Liquid crystal composition containing anthraquinone compound and light-modulating element

Abstract

The present invention relates to a liquid-crystal composition comprising (A) dye compounds and (B) a liquid-crystal material, wherein the dye compounds (A) include an anthraquinone compound represented by general formula (1) and an anthraquinone compound represented by general formula (2) in a specific proportion and further include a dye compound which is neither the anthraquinone compound represented by general formula (1) nor the anthraquinone compound represented by general formula (2). The present invention further relates to a liquid-crystal composition comprising the (A) and (B) components and further containing (C) a photocurable compound and (D) a photopolymerization initiator, a cured object obtained from the liquid-crystal composition, and a light-modulating element in which the liquid-crystal composition or the cured object is sandwiched therein.

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal composition containing an anthraquinone compound, and a light-adjusting element using the liquid crystal composition or a photocured product of the composition. [Background technology]

[0002] For purposes such as privacy protection, light-controlling panels have become commonplace in windows, doors, and partitions in vehicles such as trains and automobiles, and buildings such as business buildings and hospitals. These panels include films obtained by dispersing liquid crystals in polymers, and films with a light-controlling layer formed by utilizing the phase separation of a liquid crystal material upon photocuring of a composition containing a photocurable compound and a liquid crystal. While such light-controlling panels typically block visibility by controlling the transmission and scattering of light depending on whether or not a voltage is applied, they cannot block light itself, and therefore tend to increase glare due to light scattering. Therefore, attempts have been made to use dyes as materials for light-controlling panels in order to reduce glare and improve contrast. For example, when such light-controlling panels are used in automobile windows, they are required to provide clear visibility without fogging when light is transmitted, while also providing high light-blocking properties when scattered. This has led to a growing demand for black elements that can block visible light from the perspectives of practicality and design.

[0003] To meet the above market demands, various liquid crystal display devices called GH (guest-host) type have been proposed, which use liquid crystal compositions containing dyes. These liquid crystal display devices, which are characterized by their viewing angle and brightness, have also been put to practical use in automobiles and as light-control devices.

[0004] Dichroic dyes commonly used in liquid crystal compositions for dimming devices are required to have not only contrast when used in the device, but also lightfastness, UV resistance, heat resistance, and compatibility (solubility) of the dichroic dye with the components of the liquid crystal composition. While efforts have been made to improve these properties, color retention of the dimming device when light is transmitted through it has become an issue when used in black dimming devices. Color retention during transmission can cause poor visibility, so it is desirable to make the device as colorless and transparent as possible. Since the red region in particular has high visibility, it is important to prevent color retention in this region. The dichroic dyes described in Patent Documents 1 and 2 have improved lightfastness and contrast, but do not meet market demands for color retention during transmission. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-336366 A [Patent Document 2] Patent No. 5659512 Summary of the Invention [Problem to be solved by the invention]

