JP2008031454A - Azo dye for anisotropic dye film - Google Patents

Abstract

【選択図】なしAn organic dye having high dichroism and excellent durability in a short wavelength region (380 nm to 500 nm), which is useful for an anisotropic dye film such as a polarizing film.
For example, an azo dye for anisotropic dye film whose free acid form is represented by the following formula (1-v) is exemplified.

[Selection figure] None

Description

  The present invention relates to an anisotropic dye film useful for a light-emitting display element such as a light control element, a liquid crystal element (LCD), and an organic electroluminescence element (OLED), and a polarizing plate included in an input / output element such as a touch panel. It relates to an azo dye for use.

  In recent years, flat displays such as LCDs have come to be widely used in television receivers, and are replacing conventional televisions using CRT. Further, the color reproducibility of NTSC, which is the current television system, is determined based on the characteristics of CRT phosphors, and there is a problem that only about half of the color of an actual object can be expressed. On the other hand, imaging devices such as digital cameras and camcorders have recently been able to express a wider range of colors (color reproduction) than the range defined by NTSC, and a display compatible with an extended color space that reproduces the information more accurately is desired. It is rare.

  In such a background, a flat display that replaces a CRT, such as an LCD, is a device capable of expressing a higher saturation color than a CRT in principle, and an extended color space for a new movie that takes advantage of the high functionality of the flat display. Standardization has been promoted. As a result, “Extended-gamut YCC color space for video application-xyYCC” was issued as the international standard IEC 61966-2-4.

  The xyYCC color space is a standard that can represent almost all of the actual object colors, and thereby, it is possible to express even the material feeling and stereoscopic effect of colorful objects.

  However, when the extended color space information is to be displayed on a conventional LCD, the characteristics of various members used in the LCD are not sufficient, so there are some improvements to construct a display that supports the xyYCC color space. It is being advanced.

For example,
(1) Adoption of backlight with good color purity of RGB3 primary colors,
(2) Use of a micro color filter in which complementary colors are added to the three primary colors RGB.
Typical means of (1) is the use of LEDs and optimization of the emission wavelength of the phosphor used in the cold cathode tube, and (2) is the use of micro color filters with yellow and cyan added ( (See Patent Documents 1 and 2).

  As described above, the factors governing the color reproducibility of the LCD are members related to light emission and members having absorption in the visible light wavelength range, but a polarizing film having absorption in the visible light wavelength region as well as the micro color filter. Is not yet fully considered.

  In order to cope with the xyYCC extended color space, it is necessary to improve the characteristics of the short wavelength region and the long wavelength region corresponding to both ends of the visible light, as estimated from the improvement contents of the backlight and the micro color filter.

  However, the conventional polarizing film has a problem that the contrast ratio at a specific wavelength or color is lowered because optical characteristics such as absorbance and dichroism in the visible light wavelength region are not constant. In particular, since the dichroism in the short wavelength region (380 nm to 500 nm), which is a complementary color of blue light, is low, the color purity of blue light is lowered, and color reproducibility may not be sufficiently obtained.

In addition to extended color space compatible displays, in the case of liquid crystal projectors and in-vehicle liquid crystal panels, organic dyes with dichroism are used instead of iodine because of durability problems at high temperatures, A dye having absorption at a short wavelength has a smaller π-conjugate spread than a dye having absorption at a long wavelength, so that a sufficient aspect ratio required for a dichroic dye cannot be obtained. Therefore, it has been desired to develop a pigment having high dichroism. In these applications, since durability at high temperatures is required, there is a problem that a defect caused by shrinkage of the film due to temperature and humidity change, which is called frame failure or frame unevenness, occurs. Development of a novel dichroic dye is also desired because the combination of a polymer material such as modified polyvinyl alcohol (polyvinyl alcohol derivative) and a dichroic substance that solves the above problem has become important.
JP 2007-73290 A JP 2007-25285 A

An object of the present invention is to provide an organic dye for an anisotropic dye film having absorption in a short wavelength region (380 nm to 500 nm) that is useful for a polarizing film capable of expressing a wide range of colors.
Another object of the present invention is to provide an organic dye for an anisotropic dye film having excellent durability.

  As a result of intensive studies by the present inventors, it has been found that an azo dye for anisotropic dye film in which the form of the free acid is represented by the following formula (1) can solve the above problems, and the present invention has been achieved.

  The azo dye for anisotropic dye film of the present invention is characterized in that the form of the free acid is represented by the following formula (1).

〔式（１）中、Ａ^１およびＡ^２は、それぞれ独立に、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基、または置換基を有していてもよい芳香族複素環基を表す。
Ｙ^４およびＹ^５は、それぞれ独立に、水素原子、メチル基またはエチル基を表す。
Ａｒ^６は、１，４−フェニレン基、１，４−ナフチレン基、１，５−ナフチレン基、２，６−ナフチレン基または下記式（１−ａ１）で表される基を表す。１，４−フェニレン基、１，４−ナフチレン基、１，５−ナフチレン基、２，６−ナフチレン基および下記式（１−ａ１）で表される基は置換基を有していてもよい。

（式（１−ａ１）中、環αは５または６員環の複素環である。）〕

[In Formula (1), A ¹ and A ² each independently have a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a substituent. Represents a good aromatic heterocyclic group.
Y ⁴ and Y ⁵ each independently represent a hydrogen atom, a methyl group or an ethyl group.
Ar ⁶ represents a 1,4-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, a 2,6-naphthylene group, or a group represented by the following formula (1-a1). The 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group and the group represented by the following formula (1-a1) may have a substituent. .

