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

Abstract

One aspect of the present invention is an anthraquinone compound that satisfies expression (1) with respect to the 1H-NMR chemical shift. Expression (1): 0.015 ≤ |δ2-δB| ≤ 0.150 (δ2 is a chemical shift value (ppm) within a range of 13.5-15.0 ppm. δB represents, for a mixture obtained by mixing the anthraquinone compound and 4-cyano-4'-pentylbiphenyl at a mass ratio of 1:50, the chemical shift value (ppm) of a peak that is the same as the peak of δ2 shifted to a different position.) Preferably, the compound may further satisfy expression (2). Expression (2): 0.005 ≤ |δ1-δA| ≤ 0.120 (δ1 is a chemical shift value (ppm) within a range of 6.0-7.5 ppm. δA represents, for a mixture obtained by mixing the anthraquinone compound and 4-cyano-4'-pentylbiphenyl at a mass ratio of 1:50, the chemical shift value (ppm) of a peak that is the same as the peak of δ1 shifted to a different position.)

Description

Anthraquinone compounds, liquid crystal compositions containing the compound, and dimming elements

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

[0002] Various innovations have been proposed for dimmable films that control the transmission of external light for purposes such as protecting privacy 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 dimmable film utilizes liquid crystal. Normally, liquid crystal dimmable films can block the view by controlling the transmission and scattering of light depending on whether or not voltage is applied, but they cannot block the light itself, so glare tends to increase due to light scattering. For this reason, attempts have been made to use dyes as materials for dimmable panels in order to reduce glare and improve contrast (see Patent Documents 3 and 4). For example, when such a dimmable panel is used in the windows of an automobile, there is a strong demand for a dimmable element that has low transmittance when colored and high transmittance when transparent, i.e., high contrast, in addition to low transmittance when colored and high transmittance when transparent, i.e., high contrast, when exposed to light for long periods of time outdoors.

[0003] Dichroic dyes are commonly used as pigments in liquid crystal dimming films. The GH (guest-host) type is known as a dimming element using a liquid crystal composition containing dichroic dyes, and various dichroic dyes have been proposed.

[0004] Such dichroic dyes are desired to possess not only contrast when used as a dimming element, but also light resistance, UV resistance, heat resistance, and compatibility (solubility) with the components of liquid crystal compositions. Efforts have been made to improve these properties, but no dye has yet been found that satisfies the requirements for light resistance and contrast for automotive applications.

[0005] A guest-host type dimming element using a liquid crystal composition containing a dichroic dye controls light transmittance by changing the orientation of the liquid crystal depending on whether or not a voltage is applied. The ability of the dichroic dye added to the liquid crystal to change orientation in accordance with the liquid crystal is an important factor in the contrast of the dimming element. Whether the dichroic dye can change orientation in accordance with the liquid crystal largely depends on the intermolecular interaction between the liquid crystal and the dichroic dye. Furthermore, the light resistance of the dimming element is greatly influenced by environmental factors surrounding the dye molecule, and the intermolecular interaction between the dichroic dye and the liquid crystal is a factor that greatly contributes to light resistance. For example, Patent Document 5 discloses a dichroic dye suitable for dimming applications, but the display element using the dichroic dye in that document has insufficient light resistance and contrast.

[0006] Compounds exhibiting GH (guest-host) properties include not only liquid crystals and dyes, but also a variety of other compounds. Non-patent document 1 describes how intermolecular interactions between guest and host compounds can affect the guest molecule. １ It has been reported that the chemical shift values ​​of the H-NMR spectrum change.

[0007] Japanese Patent Publication No. 63-501512, Japanese Patent Publication No. 03-047392, Japanese Patent Publication No. 2018-205746, Japanese Patent Publication No. 2011-190314, Japanese Patent Publication No. 58-196260

[0008] Kurume Institute of Technology Research Report No. 24 (2000) pp. 67-74

[0009] The present invention aims to provide an anthraquinone compound, which is a dichroic dye used to obtain a dimming element with excellent light resistance and contrast, a liquid crystal composition containing the anthraquinone compound, and a dimming element with excellent light resistance and contrast.

[0010] Therefore, the present inventors diligently investigated the above problem and found that intermolecular interactions also occur between the host compound, the liquid crystal, and the guest compound, the dichroic dye, and the dichroic dye １ We confirmed that a chemical shift occurs in the H-NMR spectrum. After further intensive investigation, we mixed 4-cyano-4'-pentylbiphenyl, a representative liquid crystal compound, with an anthraquinone compound, a dichroic dye.１ By measuring the H-NMR spectrum, the specific area can be identified. １ The inventors have found that a photochromic element obtained using an anthraquinone compound in which the change in the chemical shift value of the H-NMR spectrum falls within a specific numerical range has excellent lightfastness and contrast, thus completing the first aspect of the present invention. Furthermore, the inventors have found a novel anthraquinone compound with a structure that can obtain a photochromic element with excellent lightfastness and contrast, thus completing the second aspect of the present invention.

[0011] In other words, the two aspects and embodiments according to the present invention are summarized as follows in sections [1] to

[22] below. • First aspect of the present invention [1] １ An anthraquinone compound characterized by satisfying the following relation (1) with respect to the chemical shift of H-NMR: 0.015 ≤ |δ2 - δB| ≤ 0.150 ... (1) In relation (1), δ2 is the chemical shift value (unit: ppm) in the range of 13.5 ppm to 15.0 ppm; δB represents the chemical shift value (unit: ppm) of the same peak as the δ2 ​​peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50; however, if there are multiple |δ2 - δB|, it means the maximum value. [2] Furthermore １ The anthraquinone compound described in item [1] above is characterized in that it satisfies the following relation (2) with respect to the chemical shift of H-NMR: 0.005 ≤ |δ1 - δA| ≤ 0.120 ... (2) In relation (2), δ1 is the chemical shift value (unit: ppm) in the range of 6.0 ppm to 7.5 ppm; δA represents the chemical shift value (unit: ppm) of the same peak as the δ1 peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50; however, if there are multiple |δ1 - δA|, it means the maximum value. [3] Furthermore １The anthraquinone compound according to item [1] above, characterized in that it satisfies the following relational expression (3) with respect to the 1H-NMR chemical shift: 0.005 ≦ |δ3−δC| ≦ 0.150 (3) In the relational expression (3), δ3 is a chemical shift value (unit: ppm) within a range of 10.5 ppm to 12.0 ppm; δC represents a chemical shift value (unit: ppm) of the same peak as the δ3 peak shifted to a different position in a mixture obtained by mixing the anthraquinone compound and 4-cyano-4'-pentylbiphenyl at a mass ratio of 1:50; provided that when a plurality of |δ3−δC| values exist, it means the maximum value thereof. [4] A liquid crystal composition comprising (I-1) the anthraquinone compound according to any one of items [1] to [3] above, and (II) a liquid crystal material. [5] A light control element, wherein the liquid crystal composition according to item [4] above is sandwiched between a pair of oppositely disposed substrates, at least one of which is a transparent substrate having a transparent electrode. [6] The light control element according to item [5] above, wherein both of the pair of substrates are transparent substrates each having a transparent electrode. [7] An in-vehicle light control window comprising the light control element according to item [5] or [6] above. Second aspect of the present invention [8] An anthraquinone compound represented by the following formula (1A). (wherein, R １ represents a substituent selected from the group consisting of a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms, a branched alkyl group having 3 to 16 carbon atoms, a linear alkoxy group having 1 to 16 carbon atoms, a branched alkoxy group having 3 to 16 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ , a cyano group, and a nitro group. R ２ and R ３ each independently represent a substituent selected from the group consisting of a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms, a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５, -COR ５ , -NR ６ R ７ , -CF ３ R represents a substituent represented by a cyano group or a nitro group. ４ Each of these independently comprises 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, or -NR ６ R ７ This represents a substituent represented by R. ５ Each of these independently represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms. ６ and R ７ Each of these independently represents a hydrogen atom, or a linear alkyl group having 1 to 12 carbon atoms, or a branched alkyl group having 3 to 12 carbon atoms. However, R ６ and R ７ Not all of them represent hydrogen atoms. n independently represents 2 to 4.) [9] R in equation (1A) １ However, hydrogen atoms, linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, linear alkoxy groups having 1 to 16 carbon atoms or branched alkoxy groups having 3 to 16 carbon atoms, -OCOR ５ , or -NR ６ R ７ A substituent represented by R ２ and R ３ However, each is 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and -OCOR ５ , or -NR ６ R ７ A substituent represented by R ４ However, each independently comprises a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or -NR ６ R ７The anthraquinone compound described in item [8] above, wherein the substituent is represented by

[10] R in formula (1A). １ However, the substituent is represented by a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms or a branched alkyl group having 3 to 16 carbon atoms, or a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 16 carbon atoms, R ２ and R ３ An anthraquinone compound according to item [9] above, wherein each is 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

[11] An anthraquinone compound according to any one of items [8] to

[10] above, wherein n in formula (1A) is 2 or 4.

[12] R in formula (1A) ３ An anthraquinone compound according to any one of the above items [8] to

[11] , wherein R is a hydrogen atom.

[13] R in formula (1A) １ and R ２ An anthraquinone compound according to any one of the above items [8] to

[12] , wherein either of the atoms is a hydrogen atom.

[14] R in formula (1A) ２ However, an anthraquinone compound as described in item

[13] above, wherein n in formula (1A) is a hydrogen atom.

[15] An anthraquinone compound as described in any one of items [8] to

[14] above, wherein n in formula (1A) is 2.

[16] R in formula (1A) １ The anthraquinone compound according to any one of the above items [8] to

[15] , wherein R in formula (1A) ４ However, the anthraquinone compound described in any one of the above items [8] to

[16] is a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

[18] R in formula (1A) ４

[19] An anthraquinone compound according to item

[17] , wherein the anthraquinone compound is a linear or branched alkoxy group having 4 to 12 carbon atoms.

[20] A liquid crystal composition comprising an anthraquinone compound according to any one of items [8] to

[18] and a liquid crystal material.

[21] A liquid crystal composition according to item

[19] , further comprising at least one dye compound other than the anthraquinone compound represented by formula (1A).

[22] A dimming element comprising a pair of opposing substrates, at least one of which is a transparent substrate having a transparent electrode, between which the liquid crystal composition according to item

[19] or

[20] is sandwiched.

[23] A dimming window for an automobile, comprising the dimming element according to item

[21] .

[0012] By using the anthraquinone compound according to the first aspect of the present invention and the liquid crystal composition containing the same, a dimming element with high contrast and excellent light resistance can be obtained. Furthermore, since the anthraquinone compound according to the second aspect of the present invention has dichroism and excellent light resistance and heat resistance, by using the liquid crystal composition containing the compound, a dimming element with minimal color change even when exposed to light at high temperatures for a long period of time can be obtained.

[0013] Figure 1 shows an anthraquinone compound of Example 1 according to the first aspect of the present invention. １ This figure shows δB (lower panel) and δ2 (upper panel) in 1H-NMR measurements.

[0014] The first and second aspects of the present invention will be described in detail below. In this invention, "lower limit to upper limit" means that both the lower limit and the upper limit are included.

