TWI734905B - Azo compound or salt thereof, dye-based polarizing film, dye-based polarizing plate, and liquid crystal display containing same - Google Patents

Abstract

The object of the present invention is to provide an azo compound useful as a dichroic dye for use in a polarizing plate.

The present invention relates to a compound represented by the following formula (1) or a salt thereof:

(In the formula, A¹ and A² each independently represent a naphthyl group which may have a substituent selected from the group consisting of hydroxyl group, C1-4 alkoxy group having a sulfo group and sulfo group, or a phenyl group which may have a substituent, R₁ to R₆ each independently represent a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group having a sulfo group, a carboxyl group, a hydroxyl group, a halogen group, or a acylamino group substituted with a C1-4 alkyl.)

Description

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

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

The polarizing plate with light transmission/shielding function is the basic constituent element of display devices such as liquid crystal and liquid crystal display (LCD) with light switching function. The application fields of this LCD range from small devices such as computers and clocks in the early days to notebook computers, word processors, liquid crystal projectors, liquid crystal televisions, car navigation and indoor and outdoor measuring equipment. Moreover, it can also be applied to lenses with polarizing function, sunglasses to improve visibility, or to polarized glasses corresponding to 3D TVs in recent years. Since the range of applications of the polarizing plate as above has become wider, it is used under a wide range of conditions from low temperature to high temperature, low humidity to high humidity, and low light intensity to high light intensity. Therefore, it is required to have high polarization performance and high durability. Polarizing plate.

At present, the polarized light of polyvinyl alcohol or its derivatives that are stretched and aligned, or polyvinyl alcohol is generated by the removal of hydrochloric acid from the polyvinyl chloride film or the dehydration of the polyvinyl alcohol-based film, and the aligned polyolefin-based film The film substrate is manufactured by dyeing it or containing iodine or dichroic dye. These are the material polarizing plates that have a great influence on the polarization characteristics and durability of the polarizing plate. The iodine-based polarizing film using iodine has good polarization performance, but it is not resistant to water and heat, and it has durability problems if it is used for a long time under high temperature and high humidity. In order to improve durability, treatment with formalin or an aqueous solution containing boric acid, or a method of using a polymer film with low moisture permeability as a protective film, etc. are considered, but the effect is not sufficient. On the other hand, dye-based polarizing films using dyes, compared with iodine-based polarizing films, have better moisture resistance and heat resistance, but generally have insufficient polarization performance.

Hitherto, in order to improve the vividness of images of liquid crystal displays, images have been displayed with high brightness. Hybrid vehicles, mobile terminals, etc. equipped with such displays require a long battery drive time. In order to reduce power consumption, liquid crystal display manufacturers require that the brightness of the image be maintained even if the brightness is reduced. The polarizing plate.

However, in a polarizing film formed by adsorbing/aligning plural dyes on a polymer film, when there is light leakage (color leakage) at a specific wavelength in the wavelength region of the visible light region, when the polarizing film is installed on the liquid crystal panel, the liquid crystal will be dark. The displayed hue will change. Therefore, when the polarizing film is installed in the liquid crystal display device, in order to prevent the discoloration of the liquid crystal display caused by the color leakage of a specific wavelength in the dark state, the neutral color polarizing film formed by dyeing the polymer film or containing multiple dyes However, the transmittance in the vertical direction (vertical transmittance) in the wavelength region of the visible light region must be similarly low. In addition, liquid crystal displays used in cars will become high-temperature and high-humidity environments in summer cars. Therefore, polarizers that do not change the degree of polarization even in harsh environments are required. In the past, a neutral gray iodine-based polarizer with good polarization performance was used. However, the iodine-based polarizing plate has the problems of insufficient light resistance, heat resistance, and moisture and heat resistance as described above. In order to solve this problem, a neutral gray polarizing plate which is dyed or a dye-based dye containing plural kinds of dichroic dyes is used. Dye-based neutral gray polarizers are generally used in combination with the three primary colors of red/blue/yellow dyes. However, the polarization performance of the aforementioned dye-based neutral gray polarizer is insufficient. Therefore, it is necessary to develop dichroic dyes with excellent polarization properties of the three primary colors.

The characteristics of the dye system are as described above, in order to control the components of the three primary colors of light, dyeing or containing respective independent dyes corresponding to this. The light sources of liquid crystal display panels used in recent years include cold-cathode tube method or LED method. The wavelength of the light source emitted by it varies depending on the method. Even if the method is the same, it varies with each panel manufacturer in many cases. Therefore, in the development of dichroic dyes with good polarization performance, it is particularly important to design dichroic dyes with absorption wavelengths that match the wavelength of the light source.

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

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 03-12606

[Patent Document 2] Japanese Patent Application Publication No. 2001-33627

[Patent Document 3] JP 2009-132794 A

[Patent Document 4] JP 2001-240762 A

[Patent Document 5] JP 2001-108828 A

[Patent Document 6] Japanese Patent Application Laid-Open No. 60-156759

[Non-Patent Literature]

[Non-Patent Document 1] Dye Chemistry P139-149; by Hosoda Toyoda, published by Jihodo, 1957

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 with good polarization performance. Another object of the present invention is to provide a polarizing plate having durability (humidity resistance, heat resistance, or light resistance). Furthermore, another object of the present invention is to provide a neutral gray polarizer formed by adsorbing/aligning two or more dichroic dyes on a polymer film, and has no color leakage in the vertical direction of the wavelength region of the visible light region, and has good performance. Polarizing plate with excellent polarization performance.

Another purpose is to provide a dye-based neutral gray polarizing plate for automotive liquid crystal displays that has high brightness, polarization performance, and durability (humidity resistance, heat resistance, or light resistance).

In order to achieve such an objective, the inventors of the present invention have continued to concentrate on research and found that a polarizing film and a polarizing plate containing a specific azo compound or a salt thereof have good polarization performance, and thus completed the present invention.

That is, the present invention relates to the following (1) to (22).

(式中，A¹及A²各自獨立地表示可具有選自羥基、具有磺基的C1-4烷氧基及磺基所組成群組的取代基的萘基或可具有取代基的苯基；R₁-R₆各自獨立地表示氫原子、C1-4烷基、C1-4烷氧基、具有磺基的C1-4烷氧基、羧基、羥基、鹵素基或經C1-4烷基取代的醯基胺基)。 (1) An azo compound or salt thereof represented by the following formula (1):

(In the formula, A ¹ and A ² each independently represent a naphthyl group which may have a substituent selected from the group consisting of a hydroxyl group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or a phenyl group which may have a substituent ; R ₁ -R ₆ each independently represents a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group with a sulfo group, a carboxyl group, a hydroxyl group, a halogen group or a C1-4 alkyl group Substituted acylamino).

(2) The azo compound or its salt as described in (1), wherein ^{one or both of A 1} and A ² (when both are independently) have one or more selected from a sulfo group, a carboxyl group, and a sulfo group. C1-4 alkoxy group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, N,N-dimethylamino group, N,N-diethylamino group , Methylamino, ethylamino, n-propylamino, n-butylamino, second butylamino and other amino groups substituted with C1-4 alkyl groups and acetylamino, propyl The phenyl group is a substituent of the group consisting of a C1-4 alkyl substituted amido group, butyamido group.

(3) The azo compound or its salt as described in (1) or (2), wherein ^{one or both of A 1} and A ² (when both are independently) have at least one sulfo group, Substituents of the group consisting of a carboxyl group and a C1-4 alkoxy group with a sulfo group, and further have a hydrogen atom, a sulfo group, a carboxyl group, a C1-4 alkoxy group with a sulfo group, a C1-4 alkyl group, and a C1- 4Alkoxy group, halogen group, nitro group, amino group, phenyl group substituted by C1-4 alkyl group or acylamino group substituted by C1-4 alkyl group.

(式中，R₇及R₈之一者為磺基、羧基或具有磺基的C1-4烷氧基，另一者為氫原子、磺基、羧基、具有磺基的C1-4烷氧基、C1-4烷基、C1-4烷氧基、鹵素基、硝基、胺基、經C1-4烷基取代的胺基或經C1-4烷基取代的醯基胺基)。 (4) The azo compound or its salt according to any one of (1) to (3), wherein ^{one or both of A 1} and A ² (when both are independently) are the following formula (2 ) Represents the phenyl group:

(In the formula, one of R ₇ and R ₈ is a sulfo group, a carboxy group or a C1-4 alkoxy group having a sulfo group, and the other is a hydrogen atom, a sulfo group, a carboxy group, or a C1-4 alkoxy group having a sulfo group Group, C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amine group, amine group substituted with C1-4 alkyl group or acylamino group substituted with C1-4 alkyl group).