[0006] A first object of the present invention is to provide a novel liquid crystal composition containing a dye compound having a specific structure. Another object of the present invention is to provide a light-adjusting element which contains the liquid crystal composition or a cured product of the liquid crystal composition and which has excellent contrast and an effect of suppressing red coloration in transmission. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found a novel liquid crystal composition containing a plurality of anthraquinone compounds (dichroic dyes) having specific structures and dye compounds other than the anthraquinone compounds. The present inventors have also found that by using such a novel liquid crystal composition, it is possible to provide a light-controlling element that is excellent in contrast and in the effect of suppressing red coloration in transmission. That is, the various aspects included in the present invention are as follows. (1). A liquid crystal composition containing (A) a dye compound and (B) a liquid crystal material, The (A) dye compound is (i) The following general formula (1) [ka] (In formula (1), one of X and Y represents a hydroxy group, and the other of X and Y represents a hydrogen atom, a hydroxy group, or an amino group. One of R1 and R2 represents a hydrogen atom, and the other of R1 and R2 represents a group represented by the following formula (a): [ka] (In formula (a), R7 represents a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a group represented by the following formula (b): [ka] (in formula (b), R8 represents a linear or branched alkyl group having 1 to 12 carbon atoms), and Z1 represents an oxygen atom or a sulfur atom. However, when X is a hydroxy group and Y is a hydrogen atom or an amino group, R1 represents a substituent represented by formula (a) and R2 represents a hydrogen atom, and when X is a hydrogen atom or an amino group and Y is a hydroxy group, R1 represents a hydrogen atom and R2 represents a substituent represented by formula (a). R3 represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or a substituent represented by the above formula (b), and R4 represents a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a substituent represented by the above formula (b). an anthraquinone compound represented by (ii) the following general formula (2) [ka] (In formula (2), R5 represents a linear or branched alkyl group having 1 to 18 carbon atoms, or a linear or branched alkoxy group having 1 to 18 carbon atoms, and R6 represents a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a substituent represented by formula (b) above.) An anthraquinone compound represented by the formula: (iii) Dye compounds other than the anthraquinone compounds represented by general formula (1) or the anthraquinone compounds represented by general formula (2) (i.e., dye compounds that are neither the anthraquinone compounds represented by general formula (1) nor the anthraquinone compounds represented by general formula (2)) Including, the mass ratio of the anthraquinone compound represented by general formula (1) to the anthraquinone compound represented by general formula (2) is 2:1 to 1:2; Liquid crystal composition. (2). The liquid crystal composition according to item (1) above, wherein X is a hydroxy group, Y is an amino group, R1 is a substituent represented by formula (a), and Z1 is an oxygen atom. (3). The liquid crystal composition according to the above item (2), wherein R4 and R7 are each independently a linear or branched alkyl group having 6 to 12 carbon atoms, or a linear or branched alkoxy group having 6 to 12 carbon atoms. (4). The liquid crystal composition according to the above item (3), wherein R3 is a linear or branched alkyl group having 4 to 7 carbon atoms, or a linear or branched alkoxy group having 4 to 7 carbon atoms. (5). The liquid crystal composition according to the preceding item (2), wherein R4 and R7 are each independently a substituent represented by the above formula (b), and R3 is a linear or branched alkyl group having 1 to 8 carbon atoms, or a linear or branched alkoxy group having 1 to 8 carbon atoms. (6). The liquid crystal composition according to the above item (5), wherein R4 and R7 are each independently a substituent represented by the above formula (b), and R8 is a linear or branched alkyl group having 3 to 8 carbon atoms. (7). The liquid crystal composition according to any one of items (1) to (6), further comprising (C) a photocurable compound and (D) a photopolymerization initiator. (8). (C) The liquid crystal composition according to the above item (7), wherein the photocurable compound contains a monofunctional monomer having one polymerizable functional group and a bifunctional monomer having two polymerizable functional groups. (9). (C) The liquid crystal composition according to item (8), wherein the photocurable compound contains a mono(meth)acrylate compound and a di(meth)acrylate compound. (10). A cured product of the liquid crystal composition according to any one of items (7) to (9). (11). A light-controlling element comprising a pair of substrates arranged opposite each other, at least one of which is a transparent substrate having a transparent electrode, and a liquid crystal composition according to any one of items (1) to (6) or a cured product according to item (10) sandwiched between the pair of substrates. (12). With a voltage applied between a pair of substrates, the hue a obtained by the method specified in JIS Z 8781-4:2013 * The light-adjusting element according to (11) above, wherein the value is 5.0 or less. (13). When a voltage is applied between the pair of substrates, the difference between the smallest and largest minimum transmittance values ​​in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less, and The light-controlling element according to the preceding item (11) or (12), wherein, when no voltage is applied, the difference between the smallest transmittance value and the largest transmittance value in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less. In this specification, the term "anthraquinone compound" refers to a compound (dye) having an anthraquinone structure as the main skeleton. [Effects of the Invention]

[0008] By using the liquid crystal composition of the present invention, a light-controlling element having excellent contrast and an effect of suppressing red coloration during transmission can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. The liquid crystal composition of the present invention (hereinafter sometimes simply referred to as "the composition of the present invention") contains an anthraquinone compound represented by the following formula (1). The anthraquinone compound represented by formula (1) contained in the composition of the present invention functions as a dichroic dye in the composition of the present invention.

[0010] [ka]

[0011] In formula (1), one of X and Y represents a hydroxy group, and the other of X and Y represents a hydrogen atom, a hydroxy group, or an amino group. One of R1 and R2 represents a hydrogen atom, and the other of R1 and R2 represents a substituent represented by the following formula (a). However, when X is a hydroxy group and Y is a hydrogen atom or an amino group, R1 represents a substituent represented by the following formula (a) and R2 represents a hydrogen atom. When X is a hydrogen atom or an amino group and Y is a hydroxy group, R1 represents a hydrogen atom and R2 represents a substituent represented by the following formula (a). It is preferred that X is a hydroxy group, Y is an amino group, R1 is a substituent represented by formula (a), and R2 is a hydrogen atom. R3 represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or a substituent represented by the following formula (b). R4 represents a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a substituent represented by the following formula (b).

[0012] [ka]

[0013] In formula (a), R7 represents a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a substituent represented by the following formula (b). Z1 represents an oxygen atom or a sulfur atom. Z1 is preferably an oxygen atom.

