JP2008081700A - Pigment for anisotropic pigmented coat formed by wet type film formation method, composition containing the pigment, anisotropic pigmented coat, and polarizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment useful for an anisotropic pigmented coat, an anisotropic pigmented coat containing the pigment, and a polarizer. <P>SOLUTION: An azo pigment for an anisotropic pigmented coat formed by a wet type film formation method is provided, the pigment being characterized by that the form of a free acid is represented by formula (1) (wherein A<SP>1</SP>is an aromatic hydrocarbon group or the like; B<SP>1</SP>is a divalent aromatic hydrocarbon group or the like; m is 0 or 1; R<SP>1</SP>is a hydroxy group or the like; R<SP>2</SP>is a hydrogen atom, a halogen atom, or the like; and R<SP>3</SP>and R<SP>4</SP>are each a hydrogen atom, an alkyl group, or the like). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an azo dye having high dichroism useful for a polarizing plate included in a display element of a light control element, a liquid crystal element (LCD), an organic electroluminescence element (OLED), a composition containing the dye, The present invention relates to an anisotropic dye film and a polarizing element.

  LCDs use linearly polarizing plates and circularly polarizing plates to control optical rotation and birefringence in display. In the OLED, a circularly polarizing plate is used for preventing reflection of external light. Conventionally, iodine has been widely used as a dichroic substance in these polarizing plates (polarizing elements). However, since iodine has a high sublimation property, when used in a polarizing element, its heat resistance and light resistance are not sufficient. Further, the extinction color is deep blue, and it cannot be said to be an ideal achromatic polarizing element over the entire visible spectrum region.

Therefore, a polarizing element using an organic dye as a dichroic material has been studied. However, these organic dyes have a problem that only a polarizing element having a dichroism considerably inferior to iodine can be obtained.
In particular, a polarizing element is an important component in an LCD that uses the optical rotation and birefringence of light as a display principle. In recent years, a new polarizing element has been developed for the purpose of improving display performance and the like. .

One method is to dissolve or adsorb a dichroic organic dye (dichroic dye) in a polymer material such as polyvinyl alcohol in the same way as a polarizing element containing iodine, and the film is formed in one direction. And a method of orienting the dichroic dye by stretching it into a shape. However, this method has a problem such that a process such as a stretching process is troublesome.
Therefore, other methods have recently attracted attention. As this method, in Non-Patent Document 1, a dichroic dye is oriented on a substrate such as glass or transparent film by utilizing intermolecular interaction of organic dye molecules, and a polarizing film (anisotropic dye film) is formed. Forming. However, it has been known that the method described in this document has a problem of heat resistance.

  In addition, orienting the dichroic dye on the substrate such as glass or transparent film by utilizing the intermolecular interaction of organic dye molecules is achieved by the wet film forming method. When a film is produced, the dye film is required to be a dye suitable for the process of the wet film forming method, in addition to the high dichroism of the dye molecule used. Examples of the process in the wet film forming method include a method of depositing and orienting a dye on a substrate, a method of controlling the orientation, and the like. Even if the dye is used in a polarizing element that has undergone the conventional stretching process, Often not suitable for wet film formation.

In Patent Documents 1 to 4, various materials suitable for the process of the wet film forming method have been proposed. However, even if these materials are suitable for the process, high polarization characteristics (extinction ratio) cannot be obtained. There was a problem.
Dreyer, JF, Journal de Physique, 1969, 4, 114., "Light Polarization From Films of Lyotropic Nematic Liquid Crystals" JP 2002-180052 A JP-T-2002-528758 JP 2002-338838 A JP-T 8-511109

  The present invention provides a dye used for an anisotropic dye film formed mainly by a wet film-forming method, which becomes an anisotropic dye film exhibiting high dichroism and a high degree of molecular orientation. The task is to do.

As a result of intensive studies to solve the above problems, the present inventors have determined that an anisotropic dye film formed by a wet film-forming method by using a dye whose free acid form is represented by the following formula (1) In the present invention, an anisotropic dye film exhibiting high dichroism and a high degree of molecular orientation can be formed, and it has been found that a polarizing element having the anisotropic dye film can have high optical performance. did.
That is, the present invention provides a dye for an anisotropic dye film formed by a wet film-forming method, wherein the free acid form is represented by the following formula (1), a different dye containing the dye and a solvent. The present invention resides in a composition for an isotropic dye film, an anisotropic dye film containing the dye, and a polarizing element having the anisotropic dye film.

(In formula (1), A ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
B ¹ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. n represents 0 or 1, and m represents 0 or 1.
R ¹ represents a hydroxyl group or —NHR ⁵ (R ⁵ represents a hydrogen atom, an alkyl group which may have a substituent or an alkyl acyl group which may have a substituent).
R ² may have a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a hydroxyl group, a sulfo group, a carboxy group, a halogen atom or a substituent. Represents a good amino group.
R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group that may have a substituent, a phenyl group that may have a substituent, an acyl group that may have a substituent, or The triazinyl group which may have a substituent is represented. )

  By using the dye of the present invention, an anisotropic dye film showing high dichroism and a high degree of molecular orientation can be provided even in an anisotropic dye film formed by a wet film forming method. Moreover, the polarizing element using the anisotropic dye film having such characteristics can be used in various fields such as a dimming element, a liquid crystal element, and an organic electroluminescence element.

