Anthraquinone compound, liquid crystal composition containing said compound, and light-controlling element

Abstract

Provided is an anthraquinone compound of formula (1). (R1 and R4 each represent -H, a C1-12 linear or branched alkyl group, a C1-12 linear or branched alkoxy group, a halogen atom, -CO2R8, -OCOR8, -COR8, -CONR9R10, -NR11R12, -CN, or -CF3. R2, R3, R5, and R6 each represent –H, a C1-4 linear or branched alkyl group, a C1-4 linear or branched alkoxy group, a halogen atom, -CO2R8, -OCOR8, -COR8, -CONR9R10, -NR11R12, -CN, or -CF3. R7 represents a C1-12 linear or branched alkyl group, a C1-12 linear or branched alkoxy group, or a substituent represented by formula (a) (wherein, R13 represents –H or a C1-8 linear alkyl group). R8 represents a C1-8 linear or branched alkyl group or the like, and R9 to R12 each represent a C1-8 linear or branched alkyl group.)

Description

Anthraquinone compound, liquid crystal composition containing the compound and light-adjusting element

[0001] The present invention relates to a novel anthraquinone compound, a liquid crystal composition containing the compound, and a light-adjusting element.

[0002] Various light-controlling films have been proposed to control the transmission of external light for purposes such as privacy protection in windows, doors, and partitions of vehicles such as trains and automobiles, and buildings such as business buildings and hospitals (see Patent Documents 1 and 2). One such light-controlling film uses liquid crystal. Typically, liquid crystal light-controlling films can block visibility by controlling the transmission and scattering of light depending on whether or not a voltage is applied, but they cannot block light itself, which tends to increase glare due to light scattering. Therefore, attempts have been made to use dyes as materials for light-controlling panels to reduce glare and improve contrast (see Patent Documents 3 and 4). For example, when such light-controlling panels are used in automobile windows, they are required to provide clear, transparent light with good visibility when transmitted light is transmitted, while also providing high light-blocking properties when scattered. Therefore, there is a growing demand for black elements that can block visible light from the perspectives of practicality and design. Furthermore, there is a strong demand for light-controlling elements that exhibit minimal color change when exposed to light for long periods of time during outdoor use, i.e., at high temperatures.

[0003] Dichroic dyes are generally used as dyes in liquid crystal light control films. GH (guest-host) type light control elements using liquid crystal compositions containing dichroic dyes are known, and various dichroic dyes have been proposed (see Patent Document 5).

[0004] Such dichroic dyes are required to have not only high contrast when used in display devices, but also lightfastness, UV resistance, and heat resistance, and efforts have been made to improve these properties. However, none have been found that satisfy these properties. On the other hand, light-blocking properties when used in black dimming devices remain an issue. Black dimming devices prepared by adding dyes are generally prepared using a mixture of yellow, red, and blue dyes. From the perspective of practicality and design, it is desirable for black dimming devices to absorb light over a wide wavelength range when blocking light, and it is particularly important to suppress light leakage in the 400 to 700 nm range. For example, Patent Document 5 discloses dichroic dyes suitable for dimming applications, but these do not meet the market demand for black dimming devices with high light-blocking properties. Furthermore, the dyes in this document have insufficient lightfastness.

[0005] Japanese Patent Publication No. 63-501512 Japanese Patent Application Laid-Open No. 03-47392 Japanese Patent Application Laid-Open No. 2018-205746 Japanese Patent Application Laid-Open No. 2011-190314 Japanese Patent Application Laid-Open No. 58-61150

[0006] An object of the present invention is to provide a dichroic dye having excellent light resistance, a liquid crystal composition containing the dichroic dye, and a light-controlling device having excellent light resistance and light-shielding properties and containing the composition.

[0007] As a result of extensive research, the present inventors have found that the above problems can be solved by using a novel anthraquinone compound having a specific structure as a dichroic dye, and have thus completed the present invention. That is, some embodiments according to the present invention are summarized as follows: [1]. An anthraquinone compound represented by the following formula (1): (In the formula, R １ and R ４ are each independently a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR ８ , -CONR ９ R １０ , -NR１１ R １２、 R represents a cyano group or a trifluoromethyl group. ２ , R ３ , R ５ and R ６ each independently represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR ８ , -CONR ９ R １０ , -NR １１ R １２、 R represents a cyano group or a trifluoromethyl group. ７ represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or a group represented by the following formula (a): (In the formula, R １３ represents a hydrogen atom or a linear alkyl group having 1 to 8 carbon atoms. ８ are each independently a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms, or a group represented by the following formula (b): (In the formula, R １４ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, a linear alkoxy group having 1 to 8 carbon atoms, or a branched alkoxy group having 3 to 8 carbon atoms, (In the formula, R １５ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, or a branched alkyl group having 3 to 8 carbon atoms. ９ ~R １２ each independently represents a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms.) [2] In formula (1), R １ and R ４each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ and R ２ , R ３ , R ５ and R ６ each independently represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, -CO ２ R ８ , or -COR ８ [3]. The anthraquinone compound according to the above item [1], which is represented by the following formula (2): (In the formula, R １ and R ４ each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ２ and R ５ each independently represents a hydrogen atom, a linear alkyl group having 1 or 2 carbon atoms, a linear alkoxy group having 1 or 2 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ７ is a linear alkyl group having 4 to 12 carbon atoms, a linear alkoxy group having 4 to 12 carbon atoms, or a group represented by the following formula (a): (In the formula, R １３ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms. ８ represents a linear alkyl group having 1 to 5 carbon atoms.) [4]. In formula (2), R １ and R ２ is a hydrogen atom, and R ４and R ５ [5]. The anthraquinone compound according to the above item [3], wherein only one of R ２ and R ５ [6] The anthraquinone compound according to the above item [4], wherein R is a hydrogen atom. １ and R ４ [7]. The anthraquinone compound according to the above item [5], wherein R is independently a linear alkyl group having 1 to 12 carbon atoms. １ is a linear alkyl group having 1 to 12 carbon atoms, and R ４ is a branched alkyl group having 3 to 8 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms, or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ [8]. The anthraquinone compound according to the above item [5], wherein R １ is a branched alkyl group having 3 to 8 carbon atoms, and R ４ is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ [9] The anthraquinone compound according to the above item [5], wherein R １ is a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ and R ４ is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８