(In formula (1-a1), ring α is a 5- or 6-membered heterocyclic ring.)]

  According to the present invention, there is provided an organic dye that is useful for an anisotropic dye film such as a polarizing film, has high dichroism in the short wavelength region (380 nm to 500 nm), and is excellent in durability.

Hereinafter, embodiments of the azo dye for anisotropic dye film of the present invention will be described in detail.
The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention 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 orthogonal in-plane 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 dye film referred to in the present invention refers to a layer containing a dye, and usually refers to a layer further containing a low molecular material and / or a polymer material, and may be a layer composed only of a dye, for example.
The anisotropic dye film produced using the azo dye for anisotropic dye film of the present invention is preferably used for a functional film having absorption anisotropy as a main effect, and is preferably used for a polarizing film. More preferred.

  In the present invention, “may have a substituent” means that it may have one or more substituents.

[Azo dyes for anisotropic dye films]
The azo dye for anisotropic dye film of the present invention is characterized in that the form of the free acid is represented by the following formula (1). Hereinafter, the azo dye for anisotropic dye film in which the form of the free acid is represented by the following formula (1) may be referred to as “dye (1)”.

〔式（１）中、Ａ^１およびＡ^２は、それぞれ独立に、置換基を有していてもよいフェニル基、置換基を有していてもよいナフチル基、または置換基を有していてもよい芳香族複素環基を表す。
Ｙ^４およびＹ^５は、それぞれ独立に、水素原子、メチル基またはエチル基を表す。
Ａｒ^６は、１，４−フェニレン基、１，４−ナフチレン基、１，５−ナフチレン基、２，６−ナフチレン基または下記式（１−ａ１）で表される基を表す。１，４−フェニレン基、１，４−ナフチレン基、１，５−ナフチレン基、２，６−ナフチレン基および下記式（１−ａ１）で表される基は置換基を有していてもよい。

（式（１−ａ１）中、環αは５または６員環の複素環である。）〕

[In Formula (1), A ¹ and A ² each independently have a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a substituent. Represents a good aromatic heterocyclic group.
Y ⁴ and Y ⁵ each independently represent a hydrogen atom, a methyl group or an ethyl group.
Ar ⁶ represents a 1,4-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, a 2,6-naphthylene group, or a group represented by the following formula (1-a1). The 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group and the group represented by the following formula (1-a1) may have a substituent. .

(In formula (1-a1), ring α is a 5- or 6-membered heterocyclic ring.)]

{A ¹ and A ² }
<Phenyl group>
In the case where A ¹ and A ² are phenyl groups that may have a substituent, the phenyl group may have a sulfo group, a carboxy group, a hydroxyl group, a nitro group, or a substituent. May have an alkoxy group which may have a substituent, an amino group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and a substituent. And a carbamoyl group which may have a substituent, a sulfamoyl group which may have a substituent, a phenyl group which may have a substituent, and an aryloxy group which may have a substituent.

  The alkoxy group as a substituent usually has 1 or more, usually 6 or less, preferably 4 or less carbon atoms. 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 an 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, or a 2,3-dihydroxypropoxy group. In particular, a lower alkoxy group which may have a substituent is preferable.

The amino group as a substituent is generally represented by —NH ₂ , —NHR ⁸¹ , —NR ⁸² R ⁸³ . R ^{81 to} R ⁸³ each independently represents an alkyl group which may have a substituent, a phenyl group which may have a substituent, or an acyl group which may have a substituent. The alkyl group usually has 1 or more, usually 12 or less, preferably 10 or less carbon atoms. The acyl group is represented by -COR ^84, R ⁸⁴ is an optionally substituted alkyl group, an optionally substituted alkoxy group, alkenyl which may have a substituent Represents a phenyl group which may have a group or a substituent. The alkyl group and the alkoxy group each have usually 1 or more carbon atoms, usually 6 or less, preferably 4 or less. Each of the alkenyl groups has usually 1 or more, usually 12 or less, preferably 10 or less. Examples of the group which may be substituted on the alkyl group, the alkoxy group, the alkenyl group and the phenyl group include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group and a halogen atom. Examples of the group that may be substituted on the alkyl group, phenyl group, or acyl group of R ^{81 to} R ⁸³ include a phenyl group, an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group, and a halogen atom that may have a substituent. Etc. Examples of the group that may be substituted on the phenyl group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a sulfo group, a carboxy group, and a hydroxyl group.

  Specific examples of the amino group include amino group, methylamino group, ethylamino group, 2-sulfoethylamino group, 4-sulfophenylamino group, 4-carboxybenzoylamino group, and fumaroylamino group.

