided with a protective layer or an AR layer and a support, if necessary, on the dye-based polarizing plate, as in the case of the neutral gray polarizing plate. Good. The color polarizing plate with a support can be obtained by, for example, applying a transparent adhesive (adhesive) to the flat surface of the support, and then attaching a dye-based polarizing plate to the coated surface. Alternatively, a transparent adhesive (adhesive) agent may be applied to a dye-based polarizing plate, and then a support may be attached to the applied surface. The adhesive (adhesive) is preferably, for example, an acrylate-based adhesive. In addition, when this dye-based polarizing plate is used as an elliptically polarizing plate, it is usual that the retardation plate side is attached to a support and the dye-based polarizing plate / the retardation plate / the support is stacked in the order given. The polarizing plate side may be attached to the support, and the order of the retardation plate / polarizing plate / support may be set.

<Liquid crystal display device>
A liquid crystal display device includes the above-mentioned dye-based polarizing film or dye-based polarizing plate. Liquid crystal display devices are used for, for example, calculators, watches, notebook computers, word processors, liquid crystal televisions, car navigation systems, and displays such as indoor and outdoor measuring instruments and displays, and particularly require high polarization performance and durability. It is suitably used for various liquid crystal displays, for example, for in-vehicle use or for outdoor display (for example, display use of industrial instruments and wearable use). The dye-based polarizing film or dye-based polarizing plate provided in the liquid crystal display device is preferably neutral gray.

  In a liquid crystal display device, a dye-based polarizing plate is arranged on one or both of an incident side and an outgoing side of a liquid crystal cell. The dye-based polarizing plate may or may not be in contact with the liquid crystal cell, but is preferably not in contact from the viewpoint of durability. When the dye-based polarizing plate is in contact with the liquid crystal cell on the emission side of the liquid crystal cell, the liquid crystal cell can be used as a support for the dye-based polarizing plate. When the dye-based polarizing plate is not in contact with the liquid crystal cell, it is preferable 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 preferable that the dye-based polarizing plate is disposed on both the incident side and the outgoing side of the liquid crystal cell. It is preferable to arrange on the light source side. Note that the incident side of the liquid crystal cell is the side of the light source, and the opposite side is called the exit side.

  A liquid crystal cell provided in a liquid crystal display device is, for example, an active matrix type, and is formed by sealing liquid crystal between a transparent substrate on which electrodes and TFTs are formed and a transparent substrate on which a counter electrode is formed. Is preferred. Light emitted from a light source such as a cold-cathode tube lamp or a white LED passes through a dye-based polarizing plate, then passes through a liquid crystal cell, a color filter, and further a dye-based polarizing plate, and is projected on a display screen.

  In liquid crystal display devices, the dye-based polarizing plate has brightness and excellent polarization performance, as well as polarization and light resistance, so that discoloration and deterioration in polarization performance are unlikely to occur even in high-temperature, high-humidity conditions such as in a car or outdoors, and reliability is high. high.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but these are illustrative and do not limit the present invention in any way. The percentages and parts in the examples are based on mass unless otherwise specified.

(Example E1: Synthesis of azo compound of formula (A-3))
30.3 parts of 7-aminonaphthalene-1,3-disulfonic acid are added to 500 parts of water, cooled, 31.3 parts of 35% hydrochloric acid is added at 10 ° C. or lower, and then 6.9 parts of sodium nitrite are added. The mixture was stirred at 〜１０10 ° C. for 1 hour to be diazotized. Thereto, 12.3 parts of 2-methoxyaniline was added, and the mixture was adjusted to pH 3 with sodium carbonate while stirring at 10 to 30 ° C. The mixture was further stirred to complete the coupling reaction, filtered, and then subjected to the following formula (A-3M) 30.6 parts of a monoazoamino compound represented by the following formula were obtained.

30.6 parts of the obtained monoazoamino compound was added to 400 parts of water, dissolved with sodium hydroxide, 21.9 parts of 35% hydrochloric acid was added at 10 to 30 ° C, and then 4.8 parts of sodium nitrite was added. The mixture was stirred at 20 to 30 ° C. for 1 hour to be diazotized. Thereto, 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid was added, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further stirred and stirred. The ring reaction was completed and filtered to obtain 38.8 parts of a disazoamino compound represented by the following formula (A-3D).