[10] . The anthraquinone compound according to the above item [5], wherein R ７

[11] . The anthraquinone compound according to the above item [3], wherein R is a linear alkyl group having 4 to 12 carbon atoms or a linear alkoxy group having 4 to 12 carbon atoms.７ is a linear alkoxy group having 4 to 12 carbon atoms.

[12] . A liquid crystal composition containing the anthraquinone compound according to any one of ...

[0008] By using the anthraquinone compound of the present invention as a dichroic dye, light leakage during light blocking can be suppressed and a light-adjusting element having excellent light resistance can be obtained.

[0009] The present invention will be described in detail below. The anthraquinone compound of the present invention is represented by the following formula (1).

[0010]

[0011] In the formula, R １ and R ４ are each independently a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR ８ , -CONR ９ R １０ , -NR １１ R １２、 R represents a cyano group or a trifluoromethyl group. ２ , R ３ , R ５ and R ６ each independently represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR８ , -CONR ９ R １０ , -NR １１ R １２ , a cyano group, or a trifluoromethyl group. ７ represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or a substituent represented by the following formula (a): ８ R each independently represents a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a substituent represented by the following formula (b) or (c): ９ ~R １２ each independently represents a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms.

[0012]

[0013] In formula (a), R １３ represents a hydrogen atom or a linear alkyl group having 1 to 8 carbon atoms. １４ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, or a linear alkoxy group having 1 to 8 carbon atoms or a branched alkoxy group having 3 to 8 carbon atoms. １５ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, or a branched alkyl group having 3 to 8 carbon atoms.

[0014] R in formula (1) １ and R ４The alkyl group having 1 to 12 carbon atoms represented by may be either linear or branched. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neo-pentyl, t-pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, 2-ethylhexyl, 2-propylhexyl, 2-butylhexyl, 2-pentylhexyl, and 2-pentylheptyl. A linear or branched alkyl group having 3 to 12 carbon atoms is preferred, a linear alkyl group having 4 to 12 carbon atoms is more preferred, and a linear alkyl group having 4 to 10 carbon atoms is even more preferred.

[0015] R in formula (1) １ and R ４ The alkoxy group having 1 to 12 carbon atoms represented by may be either linear or branched. Specific examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, an iso-butoxy group, a sec-butoxy group, a t-butoxy group, an n-pentyloxy group, an iso-pentyloxy group, a neo-pentyloxy group, a t-pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a 2-ethylhexyloxy group, a 2-propylhexyloxy group, a 2-butylhexyloxy group, a 2-pentylhexyloxy group, and a 2-pentylheptyloxy group. A straight or branched chain alkoxy group having 3 to 12 carbon atoms is preferred, a straight or branched chain alkoxy group having 4 to 12 carbon atoms is more preferred, and a straight or branched chain alkoxy group having 4 to 10 carbon atoms is even more preferred.

[0016] R in formula (1) １ and R ４ Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. A fluorine atom or a chlorine atom is preferred, and a fluorine atom is more preferred.

[0017] R in formula (1) １ and R ４Examples of the alkyl group include a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ is preferably a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ more preferably a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ It is more preferable that the alkyl group is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, or a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and it is particularly preferable that the alkyl group is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms.

[0018] R in formula (1) ８ Specific examples of the linear alkyl group having 1 to 8 carbon atoms or the branched alkyl group having 3 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms is preferred, and a linear alkyl group having 1 to 5 carbon atoms is more preferred.

[0019] R in formula (b) １４ Specific examples of the linear alkyl group having 1 to 8 carbon atoms or the branched alkyl group having 3 to 8 carbon atoms represented by R １ and R ４Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (b) include the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (b). A linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms is preferred, and a linear alkyl group having 1 to 5 carbon atoms is more preferred. １４ Specific examples of the linear alkoxy group having 1 to 8 carbon atoms or the branched alkoxy group having 3 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1). A linear alkoxy group having 1 to 5 carbon atoms or a branched alkoxy group having 3 to 5 carbon atoms is preferred, and a linear alkoxy group having 1 to 5 carbon atoms is more preferred.

[0020] R in formula (c) １５ Specific examples of the linear alkyl group having 1 to 8 carbon atoms or the branched alkyl group having 3 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms is preferred, and a linear alkyl group having 1 to 5 carbon atoms is more preferred.

[0021] R in formula (1) ８ As the alkyl group, a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms is preferred.

[0022] R in formula (1) ９ and R １０ Specific examples of the linear alkyl group having 1 to 8 carbon atoms or the branched alkyl group having 3 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A linear alkyl group having 1 to 5 carbon atoms is preferred.