(5) The azo compound or its salt according to (4), wherein 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.

(6) The azo compound or salt thereof according to any one of (1) to (5), wherein ^{at least one of A 1} and A ² is the aforementioned naphthyl group.

(7) The azo compound or the salt thereof according to any one of (1) to (5), wherein both of A ¹ and A ² are the aforementioned phenyl group.

(式中，R₉為氫原子、羥基、具有磺基的C1-4烷氧基或磺基，n為1-3的整數)。 (8) The azo compound or its salt according to any one of (1) to (6), wherein ^{one or both of A 1} and A ² (when both are independently) are the following formula (3 ) Naphthyl:

(In the formula, R ₉ is a hydrogen atom, a hydroxyl group, a C1-4 alkoxy group having a sulfo group, or a sulfo group, and n is an integer of 1 to 3).

(9) The azo compound or its salt according to (8), wherein R ₉ is a hydrogen atom and n is 2.

(式中，R₁-R₆之定義係如式(1))。 (10) The azo compound or salt thereof according to any one of (1) to (9), which is an azo compound or salt thereof represented by the following formula (4):

(In the formula, R ₁ -R _{6 are} defined as formula (1)).

(式中，R₁₀-R₁₃的至少一者為磺基，其以外為氫原子、磺基、羧基、具有磺基的C1-4烷氧基、甲基或甲氧基，R₁-R₆之定義係如式(1))。 (11) The azo compound or salt thereof according to any one of (1) to (5), which is an azo compound or salt thereof represented by the following formula (5):

(In the formula, _{at least one of R 10} -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, and R ₁ -R _{The definition of 6} is as in formula (1)).

(12) The azo compound or salt thereof according to any one of (1) to (11), wherein R _{1 to} R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, A halogen group or a C1-4 alkoxy group having a sulfo group.

(13) The azo compound or its salt according to any one of (1) to (12), wherein R _{1 to} R ₆ are each independently a C1-4 alkoxy group having a sulfo group, a hydrogen atom, a methyl group , Ethyl, halogen or methoxy.

(14) The azo compound or the 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 its salt according to (14), wherein the aforementioned C1-4 alkoxy group having a sulfo group is 3-sulfopropoxy.

(16) A dye-based polarizing film comprising a polarizing film substrate containing the azo compound or its salt as described in any one of (1) to (15).

(17) A dye-based polarizing film comprising a polarizing film containing the azo compound or its salt as described in any one of (1) to (15) and one or more organic dyes other than the azo compound or its salt Substrate.

(18) The dye-based polarizing film according to (16) or (17), wherein the polarizing film substrate is a film composed of a polyvinyl alcohol resin or a derivative thereof.

(19) A dye-based polarizing plate formed by laminating a transparent protective layer on one or both sides of the dye-based polarizing film described in any one of (16) to (18).

(20) A polarizing plate for liquid crystal display, comprising the dye-based polarizing film described in any one of (16) to (18) or the dye-based polarizing plate described in (19).

(21) A neutral gray polarizing plate provided with the dye-based polarizing film described in any one of (16) to (18) or the dye-based polarizing plate described in (19).

(22) A liquid crystal display device comprising the dye-based polarizing plate described in (19), the liquid crystal display polarizing plate described in (20), or the neutral gray polarizing plate described in (21).

The azo compound of the present invention or its salt is useful as a dye for polarizing films. Therefore, the polarizing film of the present invention containing the azo compound or its salt has a high polarization performance equivalent to that of a polarizing film using iodine. In one aspect, the polarizing film of the present invention has good durability (humidity resistance, heat resistance, or light resistance). Therefore, it is suitable for various liquid crystal displays and liquid crystal projections, as well as for automotive applications that require high polarization performance and durability, and industrial measurement display applications 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 an optionally substituted naphthyl group or an optionally substituted phenyl group. In one aspect, both A ¹ and A ² are phenyl groups. In other aspects, ^{at least one of A 1} and A ² is a naphthyl group which may have a substituent. When both A ¹ and A ² are naphthyl groups which may have a substituent, the substituents of the naphthyl group may be the same or different. When both A ¹ and A ² are optionally substituted phenyl groups, the substituents of the phenyl group may be the same or different. Here, in the scope of the specification and patent application of this case, the "lower" of the so-called "lower alkyl" and "lower alkoxy" means that the number of carbon atoms is 1 to 4. Moreover, it is also expressed as "C1-4".

The substituted phenyl group preferably has a sulfo group, a carboxyl 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, and is substituted by a lower alkyl group A phenyl group consisting of one or more substituents in the group consisting of an amine group and an acylamino group substituted by a lower alkyl group. When the phenyl group has two or more substituents, at least one of the substituents is preferably a sulfo group or a carboxyl 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 with sulfo group, carboxyl group, chlorine group, bromine group, nitro group, amino group, amine group substituted by lower alkyl group And an acylamino group substituted with a lower alkyl group is preferred. Other substituents are more preferably sulfo, hydrogen, methyl, ethyl, methoxy, ethoxy, carboxy, sulfoethoxy, sulfopropoxy, sulfobutoxy, chloro, nitro Group, amino group, N,N-dimethylamino group, N,N-diethylamino group, methylamino group, ethylamino group, n-propylamino group, n-butylamino group, the first Dibutylamino, acetamido, propanoamido, butanoamido, etc., particularly preferably sulfo group, carboxyl group, hydrogen atom, methyl group, methoxy group, sulfoethoxy group, sulfopropyl group Oxy or sulfobutoxy. 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, combination of 3-position and 5-position, Particularly preferred are only 2-position, only 4-position, combination of 2-position and 4-position, or combination of 3-position and 5-position. Furthermore, only the 2-position and only the 4-position means that only the 2-position or the 4-position has a substituent other than one hydrogen atom.

Preferably, the substituted phenyl group is represented by the following formula (2).

One of R ₇ and R ₈ is a sulfo group, a carboxy group, or a C1-4 alkoxy group having a sulfo group, and the other is a hydrogen atom, a sulfo group, a carboxy group, a lower alkoxy group having a sulfo group, a lower alkyl group, Lower alkoxy, halogen, nitro, amine, amine substituted with lower alkyl, or amine substituted with lower alkyl. Preferably, 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 carboxyl 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 hydroxyl 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 hydroxyl group, a lower alkoxy group having a sulfo group, or a sulfo group. n is an integer of 1-3. The position of the sulfo group can be on any benzene nucleus of the naphthalene ring. Preferably, R ₉ is a hydrogen atom, and n is 2. The lower alkoxy group having a sulfo group is preferably a linear alkoxy group, and the substitution position of the sulfo group is preferably at the end of the alkoxy group. The lower alkoxy group having a sulfo group is more preferably 3-sulfopropoxy and 4-sulfobutoxy. The positions of the substituents of the naphthyl group are not particularly limited. When illustrated by the number shown in formula (3), when there are two substituents, the 5-position and the 7-position, or the 6-position and the 8-position The combination of positions is preferable. In the case of three substituents, 3-position, 5-position and 7-position, or 3-position, 6-position and 8-position are preferable.

R _{1 to} R _{6 are} not particularly limited, and preferably each independently is a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxy group having a sulfo group, a carboxyl group, a hydroxyl group, a halogen group, or substituted by a lower alkyl group The acylamino group. R _{1 to} R ₆ are each independently preferably a hydrogen atom, a lower alkyl group, a lower alkoxy group, a lower alkoxy group having a sulfo group, or a halogen group, more preferably a hydrogen atom, a methyl group, an ethyl group, or a methoxy group , Ethoxy, chloro, fluoro, 3-sulfopropoxy or 4-sulfobutoxy, and more preferably hydrogen, methyl, ethyl, methoxy or 3-sulfopropoxy base.

In one aspect, _{at least one of R 1} -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, and is preferably at the end of the alkoxy group. Particularly preferred C1-4 alkoxy groups having a sulfo group are 3-sulfopropoxy and 4-sulfobutoxy, and most preferably 3-sulfopropoxy.

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

In one aspect, _{none of R 1} -R ₆ is a lower alkoxy group with a sulfo group.

The positions of R ₁ -R ₆ are preferably only 2-position, only 5-position, combination of 2-position and 6-position, combination of 2-position and 5-position, combination of 3-position and 5-position. More preferably, it is only 2-position, only 5-position, combination of 2-position and 5-position. Furthermore, the term "only 2-position and only 5-position" means that only 2-position or 5-position has a substituent other than one hydrogen atom.