[0015] 1. First aspect of the present invention: Anthraquinone compound The anthraquinone compound of the present invention is １The present invention is characterized by satisfying the following relation with respect to the change in the chemical shift of the H-NMR spectrum: 0.015 ≤ |δ2 - δB| ≤ 0.150 ... (1) [Regarding |δ2 - δB|] In relation (1), δ2 is the chemical shift value (unit: ppm) in the range of 13.5 ppm to 15.0 ppm, and δB represents the chemical shift value (unit: ppm) of the same peak as the δ2 ​​peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50. Note that there may be multiple peaks in the range of 13.5 ppm to 15.0 ppm, in which case the value refers to the peak with the largest |δ2 - δB| among the multiple peaks. The |δ2 - δB| of the anthraquinone compound of the present invention is 0.015 or more and 0.150 or less. The preferred lower limit is 0.020, 0.025, or 0.028, in order, and particularly preferred is 0.030. The preferred upper limit is 0.140, 0.130, or 0.100, in order, and particularly preferred is 0.050. That is, |δ2-δB| is preferably 0.020 to 0.140, 0.025 to 0.130, or 0.028 to 0.100, and most preferably 0.030 to 0.050. <NMR Measurement> In the present invention, NMR is measured under the following conditions. １ ¹H-NMR analysis: 1 mg of anthraquinone compound in deuterated acetone solvent (¹¹H) ３ D ６ O) Dissolve in 550 μL and measure at room temperature (usually 25°C) at 600 MHz with 32 integration cycles. However, if the anthraquinone compound does not dissolve sufficiently in deuterated acetone, deuterated chloroform, deuterated DMSO, etc. may be used. In the explanation of nuclear magnetic resonance spectra, regarding peak coupling, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, and m means multiplet. Also, regarding δB, １ H-NMR measurement is as described above. １ The anthraquinone compound used in the 1H-NMR measurement and 4-cyano-4'-pentylbiphenyl are mixed and stirred in a mass ratio of 1:50, and the resulting mixture is used as the sample. １The 1H-NMR measurement method is the same as described above, and δB is defined as the chemical shift of the same peak that has shifted to a different position, where δ2 is located between 13.5 ppm and 15.0 ppm. This explanation also applies to δA and δC.

[0016] In a preferred embodiment, the anthraquinone compound of the present invention is １ Regarding the change in the chemical shift of H-NMR, in addition to relation (1), relation (2) may also be satisfied. 0.005 ≤ |δ1 - δA| ≤ 0.120 ... (2) [Regarding |δ1 - δA|] In relation (2), δ1 is the chemical shift value (unit: ppm) in the range of 6.0 ppm to 7.5 ppm, and δA represents the chemical shift value (unit: ppm) of the same peak as the δ1 peak shifted to a different position for a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50. Note that there may be multiple peaks in the range of 6.0 ppm to 7.5 ppm, in which case it means the value of the peak for which the |δ1 - δA| is the largest among the multiple peaks. １ The 1H-NMR measurement method is the same as that for δ2 and δB described above. The |δ1-δA| of the anthraquinone compound of the present invention is 0.005 or more and 0.120 or less. The preferred lower limit is 0.006, 0.007, 0.008, or 0.009, in order, and particularly preferred is 0.010. The preferred upper limit is 0.100, 0.090, or 0.070, in order, and particularly preferred is 0.050. That is, |δ1-δA| is preferably 0.006 to 0.100, 0.007 to 0.090, 0.008 to 0.070, or 0.009 to 0.070, and most preferably 0.010 to 0.050.

[0017] In a preferred embodiment, the anthraquinone compound of the present invention is １Regarding the change in the chemical shift of H-NMR, in addition to relation (1), relation (3) may also be satisfied. 0.005 ≤ |δ3 - δC| ≤ 0.150 ... (3) [Regarding |δ3 - δC|] In relation (3), δ3 is the chemical shift value (unit: ppm) in the range of 10.5 ppm to 12.0 ppm, and δC represents the chemical shift value (unit: ppm) of the same peak as the δ3 peak shifted to a different position for a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50. Note that there may be multiple peaks in the range of 10.5 ppm to 12.0 ppm, in which case it means the value of the peak for which the |δ3 - δC| is largest among the multiple peaks. １ The 1H-NMR measurement method is the same as for δ2 and δB described above. The |δ3-δC| of the anthraquinone compound of the present invention is 0.005 or more and 0.150 or less. Its preferred lower limit is 0.006, and particularly preferred is 0.007. The preferred upper limits are 0.130, 0.110, or 0.050, respectively, with 0.025 being particularly preferred. That is, |δ3-δC| is preferably 0.006 to 0.130, 0.007 to 0.110, or 0.007 to 0.050, and most preferably 0.007 to 0.025.

[0018] The anthraquinone compounds of the present invention are, １ The structure of a compound is not particularly limited as long as it satisfies the above relation (1) regarding the change in the chemical shift of H-NMR, or satisfies relations (1) and (2), or satisfies relations (1) and (3). １In 1H-NMR measurements, peaks are observed at 13.5 ppm to 15.0 ppm, and optionally at an additional 6.0 ppm to 7.5 ppm or 10.5 ppm to 12.0 ppm, indicating a preference for the presence of multiple aromatic rings in addition to the anthraquinone skeleton. Examples of aromatic rings include phenyl, phenylene, naphthyl, naphthylene groups, and heteroaromatic rings such as pyrrolyl, thienyl, and furyl groups. Furthermore, substituents are preferred either directly from the anthraquinone skeleton or via the aromatic rings. More preferred substituents include linear alkyl groups having 1 to 16 carbon atoms, branched alkyl groups having 3 to 16 carbon atoms, linear alkoxy groups having 1 to 16 carbon atoms, branched alkoxy groups having 3 to 16 carbon atoms, halogeno groups, and -CO groups. ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ Examples include cyano groups or nitro groups. ５ R represents a linear alkyl group having 1 to 12 carbon atoms, or a branched alkyl group having 3 to 12 carbon atoms. ６ , R ７ Each of these 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. Furthermore, a structure having a hydroxyl group and / or an amino group on the anthraquinone skeleton is preferred, and a structure having two hydroxyl groups and two amino groups is particularly preferred.

[0019] ・Liquid crystal materials, liquid crystal compositions and dimming elements [Liquid crystal materials, liquid crystal compositions] The present invention also relates to (I) an anthraquinone compound of any of the embodiments described above according to the first aspect, and (II) a liquid crystal composition containing a liquid crystal material. (II) The liquid crystal material is not particularly limited as long as it is a liquid crystalline material (a liquid crystalline compound) such as a nematic liquid crystal, a cholesteric liquid crystal, or a smectic liquid crystal. Examples of liquid crystalline compounds include the liquid crystal compounds described on pages 154-192 and 715-722 of the "Liquid Crystal Device Handbook" (edited by the 142nd Committee of the Japan Society for the Promotion of Science, Nikkan Kogyo Shimbun, 1989). Specific examples include Schiff-based, azoxy-based, biphenyl-based, phenylcyclohexane-based, ester-based, terphenyl-based, biphenylcyclohexane-based, pyrimidine-based, dioxane-based, bicyclooctane-based, and cubane-based compounds.

[0020] <Other Components> The liquid crystal composition of the present invention may optionally further contain at least one of the following: an optically active substance that exhibits or does not exhibit a liquid crystal phase, such as cholesteryl nonanoate; a light stabilizer such as a benzotriazole, benzophenone, or hindered amine; an antioxidant such as a phosphite or hindered phenol; a thermal polymerization inhibitor; a thiol compound; a photosensitizer; a photosensitizer; a chain transfer inhibitor; a polymerization inhibitor; an adhesion promoter; an antifoaming agent; a crosslinking agent; a surfactant; a thermosetting accelerator; a thermoplastic resin; a thermosetting resin; a photocurable compound or photopolymerization initiator; or a thickener such as urethane diacrylate.

[0021] The liquid crystal composition of the present invention can switch between a transparent state and a colored state by applying a voltage, and it is preferable that the transmittance at the maximum absorption wavelength in the colored state is 35% or less. In this invention, voltage refers to a DC voltage, AC voltage, pulse voltage, or a combination thereof having an effective value of a threshold or higher.

[0022] In the present invention, the transparent state refers to the state of the liquid crystal composition when the above-mentioned voltage is applied or when no voltage is applied, and the state in which the total light transmittance of the liquid crystal composition is greater when the voltage is applied or when no voltage is applied is defined as the transparent state. Furthermore, the colored state also refers to the state of the liquid crystal composition when the above-mentioned voltage is applied or when no voltage is applied, and the state in which the total light transmittance of the dimming element is smaller when the voltage is applied or when no voltage is applied is defined as the colored state.

[0023] The anthraquinone compound according to the first aspect of the present invention is preferably such that, after being dissolved in the solvent toluene, the maximum absorption wavelength in the ultraviolet-visible absorption spectrum measured with a spectrophotometer "UV-3150" manufactured by Shimadzu Corporation is 600 nm to 660 nm, more preferably 600 nm to 655 nm, and particularly preferably 605 nm to 645 nm.

[0024] <Total Light Transmittance> The liquid crystal composition of the present invention (or a dimming element obtained using the liquid crystal composition) preferably has a difference of 25% or more in total light transmittance between the transparent state and the colored state. A difference of 25% or more in total light transmittance allows for control of the amount of light transmitted by the liquid crystal composition. The difference in total light transmittance is more preferably 30% or more, and even more preferably 35% or more. The total light transmittance in the transparent state is preferably 40% or more, more preferably 50% or more, and even more preferably 60% or more. The total light transmittance in the colored state is preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less. The total light transmittance in the transparent state is always higher than that in the colored state. The range of total light transmittance can be determined and adjusted according to the application. For example, in applications where it is often necessary to observe the background, transparency can be prioritized and the total light transmittance can be adjusted to a high range, such as 70% in the transparent state and 45% in the colored state. On the other hand, in applications where it is often desirable to reduce the glare of ambient light, the total light transmittance can be adjusted to a low range, such as 40% for the transparent state and 15% for the colored state. The total light transmittance in this specification can be obtained by measuring the transmittance in the visible light region (wavelength 380 nm to 780 nm) using the method described above with a spectrophotometer.

[0025] <Haze> The dimming element obtained from the liquid crystal composition of the present invention preferably has a haze of 6% or less in the transparent state. A haze of 6% or less in the transparent state ensures a clear view with minimal turbidity, providing a view similar to that of ordinary window glass. The haze is preferably 4% or less, and more preferably 2% or less. On the other hand, considering the haze of the substrate with the transparent conductive film, the haze in the transparent state is preferably 0.1% or more, more preferably 0.3% or more, and even more preferably 0.5% or more. The haze in this specification is measured by the method of JIS K7136.

[0026] <Method for Producing Liquid Crystal Composition> The liquid crystal composition of the present invention is obtained by mixing and stirring (I) an anthraquinone compound according to any of the embodiments of the first embodiment, (II) a liquid crystal material, and other optional components that may be added as needed. Mixing and stirring can be done simply by placing all the components in a container and stirring by hand, but it is preferable to stir using equipment such as a magnetic stirrer. Heating may be applied as needed during stirring and mixing, but it is preferable to stir and mix under a light source emitting the absorption wavelength of the photopolymerization initiator for as short a time as possible. After mixing each component, further stirring with a mesh or membrane is performed. イ Filtration may be performed using a filter or similar device.

