JP6459813B2 - Novel azo dichroic dye, and liquid crystal composition and liquid crystal element containing the azo dichroic dye - Google Patents

Description

  The present invention relates to a novel azo dichroic dye used for liquid crystal display and the like, and a liquid crystal composition and a liquid crystal element containing the azo dichroic dye.

  Conventionally, many types of liquid crystal display elements have been proposed. For example, as a guest-host type liquid crystal element, a liquid crystal composition containing a dichroic dye serving as a guest in a liquid crystal serving as a host (hereinafter also simply referred to as “host liquid crystal”) is sealed in a cell. It has been. This liquid crystal element employs a method of switching the display by changing the light absorption state of the cell by changing the orientation of the dichroic dye in accordance with the movement of the liquid crystal by the electric field. Since this guest-host system uses a backlight, it is expected as a reflective liquid crystal element with low power consumption.

  Here, the dichroic dye constituting the liquid crystal composition together with the host liquid crystal has properties such as suitable light absorption characteristics, a high dichroic order parameter (S value), high solubility in the host liquid crystal, and durability. Is required.

  As dichroic dyes used in this type of liquid crystal element, anthraquinone dyes and azo dyes are known. In general, anthraquinone dyes are capable of obtaining various colors from yellow to cyan depending on the molecular structure, and are said to have excellent light resistance, but have the disadvantages of a small extinction coefficient and sharp absorption spectrum. is there. In contrast, azo dyes generally have a high dichroic ratio and a large extinction coefficient. Furthermore, because the absorption spectrum is broad, the number of colorants to be mixed and the amount of each additive are compared with those of anthraquinone dyes in applications such as mixing with other dichroic dyes to form a desired black liquid crystal composition. It has the advantage that it can be reduced and the contrast can be increased.

  As the azo dichroic dye, for example, Patent Document 1 discloses a disazo dichroic dye having a thienothiazole ring, and Patent Document 2 discloses a heterocyclic azo dichroic dye having a high order parameter (S value). Various azo dichroic dyes having high S values are disclosed in Patent Documents 3 to 5.

Japanese Patent Laid-Open No. 1-146960 JP 2000-239664 A JP 2009-007486 A JP 2010-155924 A JP-A 62-000555

  Dichroic dyes are required to have high dichroic ratio order parameter (S value), which is an essential characteristic. At the same time, when used in a guest-host type liquid crystal element, it is required to have high solubility in the host liquid crystal. However, conventional high S value dichroic dyes are not sufficiently soluble in the host liquid crystal, and further improvements are required. In addition, since the solubility in the host liquid crystal usually tends to decrease at low temperatures, the dichroic dye having low solubility at low temperatures precipitates when the liquid crystal element is exposed to low temperatures. Can also be produced. In addition, unless otherwise indicated, the solubility as used in this specification has measured the solubility at -10 degreeC and 100 h stirring.

  The present invention has been made in view of the above problems. That is, the present invention is to provide a novel azo dichroic dye having improved solubility in a host liquid crystal while maintaining an order parameter (S value) having a high dichroic ratio (or contrast). Another object of the present invention is to provide a liquid crystal composition and a liquid crystal element capable of realizing a high contrast display.

  As a result of intensive studies to solve the above problems, the present inventors have found that the specific aromatic ring of the aromatic azo compound is a 1,4-phenylene group having a substituent, and the substituent is 1,4. -A linear or branched alkyl group having 1 to 10 carbon atoms, which is substituted at any of the 2-position, 3-position, 5-position and 6-position, 2-position and 5-position, and 3-position and 6-position of the phenylene group. Or an alkoxy group, wherein the substituents may be linked together to form a ring, thereby improving solubility in the host liquid crystal while maintaining a high order parameter (S value). It was also found that the change in the maximum absorption wavelength due to the introduction of this substituent is small. The present invention has been accomplished based on these findings.

（式中、
Ａｒ^１、Ａｒ^２は、それぞれ独立して、置換基を有していてもよい１，４−フェニレン基、又は置換基を有していてもよい１，４−ナフチレン基を表し、但しＡｒ^２のうち少なくとも１つは、置換基を有する１，４−フェニレン基であって、該置換基は、１，４−フェニレン基の２位及び３位、５位及び６位、２位及び５位、並びに３位及び６位のいずれかで置換する、炭素数１〜１０の直鎖又は分岐鎖の、アルキル基又はアルコキシ基である。ただし、該置換基は共に連結して環を形成してもよく、
Ｘ^１は、酸素原子又は−ＮＲ^１−を表し、ここでＲ^１は、水素原子、アルキル基、アルケニル基、アルキニル基、又はアルコキシ基を表し、
Ｌ^１は、環状構造及びアゾ結合を含まない、二価の連結基又は直接結合を表し、
Ａ^１は、置換基を有していてもよい１，４−フェニレン基又は置換基を有していてもよい（Ｅ）−シクロヘキサン−１，４−ジイル基を表し、
Ｂ^１、Ｂ^２は、環状構造及びアゾ結合を含まない、二価の連結基又は直接結合を表し、
ｎ^１は、１以上の整数を表し、ここでｎ^１が２以上の場合、一般式（I）中に存在する２以上のＡｒ^１は同一であっても異なっていてもよく、
ｎ^２は、１以上の整数を表し、ここでｎ^２が２以上の場合、一般式（I）中に存在する２以上のＡｒ^２は同一であっても異なっていてもよく、
ｎ^３は、０以上の整数を表し、ここでｎ^３が２以上の場合、一般式（I）中に存在する２以上のＡ^１は同一であっても異なっていてもよい。）
但し、Ｙ^１、Ｙ^２は、それぞれ独立して、下記一般式で表される一価の置換基である。

（式中、
Ａ^２〜Ａ^５は、それぞれ独立して、置換基を有していてもよい１，４−フェニレン基又は置換基を有していてもよい（Ｅ）−シクロヘキサン−１，４−ジイル基を表し、
Ｂ^３、Ｂ^４は、それぞれ独立して、環状構造及びアゾ結合を含まない、二価の連結基又は直接結合を表し、
Ｒ^２、Ｒ^３は、それぞれ独立して、アルキル基、アルケニル基、アルキニル基、又はアルコキシ基を表し、
ｎ^４〜ｎ^７は、それぞれ独立して、１以上の整数を表し、ここでｎ^４〜ｎ^７が２以上の場合、式中に存在する２以上のＡ^２〜Ａ^５はそれぞれ同一であっても異なっていてもよい。） That is, the present invention provides the following specific embodiments (1) to (13), for example.
(1) An azo dichroic dye represented by the following general formula (I):

(Where
Ar ¹ and Ar ² each independently represents a 1,4-phenylene group which may have a substituent, or a 1,4-naphthylene group which may have a substituent, provided that Ar ² At least one of them is a 1,4-phenylene group having a substituent, and the substituent is the 2-position, 3-position, 5-position, 6-position, 2-position and 5-position of the 1,4-phenylene group. And a linear or branched alkyl group or alkoxy group having 1 to 10 carbon atoms, which is substituted at any one of the 3-position and the 6-position. However, the substituents may be linked together to form a ring,
X ¹ represents an oxygen atom or —NR ¹ —, wherein R ¹ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group,
L ¹ represents a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
A ¹ represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent,
B ¹ and B ² represent a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
n ¹ represents an integer of 1 or more, and when n ¹ is 2 or more, two or more Ar ¹ present in the general formula (I) may be the same or different,
n ² represents an integer of 1 or more, and when n ² is 2 or more, 2 or more Ar ² present in the general formula (I) may be the same or different,
n ³ represents an integer of 0 or more. Here, when n ³ is 2 or more, two or more A ¹ present in the general formula (I) may be the same or different. )
However, Y ¹ and Y ² are each independently a monovalent substituent represented by the following general formula.

(Where
A ^{2 to} A ⁵ each independently represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent. Represent,
B ³ and B ⁴ each independently represent a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
R ² and R ³ each independently represents an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group,
n ⁴ ~n ⁷ each independently represents an integer of 1 or more, wherein when ⁿ 4 ~n ⁷ is 2 or more, there are two or more ^A 2 to A ⁵ present in Formula identical Or different. )

ｚ式中、ｎ^２は２以上の整数を表し、Ａｒ^６は置換基を有していてもよい１，４−フェニレン基、又は置換基を有していてもよい１，４−ナフチレン基を表し、その他の符号は前記一般式（I）で説明したものと同義である。）で表される、上記（１）又は（２）に記載のアゾ系二色性色素。
（４）下記一般式（Ia）〜（Ic）のいずれかで表される、上記（１）又は（２）に記載のアゾ系二色性色素。

（式中、Ａｒ^１、Ｘ^１、Ｌ^１、Ａ^１、Ｂ^１、Ｂ^２、Ｙ^１、Ｙ^２、ｎ^１及びｎ^３は、前記一般式（I）で説明したものと同義であり、Ｑは置換基を有していてもよいシクロアルカンを表す。） (2) The azo dichroic dye according to (1), wherein R ² and R ³ are an alkyl group, an alkenyl group, or an alkynyl group.
(3) The general formula (I) is represented by the following general formula (II);

In formula z, n ² represents an integer of 2 or more, and Ar ⁶ represents a 1,4-phenylene group which may have a substituent, or a 1,4-naphthylene group which may have a substituent. The other symbols are the same as those described in the general formula (I). The azo dichroic dye according to (1) or (2), which is represented by:
(4) The azo dichroic dye according to (1) or (2), which is represented by any one of the following general formulas (Ia) to (Ic).