The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents.
The anisotropic dye film referred to in the present invention differs from the electromagnetic properties in any two directions selected from a total of three directions in the three-dimensional coordinate system of the thickness direction of the dye film and any two in-plane orthogonal directions. It is a dye film having anisotropy. Examples of electromagnetic properties include optical properties such as absorption and refraction, and electrical properties such as resistance and capacitance. Examples of the film having optical anisotropy such as absorption and refraction include a linearly polarizing film, a circularly polarizing film, a retardation film, and a conductive anisotropic film.

The anisotropic dye film of the present invention is preferably used as a polarizing film, a retardation film or a conductive anisotropic film, and more preferably used as a polarizing film.
The present invention relates to an azo dye for an anisotropic dye film formed by a wet film-forming method, wherein the free acid form is represented by the following formula (1).

(In formula (1), A ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
B ¹ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. n represents 0 or 1, and m represents 0 or 1.
R ¹ represents a hydroxyl group or —NHR ⁵ (R ⁵ represents a hydrogen atom, an alkyl group which may have a substituent or an alkyl acyl group which may have a substituent).
R ² may have a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a hydroxyl group, a sulfo group, a carboxy group, a halogen atom or a substituent. Represents a good amino group.
R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group that may have a substituent, a phenyl group that may have a substituent, an acyl group that may have a substituent, or The triazinyl group which may have a substituent is represented. )
Dye represented by the formula (1) is a substituent R ^1, such as a hydroxyl group or -NHR ^5, a hydrogen atom bound to a heteroatom, on the benzene ring to which R ¹ is substituted, R ¹ It is considered that the position of the azo group is fixed and the molecular planarity is higher than that of a dye that does not have a hydrogen atom that can easily contribute to a hydrogen bond in R ^{1 because} it easily forms a hydrogen bond with an azo group substituted in the ortho position. . As a result, in the composition for an anisotropic dye film, the molecular association property is higher, and a preferable association state such as a lyotropic liquid crystal is formed, and the dye molecules are arranged in a high order even in the anisotropic dye film. In addition, it is considered that an anisotropic dye film exhibiting high dichroism can be provided. In particular, when used in anisotropic dye films, it exhibits higher dichroism than conventional dyes in the short wavelength region corresponding to the sub-absorption of the dye. It is presumed that a functional dye film can be obtained.

Hereinafter, the pigment | dye represented by the said Formula (1) of this invention is demonstrated.
<A ^1>
In formula (1), A ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
Here, in the present invention, “may have a substituent” means that one or more substituents may be present.

  The aromatic hydrocarbon group is preferably a phenyl group or a naphthyl group. Examples of the substituent that the aromatic hydrocarbon group may have include a hydrophilic group introduced to increase the solubility of the azo compound and an electron donating property introduced to adjust the color tone as a dye. A group having an electron-withdrawing property is preferable. Specifically, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an acylamino group which may have a substituent, Examples include an optionally substituted amino group, an optionally substituted carbamoyl group, a nitro group, a carboxy group, a sulfo group, a hydroxyl group, a cyano group, or a halogen atom.

  The alkyl group usually has 1 or more carbon atoms, usually 6 or less, preferably 4 or less. Examples of the group that may be substituted on the alkyl group include an alkoxy group, a hydroxyl group, a halogen atom, a sulfo group, and a carboxy group. Specific examples of the alkyl group include a lower alkyl group which may have a substituent such as a methyl group, an ethyl group, an n-propyl group, a hydroxyethyl group, or a 1,2-dihydroxypropyl group.

  The alkoxy group usually has 1 or more carbon atoms, usually 6 or less, preferably 3 or less. Examples of the group that may be substituted on the alkoxy group include an alkoxy group, a hydroxyl group, a halogen atom, a sulfo group, and a carboxy group. Specific examples of the alkoxy group include a lower alkoxy group which may have a substituent such as a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, a hydroxyethoxy group, and a 1,2-dihydroxypropoxy group. Can be mentioned.

The acylamino group is represented by —NH—COR ³¹ , and R ³¹ represents an alkyl group which may have a substituent or a phenyl group which may have a substituent. The alkyl group usually has 1 or more, usually 4 or less, preferably 2 or less carbon atoms. Examples of the group that may be substituted on the alkyl group and the phenyl group include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group, and a halogen atom. Specific examples of the acylamino group include an acetylamino group and a benzoylamino group.

The amino group is usually represented by —NH ₂ , —NHR ³² , —NR ³³ R ³⁴ , and each of R ^{32 to} R ³⁴ independently has an alkyl group or a substituent that may have a substituent. Represents an optionally substituted phenyl group. The alkyl group usually has 1 or more, usually 4 or less, preferably 2 or less carbon atoms. Examples of the group that may be substituted on the alkyl group and the phenyl group include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group, and a halogen atom. Specific examples of the amino group include a methylamino group, an ethylamino group, a propylamino group, a dimethylamino group, and a phenylamino group.

  The carbamoyl group includes an unsubstituted carbamoyl group, an optionally substituted alkylcarbamoyl group, an optionally substituted phenylcarbamoyl group, or an optionally substituted naphthylcarbamoyl group. Preferably there is. The alkyl group of the alkylcarbamoyl group, the phenyl group of the phenylcarbamoyl group, and the naphthyl group of the naphthylcarbamoyl group may each independently have a substituent. Examples of the substituent include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group, and a halogen atom. Of these substituents, a sulfo group is particularly preferable from the viewpoint of water solubilization. Specific examples of the carbamoyl group include a carbamoyl group, a phenylcarbamoyl group, a naphthylcarbamoyl group, and the like.