[0027] [Dimming Element] The dimming element of the present invention comprises a liquid crystal composition for dimming being sandwiched between a pair of substrates, each having a transparent substrate on at least one side having a transparent electrode, and arranged facing each other. Examples of substrates include colorless, colored, or opaque inorganic transparent materials such as glass and quartz, metals, metal oxides, semiconductors, ceramics, plastic plates, and plastic films. The electrodes are formed on the substrate by a known coating method, printing method, or deposition method such as sputtering, using a thin film of, for example, a metal oxide, metal, semiconductor, or organic conductive material, on the entire surface or partially of the substrate. In particular, to obtain a large-area dimming element, it is desirable to use an electrode substrate in which ITO (indium oxide, tin oxide) electrodes are formed on a transparent polymer film such as PET using a deposition method such as sputtering or printing, from the viewpoint of productivity and processability. Wiring may be provided on the substrate to connect electrodes or electrodes to the outside. For example, the substrate may be a segment driving electrode substrate, a matrix driving electrode substrate, an active matrix driving electrode substrate, etc. Furthermore, the surface of the electrodes provided on the substrate is made of polyimide, polyamide, silicone, organic compounds such as cyanide compounds, and SiO ２ , TiO ２ , ZrO ２ The entire surface or part of the surface may be covered with a protective or aligning film formed from inorganic compounds such as these, or mixtures thereof.

[0028] By using a plastic film as a substrate, a flexible and lightweight dimming element can be obtained. For this reason, the dimming element can be used by sandwiching it between a pair of flat or curved glass or hard plastic surfaces via an adhesive layer such as polyvinyl butyral, vinyl acetate ester, double-sided tape, or adhesive. Alternatively, the dimming element can be attached to the surface of a single flat or curved glass or hard plastic surface using double-sided tape or adhesive. The dimming element may also be sandwiched between soft plastics, or attached to one or both sides. Furthermore, a protective layer such as a hard coat, an ultraviolet cut layer, an infrared cut layer, or a half mirror may be provided on the substrate surface opposite to the electrode surface of the dimming element. A color filter or polarizer filter may be laminated onto the dimming element. Furthermore, an electroluminescent display element, a light-emitting diode display element, an electrochromic display element, or other liquid crystal display elements may be laminated onto the dimming element.

[0029] The drive device for applying voltage to the dimming element of the present invention is a device capable of applying a DC voltage of 2 to 100 V or an AC voltage of 10 to 1000 Hz, and when no voltage is applied, it is sufficient to open or short-circuit the electrodes. Furthermore, this drive device may be equipped with a voltage application circuit for segment driving, a voltage application circuit for matrix driving, a voltage application circuit for active matrix, and so on.

[0030] Because the above-mentioned dimming element has high contrast and high light resistance, it is suitable for outdoor building material applications such as windows, and automotive applications such as sunroofs.

[0031] Furthermore, regarding the anthraquinone compound according to the first aspect of the present invention, １ The chemical structure is not limited as long as it satisfies the above requirements regarding the change in chemical shift of H-NMR. Although not intended to be bound by theory, the present invention relates to the intermolecular interaction between anthraquinone compounds, which are dichroic dyes, and liquid crystals. １ The intention is to define the range of anthraquinone compounds that possess the desired properties (achieving the above objective) by expressing them in terms of the change in chemical shift of H-NMR.

[0032] 2. Second aspect of the present invention The anthraquinone compound according to the second aspect of the present invention is represented by the following formula (1A). (wherein R １ is a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms, a branched alkyl group having 3 to 16 carbon atoms, a linear alkoxy group having 1 to 16 carbon atoms, a branched alkoxy group having 3 to 16 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ , a cyano group, or a nitro group. R ２ and R ３ each independently represent a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms, a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ , a cyano group, or a nitro group. R ４ each independently represent a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms, a branched alkoxy group having 3 to 12 carbon atoms, or a substituent represented by -NR ６ R ７ . R ５ each independently represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms. R ６ and R ７ each independently represent a hydrogen atom, or a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, provided that not all of R ６ and R ７ represent hydrogen atoms. Each n independently represents 2 to 4.)

[0033] R in equation (1A) １ The alkyl group having 1 to 16 carbon atoms represented by can be either a linear group having 1 to 16 carbon atoms or a branched group having 3 to 16 carbon atoms, but cyclic groups are excluded. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, t-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, t-pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, 2-ethylhexyl group, 2-propylhexyl group, 2-butylhexyl group, 2-pentylhexyl group, 2-pentylheptyl group, 2-butyloctyl group, and 2-hexyldecyl group. １ The alkyl group is preferably a linear or branched alkyl group having 4 to 16 carbon atoms, more preferably a linear or branched alkyl group having 4 to 12 carbon atoms, even more preferably a linear alkyl group having 4 to 12 carbon atoms, and even more preferably a linear alkyl group having 4 to 10 carbon atoms.

[0034] R in equation (1A) １ The alkoxy group having 1 to 16 carbon atoms represented by may be either a linear chain having 1 to 16 carbon atoms or a branched chain having 3 to 16 carbon atoms. Specific examples include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, t-butoxy group, n-pentyloxy group, iso-pentyloxy group, neo-pentyloxy group, t-pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group, tridecyloxy group, tetradecyloxy group, pentadecyloxy group, hexadecyloxy group, 2-ethylhexyloxy group, 2-propylhexyloxy group, 2-butylhexyloxy group, 2-pentylhexyloxy group, 2-pentylheptyloxy group, 2-butyloctyloxy group, and 2-hexyldecyloxy group. １The alkoxy group is preferably a linear or branched alkoxy group having 4 to 16 carbon atoms, more preferably a linear or branched alkoxy group having 4 to 12 carbon atoms, even more preferably a linear or branched alkoxy group having 6 to 12 carbon atoms, and even more preferably a linear or branched alkoxy group having 6 to 10 carbon atoms.

[0035] R in equation (1A) １ Examples include hydrogen atoms, linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, linear alkoxy groups having 1 to 16 carbon atoms or branched alkoxy groups having 3 to 16 carbon atoms, and -OCOR ５ , or -NR ６ R ７ This is preferable. R in formula (1A) １ More preferably, the group consists of a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms, a branched alkyl group having 3 to 16 carbon atoms, or a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 16 carbon atoms.

[0036] R in equation (1A) ２ and R ３ The alkyl group having 1 to 4 carbon atoms represented by may be either a linear chain having 1 to 4 carbon atoms or a branched chain having 3 to 4 carbon atoms, but cyclic is excluded. R in formula (1A) ２ and R ３ Specific examples of linear alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 to 4 carbon atoms represented by are R in formula (1A). １ Examples of linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, as represented by R, are also included. ２ and R ３ A methyl group or an ethyl group is preferred as the alkyl group.

[0037] R in equation (1A) ２ and R ３Specific 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 are R in formula (1A). １ Examples of specific alkoxy groups are those represented by a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 16 carbon atoms. A linear or branched alkoxy group having 4 to 12 carbon atoms is preferred, a linear or branched alkoxy group having 6 to 12 carbon atoms is more preferred, and a linear or branched alkoxy group having 6 to 10 carbon atoms is even more preferred. ２ and R ３ A methoxy group is also preferred.

[0038] R in equation (1A) ２ and R ３ These are, 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and -OCOR ５ , or -NR ６ R ７ 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms is more preferred, and each independently, a hydrogen atom is even more preferred.

[0039] R in equation (1A) ４ The alkyl group having 1 to 12 carbon atoms represented by may be either a linear chain having 1 to 12 carbon atoms or a branched chain having 3 to 12 carbon atoms, but cyclic is excluded. R in formula (1A) ４ Specific examples of linear alkyl groups having 1 to 12 carbon atoms or branched alkyl groups having 3 to 12 carbon atoms represented by are R in formula (1A). １ Examples of linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, as represented by R, are also included. ４ The alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, and more preferably a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms.

[0040] R in equation (1A) ４ The alkoxy group having 1 to 12 carbon atoms represented by may be either a linear chain having 1 to 12 carbon atoms or a branched chain having 3 to 12 carbon atoms, but cyclic is excluded. 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 are R in formula (1A). １ Examples of specific alkoxy groups represented by are the same as those of a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms. ４ The alkoxy group is preferably a linear or branched alkoxy group having 2 to 12 carbon atoms, more preferably a linear or branched alkoxy group having 4 to 12 carbon atoms, even more preferably a linear or branched alkoxy group having 4 to 10 carbon atoms, and even more preferably a linear or branched alkoxy group having 4 to 8 carbon atoms.

[0041] R in equation (1A) ４ These can be, independently, a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or -NR ６ R ７ The substituents represented by are preferred, each independently being a hydrogen atom, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or -NR ６ R ７ More preferably, each independently, is a hydrogen atom, or a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and each independently, each independently, is a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

[0042] R in equation (1A) ５ Specific examples of linear alkyl groups having 1 to 12 carbon atoms or branched alkyl groups having 3 to 12 carbon atoms represented by are R in formula (1A). １Examples of linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, as represented by R, are also included. ５ Each of these is preferably a linear alkyl group having 1 to 9 carbon atoms or a branched alkyl group having 3 to 9 carbon atoms, each of these is more preferably a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms, and each of these is even more preferably a linear or branched alkyl group having 4 to 8 carbon atoms.

[0043] R in equation (1A) ６ and R ７ The alkyl group having 1 to 12 carbon atoms represented by may be either a linear chain having 1 to 12 carbon atoms or a branched chain having 3 to 12 carbon atoms, but cyclic is excluded. R in formula (1A) ６ and R ７ Specific examples of linear alkyl groups having 1 to 12 carbon atoms or branched alkyl groups having 3 to 12 carbon atoms represented by are R in formula (1A). １ Examples of linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 12 carbon atoms, as represented by R, are also included. ６ and R ７ The alkyl group is preferably a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms.

[0044] R in equation (1A) ６ and R ７ Each of these is preferably a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms.

[0045] In formula (1A), n is preferably 2 or 4, and more preferably 2.

[0046] In equation (1A), R １ ~R ３ The number of substituents on the phenyl group having R is 0 to 2 each (i.e., R １ ~R ３ Preferably, at least one of them is a hydrogen atom, and it is 0 to 1 (i.e., R １ ~R ３It is more preferable that at least two of them are hydrogen atoms, and 1 (i.e., R １ ~R ３ It is even more preferable that two of these atoms are hydrogen atoms. Note that "substituent" refers to a substituent other than a hydrogen atom.

[0047] Furthermore, in equation (1A), R １ ~R ３ The positions of substituents on the phenyl group having the substituents are described by the numbers shown in formula (2A) below as follows: one position only at the 2-position, one position only at the 3-position, or one position only at the 4-position; two positions at the 2-position and 4-position, 3-position and 4-position, 3-position and 5-position, 2-position and 5-position, or 2-position and 6-position; or three positions at the 2-position, 4-position and 6-position, or 3-position, 4-position and 5-position; more preferably only at the 2-position, one position only at the 3-position, one position only at the 4-position; even more preferably only at the 3-position and one position only at the 4-position; and particularly preferably only at the 4-position. For example, "only at the 4-position" means that a substituent other than a hydrogen atom is present only at the 4-position.