(In the formula, Ar ¹ , X ¹ , L ¹ , A ¹ , B ¹ , B ² , Y ¹ , Y ² , n ¹ and n ³ have the same meanings as described in the general formula (I), Q represents a cycloalkane which may have a substituent.

(5) The azo dichroism according to any one of (1) to (4) above, wherein B ¹ or B ² is a residue obtained by removing hydrogen from alkanediol, alkenediol, or alkynediol. Pigment.
(6) The azo dichroic dye according to any one of (1) to (5), wherein X ¹ is an oxygen atom or —NH—.
(7) The azo according to any one of (1) to (6), wherein n ¹ is 1 and Ar ¹ is a 1,4-phenylene group which may have a substituent. Dichroic dyes.
(8) In the case of ^{n 3} is 1 or 2, wherein ^{A 1} is optionally may 1,4-phenylene group optionally having a substituent, according to any one of the above (1) to (7) An azo dichroic dye.
(9) The azo group according to any one of (1) to (8), wherein B ² is an alkanediol residue having 2 to 8 carbon atoms, wherein hydrogen is removed from a hydroxyl group of alkanediol. Color pigment.
(10) n ^{4 to} n ⁷ are 2, A ² and A ⁵ are optionally substituted (E) -cyclohexane-1,4-diyl groups, and A ³ and A 5 The azo dichroic dye according to any one of (1) to (9), wherein ⁴ is a 1,4-phenylene group which may have a substituent.
(11) The azo group according to any one of (1) to (10), wherein R ² and R ³ are an alkyl group, alkenyl group, alkynyl group, or alkoxy group having 3 to 8 carbon atoms. Color pigment.

(12) A liquid crystal composition comprising the azo dichroic dye according to any one of (1) to (11) and a liquid crystal compound.
(13) A liquid crystal element having a liquid crystal layer containing the liquid crystal composition according to (12).

  According to the present invention, it is possible to provide a novel azo dichroic dye having improved solubility in a host liquid crystal while maintaining a high order parameter (S value). Further, by using this azo dichroic dye, it is possible to provide a liquid crystal composition and a liquid crystal element capable of performing high contrast display.

It is the schematic which shows the principal part of the voltage application state of the phase change mode guest host type | mold liquid crystal display element of this embodiment. It is the schematic which shows the principal part of the voltage-less application state of the phase change mode guest host type | mold liquid crystal display element of this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited thereto, and does not depart from the gist thereof. Any change can be made within the range.

[Dichroic dye]
The azo dichroic dye of this embodiment is represented by the following general formula (I).

In the general formula (I), Ar ¹ and Ar ² are each independently a 1,4-phenylene group which may have a substituent, or a 1,4-optional which has a substituent. Represents a naphthylene group. However, at least one of Ar ² is a 1,4-phenylene group having a substituent, and the substituent is the 2-position, 3-position, 5-position, 6-position, and 2-position of the 1,4-phenylene group. And a C1-C10 linear or branched alkyl group or alkoxy group substituted at any one of the 5-position and 3-position and 6-position. However, the substituents may be linked together to form a ring.
When the substituent forms a ring, it may be a heterocycle containing oxygen, nitrogen, sulfur, etc. as part of the ring. The number of atoms constituting the ring is usually 3 to 12, preferably 3 to 6, particularly preferably 3 or 4, excluding atoms shared with the phenylene group.
Such a ring may be substituted with a halogen atom, a methyl group, a methoxy group, a quinone or the like.
In addition, for example, a 1,4-phenylene group substituted with a linear or branched alkyl group or alkoxy group having 1 to 10 carbon atoms at the 2-position and 3-position, further at the 5-position or 6-position, It may be substituted with a linear or branched alkyl group or alkoxy group having 1 to 10 carbon atoms.
X ¹ represents an oxygen atom or —NR ¹ —, and R ¹ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group. Further, L ¹ represents a divalent linking group or a direct bond not containing a cyclic structure and an azo bond. A ¹ represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent. B ¹ and B ² represent a divalent linking group or a direct bond not containing a cyclic structure and an azo bond.

In the present invention, the reason why the solubility in the host liquid crystal is improved while the dye retains the high contrast order parameter (S value) is presumed as follows. In general, if the dye is arranged more parallel to the liquid crystal, the order parameter (S value) is increased, but the molecule is required to be elongated, so that the solubility is lowered and composition is difficult. Thus, as a result of the study, the present inventors have assumed that the solubility of azo-based dichroic dyes decreases due to the association between the dyes, and this association is reduced and the order parameter (S value) is not lowered. In order to achieve this, we have intensively studied what kind of structure it should be. As a result, by introducing an alkyl group or an alkoxy group, more preferably a substituent in which these are linked together to form a ring, to the combination of specific positions of Ar ^{2 in} the general formula (I) of the present invention, The improvement in solubility due to the improvement of the same reason can be obtained, a high order parameter (S value) can be maintained, and two characteristics that have been difficult to achieve in the past have been achieved.
Therefore, in addition to this Ar ² and its surrounding structure, for example, Y ¹ , Y ^2, etc., do not become a major obstacle to manifesting the effects of the present invention, that is, a range that does not greatly affect the order parameter (S value). Think and choose.
In addition, the introduction of the substituent of the present invention has an advantage that the color tone and the like in the liquid crystal composition can be easily controlled because there is almost no change in the maximum absorption wavelength.

Here, in the general formula (I), n ¹ represents an integer of 1 or more. Here, when n ¹ is 2 or more, the two or more Ar ¹ present in the general formula (I) may be the same or different. N ² represents an integer of 1 or more. Here, when n ² is 2 or more, the 2 or more Ar ² present in the general formula (I) may be the same or different. N ³ represents an integer of 0 or more. Here, when n ³ is 2 or more, two or more A ¹ present in the formula (I) may be the same or different.

In the general formula (I), Y ¹ and Y ² are each independently a monovalent substituent represented by the following general formula.

A ^{2 to} A ⁵ in Y ¹ and Y ² are each independently a 1,4-phenylene group which may have a substituent or (E) -cyclohexane which may have a substituent. It represents a -1,4-diyl group. B ³ and B ⁴ each independently represent a divalent linking group or a direct bond not containing a cyclic structure and an azo bond. Further, R ² and R ³ each independently represents an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group.

N ^{4 to} n ⁷ in Y ¹ and Y ² each independently represent an integer of 1 or more. Here, when n ^{4 to} n ⁷ is 2 or more, two or more A ^{2 to} A ⁵ present in the formula may be the same or different. These structures of Y ¹ and Y ² are those commonly used in conventional dichroic dyes, and at least one of Ar ² that is essential for obtaining the characteristics of the present invention, that is, effects, is a substitution. 1,4-phenylene group having a group, wherein the substituent is the 2-position and 3-position, 5-position and 6-position, 2-position and 5-position, and 3-position and 6-position of the 1,4-phenylene group, Ar ² related to “a linear or branched alkyl group or alkoxy group having 1 to 10 carbon atoms, which may be substituted with any one of them, wherein the substituents may be linked together to form a ring”. Therefore, it is considered that the effect of Ar ² substituted with a specific substituent can be obtained for each structure without greatly affecting the effect of the present invention.

<Ar ² and n ² >
When Ar ² is a 1,4-phenylene group or 1,4-naphthylene group having a substituent, examples of the substituent include an alkyl group, an alkoxy group, a cyano group, a nitro group, an alkylsulfonyl group, and a halogenated alkyl group. , Halogen atoms, alkoxycarbonyl groups and the like. And a 1,4-phenylene group having a substituent, which is substituted at the 2-position, 3-position, 5-position, 6-position, 2-position and 5-position, and 3-position and 6 of the 1,4-phenylene group. It is a C1-C10 linear or branched alkyl group or alkoxy group substituted at any of the positions. However, the substituents may be linked together to form a ring. Specific examples thereof include a 1,4-phenylene group in which both of the positions 2 and 3 are substituted with a linear or branched alkyl group having 1 to 10 carbon atoms or a linear or branched alkoxy group having 1 to 10 carbon atoms, 1,4-phenylene group substituted by a linear or branched alkyl group having 1 to 10 carbon atoms or a linear or branched alkoxy group having 1 to 10 carbon atoms at positions 5 and 6; Both 1,4-phenylene groups substituted by a linear or branched alkyl group having 1 to 10 carbon atoms or a linear or branched alkoxy group having 1 to 10 carbon atoms, and the positions of 3, 6 are both 1 to 10 carbon atoms. Or a 1,4-phenylene group substituted with a linear or branched alkoxy group having 1 to 10 carbon atoms, and these substituents are linked together to form a ring. Good
When the essential substituents are linked together to form a ring, the obtained ring is preferably a cycloalkane having 5 or 6 carbon atoms which may have a substituent, specifically Is cyclopentane, methylcyclopentane, ethylcyclopentane, dimethylcyclopentane, methylethylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane.
In addition, a linear or branched alkyl group or alkoxy having 1 to 10 carbon atoms, which is substituted at any of 2-position, 3-position, 5-position and 6-position, 2-position and 5-position, and 3-position and 6-position When the group does not form a ring, it is preferable that any one of the positions 2, 3, 5, 6, 2, 5, and 3, 6 is substituted with the same alkyl group or alkoxy group. Particularly preferably, this is a methyl group or an ethyl group.