When A ¹ is an optionally substituted aromatic hydrocarbon group, it is particularly substituted with an unsubstituted phenyl group, an unsubstituted naphthyl group, a phenyl group substituted with a sulfo group, or a sulfo group. A naphthyl group is preferred.
When A ¹ is an aromatic hydrocarbon group which may have a substituent, the aromatic hydrocarbon group may have 1 to 5 substituents, preferably 1 to 2 Is.

In the case where A ¹ is an optionally substituted aromatic heterocyclic group, the aromatic heterocyclic group is preferably a monocyclic or bicyclic heterocyclic ring-derived group. Examples of atoms other than carbon constituting the aromatic heterocyclic group include heteroatoms such as a nitrogen atom, a sulfur atom and an oxygen atom, and among these, a nitrogen atom is preferable. When the aromatic heterocyclic group has a plurality of the heteroatoms, these may be the same or different. Specific examples of the aromatic heterocyclic group include pyridyl group, quinolyl group, thiazolyl group, benzothiazolyl group,

And the like. (In the formula, R ⁴¹ represents a hydrogen atom, an optionally substituted alkyl group or an optionally substituted phenyl group. The alkyl group and the phenyl group may be substituted. Good groups include alkyl groups such as methyl and ethyl groups, alkoxy groups such as methoxy and ethoxy groups, hydroxyl groups, nitro groups, sulfo groups, carboxy groups, halogen atoms, amino groups, methylamino groups and other substituted amino groups. Among them, a pyridyl group, a quinolyl group, or a phthalimidoyl group is preferable.

  Examples of the substituent that the aromatic heterocyclic group may have include an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, a hydroxyl group, a nitro group, a sulfo group, a carboxy group, and a halogen. Examples include atoms, amino groups, substituted amino groups such as methylamino groups, amide groups, and cyano groups. Among these, an unsubstituted aromatic heterocyclic group or an aromatic heterocyclic group substituted with a hydroxyl group, a sulfo group, or a carboxy group is preferable.

The group represented by A ¹ is particularly preferably any group of the following formula (2-a) or (2-b).

(In Formula (2-a) and Formula (2-b), R ¹⁵ and R ¹⁶ each independently represent a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, or a substituent. An alkyl group which may have, an alkoxy group which may have a substituent, a carboxy group or a sulfo group, r represents an integer of 0 to 2, and s represents an integer of 0 to 3)
The reason why any one of the above formulas (2-a) and (2-b) is preferable is considered to be a structure suitable for salt formation between dye molecules. That is, the position of the sulfo group substituted on the benzene ring or naphthalene ring is in an appropriate position when salting with the amino group located at the 7th position of the naphthyl group located at the end opposite to A ^{1 of} the dye molecule. Because it can be placed, it is thought that it is easier to create a stable meeting by inquiring strongly.

R ¹⁵ and R ¹⁶ each independently have a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, an alkyl group which may have a substituent, or a substituent. Represents an alkoxy group, a carboxy group or a sulfo group. Specific examples of the amino group that may have a substituent, the alkyl group that may have a substituent, and the alkoxy group that may have a substituent include: A ¹ is an aromatic hydrocarbon; The amino group which may have a substituent, the alkyl group which may have a substituent, and the alkoxy which may have a substituent, exemplified as the substituent which may be included in the case of a group Same as the group. From the viewpoint of promoting the association of molecules, r and s are particularly preferably 0.

<B ¹ >
In formula (1), B ¹ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent.
As the aromatic hydrocarbon group, a phenylene group or a naphthylene group is preferable. Examples of the substituent that the aromatic hydrocarbon group may have include an alkyl group that may have a substituent, an alkoxy group that may have a substituent, and a substituent that may have a substituent. Examples thereof include a good amino group, an acylamino group which may have a substituent, a carbamoyl group which may have a substituent, a hydroxyl group, a nitro group, a sulfo group, a carboxy group, a cyano group, and a halogen atom. In addition, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an amino group which may have a substituent, an acylamino group which may have a substituent, Preferred carbon number of the optionally substituted carbamoyl group, examples of the optionally substituted substituent, and specific examples thereof may be possessed when A ¹ is an aromatic hydrocarbon group. The same as those described as the substituent. Among them, a group having a small polarity such as an alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom or a group having hydrogen bonding property is preferable from the viewpoint of improving the associative property by interaction in forming a lyotropic liquid crystal, and from the viewpoint of water solubility Is preferably a sulfo group.

As the phenylene group, a 1,4-phenylene group is preferable, and as the naphthylene group, a 1,4-naphthylene group is preferable because the dyes interact with each other.
The aromatic hydrocarbon group may be unsubstituted or may have 1 to 5 substituents as described above, and preferably has 1 to 2 substituents.
The aromatic hydrocarbon group is particularly preferably a 1,4-naphthylene group from the viewpoint of molecular association, and the 1,4-naphthylene group is preferably substituted by a sulfo group from the viewpoint of water solubility. Further preferred. The sulfo group is preferably substituted at the 6-position.

  As the aromatic heterocyclic group, a group derived from a monocyclic or bicyclic heterocyclic ring is preferable. Examples of the atoms other than carbon constituting the aromatic heterocyclic group include heteroatoms such as a nitrogen atom, a sulfur atom and an oxygen atom, and a nitrogen atom is particularly preferred. When the aromatic heterocyclic group has a plurality of such heteroatoms, these may be the same or different. Specific examples of the aromatic heterocyclic group include a pyridinediyl group, a quinolinediyl group, an isoquinolinediyl group, a benzothiadiazolediyl group, and a phthalimidodiyl group. Among these, a quinoline diyl group and an isoquinoline diyl group are preferable.