  24.5 parts of the monoazoamino compound (A-3M) was added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate was stirred at 30 to 50 ° C for 2 hours, and then the disazoamino compound (A -3D) 38.8 parts was added, and the mixture was stirred at 50 to 70 ° C. for 5 hours to ureide. After salting out with sodium chloride and filtration, 12.5 parts of a ureide compound represented by the above formula (A-3) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 454 nm.

(Example E2: Synthesis of azo compound of formula (A-6))
24.2 parts of 7-aminonaphthalene-1,3-disulfonic acid are added to 400 parts of water, cooled, 25.0 parts of 35% hydrochloric acid are added at 10 ° C. or lower, and 5.5 parts of sodium nitrite are added. The mixture was stirred at 〜１０10 ° C. for 1 hour to be diazotized. 8.6 parts of 2-methylaniline was added thereto, and the mixture was adjusted to pH 3 with sodium carbonate while stirring at 10 to 30 ° C. The mixture was further stirred to complete the coupling reaction, filtered, and then subjected to the following formula (A-6MR) 23.6 parts of a monoazoamino compound represented by the formula were obtained.

  38.8 parts of disazoamino compound (A-3D) and 23.6 parts of monoazoamino compound (A-6MR) are added to 500 parts of water, dissolved with sodium hydroxide, and 12.9 parts of 4-nitrophenyl chloroformate is added. The mixture was stirred at 50 to 70 ° C. for 4 hours to ureide. Salting out with sodium chloride and filtration gave 12.2 parts of a ureide compound represented by the above formula (A-6). The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 443 nm.

(Example E3: Synthesis of azo compound of formula (A-19))
29.5 parts of a monoazoamino compound (A-6MR) were added to 400 parts of water, dissolved with sodium hydroxide, and 21.9 parts of 35% hydrochloric acid was added at 10 to 30 ° C., and then 4.8 parts of sodium nitrite was added. In addition, the mixture was stirred at 20 to 30 ° C. for 1 hour to be diazotized. Thereto, 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid was added, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further stirred and stirred. The ring reaction was completed and filtered to obtain 38.0 parts of a disazoamino compound represented by the following formula (A-19D).

  38.0 parts of the obtained disazoamino compound (A-19D) and 24.5 parts of the monoazoamino compound (A-3M) were added to 500 parts of water, dissolved with sodium hydroxide, and 4-nitrophenyl chloroformate was added. 9 parts were stirred at 50-70 ° C for 4 hours to ureide. The solution was salted out with sodium chloride and filtered to obtain 9.4 parts of a ureide compound represented by the above formula (A-19). The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 438 nm.

(Example E4: Synthesis of azo compound of formula (A-20))
Example E3 except for using 16.2 parts of 3- (2-aminophenoxy) propane-1-sulfonic acid in place of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid. In the same manner as in the above, 11.2 parts of a ureide compound represented by the above formula (A-20) were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 430 nm.

(Example E5: Synthesis of azo compound of formula (A-32))
A ureide represented by the above formula (A-32) in the same manner as in Example E1, except that 9.3 parts of aniline was used in place of 2-methoxyaniline as a raw material of the disazoamino compound (A-3D). 10.2 parts of the compound were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 440 nm.

(Example E6: Synthesis of azo compound of formula (A-36))
In the same manner as in Example E3, except that 8.5 parts of 2,5-dimethylaniline was used instead of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid, the above formula (A) was used. -36) 9.0 parts of a ureide compound represented by the above formula was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 416 nm.

(Example E7: Synthesis of azo compound of formula (A-130))
11.0 parts of 4-aminobenzoic acid are added to 300 parts of water, cooled, 25.0 parts of 35% hydrochloric acid are added at 10 ° C. or less, then 5.5 parts of sodium nitrite is added, and the mixture is added at 5 to 10 ° C. for 1 hour. Stir and diazotize. Thereto, 11.0 parts of 2-methoxy-5-methylaniline was added, and sodium carbonate was added to pH 3 while stirring at 10 to 30 ° C., and the mixture was further stirred to complete the coupling reaction. A-130MR).