  Examples of the linear or branched alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and hexyl group. An octyl group and the like can be mentioned, but the invention is not particularly limited thereto. Among these, Preferably it is a C1-C9 linear or branched alkyl group, More preferably, it is a C1-C4 linear or branched alkyl group, Most preferably, it is carbon number. 1 to 3 linear or branched alkyl groups.

  Examples of the linear or branched alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group. However, it is not particularly limited to these. Carbon number of an alkoxy group is 1-10, Preferably it is 1-4, More preferably, it is 1-3. These alkoxy groups may be linear or branched.

  In addition, a part of the linear or branched alkyl group having 1 to 10 carbon atoms of the present invention may have a halogen atom. In this case, preferred halogenated alkyl groups include a trifluoromethyl group, a pen A taloethyl group, a heptafluoropropyl group, a nonafluorobutyl group and the like can be mentioned, but the invention is not particularly limited thereto. Carbon number of the alkyl group which has a halogen atom becomes like this. Preferably it is 1-4, More preferably, it is 1-3. Particularly preferred is a fluoroalkyl group having 1 to 3 carbon atoms.

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

  Further, a part of the linear or branched alkoxy group having 1 to 10 carbon atoms of the present invention may have a carbonyl group. In this case, as the preferable alkoxy group having a carbonyl group, a methoxycarbonyl group, Examples thereof include, but are not limited to, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, an isobutoxycarbonyl group, a sec-butoxycarbonyl group, and a tert-butoxycarbonyl group. 2-10 are preferable, as for carbon number of the alkoxy group which has a carbonyl group, More preferably, it is 2-4, More preferably, it is 2-3.

Among these, from the viewpoint of increasing the solubility in the host liquid crystal, Ar ² is a 1,4-phenylene group, a 1,4-naphthylene group, a 1,4- (2,3-dimethyl) phenylene group, 1,4- A (5,6,7,8-tetrahydro) naphthylene group or a 4,7-indane group is preferred.

In general formula (I), n ² is preferably 1 or 2.
Here, when n ² is 1, Ar ² is a 1,4- (5,6,7,8-tetrahydro) naphthylene group which may have a substituent from the viewpoint of enhancing the solubility in the host liquid crystal. Or it is preferable that it is a 4,7-indane group which may have a substituent.
Also, when n ² is 2, from the viewpoint of enhancing the solubility host liquid crystal, also one of Ar ² less of the general formula (I) of the two present in the Ar ² are have a substituent A good 1,4- (5,6,7,8-tetrahydro) naphthylene group or a 4,7-indane group which may have a substituent is preferable. The other Ar ² is preferably a 1,4-phenylene group which may have a substituent or a 1,4-naphthylene group which may have a substituent. At this time, the bonding order of two or more Ar ² is arbitrary.

<Ar ¹ and n ¹ >
Ar ¹ represents a 1,4-phenylene group which may have a substituent or a 1,4-naphthylene group which may have a substituent. n ¹ represents an integer of 1 or more. Here, when n ¹ is an integer of 2 or more, there are a plurality of Ar ¹ in the general formula (I). At this time, a plurality of Ar ¹ may be the same or different. Good. Particularly preferably, n ¹ is 1, and Ar ¹ is a 1,4-phenylene group which may have a substituent. As described above, the substituent for Ar ¹ is not particularly limited as long as it does not inhibit the effect of the present invention, and an alkyl group, an alkoxy group, a cyano group, a nitro group, an alkylsulfonyl group, a halogenated alkyl group, a halogen atom, and the like. An atom, an alkoxycarbonyl group, etc. are mentioned. Of these, an alkyl group, an alkoxy group, a halogenated alkyl group, and a halogen atom are preferable.

<X ¹ and R ¹ >
X ¹ represents an oxygen atom or —NR ¹ —. Here, R ¹ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group or an alkoxy group. Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a hexyl group, and an octyl group. Examples of the alkenyl group include, but are not limited to, a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group. Furthermore, examples of the alkynyl group include, but are not limited to, an ethynyl group and a prop-2-yn-1-yl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a hexyloxy group, and an octyloxy group. However, it is not limited to these. Among these, R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

<L ¹ >
L ¹ represents a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond. Examples of the divalent linking group include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, a hexylene group, and an octylene group. A linear or branched alkylene group of 2 to 10 carbon atoms such as vinylene group, propenylene group, isopropenylene group, butenylene group, isobutenylene group, sec-butenylene group, tert-butenylene group, hexenylene group, octenylene group, etc. A linear or branched alkenylene group having 2 to 10 carbon atoms such as an ethynylene group, a propynylene group, an isopropynylene group, a butynylene group, an isobutynylene group, a sec-butynylene group, a tert-butynylene group, a hexynylene group, and an octynylene group. Linear or branched alkynylene group; oxycarboni Group, methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propyleneoxycarbonyl group, isopropyleneoxycarbonyl group, oxycarbonyl group optionally substituted by alkylene group such as tert-butyleneoxycarbonyl group; carbonyloxy group, methylenecarbonyl Examples include, but are not limited to, a carbonyloxy group, an alkyleneoxy group, and an alkylenecarbonyl group that may be substituted with an alkylene group such as an oxy group. Among these, L ¹ is preferably a methylene group.

<A ¹ Oyobin ^3>
A ¹ represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent. n ³ represents an integer of 0 or more. Here, when n ³ is an integer of 2 or more, there are a plurality of A ¹ in the general formula (I). At this time, a plurality of A ¹ may be the same or different. Good. Preferably n ³ is 0, or n ³ is 1 or 2, and A ¹ is a 1,4-phenylene group which may have a substituent. Here, when n ³ is 2, two A ¹ present in the general formula (I) are both unsubstituted 1,4-phenylene groups (ie, biphenyl), or at least one A ¹ is a 1,4-phenylene group having 1 to 4 halogen atoms as a substituent, and the other A ¹ is an unsubstituted 1,4-phenylene group (that is, a halogen-substituted biphenyl). preferable. At this time, the joining order of two or more A ¹ is arbitrary.

^{<B 1} and ^B 2>
B ¹ and B ² each independently represent a divalent linking group or a direct bond not containing a cyclic structure and an azo bond. Examples of the divalent linking group include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, a hexylene group, and an octylene group. A linear or branched alkylene group of 2 to 10 carbon atoms such as vinylene group, propenylene group, isopropenylene group, butenylene group, isobutenylene group, sec-butenylene group, tert-butenylene group, hexenylene group, octenylene group, etc. A linear or branched alkenylene group having 2 to 10 carbon atoms such as an ethynylene group, a propynylene group, an isopropynylene group, a butynylene group, an isobutynylene group, a sec-butynylene group, a tert-butynylene group, a hexynylene group, and an octynylene group. Linear or branched alkynylene group; 1,2-ethane All, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,4-pentanediol, 1,5-pentanediol, 1,6-hexanediol Alkanediol residues obtained by removing hydrogen from the hydroxyl group of alkanediol such as oxycarbonyl group, methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propyleneoxycarbonyl group, isopropyleneoxycarbonyl group, tert-butyleneoxycarbonyl group, etc. An oxycarbonyl group optionally substituted with an alkylene group; a carbonyloxy group optionally substituted with an alkylene group such as a carbonyloxy group or a methylenecarbonyloxy group, an alkyleneoxy group, an alkylenecarbonyl group, etc. Limited to There. Among these, it is preferable that either one of B ¹ and B ² are directly bonded and the other is an alkane diol residue having 2 to 8 carbon atoms, more preferably, one of B ¹ and B ² on the other hand Is an alkanediol residue having 4 to 6 carbon atoms.

<R ² and R ³ >
R ² and R ³ each independently represents an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group. Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a hexyl group, and an octyl group. Examples of the alkenyl group include, but are not limited to, a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group. Furthermore, examples of the alkynyl group include, but are not limited to, an ethynyl group and a prop-2-yn-1-yl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a hexyloxy group, and an octyloxy group. However, it is not limited to these. R ² and R ³ are each a linear or branched alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. Preferably, a linear or branched alkyl group having 1 to 10 carbon atoms or a linear alkoxy group having 1 to 10 carbon atoms is more preferable, a linear alkyl group having 3 to 8 carbon atoms, or 3 carbon atoms. A linear alkoxy group of ˜8 is more preferred. In particular, from the viewpoint of increasing the solubility in the host liquid crystal, R ² and R ³ preferably have a low polarity and a structure that extends the polar molecular length, a partial structure of the liquid crystal molecule, etc., and a linear alkyl having 4 to 7 carbon atoms. Group is particularly preferable, and a linear alkyl group having 5 to 7 carbon atoms is particularly preferable. In addition, from the viewpoint of increasing the solubility in the host liquid crystal, the total number of carbon atoms of R ² and R ³ is preferably 7 to 13, and more preferably 10 to 12. Further, these alkyl group, alkenyl group, alkynyl group and alkoxy group may be substituted with a halogen atom, and a fluoroalkyl group and a fluoroalkoxy group in which all of hydrogen is replaced with a halogen atom are particularly preferable.