Examples of the substituent that the aromatic heterocyclic group may have include an alkyl group such as a methyl group and an ethyl group, an alkoxy group such as a methoxy group and an ethoxy group, an alkylamino group such as an amino group and a methylamino group, Acetylamino group, acylamino group, nitro group, carboxy group, sulfo group,
A hydroxyl group, a cyano group, a halogen atom, etc. are mentioned. Among these, a hydroxyl group, a sulfo group, and a carboxy group are preferable. The aromatic heterocyclic group may be unsubstituted or have 1 to 5 of the above substituents, preferably is an unsubstituted aromatic heterocyclic group or has 1 to 2 of the above substituents. Is an aromatic heterocyclic group.

  The aromatic heterocyclic group is preferably a divalent heterocyclic group represented by the following formula (3-a) or (3-b). That is, it is a divalent linking group bonded at the p-position of the nitrogen-containing aromatic six-membered ring, or a divalent linking group bonded at the p-position of the benzene ring of the aromatic heterocyclic ring. Dyes are preferred for showing interaction. For example, in the case of a quinoline diyl group, a 5,8-quinoline diyl group is preferable, and in the case of an isoquinoline diyl group, a 5,8-isoquinoline diyl group is preferable.

^(Wherein, Q 1 to Q ⁴ each independently represents a carbon atom or a nitrogen ^atom, one or two of Q 1 to Q ⁴ is a nitrogen atom. In ^addition, Q 1 to Q ⁴ are a substituent You may have)

(Wherein X represents a divalent linking group containing a nitrogen atom, oxygen atom or sulfur atom in the main chain and forms a 5- to 7-membered ring, and the benzene ring may have a substituent).
Note that X contains a nitrogen atom, an oxygen atom or a sulfur atom in the main chain means that the ring formed by the divalent group can be a ring containing a nitrogen atom, an oxygen atom or a sulfur atom as a hetero atom. means. As the above-mentioned formula (3-a) or (3-b) 2-valent heterocyclic group may have, substituent represented by, if the B ¹ is an aromatic heterocyclic group And those listed as substituents that may be present.

Examples of the divalent linking group represented by X in the above formula (3-b) include -N = C-C = C-, -CO-NH-CO-, = N-S-N =,- CH = N—CH═CH— and the like can be mentioned. However, C and N in CH and NH may be substituted with a substituent such as an organic group instead of H.
Examples of the divalent heterocyclic group represented by the above formula (3-a) include groups derived from pyridine, pyridazine, pyrimidine and pyrazine, and having linked positions in the p-position. Examples of the divalent heterocyclic group represented by the above formula (3-b) include groups derived from quinoline, isoquinoline, benzothiadiazole, phthalimide, and the like, and the connecting positions of the benzene rings in the p-position relative to each other. . From the viewpoint of the flatness of the entire dye, the group of formula (3-b) is preferable, and a 5,8-quinolinediyl group and a 5,8-isoquinolinediyl group are particularly preferable.

<R ¹ >
In the formula (1), R ¹ represents a hydroxyl group or —NHR ⁵ . Here, R ⁵ represents a hydrogen atom, an alkyl group which may have a substituent, or an acyl group which may have a substituent.
The alkyl group usually has 1 or more, usually 4 or less, preferably 2 or less carbon atoms. Examples of the group that may be substituted on the alkyl group include an alkoxy group, a hydroxyl group, a halogen atom, a sulfo group, and a carboxy group. Specific examples of the alkyl group include a lower alkyl group which may have a substituent such as a methyl group, an ethyl group, an n-propyl group, a hydroxyethyl group, or a 1,2-dihydroxypropyl group.

The acyl group of R ⁵ usually has 2 or more carbon atoms, usually 5 or less, preferably 3 or less. Examples of the group that may be substituted on the acyl group include an alkoxy group, a hydroxyl group, a halogen atom, a sulfo group, and a carboxy group. Specific examples of the acyl group include an acetyl group.
<R ² >
In Formula (1), R ² represents a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a hydroxyl group, a sulfo group, a carboxy group, a halogen atom, or a substituent. The amino group which may have or the acylamino group which may have a substituent is represented. In addition, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an amino group which may have a substituent, an acylamino group which may have a substituent, Preferred examples of the carbon number, and examples of the substituent which may be present are the same as those described as the substituent which may be possessed when A ¹ is an aromatic hydrocarbon group. Among them, a group that is not sterically bulky such as a methyl group, an ethyl group, a methoxy group, or a halogen atom, or a group having hydrogen bonding properties such as an amino group or a hydroxyl group is an azo group located in the ortho position as viewed from R ² . It is preferable in terms of improving the molecular associative property because it fixes the conformation and does not sterically inhibit the association.

<R ³ and R ⁴ >
In Formula (1), R ³ and R ⁴ each independently have a hydrogen atom, an alkyl group that may have a substituent, a phenyl group that may have a substituent, or a substituent. And may represent an acyl group or a triazinyl group.
Examples of the substituent that the alkyl group and the phenyl group may have include a hydroxyl group, a carboxy group, and a sulfo group.

The acyl group is an optionally substituted alkylacyl group or phenylacyl group. Examples of the substituent that the alkyl group and phenyl group may have include a hydroxyl group, a carboxy group, and a sulfo group. .
The triazinyl group may have a substituent. Examples of the substituent include alkyl groups such as a methyl group and an ethyl group, alkylamino groups such as an amino group, a methylamino group, and an ethylamino group, a methyl group, and a methoxy group. Group, carboxy group, amino group, sulfo group and the like may be substituted phenylamino group, hydroxyl group and halogen atom.