  16.0 parts of the obtained monoazoamino compound (A-130MR) was added to 500 parts of water, dissolved with sodium hydroxide, and 10.0 parts of phenyl chloroformate was stirred at 30 to 50 ° C for 2 hours, and then disazoamino. 38.0 parts of compound (A-19D) was added, and the mixture was ureidized at 50 to 70 ° C. After salting out with sodium chloride and filtration, 10.4 parts of a ureide compound represented by the above formula (A-130) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 441 nm.

(Example E8: Synthesis of azo compound of formula (A-61))
25.3 parts of 4-aminobenzene-1,3-disulfonic acid are added to 500 parts of water, cooled and, at 10 ° C. or lower, 31.3 parts of 35% hydrochloric acid are added, and then 6.9 parts of sodium nitrite are added. The mixture was stirred at 5 to 10 ° C. for 1 hour to be diazotized. Thereto, 12.1 parts of 2,5-dimethylaniline was added, and sodium carbonate was added to adjust the pH to 3 while stirring at 10 to 30 ° C., and the mixture was further stirred to complete the coupling reaction. A-61ML).

27.0 parts of the obtained monoazoamino compound are added to 400 parts of water, dissolved with sodium hydroxide, 25.0 parts of 35% hydrochloric acid are added at 10 to 30 ° C, and then 5.5 parts of sodium nitrite are added. The mixture was stirred at 20 to 30 ° C. for 1 hour to diazotize. Thereto, 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid was added, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further stirred and stirred. The ring reaction was completed and filtered to obtain 35.9 parts of a disazoamino compound represented by the following formula (A-61D).

  24.5 parts of the monoazoamino compound (A-3M) was added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate was stirred at 30 to 50 ° C for 4 hours, and then the disazoamino compound (A -61D) 35.9 parts was added, and the mixture was stirred at 50 to 70 ° C for 5 hours to ureide. Salting out with sodium chloride and filtration gave 12.1 parts of a ureide compound represented by the above formula (A-61). The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 435 nm.

(Example E9: Synthesis of azo compound of formula (A-92))
Except that 10.7 parts of 2-methylaniline was used instead of 2,5-dimethylaniline, 11.1 parts of a ureide compound represented by the above formula (A-92) was obtained in the same manner as in Example E8. Was. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 435 nm.

(Example E10: Synthesis of azo compound of formula (A-95))
Example E9 except for using 16.2 parts of 3- (2-aminophenoxy) propane-1-sulfonic acid instead of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid In the same manner as in the above, 12.7 parts of a ureide compound represented by the above formula (A-95) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 428 nm.

(Example E11: Synthesis of azo compound of formula (A-99))
A ureide represented by the above formula (A-99) in the same manner as in Example E9 except that 16.2 parts of 3- (2-aminophenoxy) propane-1-sulfonic acid was used instead of 2-methoxyaniline. 13.5 parts of compound were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 434 nm.

(Example E12: Synthesis of azo compound of formula (A-100))
11.0 parts of a ureide compound represented by the above formula (A-100) was obtained in the same manner as in Example E9 except that 12.1 parts of 2-ethylaniline was used instead of 2-methylaniline. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 435 nm.

(Example E13: Synthesis of azo compound of formula (B-17))
25.3 parts of 4-aminobenzene-1,3-disulfonic acid are added to 500 parts of water, cooled and, at 10 ° C. or lower, 31.3 parts of 35% hydrochloric acid are added, and then 6.9 parts of sodium nitrite are added. The mixture was stirred at 5 to 10 ° C. for 1 hour to be diazotized. Thereto, 12.1 parts of 2,5-dimethylaniline was added, and sodium carbonate was added to adjust the pH to 3 while stirring at 10 to 30 ° C., and the mixture was further stirred to complete the coupling reaction. B-17ML) was obtained.

30.8 parts of the obtained monoazoamino compound was added to 400 parts of water, dissolved with sodium hydroxide, 25.0 parts of 35% hydrochloric acid was added at 10 to 30 ° C., and 5.5 parts of sodium nitrite was added. The mixture was stirred at 20 to 30 ° C. for 1 hour to be diazotized. Thereto, 11.0 parts of 2-methoxy-5-methylaniline was added, and sodium carbonate was added to adjust the pH to 3 while stirring at 20 to 30 ° C., and the mixture was further stirred to simplify the coupling reaction. Thus, 34.1 parts of a disazoamino compound represented by the formula (B-17D) was obtained.