  The alkyl group as a substituent has usually 1 or more, usually 6 or less, preferably 4 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 methyl group and an ethyl group, and a lower alkyl group which may have a substituent is particularly preferable.

  The alkenyl group as a substituent has usually 1 or more, usually 12 or less, preferably 10 or less. Examples of the group that may be substituted on the alkenyl group include an alkyl group, a phenyl group, and a carboxy group.

  Specific examples of the alkenyl group include a trans-2-carboxyethenyl group and a trans-2- (2-sulfophenyl) ethenyl group.

  The carbamoyl group as a substituent usually has 1 or more, usually 6 or less, preferably 4 or less carbon atoms. Examples of the group which may be substituted on the carbamoyl group include an optionally substituted alkyl group having 1 to 4 carbon atoms.

  Specific examples of the carbamoyl group which may have a substituent include a carbamoyl group and an N-methylcarbamoyl group.

  The sulfamoyl group as a substituent usually has 1 or more, usually 6 or less, preferably 4 or less carbon atoms. Examples of the group which may be substituted on the sulfamoyl group include an optionally substituted alkyl group having 1 to 4 carbon atoms.

  Specific examples of the sulfamoyl group which may have a substituent include a sulfamoyl group and an N-methylsulfamoyl group.

  The phenyl group as a substituent usually has 6 or more, usually 10 or less, preferably 8 or less carbon atoms. Examples of the group that may be substituted on the phenyl group include an alkoxy group, a hydroxyl group, a sulfo group, and a carboxy group. Specific examples include a phenyl group which may have a substituent such as a phenyl group, a 3-sulfophenyl group, and a 4-sulfophenyl group.

  The aryl group constituting the aryloxy group as a substituent is preferably a phenyl group or a naphthyl group. The substituent that the aryl group may have is an alkyl group, an alkoxy group, a carboxy group, a sulfo group, or a hydroxyl group. Etc.

  Specific examples of the aryloxy group which may have a substituent include a phenoxy group, a 2-naphthoxy group, a p-tolyloxy group, a p-methoxyphenoxy group, and an o-carboxyphenoxy group.

When the phenyl group of A ^1, A ² has a substituent, either one, or both sulfo groups A ¹ or A ^2, be a carboxyl group, a hydrophilic group such as hydroxyl is substituted, water From the viewpoint of solubility in water. From the viewpoint of color tone, the number of amino groups or hydroxyl groups which may have a substituent is preferably 2 or less. The phenyl group may have one or two or more of these substituents, but the number of substituents is preferably 3 or less.
The substitution position of the substituent is preferably substituted at the meta position or the para position with respect to the azo group because of high molecular linearity.

<Naphthyl group>
In the case where A ¹ and A ² are naphthyl groups that may have a substituent, the naphthyl group may have a sulfo group, a carboxy group, a hydroxyl group, a nitro group, or a substituent. May have an alkoxy group which may have a substituent, an amino group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and a substituent. And a carbamoyl group which may have a substituent, a sulfamoyl group which may have a substituent, a phenyl group which may have a substituent, and an aryloxy group which may have a substituent.

  Specific examples of the substituent of the naphthyl group are the same as those described above as specific examples of the substituent of the phenyl group.

If naphthyl group A ^1, A ² has a substituent, either one, or both sulfo groups A ¹ or A ^2, be a carboxyl group, a hydrophilic group such as hydroxyl is substituted, water From the viewpoint of solubility in water. From the viewpoint of color tone, the number of amino groups or hydroxyl groups that may have a substituent is preferably 1 or less. The naphthyl group which may have a substituent may have one of these substituents or may have two or more, but the number of substituents is preferably 4 or less, and 2 or less. Is particularly preferred.

  As the substitution position of the substituent, from the viewpoint of molecular linearity, the azo group is preferably substituted at the 2-position with respect to the naphthyl group, and the other substituents are at the 1-position, 4-position, 5 It is preferably substituted at the 6-position, 7-position. On the other hand, from the viewpoint of color tone, the azo group is preferably substituted at the 1-position with respect to the naphthyl group, and the other substituents are preferably substituted at the 1-position, 4-position or 5-position. .

<Aromatic heterocyclic group>
In the case where A ¹ and A ² are an aromatic heterocyclic group which may have a substituent, 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 nitrogen atom, sulfur atom and oxygen atom. When the aromatic heterocyclic group has a plurality of atoms constituting a ring other than carbon, these may be the same or different. The aromatic heterocyclic group is preferably an aromatic heterocyclic group having usually 3 to 10 carbon atoms. In the case of a polycyclic aromatic heterocyclic ring, the heterocyclic moiety may be bonded to an azo group, or the hydrocarbon ring moiety may be bonded to an azo group.

  Specific examples of the aromatic heterocyclic group include a pyridyl group, a quinolyl group, a thiazolyl group, a benzothiazolyl group, a pyrazolyl group, a benzopyrazolyl group, a quinolonyl group, a naphthalimidoyl group, a pyrazolonyl group, and a pyridonyl group.

