WO2018181470A1 - Azo compound or salt thereof, and dye-based polarizing film, dye-based polarizing plate, and liquid-crystal display apparatus containing same - Google Patents

Abstract

The purpose of the present invention is to provide an azo compound that is useful as a dichroic dye to be used in a polarizing plate. The present invention provides an azo compound represented by formula (1) or a salt thereof. (In the formula, each of A1 and A2 is, independently of each other: a naphthyl group that may have a substituent selected from a group consisting of a hydroxy group, an alkoxy group having a sulfo group and 1 to 4 carbon atoms, and a sulfo group; or a phenyl group that may have a substituent selected from the same. Each of R1 to R6 is, independently of each other: a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxy group having a sulfo group and 1 to 4 carbon atoms, a carboxy group, a hydroxy group, a halogen group; or an alkyl-substituted acylamino group having 1 to 4 carbon atoms.)

Description

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

The present invention relates to a novel aazo 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. The 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, and indoor and outdoor measuring devices. Further, it can be applied to a lens having a polarization function, and has been applied to sunglasses with improved visibility, and in recent years to polarized glasses compatible with 3D televisions. Since the applications of polarizing plates as described above are widespread, polarizing plates are used in a wide range of conditions from low temperature to high temperature, low humidity to high humidity, low light intensity to high light intensity, so high polarization performance and high durability There is a need for a polarizing plate having a property.

Currently, polarizing plates are used for polarizing film substrates such as stretched and oriented films of polyvinyl alcohol or derivatives thereof, polyene films formed by dehydrochlorination of polyvinyl chloride films or dehydration of polyvinyl alcohol films, and the like. It is produced by dyeing or containing iodine or a dichroic dye. These are substances that greatly affect the polarization characteristics and durability of the polarizing plate. Although an iodine polarizing film using iodine is excellent in polarization performance, it is weak against 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, treatment 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, although a dye-type polarizing film using a dye is excellent in moisture resistance and heat resistance as compared with an iodine-type polarizing film, the polarizing performance is generally not sufficient.

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

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 range, when the polarizing film is mounted on a 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, a neutral color in which several dyes are dyed or contained in a polymer film is used to prevent discoloration of the liquid crystal display due to color leakage of a specific wavelength in the dark state. In such a polarizing film, the orthogonal transmittance (orthogonal transmittance) in the wavelength region of the visible light region must be uniformly reduced. In addition, in-vehicle liquid crystal displays, which are in a high temperature and high humidity environment in a summer car, there is a demand for a polarizing plate that does not change the degree of polarization even in a harsh environment. Previously, iodine-based polarizing plates with good polarization performance and neutral gray were used. However, iodine-based polarizing plates have a problem that 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 containing several kinds of dichroic dyes or containing dyes has been used. The dye-based neutral gray polarizing plate is generally used in combination with red, blue, and yellow dyes that are the three primary colors of light. However, as described above, the polarizing 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.

The characteristic of the dye system is that, as described above, in order to control the components of the three primary colors of light, each corresponding dye is dyed or contained. A light source used in a liquid crystal display panel in recent years includes a cold cathode tube method or an LED method, and the wavelength of the light source emitted from the light source differs depending on the method. Therefore, in developing a dichroic dye having good polarization performance, it is particularly important to design a dichroic dye having an absorption wavelength that matches the wavelength of the light source.

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

Japanese Patent Laid-Open No. 03-12606 JP 2001-33627 A JP 2009-132794 A JP 2001-240762 A JP 2001-108828 A JP-A-60-156759

One of the objects 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). Furthermore, another object of the present invention is a polarizing plate exhibiting a neutral gray formed by adsorbing and orienting two or more kinds of dichroic dyes on a polymer film, wherein the color is orthogonal in the wavelength region of the visible light region. An object of the present invention is to provide a polarizing plate having no polarization and excellent polarization performance.
A further object is a dye-based neutral gray polarizing plate for in-vehicle liquid crystal displays, which provides a high-performance polarizing plate with good brightness, polarization performance, and durability (moisture resistance, heat resistance, or light resistance). There is.

As a result of diligent research to achieve such an object, the present inventors have found that a polarizing film and a polarizing plate containing a specific azo compound or a salt thereof have excellent polarizing performance, and completed the present invention. did.

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

(In the formula, 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 substituted group. A phenyl group which may have a group,
R ₁ to R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C1-4 alkyl-substituted acylamino. Base)
Or a salt thereof.
(2) one or both of A ¹ and A ² (if both are independently), 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 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 A phenyl group having one or more substituents selected from the group consisting of C1-4 alkyl-substituted amino groups such as C1-4 alkyl-substituted acylamino groups such as acetylamino group, propionamide group, butyramide group, The azo compound or a salt thereof according to 1).
(3) One or both of A ¹ and A ² (in each case independently) have at least one substituent selected from a sulfo group, a carboxy group, and a C1-4 alkoxy group having a sulfo group. A C1-4 alkoxy group having a hydrogen atom, sulfo group, carboxy group, sulfo group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, C1-4 alkyl substituted amino group, Or an azo compound or a salt thereof according to (1) or (2), which is a phenyl group further having a C1-4 alkyl-substituted acylamino group.
(4) One or both of A ¹ and A ² (if both are independently), the following formula (2):