[0048]

[0049] The following are some preferred specific examples of the compound represented by formula (1A), but the present invention is not limited thereto. In addition, in the structural formulas described herein, alkyl groups that are not limited by their structure and are only expressed by the number of carbon atoms and hydrogen atoms are all linear alkyl groups.

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] The anthraquinone compound represented by formula (1A) of the present invention (the anthraquinone compound of any of the embodiments described above according to the second aspect) can be synthesized, for example, by referring to the synthesis method described in Fibers and Polymers 2017, 18, 9, 1691. Specifically, it can be synthesized by reacting an anthraquinone compound represented by the following formula (A), synthesized by a conventionally known method described in Japanese Patent Publication No. 62-5941, etc., with an alcohol derivative represented by the following formula (B) at 140 to 160°C under basic conditions such as potassium hydroxide, either without a solvent or in a solvent such as sulfolane.

[0067]

[0068] 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 (1A) (an anthraquinone compound of any of the embodiments described above relating to the second aspect) and a liquid crystal material.

[0069] The content of the anthraquinone compound represented by formula (1A) in the liquid crystal composition is not particularly limited, but is preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, per 100 parts by mass of liquid crystal material. When a dichroic dye other than the compound represented by formula (1A) (described later) is used in combination, it is preferable that the total content of the anthraquinone compound represented by formula (1A) and the dichroic dye other than the compound represented by formula (1A) is within the above range (0.5 to 10% by mass) per 100 parts by mass of liquid crystal material.

[0070] The liquid crystal material contained in the liquid crystal composition of the present invention is not particularly limited as long as it is a liquid crystal material (a liquid crystal compound) such as a nematic liquid crystal, cholesteric liquid crystal, or smectic liquid crystal. Examples of liquid crystal compounds include those described on pages 154 to 192 and 715 to 722 of the "Liquid Crystal Device Handbook" (edited by the 142nd Committee of the Japan Society for the Promotion of Science, Nikkan Kogyo Shimbun, 1989).

[0071] The liquid crystal composition of the present invention may contain optically active substances that exhibit or do not exhibit a liquid crystal phase, such as dichroic dyes or cholesteryl nonanoate other than the anthraquinone compound represented by formula (1A), various additives such as ultraviolet absorbers and antioxidants, photocurable compounds and photopolymerization initiators.

[0072] The liquid crystal composition of the present invention may be used in combination with dichroic dyes other than the anthraquinone compound represented by formula (1A). The dichroic dyes that can be used in combination are not particularly limited, but may 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, etc. Specific examples of dichroic dyes that can be used in combination include those described in "Dichroic dies for Liquid Crystal Display" (by A.V. Ivashchenko, CRC, 1994). Among these, it is preferable to use azo dyes, anthraquinone dyes, perylene dyes, or quinophthalone dyes in combination, and it is more preferable to use azo dyes or anthraquinone dyes in combination.

[0073] When using dichroic dyes other than the anthraquinone compound represented by formula (1A) in combination, the content of the dichroic dye other than the anthraquinone compound represented by formula (1A) in the total dichroic dyes is not particularly limited as long as it does not impair the effects of the present invention. The content is preferably 1 to 80% by mass, more preferably 5 to 70% by mass, and even more preferably 10 to 50% by mass.

[0074] The liquid crystal composition of the present invention may optionally contain at least one of the following: a light stabilizer such as a benzotriazole, benzophenone, or hindered amine; an antioxidant such as a phosphite or hindered phenol; a thermal polymerization inhibitor; a thiol compound; a photosensitizer; a photosensitizer; a chain transfer inhibitor; a polymerization inhibitor; an adhesion promoter; an antifoaming agent; a crosslinking agent; a surfactant; a thermosetting accelerator; a thermoplastic resin; a thermosetting resin; or a thickener such as urethane diacrylate. Furthermore, spherical or cylindrical spacers made of silica, glass, plastic, ceramic, etc., may be added to control the cell gap as a dimming element obtained using the liquid crystal composition. The cell gap in this case can be set in the range of 2 to 100 μm.

[0075] The dimming element of the present invention comprises a layer of the liquid crystal composition or its photocured product sandwiched between a pair of substrates, each having a transparent substrate, at least one of which is a transparent substrate with a transparent electrode. Examples of substrates include colorless, colored, or opaque inorganic transparent materials such as glass and quartz, metals, metal oxides, semiconductors, ceramics, plastic plates, and plastic films. The electrodes are formed on the substrate by a known coating method, printing method, or deposition method such as sputtering, using a thin film of, for example, a metal oxide, metal, semiconductor, or organic conductive material, on the entire surface or partially of the substrate. In particular, to obtain a large-area dimming element, it is desirable to use an electrode substrate in which ITO (indium oxide, tin oxide) electrodes are formed on a transparent polymer film such as PET using a deposition method such as sputtering or printing, from the viewpoint of productivity and processability. Wiring may be provided on the substrate to connect electrodes or electrodes to the outside. For example, a segment driving electrode substrate, a matrix driving electrode substrate, or an active matrix driving electrode substrate may be used. Furthermore, the electrode surface provided on the substrate contains polyimide, polyamide, silicone, organic compounds such as cyanide compounds, and SiO ２ , TiO ２ , ZrO ２ The entire surface or part of the surface may be covered with a protective or aligning film formed from inorganic compounds such as these, or mixtures thereof.

[0076] By using a plastic film as a substrate, a flexible and lightweight dimming element can be obtained. For this reason, the dimming element can be used by sandwiching it between a pair of flat or curved glass or hard plastic surfaces via an adhesive layer such as polyvinyl butyral, vinyl acetate ester, double-sided tape, or adhesive. Alternatively, the dimming element can be attached to the surface of a single flat or curved glass or hard plastic surface using double-sided tape or adhesive. Furthermore, the dimming element may be sandwiched between soft plastics, or attached to one or both sides. In addition, a protective layer such as a hard coat, an ultraviolet cut layer, an infrared cut layer, or a half mirror may be provided on the substrate surface opposite to the electrode surface of the dimming element. A color filter or a polarizer filter may be laminated onto the dimming element. Furthermore, an electroluminescent display element, a light-emitting diode display element, an electrochromic display element, or other liquid crystal display elements may be laminated onto the dimming element.

[0077] The drive device for applying voltage to the dimming element of the present invention is a device capable of applying a DC voltage of 2 to 100V or an AC voltage of 10 to 1000Hz, and when no voltage is applied, it is sufficient to open or short-circuit the electrodes. Furthermore, this drive device may be equipped with a voltage application circuit for segment driving, a voltage application circuit for matrix driving, a voltage application circuit for active matrix, and so on.

[0078] The anthraquinone compound represented by formula (1A) of the present invention (the anthraquinone compound of any of the embodiments described above according to the second aspect) has high light resistance and heat resistance, and a dimming element using it can achieve high-quality display with little color change over a long period of time. Furthermore, the dimming element of the present invention has excellent light resistance and heat resistance to long-term outdoor exposure to light at high temperatures, making it ideal for automotive or building material applications.

[0079] The first and second aspects of the present invention will be described in more detail below with reference to examples, but these are illustrative and do not limit the present invention in any way. In this text, "parts" and "%" refer to mass unless otherwise specified. The maximum absorption wavelengths in the examples were measured using a spectrophotometer "UV-3150" manufactured by Shimadzu Corporation.

[0080] 1. Examples and Comparative Examples According to the First Embodiment of the Invention Example 1 (Synthesis of the Anthraquinone Compound of the Invention Represented by Formula (1) Below) 25 parts of 4-phenyl-1-butanol were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 2.0 parts of the compound represented by Formula (2) below, synthesized by the method described in Japanese Patent Publication No. 62-5941, were added and stirred at 160°C for 11 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 75 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 2 hours. The mixture was then filtered and washed with isopropyl alcohol. The resulting solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvents. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 1 hour. The sample was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.022 parts of the anthraquinone compound represented by the following formula (1) as a dark blue solid. The maximum absorption wavelength of a toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0081]

[0082]

[0083] １ H-NMR (C ３ D ６O) δ14.809 (m, 1H), 14.457 (m, 1H), 11.534 (d, 1H) 7.267 (m, 10H), 7.234 ( m, 2H), 7.169 (m, 2H), 6.924 (s, 1H), 6.693 (d, 2H), 6.841 (d, 2H), 6.714 ( s, 1H), 4.121 (t, 2H), 4.013 (t, 2H), 2.731 (t, 2H), 2.692 (t, 2H), 2.639 ( t, 2H), 1.914-1.779 (m, 8H), 1.634 (m, 2H), 1.387 (sex, 2H), 0.935 (m, 3H)

[0084] Example 2 (Synthesis of the anthraquinone compound of the present invention represented by formula (4) below) (Step 1) Synthesis of the alcohol derivative represented by formula (3) 120 parts of DMF were mixed with 25 parts of 2-(4-hydroxyphenyl)ethanol, 30 parts of potassium carbonate, and 35 parts of 1-bromohexane, and the mixture was stirred at 80°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was vacuum dried to obtain 27 parts of the alcohol derivative represented by formula (3) below.

[0085]

[0086] (Step 2) Synthesis of the anthraquinone compound of the present invention represented by formula (4) below. 16 parts of the alcohol derivative represented by formula (3) obtained in Step 1 were added to 0.096 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 0.50 parts of the compound represented by formula (2) above were added and stirred at 160°C for 11 hours. The reaction mixture was cooled to 25°C, 24 parts of toluene and 50 parts of saturated ammonium chloride aqueous solution were added, and the organic layer was separated. After drying with anhydrous magnesium sulfate, the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 10 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering, the mixture was washed with methanol and dried in a vacuum dryer at 50°C for 12 hours to obtain 0.010 parts of the anthraquinone compound represented by formula (4) below as an orange solid. The maximum absorption wavelength of this anthraquinone compound in a toluene solution was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0087]

[0088] １ H-NMR (C ３ D ６ O) δ14.812 (m, 1H), 14.430 (m, 1H), 11.535 (dd, 1H) 7.308 (q, 6H), 7.214 (d, 2H), 6.9 33 (s, 1H), 6.888 (d, 2H), 6.843 (d, 2H), 6.722 (s, 1H), 4.233 (t, 2H), 4.153 (t, 2H), 3.968 (t, 2H), 3.951 (t, 2H), 3.097 (t, 2H), 3.020 (t, 2H), 2.650 (t, 2H), 1.758 (m, 4 H), 1.628 (m, 2H), 1.466 (m, 4H), 1.405-1.330 (m, 10H), 0.943 (t, 3H), 0.900 (m, 6H)

[0089] Example 3 (Synthesis of the anthraquinone compound of the present invention represented by formula (6) below) 7.2 parts of the alcohol derivative represented by formula (3) obtained in step 1 of Example 2 were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by formula (5) below, synthesized by the method described in Japanese Patent Publication No. 62-5941, and 5.0 parts of sulfolane were added and stirred at 140°C for 11 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 75 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 2 hours. The mixture was then filtered and washed with isopropyl alcohol. The resulting solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvents. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 1 hour. The sample was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.010 parts of the anthraquinone compound represented by the following formula (6) as a dark blue solid. The maximum absorption wavelength of a toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0090]

[0091]

[0092] １ H-NMR (C ３ D ６O) δ14.822 (m, 1H), 14.431 (m, 1H), 11.539 (m, 1H), 7.310 (q, 6H), 7.213 (d, 2 H), 6.937 (s, 1H), 6.890 (d, 2H), 6.843 (d, 2H), 6.726 (s, 1H), 4.236 (t, 2H), 4.157 (t, 2H), 3.969 (td, 4H), 3.099 (t, 2H), 3.020 (t, 2H), 2.649 (t, 2H), 1. 753 (m, 4H), 1.724 (m, 2H), 1.458 (m, 4H), 1.374-1.305 (m, 16H), 0.900 (m, 9H)

[0093] Example 4 (Synthesis of the anthraquinone compound of the present invention represented by formula (8) below) (Step 3) Synthesis of the alcohol derivative represented by formula (7) 42 parts of DMF were mixed with 15 parts of 2-(4-hydroxyphenyl)ethanol, 18 parts of potassium carbonate, and 25 parts of 1-bromooctane, and the mixture was stirred at 85°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the solution was vacuum dried to obtain 15 parts of the alcohol derivative represented by formula (7) below.