As the substituent of the aromatic heterocyclic group which may have a substituent of A ¹ or A ² , a sulfo group, a carboxy group, a hydroxyl group, a nitro group, an alkoxy group which may have a substituent, a substituent An amino group which may have a group, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, a carbamoyl group which may have a substituent, a substituent Examples thereof include a sulfamoyl group which may have, a phenyl group which may have a substituent, and a cyano group.

  Specific examples of the substituent of the aromatic heterocyclic group are the same as those described above as specific examples of the substituent of the phenyl group.

When the aromatic heterocyclic group of A ^1, A ² has a substituent, either one of A ¹ or A ^2, or both the sulfo group, the carboxy group, a hydrophilic group such as hydroxyl is substituted Is preferable from the viewpoint of solubility in water. From the viewpoint of color tone, the number of amino groups or hydroxyl groups which may have a substituent is preferably 2 or less. The aromatic heterocyclic group which may have a substituent may have one of these substituents, or may have two or more, but the number of substituents is preferably 4 or less, Two or less are particularly preferred.

<A ¹ OyobiA ² Nokonomashiirei_>
A ¹ and A ² are preferably each independently a phenyl group which may have a substituent or a naphthyl group which may have a substituent. As the substituent for A ¹ and A ^2, a sulfo group, a carboxy group, and a hydroxyl group are preferable. When there are a plurality of substituents, the substituents may be the same or different.

^{<Y 4} and ^Y 5>
Y ⁴ and Y ⁵ each independently represent a hydrogen atom, a methyl group or an ethyl group.

<Ar ⁶ >
Ar ⁶ represents a 1,4-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, a 2,6-naphthylene group, or a group represented by the following formula (1-a1). The 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group and the group represented by the following formula (1-a1) may have a substituent. .

（式（１−ａ１）中、環αは５または６員環の複素環である。）

(In formula (1-a1), ring α is a 5- or 6-membered heterocyclic ring.)

Ring α is bonded to the benzene ring in formula (1-a1) to form a condensed ring.
The fused ring group includes a quinoline diyl group, an isoquinoline diyl group, a benzothiadiazole diyl group, a phthalimido diyl group, and the like, and as shown in the formula (1-a1), the linking positions are mutually in the p-position of the benzene ring part Groups.

<Substituent of Ar ⁶ >
Examples of the substituent include an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an amino group which may have a substituent, a carboxy group, a halogen atom, and a sulfo group. And a hydroxyl group. From the viewpoint of molecular linearity and solubility in water, Ar ⁶ does not have a substituent, or as a substituent, a methyl group, a methoxy group, a 2,3-dihydroxypropoxy group, a carboxy group, a sulfo group, fluorine It preferably has an atom, an amino group or an acetylamino group.

Ar ⁶ may have one of these substituents or two or more, but the number of substituents is preferably 3 or less, and particularly preferably 2 or less. When two or more of these substituents are present, it is preferable that the substituent is not substituted with an adjacent atom of the ring.

Specific examples of the substituent that Ar ⁶ may have are given below.
The alkyl group usually has 1 or more carbon atoms, usually 6 or less, preferably 4 or less, and more preferably 3 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 methyl group and an ethyl group, and a lower alkyl group which may have a substituent is particularly preferable.

  The alkoxy group usually has 1 or more carbon atoms, usually 6 or less, preferably 4 or less, and more 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 an 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, or a 2,3-dihydroxypropoxy group. In particular, a lower alkoxy group which may have a substituent is preferable.

The amino group is usually represented by —NH ₂ , —NHR ^α , —NR ^β R ^γ , and R ^{α to} R ^γ each independently have an alkyl group which may have a substituent, or a substituent. It represents an optionally substituted phenyl group or an optionally substituted acyl group. The alkyl group usually has 1 or more, usually 4 or less, preferably 2 or less carbon atoms. The acyl group is represented by -COR ^[delta], R ^[delta] is an optionally substituted alkyl group, phenyl which may have an optionally substituted alkoxy group or an optionally substituted Represents a group. The alkyl group and the alkoxy group each have usually 1 or more, usually 4 or less, preferably 2 or less. Examples of the group that may be substituted on the alkyl group, the alkoxy group, and the phenyl group include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group, and a halogen atom. Examples of the group which may be substituted with the alkyl group, phenyl group or acyl group of R ^{α to} R ^γ include an alkoxy group, a hydroxyl group, a sulfo group, a carboxy group and a halogen atom.

  Specific examples of the amino group include amino group, methylamino group, ethylamino group, propylamino group, dimethylamino group, phenylamino group, acetylamino group, and benzoylamino group.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

<Preferred example of Ar ⁶ >
Ar ⁶ is preferably a 1,4-phenylene group or a 1,4-naphthylene group which may have a substituent from the viewpoint of molecular linearity and color tone. Preferably, it is unsubstituted or has the following preferred substituents.

The substituent for Ar ⁶ is preferably an alkyl group having 1 to 4 carbon atoms which may have a substituent, an alkoxy group having 1 to 4 carbon atoms which may have a substituent, and a substituent. An amino group, a sulfo group, a halogen atom, a carboxy group or a hydroxyl group which may have a group.
From the viewpoint of molecular linearity and solubility in water, the substituent is preferably a methyl group, a methoxy group, a 2,3-dihydroxypropoxy group, a sulfo group, a fluorine atom, an amino group, or an acetylamino group.
Ar ⁶ may have one of these substituents or two or more, but is preferably 3 or less, and particularly preferably 2 or less. In the case of having two or more substituents, it is preferable that the substituents are not substituted on adjacent atoms of the ring.