Add 11.0 parts of 4-aminobenzoic acid to 250 parts of water, cool and add, at 10 ° C or lower, 25.3 parts of 35% hydrochloric acid, then add 5.5 parts of sodium nitrite, and add 5 to 10 ° C. The mixture was stirred for 1 hour and diazotized. Thereto, 11.0 parts of 2-methoxy-5-methylaniline was added, and while stirring at 10 to 30 ° C., sodium carbonate was added to adjust the pH to 3, and the mixture was further stirred to complete the coupling reaction. Thus, 18.3 parts of a monoazoamino compound represented by the formula (B-17MR) was obtained.

  18.3 parts of the obtained monoazoamino compound (B-17MR) was added to 250 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate was stirred at 30 to 50 ° C for 4 hours, and then disazoamino 34.1 parts of the compound (B-17D) was added, and the mixture was stirred at 50 to 70 ° C. for 5 hours to ureide. After salting out with sodium chloride and filtration, 10.5 parts of a ureide compound represented by the above formula (B-17) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 435 nm.

(Example E14: Synthesis of azo compound of formula (B-1))
11. A ureido compound represented by the above formula (B-1) in the same manner as in Example E13 except that 20.3 parts of 4-aminobenzene-1,3-disulfonic acid is used instead of 4-aminobenzoic acid. 0 parts were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 427 nm.

(Example E15: Synthesis of azo compound of formula (B-20))
10.2 parts of a ureide compound represented by the above formula (B-20) in the same manner as in Example E13 except that 13.8 parts of 5-amino-2-chlorobenzoic acid is used instead of 4-aminobenzoic acid. I got The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 432 nm.

Example E16: Synthesis of azo compound of formula (B-29)
Example E14 was repeated except that 18.7 parts of 2-amino-5-methylbenzenesulfonic acid was used instead of 4-aminobenzene-1,3-disulfonic acid as a raw material of the disazoamino compound (B-17D). Similarly, 10.1 parts of a ureide compound represented by the above formula (B-29) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 425 nm.

(Example E17: Synthesis of azo compound of formula (B-48))
13.5 parts of a ureide compound represented by the above formula (B-48) was obtained in the same manner as in Example E13 except that 10.7 parts of 2-methylaniline was used instead of 2,5-dimethylaniline. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 433 nm.

(Example E18: Synthesis of azo compound of formula (C-5))
30.8 parts of a monoazoamino compound (B-17ML) are added to 400 parts of water, dissolved with sodium hydroxide, 25.0 parts of 35% hydrochloric acid are added at 10 to 30 ° C., and then 5.5 parts of sodium nitrite are added. Was added and stirred at 20 to 30 ° C. for 1 hour to diazotize. To the mixture, 19.6 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid was added, and the mixture was adjusted to pH 4 with sodium carbonate while stirring at 20 to 30 ° C., and further stirred. The ring reaction was completed and filtered to obtain 41.0 parts of a disazoamino compound represented by the following formula (C-5D).

15.0 parts of 2-amino-5-methylbenzenesulfonic acid are added to 250 parts of water, cooled and, at 10 ° C. or lower, 25.0 parts of 35% hydrochloric acid are added, and then 5.8 parts of sodium nitrite are added. The mixture was stirred at 5 to 10 ° C. for 1 hour to be diazotized. Thereto, 11.0 parts of 2-methoxy-5-methylaniline was added, and while stirring at 10 to 30 ° C., sodium carbonate was added to adjust the pH to 3, and the mixture was further stirred to complete the coupling reaction. Thus, 21.5 parts of a monoazoamino compound represented by the formula (C-5MR) was obtained.

  21.5 parts of the obtained monoazoamino compound (C-5MR) were added to 500 parts of water, dissolved with sodium hydroxide, and 10.0 parts of phenyl chloroformate was stirred at 30 to 50 ° C for 2 hours. 41.0 parts of the compound (C-5D) was added, and the mixture was stirred at 50 to 70 ° C for 5 hours to ureide. It was salted out with sodium chloride and filtered to obtain 12.9 parts of a ureide compound represented by the above formula (C-5). The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 425 nm.