[0094]

[0095] (Step 4) Synthesis of the anthraquinone compound of the present invention represented by formula (8) below. 17 parts of the alcohol derivative represented by formula (7) obtained in Step 3 were added to 0.19 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 1.0 part of the compound represented by formula (5) above was added and stirred at 160°C for 7 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added and stirred for 1 hour. The mixture was then filtered, washed with methanol, and the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and stirred in an ice bath for 1 hour. The mixture was then filtered, washed with methanol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.045 parts of the anthraquinone compound represented by formula (8) below as a dark blue solid. The maximum absorption wavelength of the toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0096]

[0097] １ H-NMR (C ３ D ６ O) δ14.814 (m, 1H), 14.422 (m, 1H), 11.569 (dd, 1H) 7.305 (m, 6H), 7.208 (d, 2 H), 6.930 (s, 1H), 6.885 (d, 2H), 6.841 (d, 2H), 6.714 (s, 1H), 4.226 (t, 2H), 4 .. 149 (t, 2H), 3.967 (sex, 4H), 3.091 (t, 2H), 3.014 (t, 2H), 2.648 (t, 2H), 1.7 52 (m, 4H), 1.650 (m, 2H), 1.470 (m, 4H), 1.390-1.302 (m, 24H), 0.904 (m, 9H),

[0098] Example 5 (Synthesis of the anthraquinone compound of the present invention represented by formula (10) below) (Step 5) Synthesis of the alcohol derivative represented by formula (9) 120 parts of DMF were mixed with 24 parts of 2-(4-hydroxyphenyl)ethanol, 36 parts of potassium carbonate, and 50 parts of 2-ethylhexyl bromide, and the mixture was stirred at 85°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was dried by vacuum drying to obtain 22 parts of the alcohol derivative represented by formula (9) below.

[0099]

[0100] (Step 6) Synthesis of the anthraquinone compound of the present invention represented by formula (10) below. 13 parts of the alcohol derivative represented by formula (9) obtained in Step 5 were added to 0.21 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 1.0 part of the compound represented by formula (2) above was added and stirred at 160°C for 15 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and column purification was performed using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.010 parts of the anthraquinone compound represented by formula (10) below as a dark blue solid. The maximum absorption wavelength of this anthraquinone compound in a toluene solution was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0101]

[0102] １ H-NMR (C ３ D ６O) δ14.824 (m, 1H), 14.434 (m, 1H), 11.539 (m, 1H) 7.312 (m, 6H), 7.219 (d , 2H), 6.937 (s, 1H), 6.909 (d, 2H), 6.862 (d, 2H), 6.730 (s, 1H), 4.240 (t , 2H), 4.159 (t, 2H), 3.871 (qd, 4H), 3.103 (t, 2H), 3.025 (t, 2H), 2.652 ( t, 2H), 1.644 (m, 2H), 1.619 (m, 2H), 1.519-1.334 (m, 18H), 0.933 (m, 15H)

[0103] Example 6 (Synthesis of the anthraquinone compound of the present invention represented by formula (11) below) 11 parts of the alcohol derivative represented by formula (9) obtained in step 5 of Example 5 were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 1.0 part of the compound represented by formula (5) above was added and stirred at 160°C for 8 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.008 parts of the anthraquinone compound represented by formula (11) below as a dark blue solid. The maximum absorption wavelength of the toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0104]

[0105] １ H-NMR (C ３ D ６O) δ14.807 (m, 1H), 14.415 (m, 1H), 11.528 (m, 1H) 7.304 (q, 6H), 7.210 (d , 2H), 6.926 (s, 1H), 6.903 (d, 2H), 6.857 (d, 2H), 6.703 (s, 1H), 4.222 (t , 2H), 4.145 (t, 2H), 3.873 (qd, 4H), 3.091 (t, 2H), 3.013 (t, 2H), 2.646 ( t, 2H), 1.707 (m, 2H), 1.665 (m, 2H), 1.528-1.299 (m, 24H), 0.900 (m, 15H)

[0106] Example 7 (Synthesis of the anthraquinone compound of the present invention represented by formula (13) below) 10 parts of the alcohol derivative represented by formula (9) obtained in step 5 of Example 5 were added to 0.18 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by formula (12) below, synthesized by the method described in Japanese Patent Publication No. 62-5941, was added and stirred at 160°C for 24 hours. The reaction solution was cooled to 25°C and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.021 parts of the anthraquinone compound represented by formula (13) below as a dark blue solid. The maximum absorption wavelength of this anthraquinone compound in a toluene solution was 610 nm. This anthraquinone compound １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0107]

[0108]

[0109] １ H-NMR (C ３ D ６O) δ14.821 (m), 14.430 (m), 11.574 (dd, 1H) 7.309 (m, 6H), 7.215 (d, 2H), 6. 936 (s, 1H), 6.908 (d, 2H), 6.860 (d, 2H), 6.722 (s, 1H), 4.237 (t, 2H), 4.15 7 (t, 2H), 3.872 (qd, 4H), 3.102 (t, 2H), 3.021 (t, 2H), 2.651 (t, 2H), 1.720 (m, 2H), 1.660 (m, 2H), 1.560-1.289 (m, 30H), 0.933 (t, 6H), 0.890 (m, 9H),

[0110] Example 8 (Synthesis of the anthraquinone compound of the present invention represented by formula (15) below) (Step 7) Synthesis of the bromobenzene derivative represented by formula (14) 13 parts of 2-ethylhexanol were added to 4.0 parts of 4-bromobenzoic acid and 1.0 part of sulfuric acid, and the mixture was stirred at 140°C for 1 hour. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. 60 parts of toluene and 60 parts of water were added to the resulting liquid, and the organic layer was separated. The organic layer was further washed with 60 parts of water, and the aqueous layer was extracted with 60 parts of toluene. The organic layer separated above and the toluene extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The mixture was then vacuum dried to obtain 5.0 parts of the bromobenzene derivative represented by formula (14) below.

[0111]

[0112] (Step 8) Synthesis of the anthraquinone compound of the present invention represented by formula (15) below To 15 parts of toluene, 0.5 parts of the anthraquinone compound represented by formula (6) above, 0.70 parts of the bromobenzene derivative represented by formula (14) obtained in Step 7, 0.013 parts of palladium acetate, 0.037 parts of BINAP and 0.37 parts of cesium carbonate were added and the mixture was stirred at 100°C for 2 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added and the mixture was stirred for 1 hour. After filtering and washing with methanol, the mixture was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 2 parts of toluene and 20 parts of methanol were added and the mixture was stirred in an ice bath for 1 hour. After filtering and washing with methanol, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.2 parts of the anthraquinone compound represented by formula (15) below as a dark blue solid. The maximum absorption wavelength of this anthraquinone compound in a toluene solution was 639 nm. This anthraquinone compound １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0113]

[0114] １ H-NMR (C ３ D ６ O) δ14.552 (m), 14.464 (m), 11.707 (dd, 1H) 8.076 (dd, 2H), 7.557 (d, 2H), 7.349 (q, 4H), 7.281 (m, 1H), 7.258 (d, 2H), 7.205 ( d, 2H), 6.993 (s, 1H), 6.848 (dd, 4H), 4.324 (t, 2H), 4.247 (m, 2H), 4.203 (t, 2H), 3.954 (m, 4H), 3.305 (m, 3H), 3.089 (m, 3H), 1.507-1.291 (m, 39H), 0.899 (m, 15H)

[0115] Example 9 (Synthesis of the anthraquinone compound of the present invention represented by formula (18) below) (Step 9) Synthesis of the alcohol derivative represented by formula (16) 120 parts of DMF were mixed with 25 parts of 2-(4-hydroxyphenyl)ethanol, 30 parts of potassium carbonate, and 25 parts of 1-bromobutane, and the mixture was stirred at 80°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the solution was dried by vacuum drying to obtain 25 parts of the alcohol derivative represented by formula (16) below.

[0116]

[0117] (Step 10) Synthesis of the anthraquinone compound of the present invention represented by formula (18) below 15 parts of the alcohol derivative represented by formula (16) above 0.20 parts of potassium hydroxide were added and stirred at 80°C for 30 minutes, then 1.0 part of the compound represented by formula (17) below, synthesized by the method described in Japanese Patent Publication No. 62-5941, was added and stirred at 160°C for 11 hours. The reaction solution was cooled to 25°C and the solvent was removed by vacuum distillation, and the obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. After filtering, the mixture was washed with isopropyl alcohol and water, and then dried in a hot air dryer at 80°C for 12 hours to obtain 0.021 parts of the anthraquinone compound represented by formula (18) below as a dark blue solid. The maximum wavelength of the toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0118]

[0119]

[0120] １ H-NMR (C ３ D ６ O) δ14.822 (m, 1H), 14.47 (d, 1H), 11.446 (dd, 1H) 7.313 (m, 2H), 7.169 (m, 4H), 6.995 (m, 1H), 6.891 (m, 2H), 6.835 (m, 3H), 6.728 (s, 1H), 4.239 (t, 2H), 4.118 (t, 2H), 4.0 44 (t, 2H), 3.974 (t, 2H), 3.955 (t, 2H), 3.102 (t, 2H), 2.994 (t, 2H), 2,225 (s, 3H), 1 .816 (m, 2H), 1.735 (m, 4H), 1.571 (m, 2H), 1.507 (m, 4H), 1.006 (t, 3H), 0.961 (t, 6H),