(In the formula, one of R ₇ and R ₈ is a C1-4 alkoxy group having a sulfo group, a carboxyl group, or a sulfo group, and the other is a C1-4 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 (1) to (3), which is a phenyl group represented by the formula:
(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 group.
(8) One or both of A ¹ and A ² (if both are independently), the following formula (3):

(Wherein 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 formula (4):

(Wherein R ₁ to R ₆ are as defined in formula (1))
The azo compound or salt thereof according to any one of (1) to (9)
(11) The following formula (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 or salt thereof according to any one of (1) to (5)
(12) R ₁ to R ₆ are each independently a C1-4 alkoxy group having a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a halogen group, or a sulfo group (1) to (11) Or an azo compound according to any one of the above.
(13) R ₁ to R ₆ are each independently a C1-4 alkoxy group having a sulfo group, a hydrogen atom, a methyl group, an ethyl group, a halogen group, or a methoxy group, and any one of (1) to (12) 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 substrate containing the azo compound or 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 a salt thereof according to any one of (1) to (15) and one or more organic dyes other than these.
(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 in which a transparent protective layer is bonded to one side or both sides 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 polarizing plate for liquid crystal display according to (20), or the neutral gray polarizing plate according to (21).

The azo compound or a salt thereof of the present invention is useful as a dye for a polarizing film. And the polarizing film of this invention containing the said azo compound or its salt has a high polarizing performance comparable to the polarizing film using an 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 display bodies and liquid crystal projectors, in-vehicle applications that require high polarization performance and durability, and display applications for 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 having a substituent. In one embodiment, both A ¹ and A ² are phenyl groups. In another embodiment, at least one of A ¹ and A ² is an optionally substituted naphthyl group. When both A ¹ and A ² are naphthyl groups which may have a substituent, the substituents which the naphthyl group has may be the same or different. When both A ¹ and A ² are phenyl groups which may have a substituent, the substituents which the phenyl group has may be the same or different. In the specification and claims of the present application, “lower” in “lower alkyl” and “lower alkoxy” represents 1 to 4 carbon atoms. It is also expressed 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 group. An alkyl-substituted acylamino group is a phenyl group having one or more substituents selected from the group consisting of phenyl groups. 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 sulfo group, hydrogen atom, lower alkyl group, lower alkoxy group, lower alkoxy group having sulfo group, carboxy group, chloro group, bromo group, nitro group, amino group, lower alkyl-substituted amino group, or A lower alkyl-substituted acylamino group is preferred. More preferably, the other substituents are 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. 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 , Butylamide group, etc., 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 preferably only 2-position, only 4-position, combination of 2-position and 6-position, combination of 2-position and 4-position, and combination of 3-position and 5-position Particularly preferred are 2-position only, 4-position only, a combination of 2-position and 4-position, or a combination of 3-position and 5-position. The 2-position only and 4-position only indicate that the 2-position or 4-position only has one substituent other than a hydrogen atom.

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

One of R ₇ and R ₈ is a lower alkoxy group having a sulfo group, a carboxyl group, or a sulfo group, and the other is a lower alkoxy group having a hydrogen atom, a sulfo group, a carboxy group, or a sulfo group, a lower alkyl group, or a lower alkoxy group. A group, a halogen group, a nitro group, an amino group, a lower alkyl-substituted amino group, or a 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 in 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 linear alkoxy group, and the substitution position of the sulfo group is preferably an alkoxy group terminal. The lower alkoxy group having a sulfo group is more preferably a 3-sulfopropoxy group and a 4-sulfobutoxy group. The position of the substituent that the naphthyl group has is not particularly limited, but as explained by the number shown in Formula (3), in the case of two substituents, the 5-position and the 7-position, or the 6-position and the 8-position A combination is preferred, and when there are three substituents, the 3-position, 5-position and 7-position, and the 3-position, 6-position and 8-position are preferred.

R ₁ to R ₆ are not particularly limited, but preferably each independently 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 It is a 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 the 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, and most preferably a 3-sulfopropoxy group.

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

In one embodiment, none of R ₁ to R ₆ is a C1-4 alkoxy group having a sulfo group.

The positions of R ₁ to R ₆ are preferably 2-position only, 5-position only, 2-position and 6-position combination, 2-position and 5-position combination, 3-position and 5-position The combination of the 2-position, the 5-position only, the 2-position and 5-position combination is more preferable. The 2-position only and the 5-position only indicate that only one substituent other than a hydrogen atom is present at the 2-position or 5-position only.

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 substituted group A phenyl group which may have a group, except that both A ¹ and A ² are phenyl groups having a substituent,
R ₁ to R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C1-4 alkyl-substituted acylamino. It is a 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 C1-4 alkyl group, a C1-4 alkoxy group, a hydroxy group, a carboxy group, a halogen group, or a C1-4 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, or 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 embodiment, the azo compound represented by formula (1) is preferably represented by formula (5).