[0023] R in formula (1) １１ and R １２Specific examples of the linear alkyl group having 1 to 8 carbon atoms or the branched alkyl group having 3 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A linear alkyl group having 1 to 5 carbon atoms is preferred.

[0024] R in formula (1) ２ , R ３ , R ５ and R ６ Specific examples of the linear alkyl group having 1 to 4 carbon atoms or the branched alkyl group having 3 to 4 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A methyl group or an ethyl group is preferred.

[0025] R in formula (1) ２ , R ３ , R ５ and R ６ Specific examples of the linear alkoxy group having 1 to 4 carbon atoms or the branched alkoxy group having 3 to 4 carbon atoms represented by R １ and R ４ Specific examples of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1). A methoxy group or an ethoxy group is preferred.

[0026] R in formula (1) ２ , R ３ , R ５ and R ６ Specific examples of the halogen atom represented by are R １ and R ４ Specific examples of the halogen atom include the same as those represented by the formula (1). A fluorine atom or a chlorine atom is preferred, and a fluorine atom is more preferred.

[0027] R in formula (1) ２ and R ３are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, -CO ２ R ８ , or -COR ８ are preferably each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, or a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, and are further preferably a hydrogen atom.

[0028] R in formula (1) ５ and R ６ are each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, -CO ２ R ８ , or -COR ８ are preferably each independently a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, or a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, and are further preferably a hydrogen atom.

[0029] R in formula (1) ７ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by R １ and R ４ Specific examples of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkyl group having 1 to 12 carbon atoms or the branched alkyl group having 3 to 12 carbon atoms represented by the formula (1). A linear or branched alkyl group having 4 to 12 carbon atoms is preferred, a linear alkyl group having 4 to 12 carbon atoms is more preferred, and a linear alkyl group having 4 to 10 carbon atoms is even more preferred.

[0030] R in formula (1) ７ Specific examples of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by R in formula (1) include１ and R ４ Specific examples of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1) are the same as those of the linear alkoxy group having 1 to 12 carbon atoms or the branched alkoxy group having 3 to 12 carbon atoms represented by the formula (1). A linear or branched alkoxy group having 4 to 12 carbon atoms is preferred, a linear alkoxy group having 4 to 12 carbon atoms is more preferred, and a linear alkoxy group having 4 to 10 carbon atoms is even more preferred.

[0031] R in formula (1) ７ is preferably a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, or a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and more preferably a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

[0032] R in formula (a) １３ Specific examples of the linear alkyl group having 1 to 8 carbon atoms represented by R １ and R ４ Specific examples of the linear or branched alkyl group having 1 to 12 carbon atoms represented by the formula (1) are the same as those of the linear or branched alkyl group having 1 to 12 carbon atoms represented by the formula (1). A linear alkyl group having 1 to 6 carbon atoms is preferred, and a linear alkyl group having 2 to 5 carbon atoms is more preferred.

[0033] In formula (1), R １ ~R ３ At least one of R is a hydrogen atom, and ４ ~R ６ Preferably, at least one of R is a hydrogen atom, １ ~R ３ At least two of R are hydrogen atoms, and ４ ~R ６ It is more preferable that at least two of R １ ~R ３ Two of R are hydrogen atoms, and ４ ~R ６ It is more preferable that two of the groups are hydrogen atoms. In this specification, the term "substituent" means a substituent other than a hydrogen atom.

[0034] In addition, in formula (1), R １~R ３ The position of the substituents on the phenyl group having R ４ ~R ６ The positions of the substituents on the phenyl group having the formula (3), when explained using the numbers shown in the following formula (3), are preferably the 2-position only, the 3-position only, the 4-position only, two positions, i.e., the 2-position and the 4-position, or two positions, i.e., the 3-position only, the 3-position only, or the 4-position only, more preferably the 3-position only or the 4-position only, further preferably the 4-position only.

[0035]

[0036] The anthraquinone compound represented by formula (1) includes the above-mentioned R １ ~R １２ , R in formula (a) １３、 R in formula (b) １４ and R in formula (c) １５ A combination of the above preferred embodiments is more preferred.

[0037] A preferred example of the compound represented by formula (1) is an anthraquinone compound represented by formula (2) below. (In the formula, R １ and R ４ each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ２ and R ５ each independently represents a hydrogen atom, a linear alkyl group having 1 or 2 carbon atoms, a linear alkoxy group having 1 or 2 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ７ is a linear alkyl group having 4 to 12 carbon atoms, a linear alkoxy group having 4 to 12 carbon atoms, or a group represented by the following formula (a): (In the formula, R １３ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms. ８represents a linear alkyl group having 1 to 5 carbon atoms.

[0038] Specific preferred examples of the compound represented by formula (1) include the following, but the present invention is not limited to these.

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] The anthraquinone compound of the present invention represented by formula (1) can be synthesized by referring to the synthesis method disclosed in U.S. Pat. No. 6,197,223, for example. A non-limiting, specific example of a method for producing an anthraquinone compound represented by formula (1) is described below. An anthraquinone compound represented by formula (A) below, synthesized by a conventional method described in JP-A-58-61150, for example, is reacted with an aniline derivative represented by formula (B) below in a solvent such as 1-pentanol at 100 to 140° C. under basic conditions such as potassium acetate in the presence of a copper catalyst such as copper acetate, to obtain a compound represented by formula (C) below.