{Molecular weight}
The molecular weight of the dye (1) is preferably 1800 or less, more preferably 1500 or less, and particularly preferably 1200 or less in the form of a free acid.

{Preferred embodiment of dye (1)}
As for the said pigment | dye (1), it is preferable that the form of a free acid is represented by a following formula (1-4). Hereinafter, the azo dye for anisotropic dye film in which the form of the free acid is represented by the following formula (1-4) may be referred to as “dye (1-4)”.

[In Formula (1-4), A ⁵¹ and A ⁵² each independently represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent.
R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a sulfo group, a carboxy group, an optionally substituted alkyl group, an optionally substituted alkoxy group or a substituted group. The amino group which may have a group is represented. ]

<A ⁵¹ OyobiA ^52>
A ⁵¹ and A ⁵² each independently represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent.
A ⁵¹ and A ⁵² may be the same or different, but are preferably the same.

When A ⁵¹ or A ⁵² is a naphthyl group, an azo group is preferably bonded to the 2-position of the naphthalene ring.

As the substituent that the phenyl group or naphthyl group of A ⁵¹ and A ⁵² may have, a sulfo group, a carboxy group, an optionally substituted carbamoyl group, or an optionally substituted group may be included. Examples thereof include a sulfamoyl group, a hydroxyl group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and an amino group which may have a substituent.

  Examples of the group which may be substituted on the carbamoyl group which may have a substituent include an optionally substituted alkyl group having 1 to 4 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 carbamoyl group which may have a substituent include a carbamoyl group and an N-methylcarbamoyl group.

  Examples of the group that may be substituted on the optionally substituted sulfamoyl group include an optionally substituted alkyl group having 1 to 4 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 sulfamoyl group which may have a substituent include a sulfamoyl group and an N-methylsulfamoyl group.

  The alkyl group which may have a substituent is usually an alkyl group having 1 to 6 carbon atoms, preferably 3 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 methyl group and an ethyl group, and a lower alkyl group which may have a substituent is particularly preferable.

  The alkoxy group which may have a substituent is usually an alkoxy group having 1 to 4 carbon atoms, preferably 3 or less carbon atoms. 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 an 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, or a 2,3-dihydroxypropoxy group. In particular, a lower alkoxy group which may have a substituent is preferable.

The amino group which may have the substituent, _{^{usually, -NH 2, -NHR F, -NR}} G R H, is represented by -NHCOR ^I, R F ~R ^I are each independently a substituent Represents an optionally substituted alkyl group or an optionally substituted phenyl group. The alkyl group is an alkyl group having usually 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, a phenylamino group, an acetylamino group, and a benzoylamino group.

As the substituent for A ⁵¹ and A ⁵² , among them, a sulfo group, a carboxy group, and a hydroxyl group are preferable.
A ⁵¹ and A ⁵² may each have one of these substituents, or may have two or more.

<R ⁵¹ and R ⁵² >
R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a sulfo group, a carboxy group, an optionally substituted alkyl group, an optionally substituted alkoxy group or a substituted group. The amino group which may have a group is represented.

  Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom.

  The alkyl group which may have a substituent is usually an alkyl group having 1 to 4 carbon atoms, preferably 3 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 methyl group and an ethyl group.

  The alkoxy group which may have a substituent is an alkoxy group having 1 to 4 carbon atoms, preferably 3 or less carbon atoms. 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 an 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, or a 2,3-dihydroxypropoxy group. It is done.

The amino group which may have the substituent, _{^{usually, -NH 2, -NHR J, -NR}} K R L, is represented by -NHCOR ^M, R J ~R ^M are each independently a substituent Represents an optionally substituted alkyl group or an optionally substituted phenyl group. The alkyl group is an alkyl group having usually 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, a phenylamino group, an acetylamino group, and a benzoylamino group.

R ⁵¹ and R ⁵² are each independently preferably a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a hydroxyethoxy group, a sulfo group, or a carboxy group. , It is preferably a non-adjacent carbon atom position.

<Molecular weight>
The molecular weight of the dye (1-4) is preferably 1500 or less, more preferably 1200 or less in the form of a free acid.

{Dichroism}
The dye of the present invention usually has high dichroism in a short wavelength region, but exhibits high dichroism in a limited range of wavelengths for use only in improving the color purity of blue light. It is preferable that the half width of the absorption of the dye is narrow. In addition, for the purpose of use in combination with a conventional dichroic substance, it is preferable to exhibit high dichroism only in a wavelength range that was insufficient with conventional materials, and the one where the half-value width of dye absorption is narrower preferable.

{Salt type}
The azo dye for anisotropic dye film of the present invention, that is, the dye (1), preferably the dye (1-4) is usually a water-soluble dye.