In one aspect, A ¹ and A ² are each independently a naphthyl group which may have a substituent selected from the group consisting of a hydroxyl group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or a benzene group which may have a substituent Except for the case where both A ¹ and A ² _{are substituted phenyl groups, R 1} -R ₆ are each independently a hydrogen atom, C1-4 alkyl group, C1-4 alkoxy group, and sulfo group C1-4 alkoxy, carboxyl, hydroxy, halogen, or acylamino substituted with C1-4 alkyl.

In one aspect, A ¹ and A ² are each independently a phenyl group which may have a substituent, and R _{1 to} R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a hydroxyl group, and a carboxyl group. , Halogen group or acylamino group substituted by C1-4 alkyl group.

In one aspect, 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 , C1-4 alkyl, C1-4 alkoxy, carboxyl, hydroxy, halogen, or acylamino substituted with C1-4 alkyl.

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

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

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.

The definition of R ₁ -R ₆ is as in formula (1).

Then, specific examples of the azo compound represented by the formula (1) are listed below. In addition, the sulfo group, carboxyl group, and hydroxyl group in the formula are expressed in the form of free acid.

Specific examples in which at least one of ^{A 1} and A ² are naphthyl are listed below.

^{Specific examples in which both A 1} and A ² are phenyl groups, and _{none of R 1 to} R ₆ are C1-4 alkoxy groups having a sulfo group are listed below.

^{Specific examples in which both A 1} and A ² are phenyl groups and _{at least one of R 1} to R ₆ are C1-4 alkoxy groups having a sulfo group are listed below.

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

The azo compound represented by formula (1) or its salt can be diazotized and coupled according to the general azo dye preparation method described in Non-Patent Document 1, and can be obtained by reacting with the urea-based agent described in Patent Document 3. manufacture.

As an example of a specific production method, the substituted anilines represented by the following formula (i) are diazotized by the same method as in Non-Patent Document 1, and coupled with the anilines of the following formula (ii) to obtain the following A monoazoamino compound represented by formula (iii).

A ¹ -NH ₂ (i) (In the formula, A ¹ has the same meaning as in the above formula (1).)

(式中，R₁及R₂表示與上述式(1)者相同的意義。)

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

(式中，A¹、R₁及R₂表示與上述式(1)者相同的意義。)

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

Then, this monoazoamine compound (iii) is diazotized, and the aniline of the following formula (iv) is secondarily coupled to obtain a bisazoamine compound represented by the following formula (v).

(式中，R₃及R₄表示與上述式(1)者相同的意義。)

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

(式中，A¹及R₁至R₄表示與上述式(1)者相同的意義。)

(In the formula, A ¹ and R ₁ to R ₄ have the same meaning as in the above formula (1).)

Similarly, the substituted aniline represented by the following formula (vi) was diazotized by the same method as in Non-Patent Document 1, and coupled with the aniline of the following formula (vii) to obtain the following formula (viii) ) Represents a monoazoamine-based compound.

A ² -NH ₂ (vi) (In the formula, A ² has the same meaning as in the above formula (1).)

(式中，R₅及R₆表示與上述式(1)者相同的意義。)

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

(式中，A²、R₅及R₆表示與上述式(1)者相同的意義。)

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

By reacting the bisazoamine compound (v) and the monoazoamine compound (viii) with a ureidolation agent such as phenyl chloroformate, the azo compound of formula (1) is obtained.

The diazotization step is based on the so-called forward method in which an aqueous solution or suspension of an inorganic acid such as hydrochloric acid or sulfuric acid of the diazonium component is mixed with nitrite such as sodium nitrite, or a neutral or weakly alkaline aqueous solution of the diazonium component Add nitrite to it and mix it with inorganic acid in the reverse process. The temperature of diazotization is suitably -10 to 40°C. Furthermore, the coupling step with anilines is to mix an acidic aqueous solution of hydrochloric acid, acetic acid, etc., with each of the above diazonium solutions, and it is preferable to perform it under acidic conditions at a temperature of -10 to 40°C and a pH of 2 to 7.

The bis-azoamine-based compound (v) and the mono-azoamine-based compound (viii) obtained by coupling are precipitated by acid precipitation, salting-out, and obtained by filtration, or the subsequent steps can be carried out as a solution or suspension. In the case that the diazonium salt becomes a suspension due to poor solubility, it can be filtered and used as a press cake in the subsequent coupling step.

The specific conditions of the ureidolation reaction using the ureidolation agent of the bisazoamine-based compound (v) and the monoazoamine-based compound (viii), for example, according to the preparation method shown on page 57 of Patent Document 3, the temperature is 10 to 90°C, pH 3 to 11 is preferred, temperature is 20 to 80°C, pH 4 to 10 is more preferred, temperature is 20 to 70°C, pH 6 to 9 is particularly preferred. In addition to phenyl chloroformate, urea-based agents can be used phosgene, triphosgene, ethyl chloroformate, butyl chloroformate, isobutyl chloroformate, 4-nitrophenyl chloroformate, 4-fluorochloroformate Phenyl ester, 4-chlorophenyl chloroformate, 4-bromophenyl chloroformate, diphenyl carbonate, bis(2-methoxyphenyl) carbonate, bis(pentafluorophenyl) carbonate, bis(4- Nitrophenyl ester) and 1,1'-carbonyldiimidazole, but not limited to these. The urea-based agent is preferably phenyl chloroformate, 4-nitrophenyl chloroformate, 4-chlorophenyl chloroformate, diphenyl carbonate, bis(4-nitrophenyl) carbonate, more preferably chloroformic acid Phenyl ester, 4-nitrophenyl chloroformate.

After the ureidolation reaction is completed, the obtained azo compound of formula (1) is precipitated by salting out, and is obtained by filtration. In the case of refining, the salting out can be repeated or the organic solvent can be used to precipitate from the water. Examples of the organic solvent used in the 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 as starting materials for synthesizing the azo compound represented by formula (1) are naphthyl amines or anilines.

As the naphthylamines, it is preferable to use naphthylamines having one or more substituents selected from the group consisting of a hydrogen atom, a hydroxyl group, a lower alkoxy group having a sulfo group, and a sulfo group. Naphthylamines, such as 4-aminonaphthalenesulfonic acid, 7-aminonaphthalene-3-sulfonic acid, 1-aminonaphthalene-6-sulfonic acid, 1-aminonaphthalene-7-sulfonic acid, 7-amine Naphthalene-1,3-disulfonic acid, 6-aminonaphthalene-1,3-disulfonic acid, 7-aminonaphthalene-1,5-disulfonic acid, 7-aminonaphthalene-1,3,6 -Trisulfonic acid, etc. With 7-aminonaphthalene-3-sulfonic acid, 6-aminonaphthalene-1,3-disulfonic acid, 7-aminonaphthalene-1,4-disulfonic acid, 7-aminonaphthalene-1,5- Disulfonic acid, 2-amino-8-hydroxy-naphthalene-6-sulfonic acid, 3-amino-8-hydroxynaphthalene-6-sulfonic acid, 1-aminonaphthalene-3,6,8-trisulfonic acid , 2-Amino-5-hydroxynaphthalene-1,7-disulfonic acid, 1-aminonaphthalene-3,8-disulfonic acid, etc. are preferred.

Naphthylamines with sulfo groups and lower alkoxy groups with sulfo groups, such as 7-amino-3-(3-sulfopropoxy)naphthalene-1-sulfonic acid, 7-amino-3-( 4-sulfobutoxy)naphthalene-1-sulfonic acid, 7-amino-4-(3-sulfopropoxy)naphthalene-2-sulfonic acid, 7-amino-4-(4-sulfo Butoxy) 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-sulfopropoxy)naphthalene-1,5-disulfonic acid, etc.