[0054]

[0055] The obtained compound represented by the above formula (C) is reacted with a phenol derivative represented by the following formula (D) at 80 to 120° C. in a solvent such as N-methyl-2-pyrrolidone (NMP) under basic conditions such as potassium carbonate, to obtain a compound represented by the following formula (E).

[0056]

[0057] The compound represented by formula (E) thus obtained is reacted with an aniline compound represented by formula (F) below in the presence of a palladium catalyst such as palladium acetate under basic conditions such as cesium carbonate in a solvent such as xylene at 100 to 140° C. to obtain an anthraquinone compound represented by formula (1). １ ~R ７ is R in the above-described formula (1). １ ~R ７ It has the same meaning as:

[0058]

[0059] The liquid crystal composition of the present invention (hereinafter also simply referred to as "the composition of the present invention") contains an anthraquinone compound represented by formula (1) and a liquid crystal material.

[0060] The content of the anthraquinone compound represented by formula (1) in the liquid crystal composition is not particularly limited, but is preferably 0.5 to 15 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the liquid crystal material.

[0061] The liquid crystal material contained in the liquid crystal composition of the present invention is not particularly limited as long as it is a material (compound having liquid crystal properties) having liquid crystallinity such as nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, etc. Examples of the compound having liquid crystallinity include the liquid crystal compounds described on pages 154 to 192 and 715 to 722 of "Liquid Crystal Device Handbook" (edited by the 142nd Committee of the Japan Society for the Promotion of Science, Nikkan Kogyo Shimbun, Ltd., 1989).

[0062] The liquid crystal composition of the present invention may or may not contain an optically active substance that exhibits or does not exhibit a liquid crystal phase, such as a dichroic dye other than the anthraquinone compound represented by formula (1) or cholesteryl noenoate, various additives such as an ultraviolet absorber and an antioxidant, a photocurable compound, a photopolymerization initiator, etc.

[0063] The composition of the present invention can be used in combination with one or a mixture of multiple dichroic dyes other than the anthraquinone compound represented by formula (1). The dichroic dyes that can be used in combination are not particularly limited, and can be selected from, for example, azo dyes, anthraquinone dyes, perylene dyes, quinophthalone dyes, merocyanine dyes, azomethine dyes, phthaloperylene dyes, indigo dyes, azulene dyes, dioxazine dyes, polythiophene dyes, and the like. Specific examples include those described in "Dichroic Dyes for Liquid Crystal Display" (A.V. Ivashchenko, CRC, 1994). Among these, it is preferable to use an azo dye, an anthraquinone dye, a perylene dye, or a quinophthalone dye in combination, and it is more preferable to use an azo dye or an anthraquinone dye in combination.

[0064] When a dichroic dye (described later) other than the compound represented by formula (1) is used in combination, the total content of the anthraquinone compound represented by formula (1) and the dichroic dye other than the compound represented by formula (1) in the liquid crystal composition is preferably within the above-mentioned range (0.5 to 15% by mass).

[0065] When a dichroic dye other than the anthraquinone compound represented by Formula (1) is used in combination, the content of the anthraquinone compound represented by Formula (1) in the total dichroic dyes is not particularly limited as long as it is within a range that does not impair the effects of the present invention, but is preferably 1 to 80 mass %, more preferably 5 to 70 mass %, and even more preferably 10 to 50 mass %.

[0066] The composition of the present invention may further contain light stabilizers such as benzotriazoles, benzophenones, and hindered amines, antioxidants such as phosphites and hindered phenols, thermal polymerization inhibitors, thiol compounds, photosensitizers, photosensitizers, chain transfer inhibitors, polymerization inhibitors, adhesion promoters, antifoaming agents, crosslinking agents, surfactants, thermosetting accelerators, thermoplastic resins, thermosetting resins, thickeners such as urethane diacrylate, etc. Furthermore, spherical or cylindrical spacers such as silica, glass, plastic, and ceramic may be added to control the cell gap of the light control element. The cell gap in the light control element can be set in the range of 2 to 100 μm.

[0067] The light-adjusting element of the present invention comprises a pair of substrates, at least one of which is a transparent substrate having a transparent electrode, and the liquid crystal composition sandwiched between them. Examples of the substrate include inorganic transparent materials such as glass and quartz, and colorless, transparent, or opaque materials such as metals, metal oxides, semiconductors, ceramics, and plastic plates and films. The electrodes are formed by forming a thin film of, for example, a metal oxide, metal, semiconductor, or organic conductive material on the entire surface or a portion of the substrate by a known coating method, printing method, or vapor deposition method such as sputtering. In particular, to obtain a large-area light-adjusting element, it is desirable to use an electrode substrate in which an ITO (indium oxide, tin oxide) electrode is formed on a transparent polymer film such as PET by a vapor deposition method such as sputtering or a printing method, from the standpoints of productivity and processability. Wiring may be provided on the substrate to connect the electrodes or the electrodes to the outside. For example, a segment-drive electrode substrate, a matrix-drive electrode substrate, or an active-matrix drive electrode substrate may be used. Furthermore, the electrode surface provided on the substrate is coated with organic compounds such as polyimide, polyamide, silicone, cyanide compounds, SiO ２ , TiO ２ , ZrO ２ The entire surface or a part of the surface may be covered with a protective film or an alignment film formed from an inorganic compound such as those mentioned above, or a mixture thereof.