  The azo dye for anisotropic dye film of the present invention may be used as it is in the free acid form (free acid form), or a part of the acid groups may be in salt form. Further, a salt-type dye and a free acid-type dye may be mixed. Further, 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 a 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 an aqueous solution of a dye obtained in a salt form, 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 solution of sodium hydroxide, hydroxide) A method in which the acidic group of the dye is neutralized with a lithium aqueous solution and the salt is exchanged.
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, sodium chloride or 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 sodium hydroxide solution) , A method of neutralizing a dye acidic group with a lithium hydroxide aqueous solution and performing salt exchange.
4) An aqueous solution of a dye obtained in a salt form is allowed to act on a strongly acidic cation exchange resin previously treated with an alkaline solution having a desired counter ion (for example, an aqueous solution of sodium hydroxide or an aqueous solution of lithium hydroxide). How to do.

  Whether the acidic group of the azo dye for anisotropic dye film of the present invention takes a free acid type or a salt type depends on the pKa of the dye and the pH of the dye solution. Therefore, the acidic group of the azo dye for anisotropic dye film of the present invention is a free acid type, any salt type, and when there are two or more acidic groups, the free acid type and salt type are mixed or two or more types are used. It can take various forms such as a mixture of salt forms. In particular, the acidic group of the azo dye in the anisotropic dye film includes a preferable pH of the composition for the anisotropic dye film described later and a dissociable salt of the base material containing the dye for the anisotropic dye film. Under the influence of the treatment with the solution, it may have a salt form different from that used in the step of forming the anisotropic dye film.

  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 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. Moreover, multiple types may be mixed in one molecule of a compound, and multiple types may be mixed in the composition.

  The preferred type of the acidic group of the azo dye for anisotropic dye film of the present invention varies depending on the production process of the dye, the content of the composition for anisotropic dye film described later, preferred pH, etc. When solubility is required (for example, when a high dye concentration is required in the composition for anisotropic dye film in order to enhance the ability of dye transfer to the substrate), lithium salt, triethylamine salt, water-soluble group It is preferable to have one or more organic amine salts substituted with or a salt thereof. On the other hand, when low solubility in water is required (for example, when the dye is desired to be precipitated from a dye solution in the dye production process), an alkali such as a free acid type, a sodium salt, a potassium salt, or a calcium salt is used. It is preferable to have one or more earth metal salts or salts thereof.

{Specific examples of pigments}
Specific examples of the azo dye for anisotropic dye film of the present invention are shown below, but the present invention is not limited thereto. Moreover, the following specific examples are described in the form of a free acid.

{Production method}
The azo dye for anisotropic dye film of the present invention can be produced according to a method known per se.
For example, a dye represented by the following formula (1-v) (Dye No. (1-v)) is obtained by diazotizing 4-aminobenzenesulfonic acid (sulfanilic acid) according to a conventional method to produce 1,4-bis (acetate). It can be obtained by condensation with (acetylamino) benzene. In addition, pigment No. (1-v) is shown in the form of the free acid.

[Anisotropic Dye Film Composition]
In producing the anisotropic dye film, an anisotropic dye film composition can be used.
The composition for anisotropic dye film contains the azo dye for anisotropic dye film of the present invention, and usually further contains a solvent.
In this composition or in the anisotropic dye film described in detail below, the azo dye for anisotropic dye film of the present invention can be used alone, but the azo dyes for anisotropic dye film of the present invention can be used together. Other dichroic substances such as iodine can also be used in combination. Furthermore, it can be used by mixing with other dyes such as an ultraviolet absorbing dye and a near infrared absorbing dye to such an extent that the orientation is not lowered. As a result, it is possible to improve the durability of the anisotropic dye film, correct the hue, improve the polarization performance, and manufacture anisotropic dye films having various hues.

  As a solvent used for the composition for anisotropic dye film, 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, N-methylpyrrolidone, N, N-dimethyl. Examples thereof include an aprotic solvent such as formamide alone or a mixed solvent of two or more.

  The concentration when the dye is dissolved in these solvents depends on the solubility of the dye and the concentration of the associated state, but is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, preferably Is 10% by weight or less, more preferably 5% by weight or less, and particularly preferably 1% by weight or less.

  In addition, an additive such as a surfactant can be added to the anisotropic dye film composition as necessary to improve the solubility of the dye. As the surfactant, any of anionic, cationic, and nonionic surfactants can be used. The addition concentration is usually preferably 0.01% by weight or more and 10% by weight or less.

  Further, the anisotropic dye film composition according to the present invention can use additives as necessary in order to improve the dyeing property to the substrate. Specifically, Asahara Teruzo “New Dye Processing Course Vol. 7 Dyeing II”, Kyoritsu Publishing Co., Ltd., published on June 15, 1972, pp. 233-251 and Yamashita Yuya, Nemoto Yoshiro “Polymer Activator” Interfacial Chemistry between Seibundo and Shinko Co., Ltd., published on September 5, 1963, pages 94 to 173, etc. Activators, alcohols, glycols, urea, sodium chloride, inorganic salts such as bow glass, and the like. The addition concentration is usually preferably 0.01% by weight or more and 10% by weight or less.