<A ² OyobiA ⁵ Narabinin ⁴ Oyobin ^7>
A ² and A ⁵ are each independently a 1,4-phenylene group which may have a substituent, or (E) -cyclohexane-1,4-diyl group which may have a substituent. Represents. n ⁴ and n ⁷ each independently represents an integer of 1 or more. Here, when n ⁴ or n ⁷ is an integer of 2 or more, a plurality of A ² or A ⁵ are present in the general formula (I). At this time, a plurality of A ² or A ⁵ is They may be the same or different. Particularly preferably, n ⁴ and n ⁷ are 1, and A ² and A ⁵ are optionally substituted (E) -cyclohexane-1,4-diyl groups.

<A ³ OyobiA ⁴ Narabinin ⁵ Oyobin ^6>
A ³ and A ⁴ are each independently a 1,4-phenylene group which may have a substituent, or (E) -cyclohexane-1,4-diyl group which may have a substituent. Represents. n ⁵ and n ⁶ each independently represents an integer of 1 or more. Here, when n ⁵ or n ⁶ is an integer of 2 or more, a plurality of A ³ or A ⁴ are present in the general formula (I). At this time, a plurality of A ³ or A ⁴ is They may be the same or different. Particularly preferably, n ⁵ and n ⁶ are 1, and A ³ and A ⁴ are 1,4-phenylene groups which may have a substituent.

In addition, in A ^{2 to} A ⁵ , examples of the substituent that the 1,4-phenylene group and (E) -cyclohexane-1,4-diyl group may have include an electron donating property such as an alkoxy group and an alkyl group. Groups such as cyano group, nitro group, alkylsulfonyl group, halogenated alkyl group, halogen atom, alkoxycarbonyl group and the like, but not limited thereto. Specific examples thereof are the same as those described in Ar ² .

^{<B 3} and ^B 4>
B ³ and B ⁴ each independently represent a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond. A preferred embodiment of B ³ and ^{B 4} are the same as ^{B 1} and ^{B 2.}

（式中、ｎ^２は２以上の整数を表し、Ａｒ^６は置換基を有していてもよい１，４−フェニレン基、又は置換基を有していてもよい１，４−ナフチレン基を表し、その他の符号は上記一般式（I）中の規定と同義である。） Among the azo dichroic dyes represented by the general formula (I), those represented by the following general formula (II) are more preferable.

(In the formula, n ² represents an integer of 2 or more, and Ar ⁶ represents a 1,4-phenylene group which may have a substituent, or a 1,4-naphthylene group which may have a substituent. And the other symbols are as defined in the general formula (I).)

The azo dichroic dye represented by the general formula (I) or (II) has a high order parameter and a host liquid crystal due to the introduction of an alkyl-substituted 1,4-phenylene group as Ar ² . It has the advantage that high solubility is compatible.
More preferably, it is an azo dichroic dye represented by any one of the following general formulas (Ia) to (Ic).

（式中、Ａｒ^１、Ｘ^１、Ｌ^１、Ａ^１、Ｂ^１、Ｂ^２、Ｙ^１、Ｙ^２、ｎ^１及びｎ^３は、前記一般式（I）で説明したものと同義であり、Ｑは置換基を有していてもよいシクロアルカンを表す。）

(In the formula, Ar ¹ , X ¹ , L ¹ , A ¹ , B ¹ , B ² , Y ¹ , Y ² , n ¹ and n ³ have the same meanings as described in the general formula (I), Q represents a cycloalkane which may have a substituent.

  In the above general formulas (Ia) to (Ic), specific examples of Q include cyclopentane, methylcyclopentane, ethylcyclopentane, dimethylcyclopentane, methylethylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, etc. And a cycloalkane having 5 or 6 carbon atoms which may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a cyano group, a nitro group, an alkylsulfonyl group, a halogenated alkyl group, a halogen atom, and an alkoxycarbonyl group, and particularly preferably a linear or branched group having 1 to 10 carbon atoms. A chain alkyl group, or a linear or branched alkoxy group having 1 to 10 carbon atoms.

The azo dichroic dyes represented by the general formulas (Ia) to (Ic) are high because a condensed ring in which a cycloalkane Q and a 1,4-phenylene group are condensed is introduced as Ar ^2. While maintaining the order parameters, the solubility in the host liquid crystal is further enhanced.

<Molecular weight>
The above azo dichroic dye has a molecular weight of usually 3000 or less, preferably 1500 or less, from the viewpoint of solubility in the host liquid crystal and response speed. The molecular weight is preferably 450 or more, and more preferably 550 or more.

<Specific example>
Examples of partial structures of the azo dichroic dyes represented by the above general formulas (I) or (Ia) to (Ic) will be exemplified below, but the present invention is not particularly limited to these unless it exceeds the gist. It is not something.

これら例示のうち、特に好ましくは最後の５つの構造、すなわち下のとおりである。

Among these, a particularly preferable partial structure is that a portion corresponding to Ar ¹ to Ar ² has the following partial structure.

Of these examples, the last five structures are particularly preferred:

<Synthesis method>
The azo dichroic dye represented by the general formula (I) can be obtained by a known method such as A.I. V. Cited by Ivashchenko, “Dicroic Dye for Liquid Crystal Display” (CMC, published in 1994), Horiguchi Hiroshi, “Review Synthetic Dye” (Sankyo Publishing, published in 1968), Japanese Patent Laid-Open No. 10-60446 It can be synthesized by reacting using methods described in the literature.

[Liquid crystal composition]
Mixing one kind or two or more kinds of azo dichroic dyes represented by the above general formula (I) into various host liquid crystal compounds or host liquid crystal compositions containing these compounds by a known method. Thus, a liquid crystal composition can be prepared. Specifically, biphenyl showing a nematic or smectic phase described in pages 154 to 192 and pages 715 to 722 of the “Liquid Crystal Device Handbook” (Nikkan Kogyo Shimbun, published in 1989) edited by the 142th Committee of the Japan Society for the Promotion of Science. Examples thereof include various host liquid crystal compounds such as phosphatides, phenylcyclohexanes, phenylpyrimidines, and cyclohexylcyclohexanes, or host liquid crystal compositions containing these compounds. Further, for example, compounds described in JP-A-3-14892 can be suitably used.

  The type of the preferred host liquid crystal varies depending on the driving method. For example, when the driving method is an active matrix type, fluorine-based liquid crystal is preferable. Examples of the host liquid crystal compound include Np-type liquid crystal compounds and Nn-type liquid crystal compounds represented by the following general formulas (VIII) to (XII).

[In Formulas (VIII) to (XII), Ring B represents a cyclohexane ring, a benzene ring, a dioxane ring, or a pyrimidine ring, and q represents an integer of 1 to 3. Z represents a direct bond, —CO—O—, —CH ₂ CH ₂ —, —CH═CH—, or —C≡C—. Y ¹ and Y ³ each independently represent a hydrogen atom or a halogen atom such as a fluorine atom or a chlorine atom, and Y ² represents a halogen atom such as a fluorine atom or a chlorine atom, or a halogen atom such as a fluorine atom or a chlorine atom. A C1-C7 alkyl group as a substituent, also an alkenyl group, an alkoxy group, a substituted alkyl group, a substituted alkenyl group, a cyclohexyl group having a substituted alkoxy group as a substituent, or a substituted alkyl group thereof, substituted The phenyl group which has an alkenyl group and a substituted alkoxy group as a substituent is shown. Y ⁷ and Y ⁸ each independently represent a cyano group or a halogen atom such as a fluorine atom or a chlorine atom. Y ¹¹ and Y ¹³ represent a cyano group. Y ⁴ , Y ⁵ , Y ⁶ , Y ⁹ , Y ¹⁰ , Y ¹² , and Y ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or 1 to 10 carbon atoms. Or an alkoxyalkyl group having 2 to 10 carbon atoms. ]

  The liquid crystal composition of the present embodiment also shows a dichroic dye other than the azo dichroic dye represented by the general formula (I) and a liquid crystal phase such as cholesteryl nonanoate. Various additives such as an optically active substance that is not necessary, an ultraviolet absorber, and an antioxidant may be contained.

  The content ratio of the azo dichroic dye represented by the general formula (I) in the liquid crystal composition is not particularly limited, but when it contains two or more, It is preferably from 15% by weight to 15% by weight, more preferably from 0.1% by weight to 5% by weight.

  The azo dichroic dye represented by the general formula (I) usually has an absorption maximum wavelength at 390 to 650 nm in chloroform.

  Here, the absorption maximum wavelength in chloroform was measured by weighing 1 mg of the dichroic dye and dissolving it in chloroform so as to be 1 mg / 100 ml. Then, the solution was put in a quartz cell having an optical path length of 1 cm. Using a spectrophotometer U4100 (manufactured by Hitachi High-Technologies Corporation) as a reference, it can be determined by measuring absorbance at 380 nm to 780 nm.