(Example E19: Synthesis of azo compound of formula (C-16))
11. A ureido compound represented by the above formula (C-16) in the same manner as in Example E18 except that 11.0 parts of 4-aminobenzoic acid was used instead of 2-amino-5-methylbenzenesulfonic acid. 8 parts were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 437 nm.

(Example E20: Synthesis of azo compound of formula (C-19))
It is represented by the above formula (C-19) in the same manner as in Example E18 except that 13.8 parts of 5-amino-2-chlorobenzoic acid was used instead of 2-amino-5-methylbenzenesulfonic acid. 13.5 parts of a ureide compound were obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 435 nm.

Example E21: Synthesis of azo compound of formula (C-46)
10.7 parts of 2-methylaniline was used instead of 2,5-dimethylaniline, and 3- (2-amino-4-methylphenoxy) propane-1 was used instead of 2-methoxy-5-methylaniline. -In the same manner as in Example E19 except that 19.7 parts of sulfonic acid was used, 13.1 parts of a ureide compound represented by the above formula (C-46) was obtained. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 440 nm.

(Example E22: Synthesis of azo compound of formula (C-49))
10.7 parts of 2-methylaniline was used instead of 2,5-dimethylaniline, and 3- (2-amino-4-chlorophenoxy) propane-1- was used instead of 2-methoxy-5-methylaniline. Except that 21.3 parts of sulfonic acid were used, 13.7 parts of a ureide compound represented by the above formula (C-49) was obtained in the same manner as in Example E19. The maximum absorption wavelength of this compound in a 20% aqueous pyridine solution was 438 nm.

(Examples F1 to F22: Production of Dye-Based Polarizing Film)
Formulas (A-3), (A-6), (A-19), (A-20), (A-32), (A-36), and (A-) obtained in Examples E1 to E22. 130), (A-61), (A-92), (A-95), (A-99), (A-100), (B-17), (B-1), (B-20) , (B-29), (B-48), (C-5), (C-16), (C-19), (C-46), and (C-49) of each azo compound. A 75 μm-thick polyvinyl alcohol was immersed for 4 minutes in each aqueous solution (dye bath) at a concentration of 03% and sodium sulfate 0.1% at 45 ° C. This film was stretched 5 times in a 3% aqueous solution of boric acid at 50 ° C., washed with water while keeping the tension, and dried to obtain a polarizing film.
Table 1 shows the absorption wavelength at which the polarization rate of the obtained dye-based polarizing film is maximized and the polarization rate. As shown in Table 1, each of the polarizing films manufactured using the compounds of the present invention had a high polarization rate.

The measurement of the absorption wavelength when the polarization ratio of the polarizing film is maximized and the calculation of the polarization ratio are performed by using a spectrophotometer (U-4100 manufactured by Hitachi, Ltd.) to measure the parallel transmittance and the orthogonal transmittance when the polarized light is incident. Calculated using the ratio.
Here, the parallel transmittance (Ky) is a transmittance measured by setting an absorption axis of an absolute polarizer (a polarizing plate having a polarization degree of 99.99%) and an absorption axis of a polarizing film in parallel, and orthogonal transmission. The rate (Kz) indicates a transmittance measured by setting the absorption axis of the absolute polarizer and the absorption axis of the polarizing film at right angles.
The parallel transmittance and the orthogonal transmittance of each wavelength were measured at 1 nm intervals at 380 to 780 nm. Using the measured values, the polarization ratio of each wavelength was calculated from the following formula (I), and the highest polarization ratio at 380 to 780 nm and the absorption wavelength (nm) at that time were obtained.

Polarization ratio (%) = [(Ky−Kz) / (Ky + Kz)] × 100 (I)

(Comparative Example 1: Production of polarizing film)
A polarizing film was produced in the same manner as in Example F1, except that C.I.Direct Orange 39 was used instead of the compound of the formula (A-3).

(Comparative Example 2: Production of polarizing film)
A polarizing film was produced in the same manner as in Example F1, except that CI Direct Yellow 44 was used instead of the compound of the formula (A-3).