[Anisotropic dye film]
An anisotropic dye film can be produced using the azo dye for anisotropic dye film of the present invention.
In addition to the azo dye for the anisotropic dye film of the present invention, this anisotropic dye film may contain other dyes as necessary, for example, known blue dichroic dyes, iodine, etc. An additive such as an agent may be contained. Of course, you may contain combining the pigment | dye represented with the azo pigment | dye for anisotropic pigment | dye films | membranes of this invention.

Examples of the method for producing the anisotropic dye film include the following methods (a) to (c).
(A) A method of dyeing a stretched polymer base material such as polyvinyl alcohol with a dye-containing solution (an anisotropic dye film composition) or the like (b) A polymer base material such as polyvinyl alcohol with a dye A method of stretching after dyeing with a containing solution (composition for anisotropic dye film) or the like (c) A solution containing a dye (polymer composition for anisotropic dye film) with a polymer substrate such as polyvinyl alcohol A method of stretching after dissolving in a solution such as

  When an anisotropic dye film is formed using the azo dye for anisotropic dye film of the present invention, for example, in any of the methods (a) to (c), the azo dye is dissolved in a suitable solvent. To use. As a solvent, the solvent contained in the said composition for anisotropic dye films is mentioned.

  In addition, as a base material dye | stained with the pigment | dye solution in the method of said (a) and (b), and a base material extended | stretched with the pigment | dye in the said method (c), polyvinyl alcohol-type resin, polyvinyl acetate resin , Ethylene / vinyl acetate (EVA) resin, nylon resin, polyester resin and the like. Among these, a polymer material having high affinity with a pigment such as polyvinyl alcohol is preferable.

  As the kind of polyvinyl alcohol, those having a high molecular weight and a high saponification degree are generally preferred from the viewpoint of optical properties such as polarization degree and dichroism, but it is possible to suppress defects due to shrinkage due to temperature and humidity and optical properties. For the purpose of achieving both environmental performance and environmental resistance, a polyvinyl alcohol derivative can be selected in which the type of dichroic material and the degree of saponification and modification of the polyvinyl alcohol (ratio of hydrophobic copolymer components) are appropriately adjusted. .

As a specific method for controlling the interaction between the polymer material and the dye, for each of the polymer material and the dye, proton-donating —OH, —NH ₂ , —NHR, —NHCO—, —NHCONH—, etc. By combining proton-accepting —N═N—, —OH, —NH ₂ , —NRR ′, —OR, —CN, —C≡C— and an aromatic ring such as a phenyl group or a naphthyl group as a functional group, It can be effective (R and R 'are optional substituents). Further, by adjusting the density of the functional group, an effect can be obtained in improving dichroism and dyeing property.

  Dyeing, film formation and stretching in the methods (a) to (c) can be performed by the following general methods.

  In the dye bath containing the above-mentioned composition for anisotropic dye film and, if necessary, an inorganic salt such as sodium chloride and bow glass, and a dyeing aid such as a surfactant, usually 35 ° C. or more, usually 80 ° C. or less. In general, the polymer film is immersed and dyed for 10 minutes or less, and then treated with boric acid as necessary, followed by drying. Alternatively, the polymer is dissolved in water and / or a hydrophilic organic solvent such as alcohol, glycerin, dimethylformamide, etc., and the composition for anisotropic dye film according to the present invention is added to perform stock solution dyeing. The stock solution is formed into a film by casting, solution coating, extrusion, or the like to produce a dyed film. The concentration of the polymer to be dissolved in the solvent varies depending on the type of polymer, but is usually 5% by weight or more, preferably about 10% by weight or more, and usually 30% by weight or less, preferably 20% by weight. It is about the following. The concentration of the dye dissolved in the solvent is usually 0.1% by weight or more, preferably about 0.8% by weight or more, usually 5% by weight or less, preferably 2.5% by weight based on the polymer. % Or less.

  The unstretched film obtained by dyeing and forming a film as described above is stretched in a uniaxial direction by an appropriate method. By performing the stretching treatment, the dye molecules are oriented and dichroism is expressed. As a method of stretching uniaxially, there are a method of stretching by a wet method, a method of stretching by a dry method, a method of compressing and stretching between rolls by a dry method, etc., and any method is used. May be. The draw ratio is 2 times or more and 9 times or less, but when polyvinyl alcohol and its derivatives are used as the polymer, a range of 3 times or more and 6 times or less is preferable.

  After the stretching and orientation treatment, boric acid treatment is performed for the purpose of improving the durability and the degree of polarization of the stretched film. The boric acid treatment improves the light transmittance and the degree of polarization of the anisotropic dye film. The conditions for the boric acid treatment vary depending on the type of the hydrophilic polymer and the dye used, but generally the boric acid concentration is usually 1% by weight or more, preferably about 5% by weight or more, usually 15%. It is about 10% by weight or less, preferably about 10% by weight or less. Further, the treatment temperature is usually 30 ° C. or higher, preferably 50 ° C. or higher and usually 80 ° C. or lower. When the boric acid concentration is less than 1% by weight or when the treatment temperature is less than 30 ° C., the treatment effect is small, and when the boric acid concentration exceeds 15% by weight or the treatment temperature exceeds 80 ° C. The anisotropic dye film becomes fragile and is not preferable.