The azo dichroic dye represented by the general formula (I) preferably has an order parameter (S value) of 0.81 or more, more preferably 0.82 or more. Here, the order parameter (S value) of the dichroic dye is based on the following formula described in the “Liquid Crystal Device Handbook” edited by the 142th Committee of the Japan Society for the Promotion of Science based on the spectroscopic measurement of the dichroic ratio. Can be sought.
S = (A _// − _A⊥ ) / ( _2A⊥ + A _// )
Here, "A _//" and "A _⊥", respectively, indicating the absorbance of the dye to light polarized parallel and perpendicular to the orientation direction of the liquid crystal. The S value theoretically takes a value in the range of 0 to 1, and as the value approaches 1, the contrast as a guest-host type liquid crystal element is improved.

[Liquid crystal element]
By sandwiching a liquid crystal layer containing the liquid crystal composition containing the azo dichroic dye represented by the general formula (I) between two substrates with electrodes, at least one of which is transparent, can do. There are various types of liquid crystal elements, but the application range of the liquid crystal elements of this embodiment is not particularly limited. For example, Shoichi Matsumoto and Ryo Tsunoda, “Latest Technology for Liquid Crystals” (Industry Research Committee, 1983). (Issued in year), p. L. Heilmeier-type guest host described in Fergason, SID85Digest, 68 (1985), “Liquid Crystal Device Handbook” (Nikkan Kogyo Shimbun, 1989), pages 315 to 329, etc. It can be configured as various liquid crystal elements utilizing a guest host effect such as a type guest host.

  Although it does not specifically limit as a board | substrate of a transparent electrode, Various synthetic resin boards, such as a glass plate, an acrylic resin, a polycarbonate resin, an epoxy resin, are used suitably. Although it does not specifically limit as a transparent electrode layer formed on a board | substrate, What consists of metal oxides, such as an indium oxide, an indium tin oxide (ITO), a tin oxide, is used suitably. The surface of the transparent electrode layer in contact with the liquid crystal can be subjected to an alignment treatment as necessary. Examples of the alignment treatment method include a method in which octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, hexadecyltrimethylammonium bromide and the like are applied for vertical alignment, a method in which polyimide is applied in parallel alignment, and a cotton cloth. Well-known methods such as a method of rubbing with absorbent cotton or the like for parallel orientation and a method of vapor-depositing SiOx from an oblique angle for parallel orientation can be appropriately used.

  The two electrode-attached substrates are arranged so that the alignment treatment surfaces face each other, and are integrated through a spacer or the like so that the distance between the two electrode-attached substrates is, for example, 1 to 50 μm, preferably 1 to An element (cell) having a space so as to be 15 μm is formed, and liquid crystal is sealed in this space.

  The liquid crystal element of the present embodiment can be applied to various types of liquid crystal element modes. In particular, a phase transition mode obtained by adding an optically active substance to a nematic liquid crystal composition is particularly preferable as a reflective liquid crystal display element because a high contrast and bright display can be achieved without using a polarizing plate.

  As an example of the liquid crystal element, FIGS. 1 and 2 are schematic cross-sectional views of an active drive type phase change mode guest-host type liquid crystal display element. FIG. 1 shows a voltage application state of the liquid crystal display element, and FIG. 2 shows a voltage non-application state. In the figure, 1 is incident light, 3 is a transparent glass plate, 4 is a transparent electrode, 5 is an alignment film, 6 is a host liquid crystal compound molecule, 7 is a dichroic dye molecule, 9 is a reflective layer, and 10 is reflected light. .

  When no voltage is applied (FIG. 2), the host liquid crystal compound molecule 6 exhibits a cholesteric phase, and the dichroic dye molecule 7 also exhibits a cholesteric structure together with the host liquid crystal compound molecule 6. Therefore, even if the incident light 1 is natural light, It is absorbed by the dichroic dye molecule 7 without using a polarizing plate. On the other hand, when voltage is applied (FIG. 1), the host liquid crystal compound molecules 6 and the dichroic dye molecules 7 are arranged in the direction of the electric field, so that light is transmitted and reflected by the reflective layer 9. Thus, this liquid crystal element can control transmission and absorption of light depending on the presence or absence of an electric field.

  The dichroic dye of this embodiment not only has a high order parameter, but also has a particularly high solubility in the host liquid crystal. Therefore, a liquid crystal composition and a liquid crystal device using the same are used in computers, watches, and the like. It can be suitably used for various electro-optical devices such as display elements for calculators, electro-optical shutters, electro-optical apertures, optical communication optical path switching switches, optical modulators, and the like.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited at all by these Examples. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention. In the following, “part” means “part by mass” unless otherwise specified.

Example 1
The azo dichroic dye of Example 1 was synthesized by the following procedure.

  Intermediate M52 (450 mg, 0.94 mmol) was diluted to NMP: DMF = 8: 17 (23 ml) and cooled in an ice bath. A 35% aqueous hydrochloric acid solution (0.26 ml, 2.8 mmol) and an aqueous solution of sodium nitrite (68 mg, 0.95 mmol) in water (0.5 ml) were added dropwise, and the mixture was stirred for 1 hour while maintaining the temperature at 5 ° C. or lower, and a diazonium salt solution Got. A separate flask was charged with intermediate M08 (587 mg, 0.94 mmol) and tetrahydrofuran (25 ml) and cooled in an ice bath. The diazonium salt solution prepared above was slowly added dropwise thereto and stirred for 30 minutes. The temperature of the reaction solution was raised to room temperature, a solution of sodium acetate (10 g) in water (150 ml) was added dropwise, and the solid obtained by filtration was subjected to silica gel column chromatography (N60 silica gel neutral, 150 ml, chloroform, manufactured by Kanto Kagaku). The distillate was concentrated to about 50 ml. The concentrated solution was allowed to stand for 30 minutes and then filtered to obtain the compound of Example 1 (102 mg, yield 10%). The hydrogenated molecular ions were confirmed by mass spectrometry (MALDI-MS), and identified as an azo dichroic dye represented by the above formula.

(Comparative Example 1)
The azo dichroic dye of Comparative Example 1 was synthesized from Intermediate M59 and Intermediate M08 under the same conditions as in Example 1.

(Example 2)
The azo dichroic dye of Example 2 was synthesized from Intermediate M47 and Intermediate M19 under the same conditions as in Example 1.

(Comparative Example 2)
The azo dichroic dye of Comparative Example 2 was synthesized from Intermediate M53 and Intermediate M19 under the same conditions as in Example 1.

(Example 3)
The azo dichroic dye of Example 3 was synthesized by the following method.

  Intermediate M49 (346 mg, 0.62 mmol) was diluted in dimethylformamide (15 ml, 43VR), intermediate M07 (350 mg, 0.62 mmol, 1MR), potassium carbonate (171 mg, 1.24 mmol, 2MR), tetra n- Butylammonium iodide (10 mg) was added. After reacting at room temperature for 4 days, water (20 ml) was added, the precipitated solid was filtered, and a silica gel column (adsorption method, N60 neutral 100 ml manufactured by Kanto Chemical Co., Ltd., 30 ml DNH silica gel produced by Fuji Silysia + 30 ml NHK silica gel produced by the same company, chloroform / The product was purified by hexane = 1 / 1-1 / 0), and the distillate was concentrated until the liquid volume became about 50 ml, filtered, and the compound of Example 3 (220 mg, LCarea 99%, Yield 33%) was obtained. The hydrogenated molecular ions were confirmed by mass spectrometry (MALDI-MS), and identified as an azo dichroic dye represented by the above formula.

(Example 4)
The azo dichroic dye of Example 4 was synthesized from Intermediate M48 and Intermediate M54 in the same manner as in Example 3.

(Comparative Example 3)
The azo dichroic dye of Comparative Example 3 was synthesized from Intermediate M53 and Intermediate M55 under the same conditions as in Example 1.

(Example 5)
The azo dichroic dye of Example 5 was synthesized from Intermediate M47 and Intermediate M32 under the same conditions as in Example 1.

(Comparative Example 4)
The azo dichroic dye of Comparative Example 4 was synthesized from Intermediate M53 and Intermediate M32 under the same conditions as in Example 1.

(Example 6)
The azo dichroic dye of Example 6 was synthesized from Intermediate M49 and Intermediate M08 under the same conditions as in Example 1.

(Example 7)
The azo dichroic dye of Example 7 was synthesized from Intermediate M49 and Intermediate M35 under the same conditions as in Example 1.

(Example 8)
The azo dichroic dye of Example 8 was synthesized from Intermediate M47 and Intermediate M34 under the same conditions as in Example 1.

(Comparative Example 5)
The azo dichroic dye of Comparative Example 5 was synthesized from Intermediate M53 and Intermediate M34 under the same conditions as in Example 1.

(Synthesis of intermediate)
The intermediates used in Examples 1-8 and Comparative Examples 1-5 were synthesized by the following procedure.