[0068] The use of a plastic film as a substrate allows for the production of a flexible and lightweight light-controlling element. Therefore, the light-controlling element can be sandwiched between a pair of flat or curved glass or hard plastic substrates via an adhesive layer such as polyvinyl butyral, vinyl acetate ester, double-sided tape, or adhesive. Alternatively, the light-controlling element can be attached to the surface of a single flat or curved glass or hard plastic substrate using double-sided tape or adhesive. The light-controlling element can also be sandwiched between soft plastic substrates or attached to one or both sides. A protective layer such as a hard coat, an ultraviolet-blocking layer, an infrared-blocking layer, or a half mirror can be provided on the substrate surface opposite the electrode surface of the light-controlling element. A color filter or a polarizer filter can be laminated on the light-controlling element. An electroluminescent display element, a light-emitting diode display element, an electrochromic display element, or another liquid crystal display element can also be laminated on the light-controlling element.

[0069] The driving device for applying a voltage to the light-adjusting element of the present invention may be a device capable of applying a DC voltage of 2 to 100 V or an AC voltage of 10 to 1000 Hz, and which opens or shorts the electrodes when no voltage is applied. The driving device may also be equipped with a voltage application circuit for segment driving, a voltage application circuit for matrix driving, a voltage application circuit for active matrix driving, etc.

[0070] The anthraquinone compound represented by formula (1) of the present invention has high light resistance and light-shielding properties, and a light-controlling device using the compound can realize a high-quality display with little color change over a long period of time. The light-controlling device of the present invention further has excellent light resistance and light-shielding properties even when exposed to light outdoors at high temperatures for a long period of time, making it ideal for use in automobiles or as a building material.

[0071] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the text, "parts" and "%" are by mass unless otherwise specified. The maximum absorption wavelength in the examples is a value measured using a spectrophotometer "UV-3150 manufactured by Shimadzu Corporation."

[0072] Example 1 (Synthesis of an anthraquinone compound of the present invention represented by specific example No. 2) (Step 1-1) Synthesis of intermediate compound represented by the following formula (12) 0.8 parts of a compound represented by the following formula (11), 0.04 parts of copper acetate, 1.2 parts of sodium acetate, and 1.8 parts of 4-n-butylaniline were added to 20 parts of 1-pentanol and stirred at 120 to 130°C for 1 hour, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for another 1 hour. Thereafter, the reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of an intermediate compound represented by the following formula (12).

[0073]

[0074] (Step 1-2) Synthesis of intermediate compound represented by the following formula (13): 0.5 parts of the compound represented by the above formula (12), 0.3 parts of 4-n-heptyloxyphenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (13).

[0075]

[0076] (Step 1-3) Synthesis of Compound Represented by Specific Example No. 2 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (13), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 4-n-heptylaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added, followed by further stirring for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off from the purified solution under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours, yielding 0.20 parts of Compound Represented by Specific Example No. 2 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 627 nm.

[0077] Example 2 (Synthesis of the Anthraquinone Compound of the Present Invention Represented by Specific Example No. 21) (Step 2-1) 0.4 parts of the compound represented by the above formula (13), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of ethyl 4-aminobenzoate, and 0.5 parts of cesium carbonate were added to 10 parts of xylene and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added, followed by further stirring for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off from the purified solution under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours, yielding 0.15 parts of the compound represented by the above specific example No. 21 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 628 nm.

[0078] Example 3 (Synthesis of an anthraquinone compound of the present invention represented by specific example No. 26) (Step 3-1) Synthesis of intermediate compound represented by the following formula (14): 0.5 parts of the compound represented by the above formula (12), 0.3 parts of 4-(trans-4-n-butylcyclohexyl)phenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours. The reaction solution was then cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (14).

[0079]

[0080] (Step 3-2) Synthesis of Compound Represented by Specific Example No. 26 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (14), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 4-n-heptylaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was removed from the purified solution by distillation under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.25 parts of Compound Represented by Specific Example No. 26 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 628 nm.

[0081] Example 4 (Synthesis of the anthraquinone compound of the present invention represented by Example No. 25)

[0082] (Step 4-1) Synthesis of intermediate compound represented by the following formula (15): 0.5 parts of the compound represented by the above formula (12), 1.0 part of 4-(trans-4-n-pentylcyclohexyl)phenol, and 0.3 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added, followed by stirring for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.5 parts of the intermediate compound represented by the following formula (15).

[0083]

[0084] (Step 4-2) Synthesis of Compound Represented by Specific Example No. 25 To 10 parts of xylene, 0.32 parts of the compound represented by the above formula (15), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.5 parts of 4-(2-ethylhexyloxy)aniline, and 0.8 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off from the purified solution under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.15 parts of Compound Represented by Specific Example No. 25 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 627 nm.

[0085] Example 5 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 28) (Step 5-1) Synthesis of intermediate compound represented by the following formula (16): 1.6 parts of the compound represented by the above formula (11), 0.08 parts of copper acetate, 2.4 parts of sodium acetate, and 6.2 parts of 4-n-dodecylaniline were added to 40 parts of 1-pentanol and stirred at 120 to 130°C for 1 hour, and then the reaction solution was cooled to 25°C, and 40 parts of methanol was added, followed by further stirring for 1 hour. Thereafter, the reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 1.0 part of the intermediate compound represented by the following formula (16).