Anilines such as 4-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 2-aminobenzenesulfonic acid, 4-aminobenzoic acid, 2-amino-5-methylbenzenesulfonic acid, 2-amine 5-ethylbenzenesulfonic 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 Acid, 2-amino-5-ethoxybenzenesulfonic acid, 2-amino-5-propoxybenzenesulfonic acid, 2-amino-5-butoxybenzenesulfonic acid, 4-amino-3 -Methoxybenzenesulfonic 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-amine Isophthalic acid, 2-amino-5-chlorobenzenesulfonic acid, 2-amino-5-bromobenzenesulfonic acid, 2-amino-5-nitrobenzenesulfonic acid, 2,5-diamino Benzenesulfonic acid, 2-amino-5-dimethylaminobenzenesulfonic acid, 2-amino-5-diethylaminobenzenesulfonic acid, 5-acetamido-2-aminobenzenesulfonic acid , 4-aminobenzene-1,3-disulfonic acid, 4-aminobenzene-1,4-disulfonic acid, 4-amino-2-methylbenzenesulfonic acid, 2-(4-aminobenzene Oxy)ethane-1-sulfonic acid, 3-(4-aminophenoxy)propane-1-sulfonic acid, 4-(4-aminophenoxy)butane-1-sulfonic acid, 2- (3-aminophenoxy)ethane-1-sulfonic acid, 3-(3-aminophenoxy)propane-1-sulfonic acid, 4-(3-aminophenoxy)butane-1 -Sulfonic acid, 2-amino-5-(2-sulfoethoxy)benzenesulfonic acid, 2-amino-5-(3-sulfopropoxy)benzenesulfonic acid, 2-amino-5 -(4-Sulfobutoxy)benzenesulfonic acid, 2-amino-5-(2-sulfoethoxy)benzoic acid, 2-amino-5-(3-sulfopropoxy)benzoin 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-methyl Phenoxy)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)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-sulfon 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-sulfonic acid, 4 -(4-Amino-3-propoxyphenoxy)butane-1-sulfonic acid, 2-(4-amino-3-butoxyphenoxy)ethane-1-sulfonic acid, 3 -(4-amino-3-butoxyphenoxy)propane-1-sulfonic acid, 4-(4-amino-3-butoxyphenoxy)butane-1-sulfonic acid, etc. These aromatic amine-based amine groups can be protected. Examples of the protecting group include ω-methanesulfonic acid group.

Aromatic amines (ii), (iv) and (vii) that are coupled in one or two times, for example, aniline, 2-methylaniline, 2-ethylaniline, 2-propylaniline, 2-butyl Aniline, 3-methylaniline, 3-ethylaniline, 3-propylaniline, 3-butylaniline, 2,5-dimethylaniline, 2,5-diethylaniline, 2-methoxyaniline , 2-ethoxyaniline, 2-propoxyaniline, 2-butoxyaniline, 3-methoxyaniline, 3-ethoxyaniline, 3-propoxyaniline, 3-butoxyaniline, 2-methoxy-5-methylaniline, 2,5-dimethoxyaniline, 3,5-dimethylaniline, 2,6-dimethylaniline, 3,5-dimethoxyaniline, 5-chloro-2-methoxyaniline, 5-chloro-2-ethoxyaniline, 5-chloro-2-propoxyaniline, 5-chloro-2-butoxyaniline, 5-fluoro-2- Methoxyaniline, 5-fluoro-2-ethoxyaniline, 5-fluoro-2-propoxyaniline, 5-fluoro-2-butoxyaniline, 3-amino-4-methoxybenzoic acid , 3-Amino-4-ethoxybenzoic acid, 3-amino-4-propoxybenzoic acid, 3-amino-4-butoxybenzoic acid, 2-aminophenol, 2-amino -4-methylphenol, 3-amino-4-methoxyacetaniline, 3-amino-4-ethoxyacetaniline, 3-amino-4-propoxyacetaniline, 3 -Amino-4-butoxyacetaniline, 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid, 3-(2-aminophenoxy)propane-1 -Sulfonic acid, 4-(2-amino-4-methylphenoxy)butane-1-sulfonic acid, 4-(2-aminophenoxy)butane-1-sulfonic acid, 2-( 2-Amino-4-methylphenoxy)ethane-1-sulfonic acid, 2-(2-aminophenoxy)ethane-1-sulfonic acid, 3-(3-aminophenoxy) 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, 3- (2-Amino-4-methoxyphenoxy)propane-1-sulfonic acid, 4-(2-amino-4-methoxyphenoxy)butane-1-sulfonic acid, 2-( 2-Amino-4-methoxyphenoxy)ethane-1-sulfonic acid, 3-(3-amino-4-methoxyphenoxy)propane-1-sulfonic acid, 4-(3 -Amino-4-methoxyphenoxy)butane-1-sulfonic acid, 2-(3-amino-4-methoxyphenoxy)ethane-1-sulfonic acid, 3-(2 -Amino-4-ethoxyphenoxy)propane-1-sulfonic acid, 4-(2-amino-4-ethoxyphenoxy)butane-1-sulfonic acid, 2-(2- Amino-4-ethoxyphenoxy)ethane-1-sulfonic acid, 3-(3-amino-4-ethoxyphenoxy)propane-1-sulfonic acid, 4-(3-amine 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-1-sulfonic acid, 2-(2- Amino-4-chlorophenoxy)ethane-1-sulfonic acid and 2-(2-amino-4-fluorophenoxy)ethane-1-sulfonic acid, etc. These aromatic amine-based amine groups can be protected. Examples of the protecting group include ω-methanesulfonic acid group.

〈Dye-based polarizing film〉

The dye-based polarizing film includes a polarizing film substrate containing the azo compound represented by formula (1) or its salt as a dichroic dye. The dye-based polarizing film may be any of a neutral gray polarizing film and a color polarizing film, and a neutral gray polarizing film is preferred. Here, the "neutral gray polarizing film" refers to a state in which two polarizing films overlap each other perpendicularly in their alignment directions (hereinafter also referred to as "vertical orientation") to reduce light leakage of a specific wavelength in the wavelength region of the visible light region ( Color leakage).

The dye-based polarizing film contains a single type of the azo compound represented by formula (1) or its salt or a combination of plural types thereof as a dichroic dye, and may further contain one or more other organic dyes as needed. Other organic dyes are not particularly limited, and may be dyes having absorption characteristics in wavelength regions different from the absorption wavelength region of the azo compound represented by formula (1) or a salt thereof, and the one having high dichroism is preferred. Other organic dyes such as CI Direct Yellow 12, CI Direct Yellow 28, CI Direct Yellow 44, CI Direct Orange 26, CI Direct Orange 39, CI Direct Orange 71, CI Direct Orange 107, CI Direct Red 2, CI Direct Red 31, CI Direct Red 79, CI Direct Red 81, CI Direct Red 247, CI Direct Green 80, CI Direct Green 59, and the dyes described in Patent Documents 1 to 6 are representative examples, and the polarizing plates described in Patent Documents 1 to 6 are used depending on the purpose. It is better to use the developed dyes. These organic dyes can be used as free acid, alkali metal salt (such as Na salt, K salt, Li salt), ammonium salt or amine salt.

When other organic dyes are used in combination, the polarizing film for the purpose is a neutral gray polarizing film, a color polarizing film for liquid crystal projectors, and other color polarizing films, and different types of organic dyes are blended separately. The blending ratio is not particularly limited. Generally, for 1 part by mass of the azo compound represented by formula (1) or its salt, at least one or more other organic dyes are used in a total of 0.01 to 100 parts by mass, preferably 0.1 The range of to 10 parts by mass is more preferable.

When the objective polarizing film is a neutral gray polarizing film, the types and blending ratios of other organic dyes used in combination are adjusted to reduce the color leakage in the wavelength region of the visible light region of the resulting polarizing film.

When the objective polarizing film is a color polarizing film, the obtained polarizing film has a high average light transmittance of a single plate in a specific wavelength region, and the average light transmittance in the vertical direction becomes low, for example, so that the specific wavelength region has 39% With the above average light transmittance of the veneer and an average light transmittance of 0.4% or less in the vertical direction, the types and blending ratios of other organic dyes used in combination can be adjusted.

The dye-based polarizing film is a dichroic dye containing the azo compound represented by the formula (1) or its salt and other dyes as needed, and is contained and aligned on the polarizing film substrate (such as high Molecular film) can be manufactured by mixing with liquid crystal or aligning by coating method.

The polarizing film substrate is preferably a polymer film, and a film composed of polyvinyl alcohol resin or its derivatives is more preferable. Specific examples of the polarizing film substrate include, for example, polyvinyl alcohol resin or its derivatives, and its combination with ethylene and propylene olefins, or 2-butenoic acid, acrylic acid, methacrylic acid and maleic acid through unsaturated carboxylation. Modifiers such as acid, etc. A film formed of a polyvinyl alcohol resin or a derivative thereof is suitable for use as a polarizing film substrate in terms of dye adsorption and orientation. The thickness of the polarizing film substrate is usually 10 to 100 μm, preferably about 20 to 80 μm.