In particular, —NR ³ R ⁴ includes an amino group in which R ³ and R ⁴ are hydrogen atoms, an alkylamino group in which R ³ is a hydrogen atom and R ⁴ is an alkyl group, R ³ is a hydrogen atom, and R ⁴ is phenyl. A phenylamino group which is a group is preferable, and the alkyl group of alkylamino preferably has 1 to 2 carbon atoms.
In particular, it is preferable that both R ³ and R ⁴ are hydrogen atoms.

<N and m>
n represents 0 or 1 and is preferably 1. m represents 0 or 1; The formula (
The dye represented by 1) is usually a disazo dye or a trisazo dye.
<Molecular weight>
The molecular weight of the dye represented by formula (1) is preferably 600 or more, preferably 1500 or less, and more preferably 1100 or less in the form of a free acid.

<Dye for anisotropic dye film>
The dye represented by the formula (1) is usually highly associative and can form a high lyotropic liquid crystal state. Therefore, the coloring matter of the present invention represented by the formula (1) is suitable as a coloring matter for an anisotropic coloring matter film formed by a wet film forming method, and also has a high dichroic ratio. If the composition to be used is used for an anisotropic dye film, an anisotropic dye film having high dichroism can be obtained.

Moreover, the pigment | dye represented by Formula (1) is a water-soluble pigment | dye normally.
<Salt>
The dye of the present invention may be used as it is in the free acid form (free acid form) as shown by the formula (1), or a part of the acid group may be in a salt form. Further, a salt-type dye and a free acid-type dye may be mixed. Moreover, when it is obtained in a salt form at the time of production, it may be used as it is or may be converted into a desired salt form. As the salt-type exchange method, a known method can be arbitrarily used, and examples thereof include the following methods.

1) A strong acid such as hydrochloric acid is added to the aqueous solution of the dye obtained in the salt form, the dye is acidified in the form of a free acid, and the dye is then added with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). A method of neutralizing acidic groups and salt exchange.
2) A method of performing salt exchange in the form of a salting-out cake by adding a large excess of a neutral salt (for example, lithium chloride) having a desired counter ion to an aqueous solution of a dye obtained in a salt form.

3) An aqueous solution of a dye obtained in a salt form is treated with a strongly acidic cation exchange resin, and the dye is acidified in the form of a free acid, and then an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution) ) To neutralize the acidic group of the dye and perform salt exchange.
4) A method of performing salt exchange by causing an aqueous solution of a dye obtained in a salt form to act on a strongly acidic cation exchange resin previously treated with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution).

In the dye used in the present invention, whether the acidic group takes the free acid form or the salt form depends on the pKa of the dye and the pH of the aqueous dye solution.
Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts which may be substituted with alkyl groups or hydroxyalkyl groups, and organic amine salts.

Examples of the alkyl group or hydroxyalkyl group which is a substituent that the ammonium salt may have include a lower alkyl group having 1 to 6 carbon atoms and a hydroxy-substituted lower alkyl group having 1 to 6 carbon atoms.
Examples of the organic amine include a lower alkyl amine having 1 to 6 carbon atoms, a hydroxy substituted lower alkyl amine having 1 to 6 carbon atoms, a carboxy substituted lower alkyl amine having 1 to 6 carbon atoms, and the like.

In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.
<Specific example>
Specific examples of the dye of the present invention include, but are not limited to, the dyes having the structures shown in the following (I-1) to (I-21) as the free acid form.

<Synthesis method>
The dye represented by formula (1) can be produced according to a method known per se. For example, no. The dye represented by (I-7) can be produced by the following steps (A), (B) and (C).
(A) 6-amino-1-naphthalene sulfonic acid (darlic acid) and 3-amino-4-chlorophenol are used in a conventional manner [for example, Yutaka Hosoda, “New Dye Chemistry” (December 21, 1973, Gihodo Issued, see page 396, page 409] to produce a monoazo compound through diazotization and coupling steps.
(B) The obtained monoazo compound is similarly diazotized by a conventional method, and subjected to a coupling reaction with 8-amino-2-naphthalenesulfonic acid (1,7-Cleves acid) to produce a disazo compound.
(C) Similarly, the resulting disazo compound is diazotized by a conventional method, coupled with 7-amino-1-naphthol-3,6-disulfonic acid (RR acid), and salted out with sodium chloride. The target dye No. (I-7) is obtained.

In particular, since the dye of the present invention represented by the structural formula (I-7) shown above forms a lyotropic liquid crystal in an aqueous solution, an anisotropic dye film exhibiting high dichroism can be produced. It is a useful dye suitable for the membrane method.
<Composition>
The composition for anisotropic dye films of the present invention contains a dye represented by formula (1) and a solvent. In the composition, the dye represented by the formula (1) can be used alone, but the dyes described in the formula (1) can be mixed with each other or mixed with other dyes so as not to lower the orientation. Thereby, anisotropic dye films having various hues can be produced.
(Dye for formulation)
Examples of preferable dyes for blending include C.I. I. Direct Yellow
12, C.I. I. Direct Yellow 34, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 142, C.I. I. Direct Y
yellow 132, C.I. I. Acid Yellow 25, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 79, C.I. I. Acid Orange 28, C.I. I. Direct Red 39, C.I. I. Direct Red 79, C.I. I. Direct Red 81, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Acid Red 37, C.I. I. Direct Violet 9, C.I. I. Direct Violet 35, C.I. I. Direct Violet 48, C.I. I. Direct Violet 57, C.I. I. Direct Blue 1, C.I. I. Direct Blue 67, C.I. I. Direct Blue 83, C.I. I. Direct Blue 90, C.I. I. Direct Green 42, C.I. I. Direct Green 51, C.I. I. Direct Green 59 etc. are mentioned.