[0086]

[0087] (Step 5-2) Synthesis of intermediate compound represented by the following formula (17): 0.6 parts of the compound represented by the above formula (16), 1.1 parts of 4-n-dodecyloxyphenol, and 0.3 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for another 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.2 parts of the intermediate compound represented by the following formula (17):

[0088]

[0089] (Step 5-3) Synthesis of Compound Represented by Specific Example No. 28 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (17), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of aniline, and 0.8 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as the developing solvent. The solvent was removed from the purified solution by distillation under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.12 parts of Compound Represented by Specific Example No. 28 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 627 nm.

[0090] Example 6 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 47) (Step 6-1) Synthesis of intermediate compound represented by the following formula (18) To 40 parts of 1-pentanol, 1.6 parts of the compound represented by the above formula (11), 0.08 parts of copper acetate, 2.4 parts of sodium acetate, and 4.4 parts of 4-n-heptylaniline were added, and the mixture was stirred at 120 to 130°C for 1 hour. The reaction solution was then cooled to 25°C, and 40 parts of methanol was added, followed by further stirring for 1 hour. Thereafter, the reaction product was filtered and washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 1.0 part of the intermediate compound represented by the following formula (18).

[0091]

[0092] (Step 6-2) Synthesis of intermediate compound represented by the following formula (19): 1.0 part of the compound represented by the above formula (18), 1.7 parts of 4-n-heptyloxyphenol, and 0.6 parts of potassium carbonate were added to 20 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 40 parts of methanol was added, and the mixture was stirred for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.7 part of the intermediate compound represented by the following formula (19).

[0093]

[0094] (Step 6-3) Synthesis of Compound Represented by Specific Example No. 47 To 10 parts of xylene, 0.7 parts of the compound represented by the above formula (19), 0.07 parts of palladium acetate, 0.18 parts of BINAP, 0.6 parts of 3-ethylaniline, and 1.6 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was removed from the purified solution by distillation under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.28 parts of Compound Represented by Specific Example No. 47 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 627 nm.

[0095] Example 7 (Synthesis of the Anthraquinone Compound of the Present Invention Represented by Specific Example No. 66) (Step 7-1) Synthesis of the Compound Represented by Specific Example No. 66 To 10 parts of xylene, 0.6 parts of the compound represented by the above formula (13), 0.07 parts of palladium acetate, 0.18 parts of BINAP, 1.4 parts of 4-n-pentylphenyl 4-aminobenzoate, and 1.6 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added, followed by further stirring for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off under reduced pressure from the purified solution, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.22 parts of the compound represented by Specific Example No. 66 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 629 nm.

[0096] Example 8 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 67) (Step 8-1) Synthesis of intermediate compound represented by the following formula (20) 0.5 parts of the compound represented by the above formula (12), 0.3 parts of 4-n-dodecylphenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added, followed by stirring for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (20).

[0097]

[0098] (Step 8-2) Synthesis of Compound Represented by Specific Example No. 67 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (20), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 3,4-dimethylaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was removed from the purified solution by distillation under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.15 parts of Compound Represented by Specific Example No. 67 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 630 nm.

[0099] Example 9 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 68) (Step 9-1) Synthesis of intermediate compound represented by the following formula (21) 0.8 parts of the compound represented by the above formula (11), 0.04 parts of copper acetate, 1.2 parts of sodium acetate, and 1.8 parts of n-butyl 4-aminobenzoate were added to 20 parts of 1-pentanol and stirred at 120 to 130°C for 1 hour, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for another 1 hour. Thereafter, the reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (21).

[0100]

[0101] (Step 9-2) Synthesis of intermediate compound represented by the following formula (22): 0.5 parts of the compound represented by the above formula (21), 0.3 parts of 4-n-butyloxyphenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for another 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (22).

[0102]

[0103] (Step 9-3) Synthesis of Compound Represented by Specific Example No. 68 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (22), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 4-n-dodecylaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off from the purified solution under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours, yielding 0.11 parts of Compound Represented by Specific Example No. 68 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 624 nm.

[0104] Example 10 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 69) (Step 10-1) Synthesis of intermediate compound represented by the following formula (23): 0.8 parts of the compound represented by the above formula (11), 0.04 parts of copper acetate, 1.2 parts of sodium acetate, and 1.8 parts of aniline were added to 20 parts of 1-pentanol and stirred at 120 to 130°C for 1 hour, and then the reaction solution was cooled to 25°C, and 20 parts of methanol was added and stirred for another 1 hour. Thereafter, the reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (23).

[0105]

[0106] (Step 10-2) Synthesis of intermediate compound represented by the following formula (24): 0.5 parts of the compound represented by the above formula (23), 0.3 parts of 4-n-butylphenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (24):

[0107]

[0108] (Step 10-3) Synthesis of Compound Represented by Specific Example No. 69 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (24), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 4-n-dodecyloxyaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was distilled off from the purified solution under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.13 parts of Compound Represented by Specific Example No. 69 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 625 nm.

[0109] Example 11 (Synthesis of anthraquinone compound of the present invention represented by specific example No. 70) (Step 11-1) Synthesis of intermediate compound represented by the following formula (25) 0.8 parts of the compound represented by the above formula (11), 0.04 parts of copper acetate, 1.2 parts of sodium acetate, and 1.8 parts of 4-n-butoxyaniline were added to 20 parts of 1-pentanol and stirred at 120 to 130°C for 1 hour, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for another 1 hour. Thereafter, the reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (25).