When the polarizing film base material is a polymer film, when the azo compound represented by formula (1) or a salt thereof is contained, the method of dyeing the polymer film is generally used. Dyeing is performed in the following manner, for example. First, the azo compound represented by formula (1) or its salt and other organic dyes as necessary are dissolved in water to prepare a dyeing bath. The dye concentration in the dyeing bath is not particularly limited, but is usually selected from the range of 0.001 to 10% by mass. Moreover, a dyeing auxiliary agent can be used as needed, for example, it is suitable to use, for example, a concentration of about 0.1 to 10% by mass of Glauber's salt. Dyeing can be performed by immersing the polymer film in the dyeing bath prepared in this way for, for example, 1 to 10 minutes. The dyeing temperature is preferably about 30 to 80°C.

The alignment of the azo compound represented by formula (1) or its salt is performed by stretching a polymer film dyed with a dichroic dye. The extension magnification is generally 2 to 8 times, and is not particularly limited, preferably 3 to 7.5 times, more preferably 4 to 7 times. The extension method can use any conventional method such as a wet method and a dry method. Depending on the situation, the extension of the polymer film can also be carried out before dyeing. In this case, the water-soluble dye is aligned at the time of dyeing. The polymer film containing/aligning the water-soluble dye may be subjected to post-treatments such as boric acid treatment by a conventional method as needed. Such post-processing is performed for the purpose of improving the light transmittance and polarization degree of the polarizing film. The conditions of the boric acid treatment vary with the type of polymer film used and the type of dye used. Generally, the boric acid concentration of the boric acid aqueous solution is, for example, 0.1 to 15% by mass, preferably in the range of 1 to 10% by mass. The immersion is performed in a temperature range of 30 to 80°C, preferably 40 to 75°C, for 0.5 to 10 minutes. Furthermore, if necessary, an aqueous solution containing a cationic polymer compound may be combined and subjected to a fixation treatment.

The use of the dye-based polarizing film includes, for example, liquid crystal projectors, calculators, clocks, notebook personal computers, word processors, liquid crystal televisions, car navigation devices, indoor and outdoor measuring instruments, displays, etc., as well as lenses, glasses, and the like. The dye-based polarizing film has high polarization performance equivalent to that of a polarizing film using iodine and has excellent durability. Therefore, it is particularly suitable for applications where high polarization performance and durability are necessary, such as various liquid crystal displays and liquid crystal projectors for vehicles and outdoor displays (such as display applications for industrial measuring instruments, wearable applications), etc.

〈Dye-based polarizing plate〉

The dye-based polarizing plate can be obtained by attaching a transparent protective film on one or both sides of the dye-based polarizing film. The dye-based polarizing plate has good polarization performance and moisture resistance/heat resistance/light resistance due to the above-mentioned dye-based polarizing film. The material for forming the transparent protective film is preferably a material with excellent optical transparency and mechanical strength, for example, fluorine-based films such as cellulose acetate film, acrylic film, tetrafluoroethylene/hexafluoropropylene copolymer, etc. are used. Ester resin, polyolefin resin, or polyamide resin film. The transparent protective film is preferably a triacetyl cellulose (TAC) film or a cycloolefin-based film. The thickness of the protective film is usually 40 to 200 μm.

Adhesives used for bonding dye-based polarizing films and protective films, such as polyvinyl alcohol-based adhesives, urethane emulsifier-based adhesives, acrylic-based adhesives, and polyester-isocyanate-based adhesives, etc., with polyvinyl alcohol-based adhesives Adhesives are suitable.

A transparent protective layer can be placed on the surface of the dye-based polarizing plate. Examples of other transparent protective layers include acrylic and polysiloxane hard coats, and urethane protective layers. Moreover, in order to further increase the light transmittance of the veneer, it is better to provide an AR layer (anti-reflection layer) on the transparent protective layer. The AR layer can be formed by, for example, silicon dioxide, titanium oxide, etc., by vapor deposition or sputtering treatment, or can be formed by coating a thin fluorine-based substance. The dye-based polarizing plate is preferably provided with a support. The dye-based polarizing plate can also be used as an elliptical polarizing plate by attaching a retardation plate to the surface.

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

The neutral gray polarizer has a neutral color, has less color leakage in the vertical direction of the polarized region of the visible light region, and has good polarization performance. It can also inhibit discoloration or degradation of polarization performance even under high temperature and high humidity. Due to its high durability, It is suitable for car or outdoor display.

The neutral gray polarizing plate for car or outdoor display is based on the polarizing plate composed of the dye-based polarizing film and the transparent protective film. In order to improve the light transmittance of the single plate, the AR layer is provided as a polarizing plate with AR layer. Preferably, a polarizing plate with AR layer and support attached to both the AR layer and support such as transparent resin is more preferred. The AR layer can be arranged on one side or both sides of the polarizing plate. The support system is preferably arranged on a single side of the polarizing plate, which can be directly arranged on the polarizing plate, or a polarizing plate with AR layer (AR layer/polarizing plate/AR layer) can be arranged on the support. The polarizer with AR layer and support is preferably provided with AR layer/polarizer/AR layer/support in sequence. The support is preferably because it has a flat surface for attaching the polarizing plate, and because it is used for optical purposes, it is preferably a transparent substrate. Transparent substrates are roughly divided into inorganic substrates and organic substrates, such as soda lime glass, borosilicate glass, quartz substrates, sapphire substrates, spinel substrates and other inorganic substrates, as well as acrylic, polycarbonate, and polyethylene terephthalate , Organic substrates such as polyethylene naphthalate and cycloolefin polymers are preferably organic substrates. The thickness and size of the transparent substrate may be the desired size.

The color polarizer system has good polarization performance, and does not cause discoloration or degradation of polarization performance even under high temperature and high humidity. Therefore, it is suitable for display devices for liquid crystal projectors, automobiles, and outdoor displays.

The color polarizing plate for liquid crystal projectors has brightness and good polarization performance. The necessary wavelength range of the polarizing plate (A. When using ultra-high pressure mercury lamps: 420 to 500 nm for blue channels, 500 to 580 nm for green channels, and 600 to 580 nm for red channels 680nm; B. Peak wavelength when using three primary color LED lights: 430 to 450nm for blue channel, 520 to 535nm for green channel, 620 to 635nm for red channel) The average light transmittance of the single board is more than 39%, the average vertical orientation The light transmittance is 0.4% or less. More preferably, the average light transmittance of the single plate in the wavelength region required by the polarizing plate is 41% or more, and the average light transmittance in the vertical direction is 0.3% or less, more preferably 0.2% or less. More preferably, the average light transmittance of the single plate in the wavelength region required by the polarizing plate is 42% or more, and the average light transmittance in the vertical direction is 0.1% or less.

In addition, the average light transmittance of the single plate is the average of the light transmittance in a specific wavelength region when natural light is incident on a single polarizing plate (hereinafter referred to as "polarizing plate") without an AR layer and transparent glass support. value. The average light transmittance in the vertical direction is the average value of the light transmittance in a specific wavelength region when natural light is incident on two polarizing plates in a state where the alignment directions of the two polarizing plates overlap each other perpendicularly.

The polarizing film used in the color polarizing plate for automobile or outdoor display, like the neutral gray polarizing plate, can be provided with a protective layer or AR layer and support on the dye-based polarizing film as required. The polarizing plate with a support can be obtained by, for example, coating a transparent adhesive (adhesive) on the flat surface of the support, and then attaching a dye-based polarizing plate to the coated surface. Alternatively, a transparent adhesive (adhesive) can be coated on a dye-based polarizing plate, and then a support can be attached to the coated surface. The next (adhesive) agent, for example, is preferably an acrylic. Furthermore, when the dye-based polarizer is used as an elliptical polarizer, the side of the phase difference plate is attached to the support, usually in the stacking order of the dye-based polarizer/phase difference plate/support, but it can also be polarized. The plate side is attached to the support to form a stacking sequence of phase difference plate/polarizer/support.

<Liquid crystal display device>

The liquid crystal display device is characterized by including the above-mentioned dye-based polarizing film or dye-based polarizing plate. Liquid crystal display devices are used for displays such as calculators, clocks, notebook personal computers, word processors, liquid crystal televisions, car navigators, and indoor and outdoor measuring instruments and displays. In particular, it is suitable for use in various liquid crystal displays that require high polarization performance and durability, such as automotive and outdoor displays (such as display applications for industrial measuring instruments, and wearable applications). The dye-based polarizing film or the dye-based polarizing plate included in the liquid crystal display device is suitably neutral gray.

In the liquid crystal display device, a dye-based polarizing plate is arranged on either or both of the incident side or the emitting side of the liquid crystal cell. The dye-based polarizing plate may or may not be in contact with the liquid crystal cell. From the viewpoint of durability, no contact is preferable. 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 better to use a dye-based polarizing plate provided with a support other than the liquid crystal cell. Moreover, from the viewpoint of durability, it is better to arrange the dye-based polarizing plate on both the incident side and the exit side of the liquid crystal cell. Furthermore, the polarizing plate surface of the dye-based polarizing plate is arranged on the liquid crystal cell side to form the support surface. It is better to be arranged on the light source side. In addition, the incident side of the liquid crystal cell refers to the light source side, and the opposite side is the emission side.