At least one of R ₁₀ to R ₁₃ is a sulfo group, and the other represents 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 given below. In addition, the sulfo group, carboxy group, and hydroxy group in a formula are represented with the form of a free acid.

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

The azo compound represented by the formula (1) may be in a free acid form or a salt form. Examples of such salts include alkali salts such as lithium salts, sodium salts, 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 normal method for producing an azo dye as described in Non-Patent Document 1, and as described in Patent Document 3. It can be produced by reacting with a ureido 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 coupled with an aniline of the following formula (ii). To obtain a monoazoamino compound represented by the following formula (iii).

(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 have the same meaning as in the above formula (1).)

Next, the monoazoamino compound (iii) is diazotized and secondarily coupled with anilines of 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 have the same meaning as in the above formula (1).)

Similarly, anilines having a substituent represented by the following formula (vi) are diazotized by the same method as in Non-Patent Document 1, coupled with anilines 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 have the same meaning as in the above formula (1).)

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

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

The diazotization step is performed by, for example, a conventional method of mixing a nitrite such as sodium nitrite into a mineral acid aqueous solution or suspension of diazo component such as hydrochloric acid or sulfuric acid, or a neutral or weak alkaline aqueous solution of diazo component. Nitrite is added to the mixture, and this is mixed with mineral acid. The diazotization temperature is suitably -10 to 40 ° C. In addition, the coupling step with anilines is preferably carried out by mixing an acidic aqueous solution such as hydrochloric acid or acetic acid with each of the above diazo solutions and at a temperature of −10 to 40 ° C. under acidic conditions of pH 2 to 7.

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

Specific conditions for the ureido reaction of the disazoamino compound (v) and the monoazoamino compound (viii) using a ureido agent are, for example, a temperature of 10 to 10 according to the production method shown on page 57 of Patent Document 3. The temperature is preferably 90 ° C. and pH 3 to 11, more preferably 20 to 80 ° C., pH 4 to 10, and particularly preferably 20 to 70 ° C. and pH 6 to 9. Examples of ureido agents 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 ureido agent is preferably phenyl chloroformate, 4-nitrophenyl chloroformate, 4-chlorophenyl chloroformate, diphenyl carbonate, bis (4-nitrophenyl) carbonate, and more preferably phenyl chloroformate, chloroformate 4 -Nitrophenyl.

After completion of the ureido reaction, the obtained azo compound of the formula (1) is precipitated by salting out and filtered out. If purification is required, salting out may be repeated or precipitated 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.

The 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, naphthylamines having one or more selected from the group consisting of a hydrogen atom, a hydroxy group, a lower alkoxy group having a sulfo group, and a sulfo group are preferably used. 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 1,7-disulfonic acid, 1-aminonaphthalene-3,8-disulfonic acid and the like are preferable.
Examples of 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-sulfobutoxy). 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, 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- Toxibenzenesulfonic 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, -Aminobenzene-1,4-disulfonic acid, 4-amino-2-methylbenzenesulfonic acid, 2- (4-aminophenoxy) ethane-1-sulfonic acid, 3- (4-aminophenoxy) propane-1-sulfone 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 Perfume 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-ethylphenoxy) Xyl) 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) Butane-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 And phenoxy) propane-1-sulfonic acid, 4- (4-amino-3-butoxyphenoxy) butane-1-sulfonic acid, and the like. In these aromatic amines, the amino group may be protected. Examples of the protecting group include ω-methanesulfone group.

Aromatic amines (ii), (iv) and (vii) which are 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 B-2-Ethoxyaniline, 5-chloro-2-propoxyaniline, 5-chloro-2-butoxyaniline, 5-fluoro-2-methoxyaniline, 5-fluoro-2-ethoxyaniline, 5-fluoro-2-propoxy Aniline, 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-sulfo Acid, 3- (2-aminophenoxy) propane-1-sulfonic acid, 4- (2-amino-4-methylphenoxy) butane-1-sulfonic acid, 4- (2-aminophenoxy) butane-1-sulfonic acid 2- (2-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- Sulfonic acid, 2- (3-amino-4-methylphenoxy) ethane-1-sulfonic acid, 2- (3-aminophenoxy) ethane-1-sulfonic acid, 3- (2-amino-4- Toxiphenoxy) propane-1-sulfonic acid, 4- (2-amino-4-methoxyphenoxy) butane-1-sulfonic acid, 2- (2-amino-4-methoxyphenoxy) ethane-1-sulfonic acid, 3- (3-Amino-4-methoxyphenoxy) propane-1-sulfonic acid, 4- (3-amino-4-methoxyphenoxy) butane-1-sulfonic acid, 2- (3-amino-4-methoxyphenoxy) ethane- 1-sulfonic acid, 3- (2-amino-4-ethoxyphenoxy) propane-1-sulfonic acid, 4- (2-amino-4-ethoxyphenoxy) butane-1-sulfonic acid, 2- (2-amino- 4-Ethoxyphenoxy) ethane-1-sulfonic acid, 3- (3-amino-4-ethoxyphenoxy) propane-1-sulfonic acid, 4- (3-amino-4- Ethoxyphenoxy) butane-1-sulfonic acid, 2- (3-amino-4-ethoxyphenoxy) ethane-1-sulfonic acid, 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 include 1-sulfonic acid, 2- (2-amino-4-chlorophenoxy) ethane-1-sulfonic acid, and 2- (2-amino-4-fluorophenoxy) ethane-1-sulfonic acid. In these aromatic amines, the amino group may be protected. Examples of the protecting group include ω-methanesulfone group.