<Synthesis of Intermediates M07 and M08>

Intermediate M01 (Kanto Kagaku, 7.5 g, 30.6 mmol) and 1,4-dibromobutane (Tokyo Kasei, 19.8 g, 91.8 mmol, 3MR) were diluted in acetone (60 ml, 30.6 mmol). , Potassium carbonate (8.5 g, 61.2 mmol, 2MR) was added, and the mixture was heated to reflux for 18 hours. The reaction liquid was cooled to room temperature, and the filtrate obtained by filtration was concentrated, methanol (150 ml) was added, and the mixture was vigorously stirred under ice cooling. The precipitated solid was filtered to obtain Intermediate M02 (9.62 g, yield 82%) as a white solid.
¹ H-NMR (400 MHz, CDCl ₃ ): 7.12-7.16 (m, 2H), 6.82-6.86 (m, 2H), 4.00 (t, J = 6.0 Hz, 2H), 3.51 (t, J = 6.8 Hz , 2H), 2.39-2.47 (m, 1H), 2.05-2.12 (m, 2H), 1.87-1.98 (m, 6H), 1.21-1.48 (m, 13H), 1.00-1.11 (m, 2H), 0.92 (t, J = 7.0 Hz, 3H)

Intermediate M03 (Tokyo Kasei, 15.0 g, 70.0 mmol) was diluted in ethanol (300 ml, 20 VR), and 98% sulfuric acid (0.5 ml) was added and reacted under reflux for 16 hours. The reaction solution was cooled to room temperature, ethanol was distilled off, and the precipitated solid was washed with hexane (50 ml) and ethyl acetate (10 ml) to give an intermediate M04 (14.3 g, yield 85%) as a white solid. Acquired.
¹ H-NMR (400 MHz, CDCl ₃ ): 8.10-8.11 (m, 2H), 7.62-7.64 (m, 2H), 7.54-7.56 (m, 2H), 6.95-6.97 (m, 2H), 4.40- 4.45 (m, 2H), 1.44 (t, J = 7.2 Hz, 3H)

  Intermediates M04 (3.49 g, 14.4 mmol) and M02 (5.50 g, 14.4 mmol) were diluted in N, N-dimethylformamide (50 ml, 14VR) and potassium carbonate (3.98 g, 28.8 mmol, 2MR) was added and the mixture was heated to 60 ° C. and reacted for 1 hour. After cooling to room temperature, water (50 ml) was added, and the precipitated solid was filtered and washed with methanol (50 ml) to obtain intermediate M05 (8.01 g, LCarea 97%) as a white solid.

_{LiAlH 4 (1.09g, 28.8mmol, 2MR} ) and dehydrated tetrahydrofuran (Kanto Chemical products, 405VR) were suspended in ml), under ice-cooling, anhydrous tetrahydrofuran intermediate M05 (7.82 g, 14.4 mmol) (40 ml, 5VR) Suspension solution was added dropwise little by little. The reaction was warmed to room temperature, and further allowed to react for 1 hour, and then slowly dropped into an ice-cooled 1N aqueous hydrochloric acid solution (160 ml). The solution was returned to room temperature, extracted with chloroform (200 ml), the organic layer was dried over magnesium sulfate, and the solvent was distilled off. Intermediate M06 (5.74 g, 80% yield) was obtained as a white solid.

  Intermediate M06 (5.7 g, 11.4 mmol) was diluted in chloroform (60 ml, 10 VR) and triphenylphosphine (4.49 g, 17.1 mmol), carbon tetrabromide (5.31 g, 6.0 mmol) was added. The mixture was added and reacted for 12 hours. Methanol (120 ml) was added dropwise to the reaction solution, and the precipitated solid was filtered to obtain Intermediate M07 (5.78 g, yield 90%) as a pale yellowish white solid.

  Intermediate M07 (5.7 g, 10.3 mmol) was diluted in N, N-dimethylformamide (57 ml, 10 VR) and potassium carbonate (1.71 g, 12.4 mmol, 1.2 MR) was added to 60 ° C. For 1 hour. The reaction solution was cooled to room temperature, water (100 ml) was slowly added dropwise, the precipitated solid was filtered, and the crystals were washed with methanol (20 ml). Intermediate M08 (5.60 g, yield 87%) was obtained as white crystals.

<Synthesis of Intermediate M19>

  Intermediate M11 (8.00 g, 33.75 mmol) was dissolved in ethanol (160 mL), sulfuric acid (1 mL) was added, and the mixture was heated to reflux for 7 hours. The reaction mixture was cooled to room temperature, water (160 mL) was added, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and the filtrate obtained after filtration was concentrated to obtain Intermediate M12 (8.823 g, yield 99%).

Intermediate M12 (2.17 g, 8.18 mmol), Intermediate M13 (p- (tert-butyldimethylsilyloxy) phenylboronic acid, manufactured by Tokyo Chemical Industry, 2.27 g, 9.00 mmol), potassium carbonate (2.26 g) , 16.4 mmol), tetrahydrofuran (100 mL), and water (50 mL) were added tetratriphenylphosphine palladium (0.236 g, 0.204 mmol) under a nitrogen atmosphere, and the mixture was heated to reflux for 6 hours. The reaction solution was cooled to room temperature and extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate, the filtrate after filtration was concentrated, and the resulting residue was purified with a silica gel column (SiO ₂ : 300 mL, chloroform to ethyl acetate) to obtain crude intermediate M14. It was. This crude intermediate M14 was dissolved in ethanol (60 mL), sulfuric acid (1 mL) was added, and the mixture was heated to reflux for 3 hours. The reaction solution was cooled to room temperature, water (60 mL) was added, and the mixture was extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate, and the filtrate after filtration was concentrated to obtain Intermediate M15 (1.540 g, yield 64%).

  Intermediate M15 (1.54 g, 5.26 mmol) and intermediate M02 (2.01 g, 5.26 mmol) were diluted in N, N-dimethylformamide (45 mL) and potassium carbonate (1.46 g, 10.53 mmol). And stirred at 60 ° C. for 2 hours. The reaction was cooled to room temperature and water (45 mL) was added. The precipitate was collected by filtration and washed with methanol to obtain Intermediate M16 (2.68 g, yield 95%).

  To a solution of lithium aluminum hydride (0.351 g, 9.27 mmol) in tetrahydrofuran (27 mL) was added dropwise a solution of intermediate M16 (2.68 g, 4.63 mmol) in tetrahydrofuran (27 mL) under ice cooling, followed by ice cooling. Stirring was continued for 1 hour. The reaction solution was slowly added dropwise to ice water, the aqueous layer was extracted with chloroform, and the organic layer was washed with 1M hydrochloric acid. The organic layer was dried over anhydrous sodium sulfate, and the filtrate after filtration was concentrated to obtain Intermediate M17 (2.04 g, yield 82%).

  Intermediate M17 (1.26 g, 2.34 mmol) and carbon tetrabromide (4.68 g, 5.53 mmol) were added to tetrahydrofuran (12 mL), and triphenylphosphine (1.23 g, 5.53 mmol) was added under ice cooling. ) Was added. The reaction solution was returned to room temperature and stirred for 1 hour. Methanol (36 mL) was added, and the mixture was cooled with ice and stirred for 30 minutes. The precipitate was collected by filtration to obtain Intermediate M18 (1.01 g, yield 73%).

  1-naphthylamine (0.726 g, 5.07 mmol) and intermediate M18 (3.0 g, 5.07 mmol) were dissolved in N, N-dimethylformamide (30 mL) and potassium carbonate (1.401 g, 10.14 mmol). And stirred at 60 ° C. for 6 hours. The reaction mixture was cooled to room temperature, water (30 mL) was added, and the precipitate was collected by filtration and washed with methanol to obtain Intermediate M19 (2.78 g, yield 85%).

<Synthesis of Intermediate M32>

  Intermediates M26 (Tokyo Kasei, 3.0 g, 14.3 mmol) and M27 (5.45 g, 1MR) were diluted in N, N-dimethylformamide (30 ml, 10VR) and potassium carbonate (3.98 g, 28.7 mmol). , 2.0 MR), and reacted at 50 ° C. for 6 hours and at 80 ° C. for 2 hours. After cooling to room temperature, water (30 ml) was added, and the precipitated solid was washed successively with water (50 ml) and hexane (30 ml) while filtering. Intermediate M28 (7.31 g, 95% yield) was obtained as a white solid.

  Intermediates M28 (3.50 g, 6.51 mmol) and M29 (Tokyo Kasei, 989 mg, 6.51 mmol) were diluted in N, N-dimethylformamide (35 ml, 10VR) and potassium carbonate (1.80 g, 2MR) was diluted. After addition and stirring for 5 minutes under nitrogen, tetrakistriphenylphosphine palladium (0) (225 mg, 3 mol%) was added, and the mixture was reacted at 80 ° C. for 8 hours. After cooling the reaction solution to room temperature, water (20 ml) was added and the precipitated solid was filtered and further purified by reprecipitation with tetrahydrofuran (20 ml) and methanol (60 ml) to obtain intermediate M30 (4.90 g) as a white solid. , Yield: provisional 100%).