  One index indicating the quality of an image is a contrast indicating a difference in luminance between white display and black display. Table 2 shows the contrast at the maximum absorption wavelength of the dye-based polarizing films obtained in Examples F1 to F22 and Comparative Examples 1 and 2. Here, the contrast indicates the ratio of the parallel transmittance and the orthogonal transmittance (contrast = parallel transmittance at the maximum absorption wavelength (Ky) / orthogonal transmittance at the maximum absorption wavelength (Kz)). It indicates that the polarization performance of the polarizing plate is excellent. The evaluation of the polarization performance was made by making a sample such that the parallel transmittance at the maximum absorption wavelength of the dye-based polarizing film was equal, and was compared. As shown in Table 2, the dye-based polarizing films of Examples F1 to F22 all had higher contrast than the dye-based polarizing films of Comparative Examples 1 and 2.

(Example P1: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (A-19) obtained in Example E3, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P2: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (A-20) obtained in Example E4, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution of 45% at a concentration of 1% was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P3: Production of neutral gray polarizing plate)
0.1% of the compound of formula (A-61) obtained in Example E8, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of a single plate at 380 to 700 nm of the obtained polarizing film was 42%, the average transmittance at the orthogonal position was 0.02%, and the polarizing film had a high degree of polarization. A triacetyl cellulose film (TAC film: manufactured by FUJIFILM Corporation: trade name: TD-80U) is laminated through an adhesive, and a support provided with an AR layer is attached using an adhesive, and a TAC / polarizing film is formed. A / TAC / AR support was laminated in this order to obtain a dye-based polarizing plate (neutral gray polarizing plate).

(Example P4: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (A-92) obtained in Example E9, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P5: Production of neutral gray polarizing plate)
0.1% of the compound of formula (A-95) obtained in Example E10, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution of 45% at a concentration of 1% was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P6: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (A-100) obtained in Example 12, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P7: Production of neutral gray polarizing plate)
0.1% of the compound of formula (B-17) obtained in Example E13, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P8: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (B-29) obtained in Example E16, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P9: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (B-48) obtained in Example E17, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P10: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (C-16) obtained in Example E19, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P11: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (C-19) obtained in Example E20, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

(Example P12: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (C-46) obtained in Example E21, 0.2% of C.I.Direct Red 81, 0.05% of C.I.Direct Blue 274, and 0.1% of sodium sulfate. A polarizing film was prepared in the same manner as in Example F1, except that an aqueous solution at a concentration of 1% and 45 ° C. was used. The average transmittance of the obtained polarizing film in a single plate at 380 to 700 nm was 42%, and the average transmittance in the orthogonal position was 0.02%, indicating a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: trade name: TD-80U, manufactured by Fuji Film Co., Ltd.) is laminated on both surfaces of this polarizing film via an adhesive of a polyvinyl alcohol aqueous solution, and an AR layer is provided using an adhesive. Was applied to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support were laminated in this order.

  The neutral gray polarizers obtained in Examples P1 to P12 show no change in single-plate average transmittance even after 400 hours under the conditions of 80 ° C. and 90% RH, and remain in a high temperature and high humidity state for a long time. It showed durability. Further, the neutral gray polarizing plates of Examples P1 to P12 did not change in the average transmittance of a single plate even after 200 hours had passed in the xenon lightfastness test, and had excellent lightfastness to long-term exposure to light. From these results, it is shown that the neutral gray polarizing plates of Examples P1 to P12 all have excellent polarizing performance and are high performance dye-based polarizing plates having moisture resistance, heat resistance, and light resistance. Was done.

Claims (22)

The following equation (1):

(Wherein, A ¹ and A ² are each independently a naphthyl group which may have a substituent selected from the group consisting of a hydroxy group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or A phenyl group which may have a group,
R _{1 to} R ₆ each independently represent a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a C 1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C 1-4 alkyl-substituted acylamino. Is the base)
Or an azo compound represented by the formula: One or both of A ¹ and A ² (if both are independent), a sulfo group, a carboxy group, a C1-4 alkoxy group having a sulfo group, a C1-4 alkyl group, a C1-4 alkoxy group, a halogen group C1 such as nitro group, amino group, N, N-dimethylamino group, N, N-diethylamino group, methylamino group, ethylamino group, n-propylamino group, n-butylamino group and sec-butylamino group A phenyl group having at least one substituent selected from the group consisting of a C1-4 alkyl-substituted acylamino group such as an acetylamino group, a propionamide group and a butylamide group; Or the salt thereof. One or both of A ¹ and A ² (each independently if both) have at least one substituent selected from a sulfo group, a carboxy group, and a C1-4 alkoxy group having a sulfo group, and Atom, sulfo group, carboxy group, C1-4 alkoxy group having a sulfo group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, C1-4 alkyl-substituted amino group, or C1 3. The azo compound or a salt thereof according to claim 1, which is a phenyl group further having a 4-alkyl-substituted acylamino group. When one or both of A ¹ and A ² (if both are independent), the following formula (2):