[0014] Specific examples of the linear or branched alkyl group having 4 to 12 carbon atoms represented by R7 in formula (a) include n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, neo-pentyl, t-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl. A linear or branched alkyl group having 6 to 12 carbon atoms, such as n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, or n-dodecyl, is preferred, a linear or branched alkyl group having 6 to 9 carbon atoms is more preferred, and a linear or branched alkyl group having 7 or 8 carbon atoms is even more preferred.

[0015] The straight-chain or branched-chain alkoxy group having 4 to 12 carbon atoms represented by R7 in formula (a) is a substituent in which an oxygen atom is bonded to a straight-chain or branched-chain alkyl group having 4 to 12 carbon atoms. Specific examples of the alkyl group (the alkyl group in the alkoxy group) include the same as the straight-chain or branched-chain alkyl group having 4 to 12 carbon atoms represented by R7 in formula (a). Specific examples of the straight-chain or branched-chain alkoxy group having 4 to 12 carbon atoms include an n-butyloxy group, an iso-butyloxy group, a t-butyloxy group, an n-pentyloxy group, an iso-pentyloxy group, a neo-pentyloxy group, a t-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-nonyloxy group, an n-decyloxy group, an n-undecyloxy group, and an n-dodecyloxy group. A straight-chain or branched-chain alkoxy group having 6 to 12 carbon atoms, such as an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, or an n-dodecyloxy group, is preferred, a straight-chain or branched-chain alkoxy group having 6 to 9 carbon atoms is more preferred, and a straight-chain or branched-chain alkoxy group having 7 or 8 carbon atoms is even more preferred.

[0016] Specific examples of the linear or branched alkyl group having 1 to 12 carbon atoms represented by R3 in formula (1) include methyl, ethyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, neo-pentyl, t-pentyl, hexyl, heptyl, octyl, and nonyl groups. Preferred are n-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, and n-dodecyl groups. More specifically, the number of carbon atoms in the linear or branched alkyl group having 1 to 12 carbon atoms represented by R3 in formula (1) is preferably 4 to 7 when R4 and R7 are alkyl groups, and is preferably 1 to 8, more preferably 3 to 8, when R4 and R7 are substituents represented by (b).

[0017] The straight-chain or branched-chain alkoxy group having 1 to 12 carbon atoms represented by R3 in formula (1) is a substituent in which an oxygen atom is bonded to a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms. Specific examples of the alkyl group (the alkyl group in the alkoxy group) include the same as the alkyl group having 1 to 12 carbon atoms represented by R3 in formula (1). Specific examples of the straight-chain or branched-chain alkoxy group having 1 to 12 carbon atoms include methyloxy, ethyloxy, n-butyloxy, iso-butyloxy, t-butyloxy, n-pentyloxy, iso-pentyloxy, neo-pentyloxy, t-pentyloxy, n-hexyloxy, n-heptyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, and n-dodecyloxy. An n-butyloxy group, a t-butyloxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, or an n-dodecyloxy group is preferred. More specifically, the number of carbon atoms in the linear or branched alkoxy group having 1 to 12 carbon atoms represented by R3 in formula (1) is preferably 4 to 7 when R4 and R7 are alkyl groups, and is preferably 1 to 8, more preferably 3 to 8, when R4 and R7 are substituents represented by formula (b).

[0018] Specific examples of the linear or branched alkyl group having 4 to 12 carbon atoms represented by R4 in formula (1) include n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, iso-pentyl, neo-pentyl, t-pentyl, hexyl, heptyl, octyl, and nonyl groups. Linear or branched alkyl groups having 6 to 12 carbon atoms, such as n-hexyl, n-heptyl, n-octyl, and n-dodecyl, are preferred, linear or branched alkyl groups having 6 to 9 carbon atoms are more preferred, and linear or branched alkyl groups having 7 to 8 carbon atoms are even more preferred.

[0019] The linear or branched alkoxy group having 4 to 12 carbon atoms represented by R4 in formula (1) is a substituent in which a linear or branched alkyl group having 4 to 12 carbon atoms is bonded to an oxygen atom. Specific examples of the alkoxy group include n-butyloxy, iso-butyloxy, t-butyloxy, n-pentyloxy, iso-pentyloxy, neo-pentyloxy, t-pentyloxy, n-hexyloxy, n-heptyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, and n-dodecyloxy. A linear or branched alkoxy group having 6 to 12 carbon atoms, such as n-hexyloxy, n-heptyloxy, n-octyloxy, or n-dodecyloxy, is preferred, a linear or branched alkoxy group having 6 to 9 carbon atoms is more preferred, and a linear or branched alkoxy group having 7 to 8 carbon atoms is even more preferred.