Intermediate M30 (3.68 g, 6.51 mmol) was diluted in chloroform (50 ml, 12 VR), triphenylphosphine (2.56 g, 9.8 mmol, 1.5 MR), carbon tetrabromide (2.59 g, 7 .81 mmol, 1.2 MR) was added and reacted for 16 hours. Methanol (70 ml) was added dropwise to the reaction solution, the precipitated solid was filtered, washed with methanol (15 ml) and tetrahydrofuran (5 ml), and the intermediate M31 (2.13 g, yield 2 steps 52% as an off-white solid) ).
¹ H-NMR (400 MHz, CDCl ₃ ): 7.45-7.54 (m, 4H), 7.09-7.15 (m, 3H), 6.80-6.87 (m, 3H), 4.77 (d, J = 5.6 Hz, 2H) , 4.11 (t, J = 6.4 Hz, 2H), 3.98 (t, J = 6.4 Hz, 2H), 2.39-2.46 (m, 1H), 1.81-1.92 (m, 8H), 1.55-1.60 (m, 2H ), 1.22-1.48 (m, 13H), 1.03-1.10 (m, 2H), 0.92 (t, J = 6.4 Hz, 3H)

  Intermediate M31 (2.00 g, 3.19 mmol), 1-naphthylamine (Tokyo Chemicals, 457 mg, 3.19 mmol) were diluted in N, N-dimethylformamide (16 ml, 8VR), and potassium carbonate (882 mg, 6.19). 38 mmol, 2.0 MR) was added and reacted at 80 ° C. for 3 hours. The reaction solution was cooled to room temperature, water (50 ml) was slowly added dropwise, the precipitated solid was filtered, and washed with a mixed solvent of methanol (30 ml) and ethyl acetate (5 ml). Intermediate M32 (1.79 g, 81% yield) was obtained as off-white crystals.

<Synthesis of Intermediates M34, M35, M54, M55>

  Intermediates M34, M35, M54, and M55 were synthesized by the method described in JP2009-7485A.

<Synthesis of Intermediates M47, M48, M49>

  Intermediates M43 (Kanto Kagaku, 17.3 g, 55.9 mmol) and M44 (Wako Pure Chemicals 10.0 g, 55.9 mmol, 1MR) were diluted in N, N-dimethylformamide (80 ml, 8VR) and calcium carbonate ( 15.4 g, 118 mmol, 2MR) was added and stirred for 10 minutes under nitrogen. Tetrakistriphenylphosphine palladium (0) (1.61 g, 2.5 mol%) was added and reacted at 80 ° C. for 2 hours. After cooling the reaction solution to room temperature, water (100 ml) was added, and the precipitated solid was filtered to obtain crude intermediate M45 (20.3 g, provisional yield 100%) as a brown powder solid.

Intermediate M45 (20.3 g, 55.9 mmol) was suspended in 4N hydrochloric acid-dioxane solution (Kokusan Kagaku, 300 ml, 15 VR), water (2 ml, 0.1 VR) was added, and the reaction was carried out at 60 ° C. for 8 hours. I let you. After cooling the reaction solution to room temperature, it was slowly added dropwise to an ice-cooled 10% NaOH aqueous solution (200 ml, 10VR), and the pH was adjusted to 10 or more with a 10% NaOH aqueous solution. This solution was returned to room temperature, extracted with chloroform (200 ml × 2 times), dried over magnesium sulfate, and the filtrate obtained by filtration was concentrated to obtain an intermediate M46 (16.7 g, 2-step yield of 93). %).
¹ H-NMR (400 MHz, CDCl ₃ ): 7.46-7.49 (m, 2H), 7.40-7.43 (m, 2H), 7.24-7.27 (m, 2H), 6.74-6.78 (m, 2H), 3.71 ( br-s, 2H), 2.48-2.52 (m, 1H), 1.88-1.97 (m, 5H), 1.46-1.57 (m, 2H), 1.24-1.37 (m, 8H), 1.07-1.12 (m, 2H ), 0.93 (t, J = 7.2 Hz, 3H)

  Intermediate M46 (3.00 g, 9.33 mmol) was diluted to acetic acid: propionic acid = 17: 8 (300 ml, 100 VR) and cooled in an ice bath. Sodium nitrite (926 mg, 1.43 mmol) was added little by little, and the mixture was stirred for 1 hour while maintaining at 5 ° C. or lower to obtain a diazonium salt solution. In a separate flask, 2,3,4,5-tetrahydro-1-naphthylamine (2.75 g, 18.7 mmol) was charged, suspended in methanol: water = 4: 1 (300 ml), and cooled in an ice bath. did. To this solution, the diazonium salt solution prepared above was slowly dropped at 5 ° C. or lower and stirred for 1 hour. The solid obtained by filtering the reaction solution was diluted in tetrahydrofuran (300 ml), silica gel (N60 silica gel neutral, 50 ml, manufactured by Kanto Kagaku) was added, and the mixture was stirred for 30 minutes and filtered. The obtained filtrate was concentrated, re-diluted in chloroform (300 ml), concentrated again to a liquid volume of about 20 ml, filtered, and intermediate M47 (2.71 g, 60% yield) as a red-orange solid. Acquired.

  Intermediate M47 (1.50 g, 2.69 mmol) was diluted with N-methyl-2-pyrrolidone: dimethylformamide = 8: 17 (60 ml) and cooled in an ice bath. A 35% aqueous hydrochloric acid solution (0.73 ml, 8.07 mmol) and an aqueous solution of sodium nitrite (195 mg, 2.82 mmol) in water (0.5 ml) were added dropwise, and the mixture was stirred for 1 hour while maintaining at 5 ° C. or less. A salt solution was obtained. A separate flask was charged with phenol (2.50 g, 26.9 mmol) and sodium acetate (8.0 g), suspended in water (100 ml), and cooled in an ice bath. The diazonium salt solution prepared above was slowly added dropwise to this aqueous solution while maintaining pH 8 to 9, and stirred for 1 hour. Water (50 ml) and methanol (50 ml) were added dropwise to the reaction solution, the solid obtained by filtration was diluted with chloroform (300 ml), and the filtrate obtained by filtration was concentrated. To this residue was added ethyl acetate (30 ml), stirred and filtered to obtain Intermediate M48 (812 mg, 52% yield) as a dark orange solid.

  Intermediate M49 was produced from intermediate M46 and 4-aminoindan by a method similar to the method for synthesizing intermediate M47.

<Synthesis of Intermediate M53>

  M46 (2.10 g, 6.53 mmol) was suspended in acetic acid (42 ml, 20VR), and intermediate M51 (994 mg, 6.53 mmol) was added and stirred for 2 hours. Water (20 ml) was added, and the solid obtained by filtration was dried to obtain Intermediate M52 (2.14 g, yield 72%).

Intermediate M52 (2.10 g, 4.60 mmol) was suspended in ethanol (63 ml, 30 VR) and a solution of sodium sulfide 9 hydrate (2.24 g, 2.05 MR) in water (6.7 ml) was added. The mixture was stirred at an oil bath temperature of 75 ° C. for 3 hours. The reaction mixture was cooled to room temperature, water (50 ml) was added, and the solid obtained by filtration was washed with tetrahydrofuran (3 ml) and methanol (30 ml) to give intermediate M53 (2.15 g, Yield: quantitative) was obtained.
¹ H-NMR (400 MHz, CDCl ₃ ): 8.40-8.43 (m, 2H), 8.05-8.09 (m, 4H), 7.78-7.82 (m, 2H), 7.62-7.65 (m, 2H), 7.35 ( d, J = 5.6 Hz, 2H), 2.53-2.57 (m, 1H), 1.91-1.99 (m, 5H), 1.48-1.56 (m, 2H), 1.26-1.36 (m, 8H), 1.09-1.15 ( m, 2H), 0.93 (t, J = 6.4Hz, 3H)

(Evaluation of azo dichroic dyes)
[Evaluation of λmax of dichroic dye and S value when no voltage is applied]
The obtained dichroic dyes “Example Compound 1-8” and “Comparative Example Compound 1-5” are Nn-type liquid crystal mixtures containing a fluorine-based compound as a main component, with an NI point of 90 ° C. and Δε of −4. And 2 were dissolved at a concentration of 0.1% by weight to prepare guest-host liquid crystal compositions. The glass substrate with a transparent electrode coated, cured, and rubbed with a polyimide resin was opposed to this, and sealed in a cell with a gap of 50 μm configured so that the liquid crystal was aligned in parallel. The absorbance (A //) for linearly polarized light parallel to the orientation direction of the colored cell and the absorbance (A⊥) for polarized light perpendicular to the orientation direction were measured, and the order parameter (S value) at the absorption peak (λmax) was determined. It calculated | required from the following formula.
S = (A // − A⊥) / (2A⊥ + A //)

<Evaluation of S value of dichroic dye during voltage application>
The obtained dichroic dyes “Example Compound 1-8” and “Comparative Example Compound 1-5” are Nn-type liquid crystal mixtures containing a fluorine-based compound as a main component, having an NI point of 91 ° C. and Δε of −4. Each was dissolved in a concentration of 0.5% by weight to prepare a guest-host liquid crystal composition. The glass substrate with a transparent electrode coated, cured and rubbed with a polyimide resin was opposed to this, and sealed in a cell having a gap of 12 μm configured so that the liquid crystal was vertically aligned. A function generator 33120A (manufactured by Agilent) was used to amplify a rectangular wave 1Kz5V with a bipolar power source (manufactured by Kikusui Electronics), and the absorbance (A20V) when an amplitude of 20V was applied and the absorbance when no voltage was applied (A0V) were measured. The order parameter (S * value) at the absorption peak (λmax) was determined from the following equation.
S * = (A _20V -A _0V ) / (2A _0V + A _20V )

<Evaluation of solubility of dichroic dye>
The solubility of each compound in the liquid crystal was measured as follows. To the place where the liquid crystal was shaken with a shaker at −10 ° C., 2% of the compound was added, and shaken at −10 ° C. for 100 hours. Filter through a 0.2 micron syringe filter. The obtained liquid crystal solution was diluted with chloroform to an appropriate concentration, and an absorption spectrum was measured with a Hitachi spectrophotometer U-4100 using a quartz cell having a measurement optical path length of 10 mm, and an absorption maximum wavelength λmax (nm ) And the relationship between the molar extinction coefficient ε (Lmol ⁻¹ · cm ⁻¹ ) measured in advance and the concentration of each compound was determined.
The above results are shown in Tables 1 to 6 divided into groups to be compared.