<Dye-type 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 can be either a neutral gray polarizing film or a color polarizing film, and is preferably a neutral gray polarizing film. Here, “neutral gray” is a specific wavelength in the wavelength region of the visible light region in a state in which two polarizing films are superposed so that their orientation directions are orthogonal to each other (hereinafter also referred to as “orthogonal position”). Means less light leakage (color leakage).

The dye-based polarizing film contains one or more kinds of azo compounds represented by the formula (1) or a salt thereof as a dichroic dye, 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 absorption characteristics 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. Examples of other organic dyes include 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. Typical examples include Green 59 and dyes described in Patent Documents 1 to 6, but dyes developed for polarizing plates as described in Patent Documents 1 to 6 may be used depending on the purpose. Is preferred. These organic dyes are used as free acids, alkali metal salts (for example, Na salt, K salt, Li salt), ammonium salts, or salts of amines.

When other organic dyes are used in combination, the types of organic dyes to be blended differ depending on whether the target polarizing film is a neutral gray polarizing film, a color polarizing film for liquid crystal projectors, or other color polarizing films. The blending ratio is not particularly limited, but generally, the total of at least one other organic dye is 0.01% with respect 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 parts by mass, more preferably in the range of 0.1˜10 parts by mass.

When the target polarizing film is a neutral gray polarizing film, the types and blending ratios of other organic dyes to be used are adjusted so that color leakage in the wavelength region of the visible light region of the obtained polarizing film is reduced. .

When the target polarizing film is a color polarizing film, it has a high single plate average light transmittance in a specific wavelength region of the obtained polarizing film, and a specific light transmittance at a perpendicular position is low, for example, a specific polarizing film The type and blending ratio of other organic dyes used in combination are adjusted so as to have a single plate average light transmittance of 39% or more in the wavelength region and an average light transmittance of 0.4% or less in the orthogonal position. .

The dye-based polarizing film is a known dichroic dye containing an azo compound represented by the formula (1) or a salt thereof and, if necessary, another dye as a polarizing film substrate (for example, a polymer film). It can be produced by containing and aligning by the above method, mixing with liquid crystal, or aligning by a coating method.

The polarizing film substrate is preferably a polymer film, and more preferably a film made of polyvinyl alcohol resin or a derivative thereof. Specific examples of the polarizing film substrate include polyvinyl alcohol resin or derivatives thereof, and modified with olefins such as ethylene and propylene, and unsaturated carboxylic acids such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid. And the like. As the polarizing film substrate, a film made of polyvinyl alcohol resin or a derivative thereof is preferably used from the viewpoint of the adsorptivity and orientation of the dye. The thickness of the polarizing film substrate is usually about 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 formula (1) or a salt thereof. For example, the staining is performed as follows. First, a dye bath is prepared by dissolving an 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 mirabilite at a concentration of, for example, about 0.1 to 10% by mass. Dyeing can be performed by immersing the polymer film in the dyeing bath thus prepared, for example, for 1 to 10 minutes. 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 draw ratio is generally 2 to 8 times, but is not limited, and preferably 3 to 7.5 times, more preferably 4 to 7 times. As a stretching method, any known method such as a wet method or a dry method may be used. The stretching of the polymer film may optionally be performed before dyeing. In this case, the water-soluble dye is oriented 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 as necessary. Such post-processing is performed for the purpose of improving the light transmittance and the degree of polarization of the polarizing film. The conditions for the boric acid treatment vary depending on the type of polymer film used and the type of dye used, but generally the boric acid concentration of the boric acid aqueous solution is, for example, 0.1 to 15% by mass, preferably 1 to 10% by mass. The treatment is performed 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 fixing 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, and lenses and glasses. The dye-based polarizing film has high polarization performance comparable to a polarizing film using iodine, and is excellent in durability. For this reason, it is particularly suitable for various liquid crystal display bodies and liquid crystal projectors for applications requiring high polarization performance and durability, for example, for in-vehicle use and outdoor display (for example, display for industrial instruments and wearable use). is there.

<Dye-based polarizing plate>
The dye-based polarizing plate can be obtained by pasting a transparent protective film on one side 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, moisture resistance, heat resistance, and light resistance. The material for forming the transparent protective film is preferably a material excellent in optical transparency and mechanical strength, such as a cellulose acetate film, an acrylic film, a tetrafluoroethylene / hexafluoropropylene copolymer, etc. 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 film. The thickness of the protective film is usually preferably 40 to 200 μm.