[0121] Example 10 (Synthesis of the anthraquinone compound of the present invention represented by formula (20) below) 10 parts of the alcohol derivative represented by formula (3) above were added to 0.18 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by formula (19) below, synthesized by the method described in Japanese Patent Publication No. 62-5941, and 5.0 parts of sulfolane were added and stirred at 140°C for 12 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added, and the mixture was stirred for 1 hour. After filtering and washing with methanol, the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol and water, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.1 parts of the compound represented by formula (20) below as a dark blue solid. The maximum wavelength of the toluene solution of this anthraquinone compound was 610 nm. This anthraquinone compound １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0122]

[0123]

[0124] １ H-NMR (C ３ D ６O) δ14.807 (m), 14.460 (d), 11.474 (dd, 1H) 7.313 (q, 4H), 7.191 (d, 2H ), 7.054 (m, 2H), 6.891 (d, 2H), 6.839 (d, 2H), 6.791 (s, 1H), 6.728 (s, 1 H), 4.238 (t, 2H), 4.126 (t, 2H), 3.950 (m, 6H), 3.102 (t, 2H), 3.004 (t , 2H), 1.745 (m, 5H), 1.478-1.316 (m, 20H), 0.966 (t, 6H), 0.890 (m, 9H)

[0125] Synthesis Example 1 (Synthesis of Comparative Compound) An anthraquinone compound represented by the following formula (X) was obtained in accordance with the description in International Publication No. 2022 / 138440 and Japanese Patent Publication No. 58-63778. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0126]

[0127] １ H-NMR (C ３ D ６ O) δ14.686 (m, 1H), 14.403 (m, 1H), 11.396 (m, 1H) 9.873 (m, 1H), 7.164 ( m, 4H), 7.143 (m, 4H), 7.061 (m, 2H), 7.046 (m, 2H), 6.772 (m, 1H), 6.509 ( s, 1H), 4.037 (t, 2H), 4.002 (t, 2H), 2.934 (d, 3H), 2.579 (t, 2H), 1.780 ( m, 4H), 1.503 (m, 2H), 1.490 (m, 4H), 1.413-1.288 (m, 20H), 0.903 (m, 9H)

[0128] [NMR Measurement] 1.0 mg of the anthraquinone compound represented by formula (1) obtained in Example 1 and 50 mg of 4-cyano-4'-pentylbiphenyl were mixed with biacetone (C ３ D ６ O) Dissolve in 550 μL and use the above measurement conditions １ H-NMR measurements were performed.

[0129] The measurement method described above is used, except that the anthraquinone compound represented by formula (1) obtained in Example 1 is replaced with the anthraquinone compound represented by formula (4) obtained in Example 2, the anthraquinone compound represented by formula (6) obtained in Example 3, the anthraquinone compound represented by formula (8) obtained in Example 4, the anthraquinone compound represented by formula (10) obtained in Example 5, the anthraquinone compound represented by formula (11) obtained in Example 6, the anthraquinone compound represented by formula (13) obtained in Example 7, the anthraquinone compound represented by formula (15) obtained in Example 8, the anthraquinone compound represented by formula (18) obtained in Example 9, the anthraquinone compound represented by formula (20) obtained in Example 10, and the anthraquinone compound represented by formula (X) obtained in Synthesis Example 1. １ H-NMR measurements were performed.

[0130] Each of the anthraquinone compounds obtained in Examples 1 to 10 and Synthesis Example 1 was mixed with 4-cyano-4'-pentylbiphenyl and measured. １ The results were obtained by measuring the 1H-NMR spectrum and the anthraquinone compound individually. １ From the H-NMR spectrum, １ The changes in the chemical shift values ​​of H-NMR (|δ1-δA|, |δ2-δB|, |δ3-δC|) were calculated. The results are shown in Table 1 below.

[0131]

[0132] Example 11 (Preparation of the liquid crystal composition of the present invention) 0.006 parts of the anthraquinone compound obtained in Example 1, 0.306 parts of 4-cyano-4'-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 the liquid crystal composition of the present invention.

[0133] Examples 12 to 20 and Comparative Example 1 (Preparation of Liquid Crystal Compositions of the Present Invention and Comparative Example) Liquid crystal compositions of the present invention and comparative liquid crystal compositions were obtained in the same manner as in Example 11, except that the anthraquinone compound represented by formula (1) obtained in Example 1 was replaced with the anthraquinone compound represented by formula (4) obtained in Example 2, the anthraquinone compound represented by formula (6) obtained in Example 3, the anthraquinone compound represented by formula (8) obtained in Example 4, the anthraquinone compound represented by formula (10) obtained in Example 5, the anthraquinone compound represented by formula (11) obtained in Example 6, the anthraquinone compound represented by formula (13) obtained in Example 7, the anthraquinone compound represented by formula (15) obtained in Example 8, the anthraquinone compound represented by formula (18) obtained in Example 9, the anthraquinone compound represented by formula (20) obtained in Example 10, and the anthraquinone compound represented by formula (X) obtained in Synthesis Example 1.

[0134] Example 21 (Fabrication of the dimming element of the present invention) The liquid crystal composition obtained in Example 11 was sealed in an element with a substrate gap of 15 μm, consisting of two glass substrates, one above the other, each having a transparent electrode and a polyamide resin rubbing on the surface in contact with the liquid crystal to perform homogeneous orientation treatment. In the element obtained in this way, the liquid crystal took on a homogeneous orientation state when no voltage was applied, and the dye molecules (anthraquinone compound obtained in Example 1) also took on a similar orientation according to the liquid crystal.

[0135] Examples 22 to 30 and Comparative Example 2 (Preparation of dimming elements for the present invention and comparison) Dimming elements of the present invention were prepared in the same manner as in Example 21, except that the liquid crystal composition obtained in Example 11 was replaced with the liquid crystal composition obtained in Examples 12 to 20 and the liquid crystal composition obtained in Comparative Example 1, respectively.

[0136] (Calculation of Transmittance Difference of Dimming Elements) For the dimming elements obtained in each of Examples 21 to 30 and Comparative Example 2, the maximum absorption wavelength was measured, and the transmittance difference (transmittance change) was calculated from the transmittance (%) measurement results at the maximum absorption wavelength when no 100V AC current (50Hz sine wave) was applied (0V) and when 100V was applied. A larger transmittance difference value indicates higher contrast. The calculated results are shown in Table 2 below.

[0137]

[0138] Examples 31 to 40 and Comparative Example 3 (Lightfastness Test of Dimming Elements) A UV-cut filter of 380 nm or less was attached to each of the dimming elements obtained in Examples 21 to 30 and Comparative Example 2, and the illuminance was tested at 63°C with an illuminance of 650 W / m². ２ The dimmers were subjected to a lightfastness test by irradiating them with a metal halide lamp for 100 hours. The transmittance of the dimmers before and after the lightfastness test was measured using a spectrophotometer in the range of 380 to 780 nm, both without voltage applied (0V) and with voltage applied (100V). From the obtained transmission spectra, the chromaticity (L) was calculated according to JIS Z 8781-4:2013. ＊ a ＊ , b ＊ ) is calculated, and the color difference (ΔE) before and after the lightfastness test is calculated. ａｂ ) were calculated using the following formula (A). ΔE ａｂ A smaller value indicates less color change before and after the lightfastness test, signifying superior lightfastness. The calculated results are shown in Table 3 below. ΔE ａｂ (L ＊ a ＊ , b ＊ ) = {(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb ＊ ) ２} １／２ ... (A)

[0139]

[0140] 2. Examples and Comparative Examples According to the Second Aspect of the Invention <NMR Measurement> In the following examples and comparative examples according to the second aspect of the invention, NMR is measured under the following conditions. １ ¹H-NMR analysis: 1 mg of anthraquinone compound in deuterated acetone solvent (¹¹H) ３ D ６ O) Dissolve in 550 μL and measure at room temperature (usually around 25°C) at 600 MHz with 32 integration cycles. However, if the anthraquinone compound does not dissolve sufficiently in deuterated acetone, deuterated chloroform, deuterated DMSO, etc. may be used. In the explanation of nuclear magnetic resonance spectra, regarding peak coupling, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, and m means multiplet.

[0141] Example 41 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 75) 25 parts of 4-phenyl-1-butanol were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 2.0 parts of the compound represented by the following formula (3A), synthesized by the method described in Japanese Patent Publication No. 62-5941, were added and stirred at 160°C for 11 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and column chromatography was performed using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 75 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 2 hours. The mixture was then filtered and washed with isopropyl alcohol. The resulting solid was dissolved in toluene and column chromatography was performed using toluene and ethyl acetate as the developing solvents. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 1 hour. The sample was then removed, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.022 parts of the compound shown in specific example No. 75 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0142]

[0143] １ H-NMR (C ３ D ６ O) δ14.809 (m, 1H), 14.457 (m, 1H), 11.534 (d, 1H) 7.267 (m, 10H), 7.234 ( m, 2H), 7.169 (m, 2H), 6.924 (s, 1H), 6.693 (d, 2H), 6.841 (d, 2H), 6.714 ( s, 1H), 4.121 (t, 2H), 4.013 (t, 2H), 2.731 (t, 2H), 2.692 (t, 2H), 2.639 ( t, 2H), 1.914-1.779 (m, 8H), 1.634 (m, 2H), 1.387 (sex, 2H), 0.935 (m, 3H)

[0144] Example 42 (Synthesis of the Anthraquinone Compound of the Present Invention Represented by Specific Example No. 1) (Step 1A) Synthesis of the Alcohol Derivative Represented by Formula (4A) 120 parts of DMF were mixed with 25 parts of 2-(4-hydroxyphenyl)ethanol, 30 parts of potassium carbonate, and 35 parts of 1-bromohexane, and the mixture was stirred at 80°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was dried by vacuum drying to obtain 27 parts of the alcohol derivative represented by the following formula (4A).