  As is clear from Table 1, the azo dichroic dye of Example 1 of the present invention has the same absorption maximum wavelength as the azo dichroic dye of Comparative Example 1, but a high order parameter. It can be seen that the high solubility in the host liquid crystal mixture is compatible. In particular, it can be seen that the azo dichroic dye of Example 1 of the present invention has 38.9% higher solubility in the host liquid crystal mixture than the azo dichroic dye of Comparative Example 1.

  As is apparent from Table 2, the azo dichroic dye of Example 2 of the present invention has the same absorption maximum wavelength as the azo dichroic dye of Comparative Example 2, but a high order parameter. It can be seen that the high solubility in the host liquid crystal mixture is compatible. In particular, it can be seen that the azo dichroic dye of Example 2 of the present invention has a solubility of 327.3% in the host liquid crystal mixture as compared with the azo dichroic dye of Comparative Example 2.

  As is apparent from Table 3, the azo dichroic dyes of Examples 3 and 4 of the present invention have the same absorption maximum wavelength as that of the azo dichroic dye of Comparative Example 3, but have a high order. It can be seen that the parameters are compatible with the high solubility in the host liquid crystal mixture. In particular, the azo dichroic dyes of Examples 3 and 4 of the present invention have a solubility in the host liquid crystal mixture of 136.4% and 763.6%, respectively, as compared with the azo dichroic dye of Comparative Example 3. You can see that it has been raised.

  As is apparent from Table 4, the azo dichroic dye of Example 5 of the present invention has an absorption maximum wavelength equivalent to that of the azo dichroic dye of Comparative Example 4, but a high order parameter. It can be seen that the high solubility in the host liquid crystal mixture is compatible. In particular, it can be seen that the solubility of the azo dichroic dye of Example 5 of the present invention in the host liquid crystal mixture is 10 times or more higher than that of the azo dichroic dye of Comparative Example 4.

  As is clear from Table 5, the azo dichroic dye of Example 6 of the present invention has the same absorption maximum wavelength as the azo dichroic dye of Comparative Example 1, but has a high order parameter. It can be seen that the high solubility in the host liquid crystal mixture is compatible. In particular, it can be seen that the azo dichroic dye of Example 6 of the present invention has 566.7% higher solubility in the host liquid crystal mixture than the azo dichroic dye of Comparative Example 1.

  As is clear from Table 6, the azo dichroic dyes of Examples 7 and 8 of the present invention have an absorption maximum wavelength equivalent to that of the azo dichroic dye of Comparative Example 5, but at a high order. It can be seen that the parameters are compatible with the high solubility in the host liquid crystal mixture. In particular, the azo dichroic dyes of Examples 7 and 8 of the present invention have a solubility in the host liquid crystal mixture of 46.7% and 53.3% as compared with the azo dichroic dye of Comparative Example 5, respectively. You can see that it has been raised.

  From the above results, the azo dichroic dye compound of the present invention is a compound having a high order parameter (S value) and enhanced solubility in the host liquid crystal, and a liquid crystal produced using this compound. It was confirmed that the composition and the liquid crystal element can realize a display with high contrast.

  Since the azo dichroic dye compound of the present invention has a high order parameter (S value) and has improved solubility in the host liquid crystal, in various modes of liquid crystal compositions and liquid crystal elements, It can be used widely and effectively, and in particular, it can be used particularly effectively in various liquid crystal device applications using the guest host effect such as a Heilmeier type guest host and a phase transition type guest host. The liquid crystal composition and liquid crystal element of the present invention are used in various electro-optical devices such as display elements for computers, watches, calculators, etc., electro-optical shutters, electro-optical apertures, optical communication optical path switching switches, optical modulators, etc. It can be used widely and effectively.

DESCRIPTION OF SYMBOLS 1 ... Incident light 3 ... Transparent glass substrate 4 ... Transparent electrode 5 ... Alignment film 6 ... Host liquid crystal compound molecule 7 ... Dichroic dye molecule 9 ... Reflective layer 10 ··reflected light

Claims (12)

An azo dichroic dye represented by the following general formula (I) ,

(In the formula, Ar ¹ and Ar ² each independently represent a 1,4-phenylene group which may have a substituent, or a 1,4-naphthylene group which may have a substituent. However, at least one of Ar ² is a 1,4-phenylene group substituted with cyclopentane or cyclohexane which may have a substituent at the 2-position and 3-position, or the 5-position and 6-position. There ,
X ¹ represents an oxygen atom or —NR ¹ —, wherein R ¹ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group,
L ¹ represents a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
A ¹ represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent,
B ¹ and B ² represent a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
n ¹ represents an integer of 1 or more, and when n ¹ is 2 or more, two or more Ar ¹ present in the general formula (I) may be the same or different,
n ² represents an integer of 1 or more, and when n ² is 2 or more, 2 or more Ar ² present in the general formula (I) may be the same or different,
n ³ represents an integer of 0 or more. Here, when n ³ is 2 or more, two or more A ¹ present in the general formula (I) may be the same or different. )
However, Y ¹ and Y ² are each independently a monovalent substituent represented by the following general formula.

(Where
A ^{2 to} A ⁵ each independently represents a 1,4-phenylene group which may have a substituent or a (E) -cyclohexane-1,4-diyl group which may have a substituent. Represent,
B ³ and B ⁴ each independently represent a divalent linking group or a direct bond that does not contain a cyclic structure and an azo bond,
R ² and R ³ each independently represents an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group,
n ⁴ ~n ⁷ each independently represents an integer of 1 or more, wherein when ⁿ 4 ~n ⁷ is 2 or more, there are two or more ^A 2 to A ⁵ present in Formula identical Or different. )
An azo dichroic dye, wherein the general formula (I) is represented by any one of the following general formulas (Ia) to (Ic).

(In the formula, Ar ¹ , X ¹ , L ¹ , A ¹ , B ¹ , B ² , Y ¹ , Y ² , n ¹ and n ³ have the same meanings as described in the general formula (I), Q represents cyclopentane or cyclohexane which may have a substituent. R ² and R ³ are an alkyl group, an alkenyl group or an alkynyl group,
The azo dichroic dye according to claim 1. The general formula (I) is represented by the following general formula (II):

(In the formula, n ² represents an integer of 2 or more, and Ar ⁶ represents a 1,4-phenylene group which may have a substituent, or a 1,4-naphthylene group which may have a substituent. The other symbols are the same as those described in the general formula (I).)
The azo dichroic dye according to claim 1 or 2, represented by: B ¹ or B ² is a residue obtained by removing hydrogen from alkanediol, alkenediol, or alkynediol,
The azo dichroic dye according to any one of claims 1 to 3 . X ¹ is an oxygen atom or -NH-.
The azo dichroic dye according to any one of claims 1 to 4 . N ¹ is 1, and Ar ¹ is a 1,4-phenylene group which may have a substituent;
The azo dichroic dye according to any one of claims 1 to 5 . N ³ is 1 or 2, and A ¹ is an optionally substituted 1,4-phenylene group.
The azo dichroic dye according to any one of claims 1 to 6 . B ² is an alkanediol residue having 2 to 8 carbon atoms in which hydrogen is removed from the hydroxyl group of alkanediol.
The azo dichroic dye according to any one of claims 1 to 7 . N ^{4 to} n ⁷ are 2, A ² and A ⁵ are optionally substituted (E) -cyclohexane-1,4-diyl groups, and A ³ and A ⁴ are substituted. A 1,4-phenylene group optionally having a group;
The azo dichroic dye according to any one of claims 1 to 8 . R ² and R ³ are an alkyl group having 3 to 8 carbon atoms, an alkenyl group, an alkynyl group, or an alkoxy group.
The azo dichroic dye according to any one of claims 1 to 9 . Containing the azo dichroic dye according to any one of claims 1 to 10 and a liquid crystal compound,
Liquid crystal composition. The liquid crystal element which has a liquid-crystal layer containing the liquid-crystal composition of Claim 11 .

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