The liquid crystal cell included in the liquid crystal display device is, for example, an active matrix type, and it is preferably formed by sealing liquid crystal between a transparent substrate on which electrodes and TFTs are formed and a transparent substrate on which a counter electrode is formed. Light emitted from a light source such as a cold cathode tube lamp or a white LED passes through a dye-based polarizer, then a liquid crystal cell, a color filter, and then a dye-based polarizer to be projected on the display screen.

Since the dye-based polarizing plate has brightness, good polarization performance, polarization and light resistance, liquid crystal display devices are unlikely to cause discoloration and degradation of polarization performance even in high temperature and high humidity conditions such as indoors and outdoors, and have high reliability.

[Example]

Hereinafter, the present invention will be described in more detail through examples, which are examples and do not limit the present invention. The% and parts in the examples are quality standards 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 to below 10°C, add 31.3 parts of 35% hydrochloric acid, then add 6.9 parts of sodium nitrite, and stir at 5 to 10°C for 1 Hours, diazotization. Add 12.3 parts of 2-methoxyaniline to it, add sodium carbonate to make pH 3 while stirring at 10 to 30°C, and then stir to complete the coupling reaction and filter to obtain the following formula (A-3M) 30.6 parts of monoazoamine-based compounds.

Add 30.6 parts of the monoazoamine compound obtained in 400 parts of water, dissolve it with sodium hydroxide, add 21.9 parts of 35% hydrochloric acid at 10 to 30°C, then add 4.8 parts of sodium nitrite, and stir at 20 to 30°C for 1 Hours, diazotization. Add 17.2 parts of 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid to it. While stirring at 20 to 30°C, add sodium carbonate to make the pH 4, and then stir to complete The coupling reaction and filtration were performed to obtain 38.8 parts of bisazoamino compounds represented by the following formula (A-3D).

Add 24.5 parts of monoazoamine compound (A-3M) in 500 parts of water, dissolve with sodium hydroxide, add 10.0 part of phenyl chloroformate, stir for 2 hours at 30-50°C, then add bisazoamine compound (A-3D) 38.8 parts, stirred at 50 to 70°C for 5 hours for ureidolation. Salting out with sodium chloride and filtration were performed to obtain 12.5 parts of the ureido compound represented by the above formula (A-3). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 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 to below 10°C, add 25.0 parts of 35% hydrochloric acid, then add 5.5 parts of sodium nitrite, and stir at 5 to 10°C for 1 Hours, diazotization. 8.6 parts of 2-methylaniline was added to it, and while stirring at 10 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the formula (A-6MR) represented by the following formula (A-6MR) 23.6 parts of monoazoamine-based compound.

Add 38.8 parts of bisazoamine compound (A-3D) and 23.6 parts of monoazoamine compound (A-6MR) in 500 parts of water, dissolve with sodium hydroxide, and add 12.9 4-nitrophenyl chloroformate The portions were stirred at 50 to 70°C for 4 hours for urealation. It salted out with sodium chloride and filtered, and 12.2 parts of ureido compounds represented by the said formula (A-6) were obtained. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 443 nm.

(Example E3: Synthesis of azo compound of formula (A-19))

Add 29.5 parts of monoazoamine compound (A-6MR) in 400 parts of water, dissolve it with sodium hydroxide, add 21.9 parts of 35% hydrochloric acid at 10 to 30°C, and then add 4.8 parts of sodium nitrite, at 20 to 30 Stir at °C for 1 hour to perform diazotization. Add 17.2 parts of 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid to it. While stirring at 20 to 30°C, add sodium carbonate to make the pH 4, and then stir to complete The coupling reaction was performed by filtration, and 38.0 parts of bisazoamino compounds represented by the following formula (A-19D) were obtained.

Add 38.0 parts of the obtained bisazoamine compound (A-19D) and 24.5 parts of the monoazoamine compound (A-3M) to 500 parts of water, dissolve it with sodium hydroxide, and add 4-nitrobenzene chloroformate 12.9 parts of the ester was stirred at 50 to 70°C for 4 hours for urealation. It salted out with sodium chloride and filtered, and 9.4 parts of ureido compounds represented by the said formula (A-19) were obtained. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 438 nm.

(Example E4: Synthesis of azo compound of formula (A-20))

Except for the use of 16.2 parts of 3-(2-aminophenoxy)propane-1-sulfonic acid to replace 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid, the implementation Example E3 was operated in the same manner to obtain 11.2 parts of a ureido compound represented by the above formula (A-20). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 430nm.

(Example E5: Synthesis of an azo compound of formula (A-32))

Except for the use of 9.3 parts of aniline, which is the raw material 2-methoxyaniline of the substituted bisazoamino compound (A-3D), the same procedure as in Example E1 was carried out to obtain the ureido compound represented by the above formula (A-32) 10.2 copies. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 440nm.

(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 same procedure as in Example E3 was carried out to obtain the above formula 9.0 parts of ureido compounds represented by (A-36). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 416 nm.

(Example E7: Synthesis of an azo compound of formula (A-130))

Add 11.0 parts of 4-aminobenzoic acid to 300 parts of water, cool to below 10°C, add 25.0 parts of 35% hydrochloric acid, and then add 5.5 parts of sodium nitrite, and stir at 5 to 10°C for 1 hour to perform diazotization. 11.0 parts of 2-methoxy-5-methylaniline was added thereto, and while stirring at 10 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the following formula ( A-130MR) 16.0 parts of the monoazoamino compound represented by.

Add 16.0 parts of the monoazoamine compound (A-130MR) obtained in 500 parts of water, dissolve it with sodium hydroxide, 10.0 parts of phenyl chloroformate, stir at 30 to 50°C for 2 hours, and then add the bisazoamine 38.0 parts of compound (A-19D) were ureidolated at 50 to 70°C. It was salted out with sodium chloride and filtered to obtain 10.4 parts of the ureido compound represented by the above formula (A-130). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 441 nm.

(Example E8: Synthesis of an azo compound of formula (A-61))

Add 25.3 parts of 4-aminobenzene-1,3-disulfonic acid to 500 parts of water, cool to below 10°C, add 31.3 parts of 35% hydrochloric acid, then add 6.9 parts of sodium nitrite, and stir at 5 to 10°C for 1 Hours, diazotization. 12.1 parts of 2,5-dimethylaniline was added to it, and while stirring at 10 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the following formula (A-61ML 27.0 parts of monoazoamine based compounds represented by ).

Add 27.0 parts of the monoazoamine compound obtained in 400 parts of water, dissolve it with sodium hydroxide, add 25.0 parts of 35% hydrochloric acid at 10 to 30°C, then add 5.5 parts of sodium nitrite, and stir at 20 to 30°C for 1 Hours, diazotization. Add 17.2 parts of 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid to it. While stirring at 20 to 30°C, add sodium carbonate to make the pH 4, and then stir to complete The coupling reaction and filtration were performed to obtain 35.9 parts of a bisazoamino compound represented by the following formula (A-61D).

Add 24.5 parts of monoazoamine compound (A-3M) in 500 parts of water, dissolve with sodium hydroxide, 10.0 parts of phenyl chloroformate, stir at 30 to 50°C for 4 hours, then add bisazoamine compound ( A-61D) 35.9 parts, stirred at 50 to 70°C for 5 hours for urealation. It salted out with sodium chloride and filtered, and 12.1 parts of ureido compounds represented by the said formula (A-61) were obtained. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 435nm.

(Example E9: Synthesis of an azo compound of formula (A-92))

Except having used 10.7 parts of 2-methylaniline in place of 2,5-dimethylaniline, it carried out similarly to Example E8, and obtained 11.1 parts of ureido compounds represented by said formula (A-92). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 435nm.

(Example E10: Synthesis of an azo compound of formula (A-95))

Except for the use of 16.2 parts of 3-(2-aminophenoxy)propane-1-sulfonic acid to replace 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid, the implementation Example E9 was operated in the same manner to obtain 12.7 parts of the ureido compound represented by the above formula (A-95). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 428 nm.

(Example E11: Synthesis of an azo compound of formula (A-99))

Except that 16.2 parts of 3-(2-aminophenoxy)propane-1-sulfonic acid was used in place of 2-methoxyaniline, the same procedure as in Example E9 was carried out to obtain the formula (A-99) 13.5 parts of ureido compound. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 434nm.