Examples of adhesives that can be used to bond the dye-based polarizing film and the protective film include polyvinyl alcohol adhesives, urethane emulsion adhesives, acrylic adhesives, and polyester-isocyanate adhesives. System adhesives are 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 an acrylic or polysiloxane hard coat layer and a urethane protective layer. In order to further improve the single-plate light transmittance, it is preferable to provide an AR layer (antireflection layer) on the transparent protective layer. The AR layer can be formed by vapor deposition or sputtering treatment of a material such as silicon dioxide or titanium oxide, and can be formed by thinly applying a fluorine-based material. The dye-based polarizing plate preferably further includes a support. The dye-based polarizing plate can be used as an elliptical 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 polarizing plate has a neutral color, has little orthogonal color leakage in the polarization region of the visible light region, has excellent polarization performance, and is resistant to discoloration and deterioration of polarization performance even in high temperature and high humidity conditions. Because of its high performance, it is suitable for in-vehicle use or outdoor display.

The neutral gray polarizing plate for in-vehicle use or outdoor display is provided with an AR layer on a polarizing plate composed of a dye-based polarizing film and a transparent protective film to further improve the single light transmittance. It is preferable that the AR layer and the polarizing plate with a support on which both the AR layer and a support such as a transparent resin are attached are more preferable. 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 the support may be provided with a polarizing plate with an AR layer (AR layer / polarizing plate / AR layer). . The AR layer and the polarizing plate with a support preferably include AR layer / polarizing plate / AR layer / support in this order. The support preferably has a flat part for attaching the polarizing plate, and is preferably a transparent substrate because it is used for optical purposes. The transparent substrate is roughly divided into an inorganic substrate and an organic substrate, inorganic substrates such as soda glass, borosilicate glass, crystal substrate, sapphire substrate, and spinel substrate, and acrylic, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, and Although organic substrates, such as a cycloolefin polymer, are mentioned, an organic substrate is preferable. The thickness and size of the transparent substrate may be a desired size.

A color polarizing plate is suitable for liquid crystal projectors and display devices such as in-vehicle and outdoor displays because it has excellent polarization performance and does not cause discoloration or deterioration of polarization performance even in a high-temperature and high-humidity state.

A color polarizing plate for a liquid crystal projector has brightness and excellent polarization performance. A necessary 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 green channels) 580 nm, red channel 600-680 nm, peak wavelength when using B.3 primary color LED lamp: blue channel 430-450 nm, green channel 520-535 nm, red channel 620-635 nm) 39% or more, the average light transmittance in the orthogonal position is 0.4% or less, more preferably, the single plate average light transmittance in the necessary wavelength region of the polarizing plate is 41% or more, and the average light transmittance in the orthogonal position is 0. .3% or less, more preferably 0.2% or less. More preferably, the single plate average light transmittance in the necessary 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 a specific wavelength region when natural light is incident on one polarizing plate (hereinafter also simply referred to as “polarizing plate”) not provided with a support such as an AR layer and a transparent glass plate. It is the average value of the light transmittance in. The average light transmittance at the orthogonal position is an average value of 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 color polarizing plate for in-vehicle use or outdoor display may be provided with a protective layer or an AR layer and a support, etc., if necessary, on the dye-based polarizing plate, as with the neutral gray polarizing plate. Good. The support-attached color polarizing plate can be obtained, for example, by applying a transparent adhesive (adhesive) agent on 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 the dye-based polarizing plate, and then a support may be attached to the coated surface. The adhesive (adhesive) agent is preferably, for example, an acrylic ester-based one. When this dye-based polarizing plate is used as an elliptical polarizing plate, it is usual that the retardation plate side is attached to a support and the lamination order of the dye-based polarizing plate / retardation plate / support is set. The polarizing plate side may be attached to the support, and the retardation plate / polarizing plate / support may be laminated.

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

In the liquid crystal display device, a dye-based polarizing plate is disposed on either or both of the incident side and the emission side of the 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. Further, from the viewpoint of durability, it is preferable that a dye-type polarizing plate is disposed on both the incident side and the emission side of the liquid crystal cell. Further, the polarizing plate surface of the dye-type polarizing plate is on the liquid crystal cell side, and the support surface is It is preferable to arrange on the light source side. The incident side of the liquid crystal cell is the light source side, and the opposite side is referred to as the emission side.

A liquid crystal cell included 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 counter electrodes are formed. It is preferable. Light emitted from a light source such as a cold-cathode tube lamp or a white LED passes through a dye-based polarizing plate, and then passes through a liquid crystal cell, a color filter, and further a dye-based polarizing plate and is projected on a display screen.

The liquid crystal display device has high brightness and excellent polarization performance as well as polarization and light resistance, so it is difficult to cause discoloration or deterioration of polarization performance even in high temperature and high humidity conditions such as in a car or outdoors. high.

Hereinafter, the present invention will be described in more detail by way of examples, but these are illustrative and do not limit the present invention in any way. In the examples, “%” and “parts” are based on mass unless otherwise specified.