[0020] [ka]

[0021] In formula (b), R8 represents a linear or branched alkyl group having 1 to 12 carbon atoms. Specific examples of the linear or branched alkyl group having 1 to 12 carbon atoms represented by R8 in formula (b) include a methyl group, an ethyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neo-pentyl group, a t-pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group, etc. An n-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, or an n-dodecyl group is preferred. In addition, in the composition of the present invention, a plurality of anthraquinone compounds included in formula (1) may be used in combination.

[0022] The composition of the present invention contains an anthraquinone compound represented by the following formula (2). The anthraquinone compound represented by formula (2) contained in the composition of the present invention functions as a dichroic dye in the composition of the present invention.

[0023] [ka]

[0024] In formula (2), R5 represents a linear or branched alkyl group having 1 to 18 carbon atoms, or a linear or branched alkoxy group having 1 to 18 carbon atoms. R6 represents a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a substituent represented by formula (b) above.

[0025] Specific examples of the linear or branched alkyl group having 1 to 18 carbon atoms represented by R5 in formula (2) include a methyl group, an ethyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an iso-pentyl group, a neo-pentyl group, a t-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, etc. A linear or branched alkyl group having 1 to 8 carbon atoms such as a methyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a hexyl group, a heptyl group, an octyl group, etc. is preferred.

[0026] The linear or branched alkoxy group having 1 to 18 carbon atoms represented by R5 in formula (2) is a substituent in which a linear or branched alkyl group having 1 to 18 carbon atoms is bonded to an oxygen atom. Specific examples of the alkoxy group include methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, isobutyloxy, t-butyloxy, n-pentyloxy, isopentyloxy, neo-pentyloxy, t-pentyloxy, n-hexyloxy, n-heptyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, and n-dodecyloxy. Linear or branched alkoxy groups having 6 to 12 carbon atoms, such as n-hexyloxy, n-heptyloxy, n-octyloxy, and n-dodecyloxy, are preferred, and linear or branched alkoxy groups having 6 to 10 carbon atoms are more preferred.

[0027] Specific examples of the linear or branched alkyl group having 1 to 18 carbon atoms represented by R6 in formula (2) include a methyl group, an ethyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an iso-pentyl group, a neo-pentyl group, a t-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, etc. Linear or branched alkyl groups having 4 to 10 carbon atoms, such as an n-butyl group, a t-butyl group, an n-heptyl group, an n-decyl group, etc., are preferred.

[0028] The linear or branched alkoxy group having 1 to 18 carbon atoms represented by R6 in formula (2) is a substituent in which an oxygen atom is bonded to a linear or branched alkyl group having 1 to 18 carbon atoms. Specific examples of the alkyl group (the alkyl group in the alkoxy group) include the same as the linear or branched alkyl group having 1 to 18 carbon atoms represented by R6 in formula (2). Linear or branched alkoxy groups having 4 to 10 carbon atoms, such as n-butyloxy, iso-butyloxy, t-butyloxy, n-pentyloxy, iso-pentyloxy, neo-pentyloxy, t-pentyloxy, n-hexyloxy, n-heptyloxy, n-nonyloxy, and n-decyloxy, are preferred. In addition, in the composition of the present invention, a plurality of anthraquinone compounds included in formula (2) may be used in combination.

[0029] The composition of the present invention contains a dye compound other than the anthraquinone compound represented by the above formula (1) or the anthraquinone compound represented by the above formula (2). The dye compound other than the anthraquinone compound represented by the formula (1) or the anthraquinone compound represented by the formula (2) is used to give the light-adjusting element a desired hue (preferably black). The dye compound other than the anthraquinone compound represented by formula (1) or the anthraquinone compound represented by formula (2) is not particularly limited, but is preferably one having a maximum absorption wavelength in the range of 420 to 460 nm, and more preferably a dichroic dye having a maximum absorption wavelength in the range of 420 to 460 nm. Suitable skeletons of dye compounds other than the anthraquinone compound represented by formula (1) or the anthraquinone compound represented by general formula (2) include anthraquinone-based compounds (compounds having an anthraquinone skeleton; hereinafter, "based compounds" have the same meaning), azo-based compounds, quinophthalone-based compounds, perylene-based compounds, coumarin-based compounds, and naphthalimide-based compounds. Among these, anthraquinone-based compounds, azo-based compounds, and quinophthalone-based compounds are preferred. In the composition of the present invention, a plurality of dye compounds other than the anthraquinone compound represented by formula (1) or the anthraquinone compound represented by formula (2) may be used in combination.