[0110]

[0111] (Step 11-2) Synthesis of intermediate compound represented by the following formula (26): 0.5 parts of the compound represented by the above formula (25), 0.3 parts of 4-n-octyloxyphenol, and 0.2 parts of potassium carbonate were added to 10 parts of NMP and stirred at 120°C for 2 hours, and then the reaction solution was cooled to 25°C, 20 parts of methanol was added, and the mixture was stirred for an additional 1 hour. The reaction product was collected by filtration, washed with methanol, and then dried in a hot air dryer at 80°C for 24 hours to obtain 0.4 parts of the intermediate compound represented by the following formula (26).

[0112]

[0113] (Step 11-3) Synthesis of Compound Represented by Specific Example No. 70 To 10 parts of xylene, 0.4 parts of the compound represented by the above formula (26), 0.03 parts of palladium acetate, 0.09 parts of BINAP, 0.3 parts of 4-n-hexanoylaniline, and 0.5 parts of cesium carbonate were added and stirred at 120 to 130°C for 2 hours. The reaction solution was then cooled to 25°C, and 20 parts of methanol was added. The mixture was further stirred for 1 hour. The reaction product was collected by filtration, washed with methanol and water, and then dried in a hot air dryer at 80°C for 24 hours. The resulting crude product was dissolved in toluene and subjected to column purification using toluene as a developing solvent. The solvent was removed from the purified solution by distillation under reduced pressure, and the residue was dried in a hot air dryer at 80°C for 24 hours to obtain 0.15 parts of Compound Represented by Specific Example No. 70 as a dark purple solid. The maximum absorption wavelength of this compound in toluene was 628 nm.

[0114] Synthesis Example 1 (Synthesis of Comparative Compound) A compound represented by the following formula (X) was obtained according to the description of Example 102 of JP-A-58-61150.

[0115]

[0116] Example 12 (Preparation of Liquid Crystal Composition of the Present Invention) 0.006 parts of the compound represented by Specific Example No. 2 obtained in Example 1, 0.306 parts of 1-cyano-4'-n-pentylbiphenyl, 0.15 parts of 1-cyano-4'-n-heptylbiphenyl, 0.096 parts of 1-cyano-4'-n-octyloxybiphenyl, and 0.048 parts of 1-cyano-4''-n-pentylterphenyl were mixed at room temperature to obtain a liquid crystal composition of the present invention.

[0117] Examples 13 to 22 and Comparative Example 1 (Preparation of Liquid Crystal Compositions of the Invention and Comparative Examples) Liquid crystal compositions of the invention and comparative examples were obtained in the same manner as in Example 12, except that the compound represented by No. 2 obtained in Example 1 was changed to the compound represented by No. 21 obtained in Example 2, the compound represented by No. 26 obtained in Example 3, the compound represented by No. 25 obtained in Example 4, the compound represented by No. 28 obtained in Example 5, the compound represented by No. 47 obtained in Example 6, the compound represented by No. 66 obtained in Example 7, the compound represented by No. 67 obtained in Example 8, the compound represented by No. 68 obtained in Example 9, the compound represented by No. 69 obtained in Example 10, the compound represented by No. 70 obtained in Example 11, or the compound represented by Formula (X) obtained in Synthesis Example 1, respectively.

[0118] The liquid crystal composition obtained in Example 12 was sealed in a device having a gap of 15 μm between two glass substrates, one above the other, which had transparent electrodes and had been subjected to a homogeneous alignment treatment by rubbing a polyamide resin on the surface in contact with the liquid crystal. In the device obtained above, the liquid crystal was in a homogeneous alignment state when no voltage was applied, and the dye molecules (the anthraquinone compound obtained in Example 1) also took the same alignment according to the liquid crystal.

[0119] Examples 24 to 33 and Comparative Example 2 (Preparation of light-controlling elements of the present invention and comparative examples) The light-controlling elements of the present invention and comparative examples were prepared in accordance with Example 23, except that the liquid crystal composition obtained in Example 12 was changed to the liquid crystal compositions obtained in Examples 13 to 22 and Comparative Example 1, respectively.

[0120] (Light Resistance Test of Light Control Device) The light control devices obtained in Examples 23 to 33 and Comparative Example 2 were subjected to a light resistance test at an illuminance of 650 W / m under a condition of 63°C. ２The light resistance test was carried out by irradiating the light from a metal halide lamp of 1000 nm for 24 hours. The transmittance of each light-adjusting element before and after the light resistance test was measured using a spectrophotometer in the wavelength range of 380 to 780 nm. For each light-adjusting element, the absorbance at the maximum absorption wavelength before and after the light resistance test was calculated from the obtained transmission spectrum, and the dye residual rate (%) was calculated using the following calculation formula (Y). A higher dye residual rate value indicates that the dye is less likely to be decomposed by light and has better light resistance. The results are shown in Table 1. Dye residual rate (%) = (absorbance after light resistance test) ÷ (absorbance before light resistance test) × 100 Formula (Y)

[0121]

[0122] As shown in Table 1, the light-adjusting elements of Examples 23 to 33 had higher dye residual rates after the light resistance test than the light-adjusting element of Comparative Example 2, and it was confirmed that they had excellent light resistance.

[0123] Example 34 (Preparation of liquid crystal composition of the present invention and preparation of black dimming element) A black liquid crystal composition of the present invention was prepared by adding 0.005 parts of a compound represented by the following formula (30) and 0.009 parts of a compound represented by the following formula (31) to the liquid crystal composition obtained in Example 12 and mixing them at room temperature. A black liquid crystal composition of the present invention was prepared in accordance with Example 23, except that the liquid crystal composition obtained in Example 12 was changed to the black liquid crystal composition obtained above.