Example E1: Synthesis of azo compound of formula (A-3)
Add 30.3 parts of 7-aminonaphthalene-1,3-disulfonic acid to 500 parts of water, cool and add 31.3 parts of 35% hydrochloric acid at 10 ° C. or lower, and then add 6.9 parts of sodium nitrite. The mixture was stirred at -10 ° C for 1 hour to diazotize. Thereto, 12.3 parts of 2-methoxyaniline was added and stirred at 10-30 ° C., sodium carbonate was added to adjust the pH to 3, further stirring to complete the coupling reaction, filtration, and the following formula (A-3M) 30.6 parts of a monoazoamino compound represented by the formula:

Add 30.6 parts of the resulting monoazoamino compound to 400 parts of water, dissolve with sodium hydroxide, add 21.9 parts of 35% hydrochloric acid at 10-30 ° C., and then add 4.8 parts of sodium nitrite. The mixture was stirred at 20-30 ° C. for 1 hour to diazotize. Thereto was added 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further 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 monoazoamino compound (A-3M) is added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate is stirred at 30-50 ° C. for 2 hours, and then disazoamino compound (A -3D) 38.8 parts was added and stirred at 50-70 ° C. for 5 hours to ureide. It was salted out with sodium chloride and filtered to obtain 12.5 parts of a ureido compound represented by the above formula (A-3). 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)
Add 24.2 parts of 7-aminonaphthalene-1,3-disulfonic acid to 400 parts of water, cool and add 25.0 parts of 35% hydrochloric acid at 10 ° C. or lower, then add 5.5 parts of sodium nitrite and add 5 parts. The mixture was stirred at -10 ° C for 1 hour to diazotize. Thereto was added 8.6 parts of 2-methylaniline, and while stirring at 10-30 ° C., sodium carbonate was added to adjust the pH to 3, further stirring to complete the coupling reaction, filtration, and the following formula (A-6MR) 23.6 parts of a monoazoamino compound represented by the formula:

Add 38.8 parts of disazoamino compound (A-3D) and 23.6 parts of monoazoamino compound (A-6MR) to 500 parts of water, dissolve with sodium hydroxide, and add 12.9 parts of 4-nitrophenyl chloroformate. 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 ureido 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)
Add 29.5 parts of monoazoamino compound (A-6MR) to 400 parts of water, dissolve with sodium hydroxide, add 21.9 parts of 35% hydrochloric acid at 10-30 ° C., then add 4.8 parts of sodium nitrite. In addition, the mixture was stirred at 20 to 30 ° C. for 1 hour to diazotize. Thereto was added 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further 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 monoazoamino compound (A-3M) are added to 500 parts of water, dissolved in sodium hydroxide, and 4-nitrophenyl chloroformate 12. Nine parts were stirred at 50 to 70 ° C. for 4 hours to ureide. It was salted out with sodium chloride and filtered to obtain 9.4 parts of a ureido 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 that 16.2 parts of 3- (2-aminophenoxy) propane-1-sulfonic acid were used instead of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid In the same manner as above, 11.2 parts of a ureido compound represented by the above formula (A-20) was 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 ureido represented by the above formula (A-32) was obtained in the same manner as in Example E1, except that 9.3 parts of aniline was used instead of 2-methoxyaniline which is a raw material of the disazoamino compound (A-3D). 10.2 parts of 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)
Except that 8.5 parts of 2,5-dimethylaniline was used in place of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid, the above formula (A 9.0 parts of a ureido compound represented by -36) were 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)
Add 11.0 parts of 4-aminobenzoic acid to 300 parts of water, cool and add 25.0 parts of 35% hydrochloric acid at 10 ° C. or lower, then add 5.5 parts of sodium nitrite and add at 5-10 ° C. for 1 hour. Stir and diazotize. Thereto was added 11.0 parts of 2-methoxy-5-methylaniline, and while stirring at 10-30 ° C., sodium carbonate was added to adjust the pH to 3, further stirring to complete the coupling reaction, filtration, and the following formula ( A-130MR) was obtained, 16.0 parts of a monoazoamino compound.

16.0 parts of the obtained monoazoamino compound (A-130MR) is added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate is stirred at 30 to 50 ° C. for 2 hours, and then disazoamino 38.0 parts of compound (A-19D) was added, and ureido was carried out at 50 to 70 ° C. It was salted out with sodium chloride and filtered to obtain 10.4 parts of a ureido compound represented by the above formula (A-130). 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)
Add 25.3 parts of 4-aminobenzene-1,3-disulfonic acid to 500 parts of water, cool, add 31.3 parts of 35% hydrochloric acid at 10 ° C. or lower, and then add 6.9 parts of sodium nitrite. The mixture was stirred at 5-10 ° C. for 1 hour to diazotize. Thereto, 12.1 parts of 2,5-dimethylaniline was added, and while stirring at 10-30 ° C., sodium carbonate was added to adjust the pH to 3, further stirring to complete the coupling reaction, filtration, and the following formula ( 27.0 parts of a monoazoamino compound represented by A-61ML) was obtained.