(solvent)
As the solvent used in the composition for an anisotropic dye film of the present invention, water, a water-miscible organic solvent, or a mixture thereof is suitable. Specific examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, glycols such as ethylene glycol and diethylene glycol, cellosolves such as methyl cellosolve and ethyl cellosolve, and a single or a mixed solvent of two or more. Can be mentioned.

(concentration)
The concentration when the dye is dissolved depends on the solubility of the dye and the concentration of the associated state such as the lyotropic liquid crystal state, but is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, Preferably it is 30 weight% or less, More preferably, it is 20 weight% or less.
(Additive)
Moreover, in order to improve the wettability to a base material and applicability | paintability, the composition for anisotropic dye films of this invention can add additives, such as surfactant, as needed. As the surfactant, any of anionic, cationic, and nonionic surfactants can be used. The addition concentration is usually preferably 0.05% by weight or more and 0.5% by weight or less.

<Anisotropic dye film>
The anisotropic dye film of the present invention is an anisotropic dye film containing the dye of the present invention represented by the formula (1) and preferably formed by a wet film forming method. Usually, the anisotropic dye film of the present invention is obtained by forming the composition for an anisotropic dye film of the present invention on a substrate by a wet film forming method.

As described above, the dye of the present invention represented by the above formula (1) can form a high lyotropic liquid crystal state, can exhibit a high-order molecular alignment state, and can exhibit high dichroism. . Therefore, the anisotropic dye film of the present invention is a useful dye film exhibiting high dichroism.
Although the anisotropic dye film of the present invention exhibits a high dichroic ratio, the dichroic ratio is preferably 9 or more, more preferably 12 or more, and particularly preferably 15 or more.

In particular, when used for a polarizing film, a film having a neutral color tone is preferable. In the L ^* a ^* b ^* color system, √ {(a ^* ) ² + (b ^* ) ² } ≦ 30, preferably √ {(a ^* ) ² + (b ^* ) ² } ≦ 10, more preferably √ {(a ^* ) ² + (b ^* ) ² } ≦ 5, and the transmittance of the dye film is 35% or more, A film satisfying 40% or more, more preferably 44% or more is preferable as a display element, particularly as a polarizer for a color display element.

<Wet deposition method>
In the present invention, an anisotropic dye film is produced by a wet film formation method. Examples include known methods such as a method in which the anisotropic dye film composition is prepared and then applied to various substrates such as a glass plate, and the dye is oriented and laminated.
The method for forming the anisotropic dye film is not particularly limited. For example, the dye of the present invention described above formed an aggregate due to a good intermolecular interaction such as a lyotropic liquid crystal state in the composition for the anisotropic dye film. Since a state is formed, an anisotropic dye film can be obtained by applying this to a substrate such as glass, applying shearing force to orient the dye in a certain direction, and then drying.

As the substrate, a transparent material having a thickness of about 10 to 1500 μm made of glass, resin or the like is used. Examples of the resin include triacetate, acrylic resin, polyester resin, triacetyl cellulose, urethane resin, and the like.
On the surface of the substrate, in order to control the orientation direction of the dye molecules in the composition for anisotropic dye film, “Liquid Crystal Handbook” (Maruzen Co., Ltd., issued on October 30, 2000), page 226- The alignment treatment layer may be applied by a known method described on page 239 and the like.

  As a method for applying the composition for the anisotropic dye film onto the substrate, a conventionally known method may be used. For example, Yuji Harasaki, “Coating Engineering” (Asakura Shoten Co., Ltd., issued March 20, 1971). ) Pages 253 to 277 or “Creation and Application of Molecular Coordinating Materials” supervised by Kunihiro Ichimura (CMC Publishing Co., Ltd., published on March 3, 1998), pages 118 to 149, etc. For example, a spin coating method, a spray coating method, a bar coating method, a roll coating method, a blade coating method, a free span coating method, a die coating method, and the like may be used on a substrate that has been previously subjected to an alignment treatment.

By applying a shearing force to the dye in the anisotropic dye film composition coated on the substrate, the dye is oriented in a certain direction. The bar coat, roll coat, blade coat, free span coat method, die coat method and the like are preferable because a shearing force can be applied simultaneously with application.
The temperature during application is preferably 0 ° C. or higher and 80 ° C. or lower, and the humidity is preferably about 10% RH or higher and 80% RH or lower. The drying temperature is preferably 0 ° C. or more and 120 ° C. or less, and the humidity is preferably about 10% RH or more and 80% RH or less.

The film thickness of the anisotropic dye film thus obtained is usually 50 nm or more, and preferably 100 nm or more. The upper limit is usually 50 μm or less, preferably 1 μm or less.
The transmittance of the anisotropic dye film in the visible light wavelength region is preferably 25% or more. The higher the transmittance, the better. Usually, it is preferably 35% or more, particularly 40% or more. Most preferably, it is 44% or more. When the transmittance is low, it is difficult to use as a polarizer for a display element, particularly a color display element.

Since the anisotropic dye film produced by such a method may have a low mechanical strength, a protective layer is provided if necessary. This protective layer is formed by lamination with a transparent polymer film such as triacetate, acrylic, polyester, polyimide, triacetylcellulose, or urethane film, and is practically used.
In addition, when the anisotropic dye film of the present invention is used as a polarizing film or the like for various display elements such as LCDs and OLEDs, the dye film is directly formed on the electrode substrate constituting these display elements, or the dye A substrate on which a film is formed can be used as a constituent member of these display elements.