[0145]

[0146] (Step 2A) Synthesis of the compound of the present invention represented by Specific Example No. 1 16 parts of the alcohol derivative represented by formula (4A) obtained in Step 1A were added to 0.096 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 0.50 parts of the compound represented by formula (3A) were added and stirred at 160°C for 11 hours. The reaction mixture was cooled to 25°C and 24 parts of toluene and 50 parts of saturated ammonium chloride aqueous solution were added, and the organic layer was separated. After drying with anhydrous magnesium sulfate, the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 10 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol, the mixture was dried in a vacuum dryer at 50°C for 12 hours to obtain 0.010 parts of the compound shown in Specific Example No. 1 as an orange solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0147] １ H-NMR (C ３ D ６ O) δ14.812 (m, 1H), 14.430 (m, 1H), 11.535 (dd, 1H) 7.308 (q, 6H), 7.214 (d, 2H), 6.9 33 (s, 1H), 6.888 (d, 2H), 6.843 (d, 2H), 6.722 (s, 1H), 4.233 (t, 2H), 4.153 (t, 2H), 3.968 (t, 2H), 3.951 (t, 2H), 3.097 (t, 2H), 3.020 (t, 2H), 2.650 (t, 2H), 1.758 (m, 4 H), 1.628 (m, 2H), 1.466 (m, 4H), 1.405-1.330 (m, 10H), 0.943 (t, 3H), 0.900 (m, 6H)

[0148] Example 43 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 6) 7.2 parts of the alcohol derivative represented by formula (4A) obtained in step 1A were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by the following formula (5A) synthesized by the method described in Japanese Patent Publication No. 62-5941 and 5.0 parts of sulfolane were added and stirred at 140°C for 11 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 75 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 2 hours. The mixture was then filtered and washed with isopropyl alcohol. The resulting solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvents. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and the mixture was stirred in an ice bath for 1 hour. The sample was then removed, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.010 parts of the compound shown in specific example No. 6 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0149]

[0150] １ H-NMR (C ３ D ６ O) δ14.822 (m, 1H), 14.431 (m, 1H), 11.539 (m, 1H) 7.310 (q, 6H), 7.213 (d, 2H ), 6.937 (s, 1H), 6.890 (d, 2H), 6.843 (d, 2H), 6.726 (s, 1H), 4.236 (t, 2H), 4 .. 157 (t, 2H), 3.969 (td, 4H), 3.099 (t, 2H), 3.020 (t, 2H), 2.649 (t, 2H), 1.7 53 (m, 4H), 1.724 (m, 2H), 1.458 (m, 4H), 1.374-1.305 (m, 16H), 0.900 (m, 9H)

[0151] Example 44 (Synthesis of the Anthraquinone Compound of the Present Invention Represented in Specific Example No. 15) (Step 3A) Synthesis of the Alcohol Derivative Represented by Formula (6A) 42 parts of DMF were mixed with 15 parts of 2-(4-hydroxyphenyl)ethanol, 18 parts of potassium carbonate, and 25 parts of 1-bromooctane, and the mixture was stirred at 85°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was dried by vacuum drying to obtain 15 parts of the alcohol derivative represented by the following formula (6A).

[0152]

[0153] (Step 4A) Synthesis of the compound of the present invention represented by Specific Example No. 15: 17 parts of the alcohol derivative represented by formula (6A) obtained in Step 3A were added to 0.19 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by formula (5A) was added and stirred at 160°C for 7 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added and stirred for 1 hour. After filtering and washing with methanol, the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol and water, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.045 parts of the compound shown in Specific Example No. 15 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0154] １ H-NMR (C ３ D ６O) δ14.814 (m, 1H), 14.422 (m, 1H), 11.569 (dd, 1H) 7.305 (m, 6H), 7.208 (d, 2 H), 6.930 (s, 1H), 6.885 (d, 2H), 6.841 (d, 2H), 6.714 (s, 1H), 4.226 (t, 2H), 4 .. 149 (t, 2H), 3.967 (sex, 4H), 3.091 (t, 2H), 3.014 (t, 2H), 2.648 (t, 2H), 1.7 52 (m, 4H), 1.650 (m, 2H), 1.470 (m, 4H), 1.390-1.302 (m, 24H), 0.904 (m, 9H)

[0155] Example 45 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 30) 10 parts of the alcohol derivative represented by formula (4A) obtained in step 1A were added to 0.18 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 0.85 parts of the compound represented by the following formula (7A), synthesized by the method described in Japanese Patent Publication No. 62-5941, and 5.0 parts of sulfolane were added and stirred at 140°C for 7 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added, and the mixture was stirred for 1 hour. After filtering and washing with methanol, the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and the mixture was stirred in an ice bath for 1 hour. After filtering and washing with methanol and water, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.019 of the compound represented by specific example No. 30 as a dark blue solid. The maximum wavelength of this compound in a toluene solution was 610 nm.

[0156]

[0157] Example 46 (Synthesis of the Anthraquinone Compound of the Present Invention Represented in Specific Example No. 20) (Step 5A) Synthesis of the Alcohol Derivative Represented by Formula (8A) 120 parts of DMF were mixed with 24 parts of 2-(4-hydroxyphenyl)ethanol, 36 parts of potassium carbonate, and 50 parts of 2-ethylhexyl bromide, and the mixture was stirred at 85°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was dried by vacuum drying to obtain 22 parts of the alcohol derivative represented by the following formula (8A).

[0158]

[0159] (Step 6A) Synthesis of the compound of the present invention represented by specific example No. 20: 13 parts of the alcohol derivative represented by formula (8A) obtained in Step 5A were added to 0.21 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by formula (3A) was added and stirred at 160°C for 15 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.010 parts of the compound shown in specific example No. 20 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0160] １ H-NMR (C ３ D ６O) δ14.824 (m, 1H), 14.434 (m, 1H), 11.539 (m, 1H) 7.312 (m, 6H), 7.219 (d , 2H), 6.937 (s, 1H), 6.909 (d, 2H), 6.862 (d, 2H), 6.730 (s, 1H), 4.240 (t , 2H), 4.159 (t, 2H), 3.871 (qd, 4H), 3.103 (t, 2H), 3.025 (t, 2H), 2.652 ( t, 2H), 1.644 (m, 2H), 1.619 (m, 2H), 1.519-1.334 (m, 18H), 0.933 (m, 15H)

[0161] Example 47 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 24) 11 parts of the alcohol derivative represented by formula (8A) obtained in step 5A were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 1.0 part of the compound represented by formula (5A) was added and stirred at 160°C for 8 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.008 parts of the compound represented by specific example No. 24 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0162] １ H-NMR (C ３ D ６O) δ14.807 (m, 1H), 14.415 (m, 1H), 11.528 (m, 1H), 7.304 (q, 6H), 7.210 ( d, 2H), 6.926 (s, 1H), 6.903 (d, 2H), 6.857 (d, 2H), 6.703 (s, 1H), 4.222 (t , 2H), 4.145 (t, 2H), 3.873 (qd, 4H), 3.091 (t, 2H), 3.013 (t, 2H), 2.646 ( t, 2H), 1.707 (m, 2H), 1.665 (m, 2H), 1.528-1.299 (m, 24H), 0.900 (m, 15H)

[0163] Example 48 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 27) 10 parts of the alcohol derivative represented by formula (8A) obtained in step 5A were added to 0.18 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then 1.0 part of the compound represented by formula (7A) was added and stirred at 160°C for 24 hours. The reaction mixture was cooled to 25°C and the solvent was removed by vacuum distillation. The resulting liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.021 parts of the compound shown in specific example No. 27 as a dark blue solid. The maximum wavelength of the toluene solution of this compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0164] １ H-NMR (C ３ D ６O) δ14.821 (m), 14.430 (m), 11.574 (dd, 1H) 7.309 (m, 6H), 7.215 (d, 2H), 6.936 (s, 1H), 6.908 (d, 2H), 6.860 ( d, 2H), 6.722 (s, 1H), 4.237 (t, 2H), 4.157 (t, 2H), 3.872 (qd, 4H), 3.102 (t, 2H), 3.021 (t, 2H), 2.651 (t, 2H), 1.720 (m, 2H), 1.660 (m, 2H), 1.560-1.289 (m, 30H), 0.933 (t, 6H), 0.890 (m, 9H)

[0165] Example 49 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 21) 10 parts of the alcohol derivative represented by formula (4A) obtained in step 1A were added to 0.18 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by the following formula (9A), synthesized by the method described in Japanese Patent Publication No. 62-5941, and 5.0 parts of sulfolane were added and stirred at 140°C for 12 hours. The reaction mixture was cooled to 25°C, 60 parts of methanol were added, and the mixture was stirred for 1 hour. After filtering and washing with methanol, the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol and water, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.1 parts of the compound represented by specific example No. 21 as a dark blue solid. The maximum wavelength of this compound in a toluene solution was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0166]

[0167] １ H-NMR (C ３ D ６O) δ14.807 (m), 14.460 (d), 11.474 (dd, 1H) 7.313 (q, 4H), 7.191 (d, 2H ), 7.054 (m, 2H), 6.891 (d, 2H), 6.839 (d, 2H), 6.791 (s, 1H), 6.728 (s, 1 H), 4.238 (t, 2H), 4.126 (t, 2H), 3.950 (m, 6H), 3.102 (t, 2H), 3.004 (t , 2H), 1.745 (m, 5H), 1.478-1.316 (m, 20H), 0.966 (t, 6H), 0.890 (m, 9H)

[0168] Example 50 (Synthesis of the Anthraquinone Compound of the Present Invention Represented in Specific Example No. 37) (Step 7A) Synthesis of the Alcohol Derivative Represented by Formula (10A) 120 parts of DMF were mixed with 25 parts of 2-(4-hydroxyphenyl)ethanol, 30 parts of potassium carbonate, and 25 parts of 1-bromobutane, and the mixture was stirred at 80°C for 6 hours. After the reaction mixture was cooled to 25°C, 60 parts of toluene, 60 parts of ethyl acetate, and 240 parts of water were added, and the organic layer was separated. The organic layer was further washed with 160 parts of water, and the aqueous layer was extracted with 120 parts of ethyl acetate. The organic layer separated above and the ethyl acetate extract were mixed, dried over anhydrous magnesium sulfate, and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After the solvent was removed from the purified solution by vacuum distillation, the mixture was dried by vacuum drying to obtain 25 parts of the alcohol derivative represented by the following formula (10A).

[0169]

[0170] (Step 8A) Synthesis of the compound of the present invention represented by specific example No. 37: 15 parts of the alcohol derivative represented by formula (10A) obtained in Step 7A were added to 0.20 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by the following formula (11A) synthesized by the method described in Japanese Patent Publication No. 62-5941 was added and stirred at 160°C for 11 hours. The reaction solution was cooled to 25°C and the solvent was removed by vacuum distillation. The obtained liquid was dissolved in toluene and purified by column chromatography using toluene as the developing solvent. After removing the solvent from the purified solution by vacuum distillation, 5.0 parts of toluene and 50 parts of isopropyl alcohol were added and stirred in an ice bath for 3 hours. The mixture was then filtered, washed with isopropyl alcohol and water, and dried in a hot air dryer at 80°C for 12 hours to obtain 0.021 parts of the anthraquinone compound shown in specific example No. 37 as a dark blue solid. The maximum wavelength of the toluene solution of this anthraquinone compound was 610 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0171]

[0172] １ H-NMR (C ３ D ６ O) δ14.822 (m, 1H), 14.47 (d, 1H), 11.446 (dd, 1H) 7.313 (m, 2H), 7.169 (m, 4H), 6.995 (m, 1H), 6.891 (m, 2H), 6.835 (m, 3H), 6.728 (s, 1H), 4.239 (t, 2H), 4.118 (t, 2H), 4.0 44 (t, 2H), 3.974 (t, 2H), 3.955 (t, 2H), 3.102 (t, 2H), 2.994 (t, 2H), 2,225 (s, 3H), 1 .816 (m, 2H), 1.735 (m, 4H), 1.571 (m, 2H), 1.507 (m, 4H), 1.006 (t, 3H), 0.961 (t, 6H),

[0173] Example 51 (Synthesis of the anthraquinone compound of the present invention represented by specific example No. 81) 14.8 parts of the alcohol derivative represented by formula (4A) obtained in step 1A were added to 0.47 parts of potassium hydroxide and stirred at 80°C for 30 minutes. Then, 1.0 part of the compound represented by the following formula (12A) synthesized by the method described in Japanese Patent Publication No. 62-5941 and 10 parts of sulfolane were added and stirred at 140°C for 7 hours. The reaction mixture was cooled to 25°C and 60 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol, the obtained solid was dissolved in toluene and purified by column chromatography using toluene and ethyl acetate as the developing solvent. After removing the solvent from the purified solution under reduced pressure, 5.0 parts of toluene and 50 parts of methanol were added and stirred in an ice bath for 1 hour. After filtering and washing with methanol and water, the mixture was dried in a hot air dryer at 80°C for 12 hours to obtain 0.21 parts of the compound represented by specific example No. 81 as a dark blue solid. The maximum wavelength of this compound in a toluene solution was 614 nm. １ The 1H-NMR measurement results (chemical shift values ​​in ppm units) are shown below.