27.0 parts of the obtained monoazoamino compound is added to 400 parts of water, dissolved with sodium hydroxide, 25.0 parts of 35% hydrochloric acid is added at 10-30 ° C., and 5.5 parts of sodium nitrite is then added. The mixture was stirred at 20-30 ° C. for 1 hour to diazotize. Thereto was added 17.2 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid, and while stirring at 20 to 30 ° C., sodium carbonate was added to pH 4, and the mixture was further 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 monoazoamino compound (A-3M) is added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate is stirred at 30 to 50 ° C. for 4 hours, and then disazoamino compound (A -61D) 35.9 parts were added and stirred at 50-70 ° C. for 5 hours to ureide. It was salted out with sodium chloride and filtered to obtain 12.1 parts of a ureido 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)
11.1 parts of ureido compound represented by the above formula (A-92) was obtained in the same manner as in Example E8 except that 10.7 parts of 2-methylaniline was used instead of 2,5-dimethylaniline. It 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 that 16.2 parts of 3- (2-aminophenoxy) propane-1-sulfonic acid were used instead of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid In the same manner as above, 12.7 parts of a ureido 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 ureido 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 ureido 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)
Add 25.3 parts of 4-aminobenzene-1,3-disulfonic acid to 500 parts of water, cool, add 31.3 parts of 35% hydrochloric acid at 10 ° C. or lower, and then add 6.9 parts of sodium nitrite. The mixture was stirred at 5-10 ° C. for 1 hour to diazotize. Thereto, 12.1 parts of 2,5-dimethylaniline was added, and while stirring at 10-30 ° C., sodium carbonate was added to adjust the pH to 3, further stirring to complete the coupling reaction, filtration, and the following formula ( 30.8 parts of a monoazoamino compound represented by B-17ML).

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

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

18.3 parts of the obtained monoazoamino compound (B-17MR) is added to 250 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate is stirred at 30 to 50 ° C. for 4 hours, and then disazoamino is added. 34.1 parts of compound (B-17D) 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 10.5 parts of a ureido compound represented by the above formula (B-17). 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)
12. 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 ureido 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 in place of 4-aminobenzoic acid. 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 except that 18.7 parts of 2-amino-5-methylbenzenesulfonic acid was used instead of 4-aminobenzene-1,3-disulfonic acid, which is a raw material of the disazoamino compound (B-17D). Similarly, 10.1 parts of a ureido compound represented by the above formula (B-29) were 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 ureido 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)
Add 30.8 parts of monoazoamino compound (B-17ML) to 400 parts of water, dissolve with sodium hydroxide, add 25.0 parts of 35% hydrochloric acid at 10-30 ° C., and then 5.5 parts of sodium nitrite And stirred at 20-30 ° C. for 1 hour to diazotize. Thereto, 19.6 parts of 3- (2-amino-4-methylphenoxy) propane-1-sulfonic acid was added, and while stirring at 20-30 ° C., sodium carbonate was added to pH 4, and the mixture was 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).

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

21.5 parts of the obtained monoazoamino compound (C-5MR) is added to 500 parts of water, dissolved with sodium hydroxide, 10.0 parts of phenyl chloroformate is stirred at 30-50 ° C. for 2 hours, and then disazoamino 41.0 parts of 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 ureido 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)
12. 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 is used in place of 2-amino-5-methylbenzenesulfonic acid. 13.5 parts of ureido 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 instead of 2,5-dimethylaniline, and 3- (2-amino-4-methylphenoxy) propane-1 instead of 2-methoxy-5-methylaniline -13.1 parts of a ureido compound represented by the above formula (C-46) was obtained in the same manner as in Example E19 except that 19.7 parts of sulfonic acid was used. 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 for using 21.3 parts of sulfonic acid, 13.7 parts of a ureido 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)
The above formulas (A-3), (A-6), (A-19), (A-20), (A-32), (A-36), (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), (C-49) of each azo compound. Polyvinyl alcohol having a thickness of 75 μm was immersed in each aqueous solution (dye bath) at 45 ° C. having a concentration of 03% and sodium sulfate 0.1% for 4 minutes. This film was stretched 5 times at 50 ° C. in a 3% boric acid aqueous solution, washed with water and dried while maintaining a tensioned state to obtain a polarizing film.
Table 1 shows the absorption wavelength and the polarization rate when the polarization rate of the obtained dye-based polarizing film is maximized. As shown in Table 1, the polarizing films prepared using the compounds of the present invention all had a high polarization rate.

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

Polarization rate (%) = [(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 C-I Direct Yellow 44 was used instead of the compound of the formula (A-3).

As one index representing image quality, there 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 between the parallel transmittance and the orthogonal transmittance (contrast = parallel transmittance (Ky) at the maximum absorption wavelength / orthogonal transmittance (Kz) at the maximum absorption wavelength). It represents that the polarizing performance of the polarizing plate is excellent. The polarization performance was evaluated by preparing samples so that the parallel transmittance at the maximum absorption wavelength of the dye-based polarizing film would be equal. As shown in Table 2, all of the dye-based polarizing films of Examples F1 to F22 had a 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 Eye Direct Red 81, 0.05% of C Eye Direct Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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 Eye Direct Red 81, 0.05% of C Eye Direct Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was laminated in this order.