(Example E12: Synthesis of an azo compound of formula (A-100))

Except having used 12.1 parts of 2-ethylaniline in place of 2-methylaniline, it carried out similarly to Example E9, and obtained 11.0 parts of ureido compounds represented by the said formula (A-100). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 435nm.

(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 to below 10°C, add 31.3 parts of 35% hydrochloric acid, then add 6.9 parts of sodium nitrite, and stir at 5 to 10°C for 1 Hours, diazotization. Add 12.1 parts of 2,5-dimethylaniline to it, add sodium carbonate to make pH 3 while stirring at 10 to 30°C, and then stir to complete the coupling reaction and filter to obtain the following formula (B-17ML 30.8 parts of the monoazoamine compound represented by ).

Add 30.8 parts of the monoazoamine compound obtained in 400 parts of water, dissolve it with sodium hydroxide, add 25.0 parts of 35% hydrochloric acid at 10 to 30°C, then add 5.5 parts of sodium nitrite, and stir at 20 to 30°C for 1 Hours, diazotization. 11.0 parts of 2-methoxy-5-methylaniline was added to it, and while stirring at 20 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the following formula ( 34.1 parts of the bisazoamino compound represented by B-17D).

Add 11.0 parts of 4-aminobenzoic acid to 250 parts of water, cool to below 10°C, add 25.3 parts of 35% hydrochloric acid, and then add 5.5 parts of sodium nitrite, and stir at 5-10°C for 1 hour for diazotization. 11.0 parts of 2-methoxy-5-methylaniline was added thereto, and while stirring at 10 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the following formula ( B-17MR) 18.3 parts of monoazoamine based compounds.

Add 18.3 parts of the obtained monoazoamine compound (B-17MR) in 250 parts of water, dissolve it with sodium hydroxide, add 10.0 parts of phenyl chloroformate, stir for 4 hours at 30 to 50°C, then add bisazoamine 34.1 parts of the base compound (B-17D), stirred at 50 to 70°C for 5 hours for urealation. Salting out with sodium chloride and filtration were performed to obtain 10.5 parts of the ureido compound represented by the above formula (B-17). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 435nm.

(Example E14: Synthesis of an azo compound of formula (B-1))

Except that 20.3 parts of 4-aminobenzene-1,3-disulfonic acid was used in place of 4-aminobenzoic acid, the same procedure as in Example E13 was carried out to obtain the ureido compound represented by the above formula (B-1) 12.0 share. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution was 427 nm.

(Example E15: Synthesis of azo compound of formula (B-20))

Except having used 13.8 parts of 5-amino-2-chlorobenzoic acid in place of 4-aminobenzoic acid, it carried out similarly to Example E13, and obtained 10.2 parts of ureido compounds represented by the said formula (B-20). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 432 nm.

(Example E16: Synthesis of an azo compound of formula (B-29))

Except for the use of 18.7 parts of 2-amino-5-methylbenzenesulfonic acid to replace 4-aminobenzene-1,3-disulfonic acid, which is the raw material of the bisazoamino compound (B-17D), the same as the examples Similarly to E14, 10.1 parts of the ureido compound represented by the above formula (B-29) was obtained. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 425 nm.

(Example E17: Synthesis of an azo compound of formula (B-48))

Except that 10.7 parts of 2-methylaniline was used in place of 2,5-dimethylaniline, the same procedure as in Example E13 was carried out to obtain 13.5 parts of the ureido compound represented by the above formula (B-48). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 433nm.

(Example E18: Synthesis of an azo compound of formula (C-5))

Add 30.8 parts of monoazoamine compound (B-17ML) in 400 parts of water, dissolve it with sodium hydroxide, add 25.0 parts of 35% hydrochloric acid at 10 to 30°C, then add 5.5 parts of sodium nitrite, at 20 to 30 Stir at °C for 1 hour to perform diazotization. Add 19.6 parts of 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid to it. While stirring at 20 to 30°C, add sodium carbonate to make the pH 4, and then stir to complete The coupling reaction and filtration were performed to obtain 41.0 parts of the bisazoamino compound represented by the following formula (C-5D).

Add 15.0 parts of 2-amino-5-methylbenzenesulfonic acid to 250 parts of water, cool to below 10°C, add 25.0 parts of 35% hydrochloric acid, then add 5.8 parts of sodium nitrite, and stir at 5 to 10°C for 1 hour. Carry out diazotization. 11.0 parts of 2-methoxy-5-methylaniline was added thereto, and while stirring at 10 to 30°C, sodium carbonate was added to make the pH 3, and then stirred to complete the coupling reaction and filtered to obtain the following formula ( C-5MR) represents 21.5 parts of monoazoamino compound.

Add 21.5 parts of the obtained monoazoamine compound (C-5MR) in 500 parts of water, dissolve it with sodium hydroxide, add 10.0 parts of phenyl chloroformate, stir for 2 hours at 30 to 50°C, then add bisazoamine 41.0 parts of the base compound (C-5D) was stirred at 50 to 70°C for 5 hours for urealation. It salted out with sodium chloride and filtered, and 12.9 parts of ureido compounds represented by the said formula (C-5) were obtained. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 425 nm.

(Example E19: Synthesis of an azo compound of formula (C-16))

Except that 11.0 parts of 4-aminobenzoic acid was used in place of 2-amino-5-methylbenzenesulfonic acid, the same procedure as in Example E18 was carried out to obtain 12.8 parts of the ureido compound represented by the above formula (C-16) . The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution was 437 nm.

(Example E20: Synthesis of an azo compound of formula (C-19))

Except that 13.8 parts of 5-amino-2-chlorobenzoic acid was used in place of 2-amino-5-methylbenzenesulfonic acid, the same procedure as in Example E18 was carried out to obtain the urea represented by the above formula (C-19) 13.5 parts of base compound. The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 435nm.

(Example E21: Synthesis of an azo compound of formula (C-46))

Except for the use of 10.7 parts of 2-methylaniline to replace 2,5-dimethylaniline, and the use of 19.7 parts of 3-(2-amino-4-methylphenoxy)propane-1-sulfonic acid to replace 2-methoxy Except for the phenyl-5-methylaniline, the same procedure as in Example E19 was carried out to obtain 13.1 parts of the ureido compound represented by the above formula (C-46). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 440nm.

(Example E22: Synthesis of an azo compound of formula (C-49))

Except for the use of 10.7 parts of 2-methylaniline to replace 2,5-dimethylaniline, and the use of 21.3 parts of 3-(2-amino-4-chlorophenoxy)propane-1-sulfonic acid to replace 2-methoxy Except for -5-methylaniline, it was operated in the same manner as in Example E19 to obtain 13.7 parts of the ureido compound represented by the above formula (C-49). The maximum absorption wavelength of this compound in a 20% pyridine aqueous solution is 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-130) obtained in Examples E1 to E22 ), (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 0.03% and Glauber's salt In each 45°C aqueous solution (dye bath) with a concentration of 0.1%, polyvinyl alcohol having a thickness of 75 μm was immersed for 4 minutes. The film was stretched 5 times in a 3% boric acid aqueous solution at 50° C., and washed and dried under tension to obtain a polarized film.

Table 1 shows the absorption wavelength at the maximum polarization rate of the obtained dye-based polarizing film and its polarization rate. As shown in Table 1, the polarizing films produced by using the compounds of the present invention all have high polarization rates.

The absorption wavelength at the maximum polarization rate of the polarizing film and the calculation of the polarization rate are calculated using a spectrophotometer (U-4100 manufactured by Hitachi, Ltd.) when parallel transmittance and vertical transmittance are measured when polarized light is incident.

Here, the so-called parallel transmittance (Ky) refers to the transmittance measured so that the absorption axis of the absolute polarizer (the polarizing plate with a degree of polarization of 99.99%) is set parallel to the absorption axis of the polarizing film. The so-called vertical transmittance ( Kz) refers to the transmittance measured by setting the absorption axis of the absolute polarizer perpendicular to the absorption axis of the polarizing film.

The parallel transmittance and vertical transmittance of each wavelength are between 380 and 780 nm, measured at intervals of 1 nm. Using the values measured separately, the polarization rate of each wavelength is calculated from the following formula (I), and the highest polarization rate of 380 to 780 nm and the absorption wavelength (nm) at this time are obtained.

Polarization rate (%)=[(Ky-Kz)/(Ky+Kz)]×100 (I)

(Comparative Example 1: Production of Polarizing Film)

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

(Comparative Example 2: Production of Polarizing Film)

Except that C.I. Direct Yellow 44 was used instead of the compound of formula (A-3), a polarizing film was produced in the same manner as in Example F1.