  The film thickness of the anisotropic dye film obtained by the methods (a) to (c) is usually 50 μm or more, particularly 80 μm or more, preferably 200 μm or less, and particularly preferably 100 μm or less.

  The anisotropic dye film containing the azo dye of the present invention uses anisotropy of light absorption and functions as a polarizing film for obtaining linearly polarized light, circularly polarized light, elliptically polarized light, etc. By selecting the process and the composition containing the base material and pigment, it can be functionalized as various anisotropic films such as refractive index anisotropy and conduction anisotropy, and can be applied to various types and various uses. A polarizing element can be obtained.

  When the anisotropic dye film is used as a polarizing element, the anisotropic dye film itself produced by the method represented by the above (a) to (c) may be used, or on the dye film. Layers having various functions such as a protective layer, an adhesive layer, an antireflection layer, and a retardation layer may be laminated and used as a laminate.

  When the anisotropic dye film of the present invention is formed on a substrate and used as a polarizing element, the formed anisotropic dye film itself may be used. In addition to the protective layer as described above, an adhesive layer Or a layer having an optical function such as an antireflection layer, an alignment film, a function as a retardation film, a function as a brightness enhancement film, a function as a reflection film, a function as a transflective film, a function as a diffusion film, etc. Layers having various functions may be laminated by a wet film formation method or the like, and used as a laminate.

  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.

  The layer having a function as a brightness enhancement film may be formed by forming a fine hole by a method as described in, for example, Japanese Patent Application Laid-Open Nos. 2002-169025 and 2003-29030, 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 azo dye for anisotropic dye film of the present invention can express a wide range of colors, and can obtain a highly heat-resistant polarizing element, so that a liquid crystal display or an organic EL display can be obtained. In addition, it can be suitably used for applications requiring 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 a prism polarizer 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 90 parts by weight of water, the dye No. 1 represented by the following formula (iv-1) 0.05 parts by weight of sodium salt of (iv-1) and 10 parts by weight of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: GL-05) are added and stirred and dissolved in a water bath, and then developed to a thickness of about 1 mm. The pigment-containing polyvinyl alcohol (PVA) film was obtained by drying.
This PVA film was immersed in a 5% by weight boric acid aqueous solution and then stretched 3 times to obtain an anisotropic dye film. This anisotropic dye film had a maximum absorption wavelength (λmax) of 397 nm and was found to have a high dichroic ratio.

Example 2
The above dye No. The sodium salt of (iv-1) is dye No. 1 represented by the following formula (iv-2). A pigment-containing polyvinyl alcohol (PVA) film was obtained by the same method as that described in Example 1, except that the sodium salt of (iv-2) was used.
This PVA film was immersed in a 5% by weight boric acid aqueous solution and then stretched 3 times to obtain an anisotropic dye film.
This anisotropic dye film had a maximum absorption wavelength (λmax) of 405 nm and was found to have a high dichroic ratio.

Example 3
The above dye No. The sodium salt of (iv-1) is dye No. 1 represented by the following formula (iv-3). A pigment-containing polyvinyl alcohol (PVA) film was obtained by the same method as that described in Example 1, except that the sodium salt of (iv-3) was used.
This PVA film was immersed in a 5% by weight boric acid aqueous solution and then stretched 3 times to obtain an anisotropic dye film.
This anisotropic dye film had a maximum absorption wavelength (λmax) of 423 nm, a high dichroic ratio, and exhibited durability over a long period of time at high temperature and high humidity.

Example 4
The above-mentioned dye is No. The sodium salt of (iv-1) is dye No. 4 represented by the following formula (iv-4). A pigment-containing polyvinyl alcohol (PVA) film was obtained by the same method as that described in Example 1, except that the sodium salt of (iv-4) was used.
This PVA film was immersed in a 5% by weight boric acid aqueous solution and then stretched 3 times to obtain an anisotropic dye film. This anisotropic dye film has a maximum absorption wavelength (λmax) of 417 nm and was found to have a high dichroic ratio.

Claims (2)

An azo dye for anisotropic dye film, wherein the form of the free acid is represented by the following formula (1):

[In Formula (1), A ¹ and A ² each independently have a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a substituent. Represents a good aromatic heterocyclic group.
Y ⁴ and Y ⁵ each independently represent a hydrogen atom, a methyl group or an ethyl group.
Ar ⁶ represents a 1,4-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, a 2,6-naphthylene group, or a group represented by the following formula (1-a1). The 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group and the group represented by the following formula (1-a1) may have a substituent. .

(In formula (1-a1), ring α is a 5- or 6-membered heterocyclic ring.)] The azo dye for anisotropic dye film according to claim 1, wherein the formula (1) is represented by the following formula (1-4).

[In Formula (1-4), A ⁵¹ and A ⁵² each independently represent a phenyl group which may have a substituent or a naphthyl group which may have a substituent.
R ⁵¹ and R ⁵² each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a sulfo group, a carboxy group, an optionally substituted alkyl group, an optionally substituted alkoxy group or a substituted group. The amino group which may have a group is represented. ]