[0174]

[0175] １ H-NMR (C ３ D ６ O) δ14.807 (m), 14.460 (d), 11.458 (dd, 1H) 7.315 (m, 2H), 7.191 (m, 2H), 7.2 06 (m, 4H), 6.891 (m, 2H), 6.832 (m, 2H), 6.802 (m, 3H), 6.715 (s, 1H), 4.236 ( t, 2H), 4.113 (t, 2H), 3.959 (td, 4H), 3.440 (t, 4H), 3.101 (t, 2H), 2.997 (t, 2H), 1.745 (m, 4H), 1.467 (m, 4H), 1.349 (m, 8H), 1.177 (t, 6H), 0.900 (t, 6H)

[0176] Synthesis Example 2 (Synthesis of Comparative Example Compound) Following the description in Example 411 of Japanese Patent Publication No. 58-196260, a compound represented by the following formula (XA) was obtained.

[0177]

[0178] Example 52 (Preparation of the liquid crystal composition of the present invention) 0.006 parts of the compound represented by specific example No. 75 obtained in Example 41, 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 the liquid crystal composition of the present invention.

[0179] Examples 53 to 62 and Comparative Example 4 (Preparation of Liquid Crystal Compositions of the Present Invention and Comparative Example) Liquid crystal compositions of the present invention and comparative examples were obtained in accordance with Example 52, except that the compound represented by No. 75 obtained in Example 41 was replaced with the compound represented by Specific Example No. 1 obtained in Example 42, the compound represented by Specific Example No. 6 obtained in Example 43, the compound represented by Specific Example No. 15 obtained in Example 44, the compound represented by Specific Example No. 30 obtained in Example 45, the compound represented by Specific Example No. 20 obtained in Example 46, the compound represented by Specific Example No. 24 obtained in Example 47, the compound represented by Specific Example No. 27 obtained in Example 48, the compound represented by Specific Example No. 21 obtained in Example 49, the compound represented by Specific Example No. 37 obtained in Example 50, the compound represented by Specific Example No. 81 obtained in Example 51, and the compound represented by formula (XA) obtained in Synthesis Example 2.

[0180] Example 63 (Fabrication of the dimming element of the present invention) The liquid crystal composition obtained in Example 52 was sealed in an element with a substrate gap of 15 μm, consisting of two glass substrates, one above the other, each having a transparent electrode and a polyamide resin rubbing on the surface in contact with the liquid crystal to perform homogeneous orientation treatment. In the element obtained above, the liquid crystal took on a homogeneous orientation state when no voltage was applied, and the dye molecules (anthraquinone compound obtained in Example 41) also took on a similar orientation according to the liquid crystal.

[0181] Examples 64 to 73 and Comparative Example 5 (Preparation of the present invention and comparative dimming elements) The present invention and comparative dimming elements were prepared in accordance with Example 63, except that the liquid crystal composition obtained in Example 52 was replaced with the liquid crystal compositions obtained in Examples 53 to 62 and Comparative Example 4, respectively.

[0182] (Calculation of Transmittance Difference of Dimming Elements) For each of the dimming elements obtained in Examples 63 to 73 and Comparative Example 5, the maximum absorption wavelength was measured, and the transmittance difference (transmittance change) was calculated from the transmittance (%) measurement results at the maximum absorption wavelength when no 100V AC current (50Hz sine wave) was applied (0V) and when it was applied (100V). A larger transmittance difference value indicates higher contrast. The results are shown in Table 4.

[0183]

[0184] As shown in Table 4, the dimming elements of Examples 63 to 73 have higher contrast values ​​than the dimming element of Comparative Example 5, clearly demonstrating their superiority as dimming elements.

[0185] (Lightfastness test of dimming elements) Each of the dimming elements obtained in Examples 63 to 73 and Comparative Example 5 was fitted with a UV cut filter of 380 nm or less, and tested at an illuminance of 650 W / m² at 63°C. ２ The light-resistant elements were subjected to a light-resistance test by irradiating them with a metal halide lamp for 100 hours. The transmittance of the light-resistant elements before and after the light-resistance test was measured using a spectrophotometer in the range of 380 to 780 nm. From the obtained transmission spectra, the chromaticity (L*, a*, b*) was calculated according to JIS Z 8781-4:2013, and the color difference (ΔE) before and after the light-resistance test was calculated. ａｂ The following formulas (C) were used to calculate ΔE. ａｂ A smaller value indicates less color change before and after the lightfastness test, signifying superior lightfastness. The results are shown in Table 5. ΔE ａｂ (L*, a*, b*) = {(ΔL*) ２ + (Δa*) ２ + (Δb*) ２} １／２ ...Formula (C)

[0186]

[0187] As shown in Table 5, the dimming elements of Examples 63 to 73 showed a smaller color difference before and after the lightfastness test than the dimming element of Comparative Example 5, confirming that they have superior lightfastness.

[0188] By using a liquid crystal composition containing an anthraquinone compound according to the first embodiment of the present invention or an anthraquinone compound according to the second embodiment, a dimmable liquid crystal element having high light resistance and high contrast can be obtained. Such a dimmable element can be suitably used in a wide range of applications, such as outdoor building materials and automotive applications, where high durability, two-color ratio, and design are required.

Claims

1. １ An anthraquinone compound characterized by satisfying the following relation (1) with respect to the chemical shift of H-NMR: 0.015 ≤ |δ2 - δB| ≤ 0.150 ... (1) In relation (1), δ2 is the chemical shift value (unit: ppm) in the range of 13.5 ppm to 15.0 ppm; δB represents the chemical shift value (unit: ppm) of the same peak as the δ2 ​​peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl in a mass ratio of 1:50; however, if there are multiple |δ2 - δB|, it represents the maximum value.

2. Furthermore １ The anthraquinone compound according to claim 1 is characterized in that it satisfies the following relation (2) with respect to the chemical shift of H-NMR: 0.005 ≤ |δ1 - δA| ≤ 0.120 ... (2) In relation (2), δ1 is the chemical shift value (unit: ppm) in the range of 6.0 ppm to 7.5 ppm; δA represents the chemical shift value (unit: ppm) of the same peak as the δ1 peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50; however, if there are multiple |δ1 - δA|, it means the maximum value.

3. Furthermore １ The anthraquinone compound according to claim 1 is characterized in that it satisfies the following relation (3) with respect to the chemical shift of H-NMR: 0.005 ≤ |δ3 - δC| ≤ 0.150 ... (3) In relation (3), δ3 is the chemical shift value (unit: ppm) in the range of 10.5 ppm to 12.0 ppm; δC represents the chemical shift value (unit: ppm) of the same peak as the δ3 peak shifted to a different position in a mixture of the anthraquinone compound and 4-cyano-4'-pentylbiphenyl mixed in a mass ratio of 1:50; however, if there are multiple |δ3 - δC|, it means the maximum value.

4. (I-1) an anthraquinone compound according to any one of claims 1 to 3, and (II) a liquid crystal composition containing a liquid crystal material.

5. A dimming element comprising a pair of opposing substrates, at least one of which is a transparent substrate having a transparent electrode, with the liquid crystal composition according to claim 4 sandwiched between them.

6. The dimming element according to claim 5, wherein both of the pair of substrates are transparent substrates having transparent electrodes.

7. A vehicle-mounted dimmable window comprising the dimming element described in claim 5 or claim 6.

8. An anthraquinone compound represented by the following formula (1A). (wherein R １ represents a substituent selected from the group consisting of a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms or a branched alkyl group having 3 to 16 carbon atoms, a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 16 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ , a cyano group, and a nitro group. R ２ and R ３ each independently represent a substituent selected from the group consisting of 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, a halogen atom, -CO ２ R ５ , -OCOR ５ , -COR ５ , -NR ６ R ７ , -CF ３ , a cyano group, and a nitro group. R ４ each independently represent a substituent selected from the group consisting of 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, and -NR ６ R ７ R ５ each independently represent a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms. R ６ and R ７ each independently represent a hydrogen atom, or a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, provided that not all of R ６ and R ７ are hydrogen atoms. n each independently represent 2 to 4.) 9. R in equation (1A) １ However, hydrogen atoms, linear alkyl groups having 1 to 16 carbon atoms or branched alkyl groups having 3 to 16 carbon atoms, linear alkoxy groups having 1 to 16 carbon atoms or branched alkoxy groups having 3 to 16 carbon atoms, -OCOR ５ , or -NR ６ R ７ A substituent represented by R ２ and R ３ However, each is 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, and -OCOR ５ , or -NR ６ R ７ A substituent represented by R ４ However, each independently comprises a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms, a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, or -NR ６ R ７ The anthraquinone compound according to claim 8, wherein the substituent is represented by .

10. R in equation (1A) １ However, the substituent is represented by a hydrogen atom, a linear alkyl group having 1 to 16 carbon atoms or a branched alkyl group having 3 to 16 carbon atoms, or a linear alkoxy group having 1 to 16 carbon atoms or a branched alkoxy group having 3 to 16 carbon atoms, R ２ and R ３ The anthraquinone compound according to claim 9, wherein each is 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 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

11. The anthraquinone compound according to claim 10, wherein n in formula (1A) is 2 or 4.

12. R in equation (1A) ３ The anthraquinone compound according to claim 11, wherein is a hydrogen atom.

13. R in equation (1A) １ and R ２ The anthraquinone compound according to claim 12, wherein one of the atoms is a hydrogen atom.

14. R in equation (1A) ２ The anthraquinone compound according to claim 13, wherein the atom is a hydrogen atom.

15. The anthraquinone compound according to claim 14, wherein n in formula (1A) is 2.

16. R in equation (1A) １ The anthraquinone compound according to claim 15, wherein the anthraquinone compound is a linear or branched alkyl group having 4 to 12 carbon atoms, or a linear or branched alkoxy group having 4 to 12 carbon atoms.

17. R in equation (1A) ４ The anthraquinone compound according to claim 8, wherein the group is a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms.

18. R in equation (1A) ４ The anthraquinone compound according to claim 17, wherein the alkoxy group is a straight-chain or branched-chain having 4 to 12 carbon atoms.

19. A liquid crystal composition comprising an anthraquinone compound and a liquid crystal material according to any one of claims 8 to 18.

20. The liquid crystal composition according to claim 19, further comprising at least one dye compound other than the anthraquinone compound represented by formula (1A).

21. A dimming element comprising a pair of opposing substrates, at least one of which is a transparent substrate having a transparent electrode, with the liquid crystal composition according to claim 19 or 20 sandwiched between them.

22. A vehicle-mounted dimmable window comprising the dimming element described in claim 21.

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