One indicator of image quality is contrast, which is the difference in brightness between white display and black display. The comparison of the maximum absorption wavelength of the dye-based polarizing films obtained in Examples F1 to F22 and Comparative Examples 1 and 2 is shown in Table 2. Here, the contrast system represents the ratio of parallel transmittance to vertical transmittance (contrast = parallel transmittance at the maximum absorption wavelength (Ky)/vertical transmittance (Kz) at the maximum absorption wavelength). The larger the value, the polarizer. The better the polarization performance. In addition, the evaluation of the polarization performance was to prepare samples so that the parallel transmittance of the maximum absorption wavelength of the dye-based polarizing film became equal, and to compare them. As shown in Table 2, the dye-based polarizing films of Examples F1 to F22 all have higher contrast than the dye-based polarizing films of Comparative Examples 1 and 2.

(Example P1: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-19) obtained in Example E3, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P2: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-20) obtained in Example E4, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P3: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-61) obtained in Example E8, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in various aqueous solutions at 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P4: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-92) obtained in Example E9, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P5: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-95) obtained in Example E10, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P6: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (A-100) obtained in Example E12, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P7: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (B-17) obtained in Example E13, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P8: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (B-29) obtained in Example E16, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P9: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (B-48) obtained in Example E17, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P10: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (C-16) obtained in Example E19, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P11: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (C-19) obtained in Example E20, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

(Example P12: Production of neutral gray polarizing plate)

Except for the use of 0.1% of the compound of formula (C-46) obtained in Example E21, 0.2% of CI Direct Red 81, 0.05% of CI Direct Blue 274, and 0.1% of Glauber's salt in each aqueous solution at a concentration of 45°C, and the implementation In Example F1, a polarizing film was produced in the same manner. The obtained polarizing film has an average transmittance of 42% for a single plate of 380 to 700 nm, and an average transmittance of 0.02% in a vertical direction, which has a high degree of polarization.

On both sides of the polarizing film, a polyvinyl alcohol aqueous solution adhesive was interposed, and a triacetyl cellulose film (TAC film: manufactured by Fuji Film Co., Ltd.: trade name TD-80U) was laminated, and an AR layer was attached using an adhesive. The support is a dye-based polarizing plate (neutral gray polarizing plate) laminated in the order of TAC/polarizing film/TAC/AR support.

The neutral gray polarizers obtained in Examples P1 to P12 showed no change in the average transmittance of the veneer after 400 hours under the conditions of 80°C and 90% RH, and showed a long time under the conditions of high temperature and high humidity. Durability. Furthermore, the neutral gray polarizing plates of Examples P1 to P12 have been subjected to the xenon lamp light resistance test, and even after 200 hours, the average transmittance of the single plate does not change, and the light resistance to long-term exposure to light is also good. These results show that the neutral gray polarizers of Examples P1 to P12 all have good polarization performance, and are high-performance dye-based polarizers with moisture resistance/heat resistance/light resistance.

Claims (23)

An azo compound represented by the following formula (1) or its salt,

In the formula, A ¹ and A ² each independently represent a naphthyl group which may have a substituent selected from the group consisting of a hydroxyl group, a C1-4 alkoxy group having a sulfo group, and a sulfo group, or a phenyl group which may have a substituent; R ₁ -R ₆ each independently represents a hydrogen atom, a C1-4 alkyl group, a C1-4 alkoxy group, a C1-4 alkoxy group having a sulfo group, a carboxyl group, a hydroxyl group, a halogen group, or a C1-4 alkyl group substituted The acylamino group. The azo compound or its salt as described in item 1 of the scope of the patent application, wherein ^{one or both of A 1} and A ² (when both are independently) have one or more selected from the group consisting of sulfo group, carboxyl group, and C1-4 alkoxy, C1-4 alkyl, C1-4 alkoxy, halogen, nitro, amino, amine substituted by C1-4 alkyl and substituted by C1-4 alkyl of sulfo group The phenyl group is the substituent of the group consisting of the acylamino group. The azo compound or its salt as described in item 2 of the scope of patent application, wherein the aforementioned amino group substituted by C1-4 alkyl is N,N-dimethylamino, N,N-diethylamino , Methylamino, ethylamino, n-propylamino, n-butylamino, or second butylamino, the aforementioned C1-4 alkyl substituted acylamino group is acetyl Amino, acrylamido, or butamido. The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application, wherein ^{one or both of A 1} and A ² (when both are independently) have at least one A substituent selected from the group consisting of a sulfo group, a carboxy group and a C1-4 alkoxy group with a sulfo group, and also has a hydrogen atom, a sulfo group, a carboxyl group, a C1-4 alkoxy group with a sulfo group, and C1-4 Alkyl, C1-4 alkoxy, halogen, nitro, amino, phenyl substituted with C1-4 alkyl or acylamino substituted with C1-4 alkyl. The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application, wherein ^{one or both of A 1} and A ² (when both are independently) are the following formula ( 2) Represented by phenyl,

In the formula, one of R ₇ and R ₈ is a sulfo group, a carboxy group or a C1-4 alkoxy group having a sulfo group, and the other is a hydrogen atom, a sulfo group, a carboxy group, or a C1-4 alkoxy group having a sulfo group , C1-4 alkyl group, C1-4 alkoxy group, halogen group, nitro group, amino group, amino group substituted by C1-4 alkyl group or acylamino group substituted by C1-4 alkyl group. The azo compound or its salt according to item 5 of the scope of patent application, wherein 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 azo compound or its salt according to any one of the first to third items in the scope of the patent application, wherein ^{at least one of A 1} and A ² is the aforementioned naphthyl group. The azo compound or the salt thereof as described in any one of items 1 to 3 in the scope of the patent application, wherein both of A ¹ and A ² are the aforementioned phenyl groups. The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application, wherein ^{one or both of A 1} and A ² (when both are independently) are the following formula ( 3) Naphthyl,

In the formula, R ₉ is a hydrogen atom, a hydroxyl 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 its salt according to item 9 of the scope of patent application, wherein R ₉ is a hydrogen atom and n is 2. The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application, which is an azo compound or its salt represented by the following formula (4),

In the formula, R ₁ -R _{6 are} defined as formula (1). The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application is an azo compound or its salt represented by the following formula (5),

In the formula, _{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, and R ₁ -R ₆ The definition is as formula (1). The azo compound or its salt according to any one of items 1 to 3 in the scope of the patent application, wherein R _{1 to} R ₆ are each independently a hydrogen atom, a C1-4 alkyl group, and a C1-4 alkoxy group , A halogen group or a C1-4 alkoxy group having a sulfo group. The azo compound or its salt as described in any one of items 1 to 3 in the scope of the patent application, wherein R _{1 to} R ₆ are each independently a C1-4 alkoxy group having a sulfo group, a hydrogen atom, a methyl group Group, ethyl group, halogen group or methoxy group. The azo compound or the salt thereof according to any one of items 1 to 3 in the scope of the patent application, wherein _{at least one of R 1 to} R ₆ is a C1-4 alkoxy group having a sulfo group. The azo compound or its salt according to item 15 of the scope of the patent application, wherein the aforementioned C1-4 alkoxy group having a sulfo group is 3-sulfopropoxy. A dye-based polarizing film includes a polarizing film substrate containing the azo compound or its salt as described in any one of items 1 to 16 in the scope of the patent application. A dye-based polarizing film comprising a polarizer containing the azo compound or its salt as described in any one of items 1 to 16 in the scope of the patent application and one or more organic dyes other than the azo compound or its salt Film substrate. The dye-based polarizing film described in item 17 or item 18 of the scope of patent application, wherein the aforementioned polarizing film substrate is a film composed of polyvinyl alcohol resin or its derivatives. A dye-based polarizing plate, which is attached to one or both sides of the dye-based polarizing film described in any one of items 17 to 19 in the scope of the patent application It is combined with a transparent protective layer. A polarizing plate for liquid crystal display is provided with the dye-based polarizing film as described in any one of the 17th to 19th items of the patent application or the dye-based polarizing plate as described in the 20th item of the patent application. A neutral gray polarizing plate is provided with the dye-based polarizing film as described in any one of the 17th to 19th patent applications or the dye-based polarizing plate as described in the 20th patent application. A liquid crystal display device equipped with the dye-based polarizing plate as described in the scope of patent application 20, the polarizing plate for liquid crystal display as described in the scope of patent application 21 or neutral as described in the 22nd patent application scope Gray polarizer.