[0124]

[0125]

[0126] Examples 35 to 44 and Comparative Example 3 (Preparation of liquid crystal compositions of the present invention and comparisons, and fabrication of black dimming devices) Black liquid crystal compositions of the present invention and comparisons were prepared in accordance with Example 34, except that the liquid crystal composition obtained in Example 12 was changed to the liquid crystal compositions obtained in Examples 13 to 22 and Comparative Example 1, respectively. Black dimming devices of the present invention and comparisons were prepared in accordance with Example 23, except that the liquid crystal composition obtained in Example 12 was changed to the black liquid crystal composition obtained above.

[0127] (Evaluation of Light Leakage of Black Photochromic Device) The transmittance of each of the black photochromic devices obtained in Examples 34 to 44 and Comparative Example 3 was measured using a spectrophotometer when shielded (no voltage applied), and the average transmittance at wavelengths of 400 to 700 nm was calculated. The smaller the average transmittance value at wavelengths of 400 to 700 nm of the black photochromic device, the more suppressed the light leakage of the black photochromic device and the better the light-shielding properties. The results are shown in Table 2.

[0128]

[0129] As shown in Table 2, the black photochromic elements of Examples 34 to 44 had smaller average transmittance values ​​in the wavelength range of 400 to 700 nm than the black photochromic element of Comparative Example 3, and were able to suppress light leakage in the visible light range, confirming that they had excellent light-blocking properties.

[0130] By using the anthraquinone compound of the present invention as a dichroic dye for a liquid crystal light control device, a light control device excellent in light resistance and light blocking properties can be obtained. The light control device obtained by the present invention can be suitably used for construction materials such as windows, partitions, and doors, automotive materials such as windows and sunroofs, displays that show letters and numbers, and exhibit materials such as show windows.

Claims

1. An anthraquinone compound represented by the following formula (1): (In the formula, R １ and R ４ are each independently a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR ８ , -CONR ９ R １０ , -NR １１ R １２ , a cyano group, or a trifluoromethyl group. ２ , R ３ , R ５ and R ６ each independently represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, a halogen atom, -CO ２ R ８ , -OCOR ８ , -COR ８ , -CONR ９ R １０ , -NR １１ R １２ , a cyano group, or a trifluoromethyl group. ７ represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or a group represented by the following formula (a): (In the formula, R １３ represents a hydrogen atom or a linear alkyl group having 1 to 8 carbon atoms. ８ are each independently a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms, or a group represented by the following formula (b): (In the formula, R １４ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, a branched alkyl group having 3 to 8 carbon atoms, a linear alkoxy group having 1 to 8 carbon atoms, or a branched alkoxy group having 3 to 8 carbon atoms, (In the formula, R １５ represents a hydrogen atom, a linear alkyl group having 1 to 8 carbon atoms, or a branched alkyl group having 3 to 8 carbon atoms. ９ ~R １２ each independently represents a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms.

2. In formula (1), R １ and R ４ each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ and R ２ , R ３ , R ５ and R ６ each independently represents a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms, -CO ２ R ８ , or -COR ８ The anthraquinone compound according to claim 1, wherein 3. The anthraquinone compound according to claim 1, represented by the following formula (2): (In the formula, R １ and R ４ each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ２ and R ５ each independently represents a hydrogen atom, a linear alkyl group having 1 or 2 carbon atoms, a linear alkoxy group having 1 or 2 carbon atoms, -CO ２ R ８ , or -COR ８ Represents R ７ is a linear alkyl group having 4 to 12 carbon atoms, a linear alkoxy group having 4 to 12 carbon atoms, or a group represented by the following formula (a): (In the formula, R １３ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms. ８ represents a linear alkyl group having 1 to 5 carbon atoms.

4. In formula (2), R １ and R ２ is a hydrogen atom, and R ４ and R ５ The anthraquinone compound according to claim 3, wherein only one of the following is a hydrogen atom:

5. In formula (2), R ２ and R ５ The anthraquinone compound according to claim 4, wherein is a hydrogen atom.

6. In formula (2), R １ and R ４ and each independently represent a linear alkyl group having 1 to 12 carbon atoms.

7. In formula (2), R １ is a linear alkyl group having 1 to 12 carbon atoms, and R ４ is a branched alkyl group having 3 to 8 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms, or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ The anthraquinone compound according to claim 5, wherein 8. In formula (2), R １ is a branched alkyl group having 3 to 8 carbon atoms, and R ４ is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ The anthraquinone compound according to claim 5, wherein 9. In formula (2), R １ is a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ and R ４ is a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or —CO ２ R ８ The anthraquinone compound according to claim 5, wherein 10. In formula (2), R ７ The anthraquinone compound according to claim 3, wherein is a linear alkyl group having 4 to 12 carbon atoms or a linear alkoxy group having 4 to 12 carbon atoms.

11. In formula (2), R ７ The anthraquinone compound according to claim 10, wherein is a linear alkoxy group having 4 to 12 carbon atoms.

12. A liquid crystal composition comprising the anthraquinone compound according to any one of claims 1 to 11 and a liquid crystal material.

13. The liquid crystal composition according to claim 12, further comprising at least one dye compound other than the anthraquinone compound represented by formula (1).

14. A light-adjusting element comprising a pair of opposing substrates, at least one of which is a transparent substrate having a transparent electrode, and the liquid crystal composition according to claim 12 sandwiched between the substrates.

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