(Example P3: Production of neutral gray polarizing plate)
0.1% of the compound of the 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. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance at 380 to 700 nm of 42% and an orthogonal average transmittance of 0.02%, and had a high degree of polarization. A triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated through an adhesive of the above, and a support provided with an AR layer is pasted using an adhesive, and a TAC / polarizing film A dye-based polarizing plate (neutral gray polarizing plate) in which the / TAC / AR support was laminated in this order was obtained.

(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. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was laminated in this order.

(Example P5: Production of neutral gray polarizing plate)
0.1% of the compound of the 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. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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-IDirect Red 81, 0.05% of C-IDirect Blue 274, and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was laminated in this order.

(Example P7: Production of neutral gray polarizing plate)
0.1% of the compound of the formula (B-17) obtained in Example E13, 0.2% of C-IDirect Red 81, 0.05% of C-IDirect Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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-IDirect Red 81, 0.05% of C-IDirect Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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-IDirect Red 81, 0.05% of C-IDirect Blue 274, and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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 Eye Direct Red 81, 0.05% of C Eye Direct Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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-IDirect Red 81, 0.05% of C-IDirect Blue 274 and 0. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was 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. A polarizing film was produced in the same manner as in Example F1 except that a 45 ° C. aqueous solution having a concentration of 1% was used. The obtained polarizing film had a single plate average transmittance of 380 to 700 nm of 42% and an orthogonal transmittance of 0.02%, and had a high degree of polarization.
A support in which a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd .: trade name TD-80U) is laminated on both surfaces of this polarizing film via an adhesive of an aqueous polyvinyl alcohol solution, and an AR layer is provided using an adhesive. Was attached to obtain a dye-based polarizing plate (neutral gray polarizing plate) in which TAC / polarizing film / TAC / AR support was laminated in this order.

The neutral gray polarizing plates obtained in Examples P1 to P12 have no change in the single-plate average transmittance even after 400 hours under the conditions of 80 ° C. and 90% RH, and they last for a long time even at high temperature and high humidity. Shows durability. Further, the neutral gray polarizing plates of Examples P1 to P12 showed no change in single-plate average transmittance even after 200 hours in the xenon light resistance test, and were excellent in light resistance against long-time exposure to light. From these results, it is shown that the neutral gray polarizing plates of Examples P1 to P12 are high-performance dye-based polarizing plates having excellent polarization performance and having moisture resistance, heat resistance, and light resistance. It was done.

Claims (22)

1. Following formula (1):
   

   

   
   (In the formula, 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 substituted group. A phenyl group which may have a group,
   R ₁ to R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group having a sulfo group, a carboxy group, a hydroxy group, a halogen group, or a C1-4 alkyl-substituted acylamino. Base)
   Or a salt thereof.
2. One or both of A ¹ and A ² (if both are independently), 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, sec-butylamino group, etc. 2. A phenyl group having 1 to 4 alkyl-substituted amino groups and one or more substituents selected from the group consisting of C1-4 alkyl-substituted acylamino groups such as acetylamino group, propionamide group, butyramide group and the like. The azo compound or its salt as described.
3. One or both of A ¹ and A ² (in each case independently) have at least one substituent selected from a sulfo group, a carboxy group, and a C1-4 alkoxy group having a sulfo group, and hydrogen 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˜ The azo compound or a salt thereof according to claim 1 or 2, which is a phenyl group further having a 4-alkyl-substituted acylamino group.
4. One or both of A ¹ and A ² (if both are independently) are represented by the following formula (2):
   

   

   
   (In the formula, one of R ₇ and R ₈ is a C1-4 alkoxy group having a sulfo group, a carboxyl group, or a sulfo group, and the other is a C1-4 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:
5. 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.
6. 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.
7. 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.
8. One or both of A ¹ and A ² (if both are independently) are represented by the following formula (3):
   

   

   
   (Wherein 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 formula:
9. The azo compound or a salt thereof according to claim 8, wherein R ₉ is a hydrogen atom and n is 2.
10. Following formula (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, represented by:
11. Following formula (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 or a salt thereof according to any one of claims 1 to 5, represented by:
12. The R ₁ to R ₆ are each independently a C1-4 alkoxy group having a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a halogen group, or a sulfo group. Or an azo compound thereof.
13. 13. Each of R ₁ to R ₆ is independently a C1-4 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 thereof.
14. 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.
15. 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.
16. A dye-based polarizing film comprising a polarizing film substrate containing the azo compound or a salt thereof according to any one of claims 1 to 15.
17. A dye-based polarizing film comprising a polarizing film substrate comprising the azo compound or a salt thereof according to any one of claims 1 to 15 and one or more organic dyes other than these.
18. The dye-based polarizing film according to claim 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 in which a transparent protective layer is bonded to one side or both sides of the dye-based polarizing film according to any one of claims 16 to 18.
20. A polarizing plate for 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.
21. 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).
22. A liquid crystal display comprising the dye-based polarizing plate according to claim 19, the polarizing plate for liquid crystal display according to claim 20, or the neutral gray polarizing plate according to claim 21.