When an anisotropic dye film is formed on a substrate by the above method or the like, the film thickness after drying is usually 50 nm or more, more preferably 100 nm or more, preferably 50 μm or less, more preferably 1 μm or less. .
<Polarizing element>
The anisotropic dye film of the present invention functions as a polarizing film that obtains linearly polarized light, circularly polarized light, elliptically polarized light, etc. by utilizing the anisotropy of light absorption, and also includes a film forming process and a composition containing a substrate and a dye Thus, it is possible to make it functional as various anisotropic films such as refraction anisotropy and conduction anisotropy, and it is possible to obtain various kinds of polarizing elements that can be used for various purposes.

The polarizing element of the present invention uses the above-described anisotropic dye film of the present invention, but may be a polarizing element composed only of an anisotropic dye film, or an anisotropic dye on a substrate. A polarizing element having a film may be used. In the present invention, a polarizing element having an anisotropic dye film on a substrate is called a polarizing element including the substrate.
When the anisotropic dye film of the present invention is formed on a substrate and used as a polarizing element, it may be used only on the substrate and the formed anisotropic dye film, or the protective layer as described above may be used. In addition, optical functions such as adhesive layer or antireflection layer, alignment film, retardation film function, brightness enhancement film function, reflection film function, transflective film function, diffusion film function, etc. A layer having various functions such as a layer having a plurality of functions may be stacked by a wet film formation method or the like to be used as a stacked body.

These layers having optical functions can be formed, for example, by the following method.
The layer having a function as a retardation film is subjected to, for example, a stretching process described in Japanese Patent No. 2841377, Japanese Patent No. 3094113, or a process described in Japanese Patent No. 3168850. Can be formed.
In addition, the layer having a function as a brightness enhancement film may be formed by, for example, forming a fine hole by a method described in JP 2002-169025 A or JP 2003-29030 A, or the center of selective reflection. It can be formed by overlapping two or more cholesteric liquid crystal layers having different wavelengths.

The layer having a function as a reflective film or a transflective film can be formed using a metal thin film obtained by vapor deposition or sputtering. The layer having a function as a diffusion film can be formed by coating the protective layer with a resin solution containing fine particles.
The layer having a function as a retardation film or an optical compensation film can be formed by applying and aligning a liquid crystal compound such as a discotic liquid crystal compound or a nematic liquid crystal compound.

  The anisotropic dye film using the dye of the present invention can be directly formed on a high heat-resistant substrate such as glass, and a high heat-resistant polarizing element can be obtained. It can be suitably used not only for organic electroluminescence displays but also for applications that require high heat resistance such as liquid crystal projectors and in-vehicle display panels.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the following examples, the dichroic ratio was calculated by the following equation after measuring the transmittance of the anisotropic dye film with a spectrophotometer in which an iodine polarizing element was arranged in the incident optical system.
Dichroic ratio (D) = Az / Ay
Az = -log (Tz)
Ay = -log (Ty)
Tz: Transmittance for polarized light in the direction of the absorption axis of the dye film Ty: Transmittance for polarized light in the direction of the polarization axis of the dye film (Example 1)
In 84 parts of water, the dye No. Add 16 parts of the lithium salt of (I-1), dissolve with stirring, and filter to pH.
7 aqueous dye solution (anisotropic dye film composition) was obtained. This aqueous dye solution showed lyotropic liquid crystallinity.

  On the other hand, a glass substrate (75 mm × 25 mm, 1.1 mm thickness, polyimide film thickness of about 800 mm) is preliminarily rubbed with a cloth. Was prepared, and the aqueous dye solution was applied with an applicator having a gap of 10 μm (manufactured by Imoto Seisakusho Co., Ltd.), followed by natural drying to obtain an anisotropic dye film.

  In the obtained anisotropic dye film, transmitted light (Tz) with respect to polarized light having a vibration surface in the absorption axis direction within the dye film surface, and transmitted light (Ty) with respect to polarized light having a vibration surface in the polarization axis direction within the dye film surface. Table 1 shows the dichroic ratio (D) obtained from the above. The obtained polarizing film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film in both the short wavelength region (500 nm) and the maximum absorption wavelength (565 nm) of the dye.

(Example 2)
In 72 parts of water, the dye No. 28 parts of the sodium salt of (I-2) was added, dissolved with stirring, and filtered to obtain a pH 7 dye aqueous solution (an anisotropic dye film composition). This aqueous dye solution showed lyotropic liquid crystallinity.
An anisotropic dye film was obtained by applying the dye aqueous solution to a slide glass (manufactured by Matsunami Glass Industrial Co., Ltd., slide glass white edge polishing frost No. 1) with an applicator (manufactured by Imoto Seisakusho) with a gap of 10 μm and then naturally drying. .

Table 1 shows the dichroic ratio (D) of the obtained anisotropic dye film. The obtained polarizing film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film in both the short wavelength region (500 nm) and the maximum absorption wavelength of dye (560 nm).
(Example 3)
In 80 parts of water, the dye No. 20 parts of the sodium salt of (I-7) was added, dissolved with stirring, and filtered to obtain a pH 7 dye aqueous solution (an anisotropic dye film composition). This aqueous dye solution showed lyotropic liquid crystallinity.