(In the formula, one of R ₇ and R ₈ is a C 1-4 alkoxy group having a sulfo group, a carboxyl group, or a sulfo group, and the other is a C 1-4 alkoxy group having a hydrogen atom, a sulfo group, a carboxy group, or a sulfo group. Group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, C1-4 alkyl-substituted amino group, or C1-4 alkyl-substituted acylamino group)
The azo compound or a salt thereof according to any one of claims 1 to 3, which is a phenyl group represented by the formula: The azo compound or a salt thereof according to claim 4, wherein one of R ₇ and R ₈ is a sulfo group or a carboxyl group, and the other is a hydrogen atom, a sulfo group, a carboxy group, a methyl group, or a methoxy group. The azo compound or a salt thereof according to any one of claims 1 to 5, wherein at least one of A ¹ and A ² is the naphthyl group. The azo compound or a salt thereof according to any one of claims 1 to 6, wherein both A ¹ and A ² are the phenyl group. When one or both of A ¹ and A ² (if both are independent), the following formula (3):

(In the formula, R ₉ is a hydrogen atom, a hydroxy group, a C1-4 alkoxy group having a sulfo group, or a sulfo group, and n is an integer of 1 to 3.)
The azo compound or a salt thereof according to any one of claims 1 to 6, which is a naphthyl group represented by the following formula: The azo compound or a salt thereof according to claim 8, wherein R ₉ is a hydrogen atom and n is 2. The following equation (4):

(Wherein, R _{1 to} R ₆ are as defined in formula (1))
The azo compound or a salt thereof according to any one of claims 1 to 9, which is represented by the formula: The following equation (5):

(Wherein, at least one of R _{10 to} R ₁₃ is a sulfo group, and the others are a hydrogen atom, a sulfo group, a carboxyl group, a C1-4 alkoxy group having a sulfo group, a methyl group, or a methoxy group; _{1 to} R ₆ are as defined in formula (1))
The azo compound according to any one of claims 1 to 5, or a salt thereof. R _{1 to} R ₆ are each independently a hydrogen atom, a C 1-4 alkyl group, a C 1-4 alkoxy group, a halogen group, or a C 1-4 alkoxy group having a sulfo group. Or the salt thereof. The R ₁ to R ₆ are each independently, C1 -4 alkoxy group having a sulfo group, a hydrogen atom, a methyl group, an ethyl group, a halogen group, or a methoxy group, according to any one of claims 1 to 12 Or an salt thereof. The azo compound or a salt thereof according to any one of claims 1 to 13, wherein at least one of R _{1 to} R ₆ is a C1-4 alkoxy group having a sulfo group.   The azo compound or a salt thereof according to claim 14, wherein the C1-4 alkoxy group having a sulfo group is a 3-sulfopropoxy group.   A dye-based polarizing film comprising a polarizing film substrate containing the azo compound according to any one of claims 1 to 15 or a salt thereof.   A dye-based polarizing film comprising a polarizing film substrate comprising the azo compound according to any one of claims 1 to 15 or a salt thereof, and at least one other organic dye.   18. The dye-based polarizing film according to claim 16, wherein the polarizing film substrate is a film made of a polyvinyl alcohol resin or a derivative thereof.   A dye-based polarizing plate having a transparent protective layer attached to one or both surfaces of the dye-based polarizing film according to any one of claims 16 to 18.   A polarizing plate for a liquid crystal display comprising the dye-based polarizing film according to any one of claims 16 to 18 or the dye-based polarizing plate according to claim 19.   A neutral gray polarizing plate comprising the dye-based polarizing film according to any one of claims 16 to 18 or the dye-based polarizing plate according to (19).   A liquid crystal display device comprising the dye-based polarizing plate according to claim 19, the liquid crystal display polarizing plate according to claim 20, or the neutral gray polarizing plate according to claim 21.