  On the other hand, a glass substrate (75 mm × 25 mm, 1.1 mm thickness, polyimide film thickness of about 800 mm) is preliminarily rubbed with a cloth. Was prepared, and the aqueous dye solution was applied with an applicator having a gap of 5 μm (manufactured by Imoto Seisakusho Co., Ltd.), followed by natural drying to obtain an anisotropic dye film.

  In the obtained anisotropic dye film, transmitted light (Tz) with respect to polarized light having a vibration surface in the absorption axis direction within the dye film surface, and transmitted light (Ty) with respect to polarized light having a vibration surface in the polarization axis direction within the dye film surface. Table 1 shows the dichroic ratio (D) obtained from the above. The obtained polarizing film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film in both the short wavelength region (500 nm) and the maximum absorption wavelength of the dye (615 nm).

Example 4
In 80 parts of water, the dye No. Add 20 parts of the lithium salt of (I-8), dissolve with stirring and filter to pH.
7 aqueous dye solution (anisotropic dye film composition) was obtained. This aqueous dye solution showed lyotropic liquid crystallinity.
On the other hand, a glass substrate (75 mm × 25 mm, 1.1 mm thickness, polyimide film thickness of about 800 mm) is preliminarily rubbed with a cloth. Was prepared), and the aqueous dye solution was applied with an applicator having a gap of 20 μm (manufactured by Imoto Seisakusho Co., Ltd.), followed by natural drying to obtain an anisotropic dye film.

  In the obtained anisotropic dye film, transmitted light (Tz) with respect to polarized light having a vibration surface in the absorption axis direction within the dye film surface, and transmitted light (Ty) with respect to polarized light having a vibration surface in the polarization axis direction within the dye film surface. Table 1 shows the dichroic ratio (D) obtained from the above. The obtained polarizing film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film in both the short wavelength region (500 nm) and the maximum absorption wavelength of the dye (615 nm).

(Example 5)
In 74 parts of water, the dye No. 26 parts of the lithium salt of (I-13) was added, dissolved by stirring, and filtered to obtain a pH 7 dye aqueous solution (an anisotropic dye film composition). This aqueous dye solution showed lyotropic liquid crystallinity.
On the other hand, a glass substrate (75 mm × 25 mm, 1.1 mm thickness, polyimide film thickness of about 800 mm) is preliminarily rubbed with a cloth. Was prepared, and the aqueous dye solution was applied with an applicator having a gap of 10 μm (manufactured by Imoto Seisakusho Co., Ltd.), followed by natural drying to obtain an anisotropic dye film.

  In the obtained anisotropic dye film, transmitted light (Tz) with respect to polarized light having a vibration surface in the absorption axis direction within the dye film surface, and transmitted light (Ty) with respect to polarized light having a vibration surface in the polarization axis direction within the dye film surface. Table 1 shows the dichroic ratio (D) obtained from the above. The obtained polarizing film had a high dichroic ratio (light absorption anisotropy) capable of functioning sufficiently as a polarizing film in both the short wavelength region (500 nm) and the maximum absorption wavelength of the dye (625 nm).

  (Comparative Example 1)

Pigment No. Although aqueous solutions of all concentrations of the sodium salt of (II-1) were prepared, lyotropic liquid crystallinity was not confirmed.
(Comparative Example 2)

Pigment No. Although aqueous solutions of all concentrations of the sodium salt of (II-2) were prepared, lyotropic liquid crystallinity was not confirmed.
(Comparative Example 3)

Pigment No. Although aqueous solutions of all concentrations of sodium salt and lithium salt of (II-3) were prepared, lyotropic liquid crystallinity was not confirmed.
(Comparative Example 4)

  Pigment No. Although aqueous solutions of all concentrations of the sodium salt and lithium salt of (II-4) were prepared, lyotropic liquid crystallinity was not confirmed.

Claims (6)

A dye for anisotropic dye film formed by a wet film-forming method, wherein the form of the free acid is represented by the following formula (1):

(In formula (1), A ¹ represents an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent.
B ¹ represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent. n represents 0 or 1, and m represents 0 or 1.
R ¹ represents a hydroxyl group or —NHR ⁵ (R ⁵ represents a hydrogen atom, an alkyl group which may have a substituent or an alkyl acyl group which may have a substituent).
R ² may have a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a hydroxyl group, a sulfo group, a carboxy group, a halogen atom or a substituent. Represents a good amino group.
R ³ and R ⁴ are each independently a hydrogen atom, an alkyl group that may have a substituent, a phenyl group that may have a substituent, an acyl group that may have a substituent, or The triazinyl group which may have a substituent is represented. ) The formula (1), A ¹ is characterized by being represented by any of the groups of the following formulas (2-a) or (2-b), formed by a wet film-forming method according to claim 1 Dye for anisotropic dye film.

(In Formula (2-a) and Formula (2-b), R ¹⁵ and R ¹⁶ each independently represent a halogen atom, a hydroxyl group, a nitro group, an amino group which may have a substituent, or a substituent. An alkyl group which may have, an alkoxy group which may have a substituent, a carboxy group or a sulfo group, r represents an integer of 0 to 2, and s represents an integer of 0 to 3) In the said Formula (1), B1 is the ¹ , 4- naphthylene group which may have a substituent, The difference formed by the wet film-forming method of Claim 1 or 2 characterized by the above-mentioned. Dye for isotropic dye film.   An anisotropic dye film composition comprising the dye for an anisotropic dye film according to any one of claims 1 to 3 and a solvent.   An anisotropic dye film formed by a wet film-forming method, comprising the dye for an anisotropic dye film according to claim 1.   A polarizing element having the anisotropic dye film according to claim 5.