[0030] In the composition of the present invention, the total proportion of the anthraquinone compound represented by formula (1) and the anthraquinone compound represented by formula (2) in the dye compound (A) is preferably 50% by mass or more. Furthermore, the content ratio (mass ratio) of the anthraquinone compound represented by formula (1) to the anthraquinone compound represented by formula (2) in the composition of the present invention is 2: 1 to 1: 2. By setting the content ratio of the compound of formula (1) to the compound of formula (2) within this range, it is possible to obtain the effect of sufficient coloring when no voltage is applied in a light-adjusting element described later and eliminating the residual color in the red region when voltage is applied. The content of the dye compound other than the anthraquinone compound represented by formula (1) or the anthraquinone compound represented by formula (2) in the composition of the present invention cannot be generally determined because the purpose of adding such a dye compound is to adjust the hue of the photochromic element, but is preferably about 4 to 60 mass %, more preferably about 10 to 30 mass %, based on the total of the anthraquinone compound represented by formula (1) and the anthraquinone compound represented by formula (2).

[0031] The compound represented by formula (1) and the compound represented by formula (2) can be synthesized by a conventional method described in, for example, JP-A-62-5941, JP-A-2017-518413, JP-A-58-196260, etc.

[0032] Specific examples of suitable anthraquinone compounds represented by the above formula (1) are shown in Tables 1 and 2 below. In the table, when representing alkyl or alkoxy groups, "t" stands for "tertiary" group, but groups without "t" are considered to be "normal" groups.

[0033] [Table 1]

[0034] [Table 2]

[0035] Preferred specific examples of the anthraquinone compound represented by the above formula (2) are shown in Table 3.

[0036] [Table 3]

[0037] Specific examples of suitable dye compounds other than the anthraquinone compound represented by formula (1) or the anthraquinone compound represented by formula (2) include the following compounds represented by formulas (3) to (6).

[0038] [ka]

[0039] [Table 4-1] [Table 4-2]

[0040] [Table 5]

[0041] [ka]

[0042] [Table 6]

[0043] [Table 7]

[0044] [ka]

[0045] [Table 8]

[0046] [Table 9]

[0047] [ka]

[0048] [Table 10]

[0049] The liquid crystal material (B) contained in the liquid crystal composition of the present invention is not particularly limited as long as it is a material (compound having liquid crystal properties) having liquid crystal properties such as nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, etc., but among these, nematic liquid crystal is preferred. Examples of such liquid crystal compounds include those described in pages 154 to 192 and 715 to 722 of "Liquid Crystal Device Handbook" (edited by the 142nd Committee of the Japan Society for the Promotion of Science, Nikkan Kogyo Shimbun, Ltd., 1989).

[0050] The total solubility of the (A) dye compound contained in a liquid crystal composition is defined as the concentration of the (A) dye compound relative to all other components of the liquid crystal composition other than the (A) dye compound in the liquid crystal composition obtained by adding the (A) dye compound to all other components of the liquid crystal composition, stirring at 40 to 50°C for 1 hour, and then filtering. This concentration is preferably 0.5 to 10% by mass, more preferably 1 to 6% by mass. By setting the solubility of the (A) dye compound within this range, sufficient dye addition effects can be obtained, resulting in a good black device. Furthermore, even when a (C) photocurable compound and a (D) photopolymerization initiator are added and irradiated with light to form a cured product, setting the solubility of the (A) dye compound within this range ensures good curability without inhibiting the polymerization of the (C) photocurable compound.

[0051] The photocurable compound (C) contained in the liquid crystal composition of the present invention is not particularly limited as long as it is a compound having a functional group that can be polymerized by the action of a photopolymerization initiator described below when irradiated with light. As the photocurable compound, it is preferable to use both a monofunctional monomer having one polymerizable functional group and a bifunctional monomer having two polymerizable functional groups in combination.

[0052] The monofunctional monomer used as the photocurable compound in the liquid crystal composition of the present invention is compatible with the liquid crystal in the liquid crystal composition before light irradiation, and when polymerized by light irradiation, it phase-separates from the liquid crystal to form a cured phase, thereby mitigating the interfacial interaction with the liquid crystal phase. Therefore, if the polarity of the monofunctional monomer is excessively high, the interfacial interaction with the liquid crystal phase becomes too strong, inhibiting the movement of the liquid crystal and requiring a high driving voltage. Therefore, it is preferable that the polarity of the monofunctional monomer is low.

[0053] The bifunctional monomer used as the photocurable compound in the liquid crystal composition of the present invention phase-separates from the liquid crystal to form a cured phase when polymerized by light irradiation, and serves to stabilize the separated state from the liquid crystal phase. Therefore, if the polarity of the bifunctional monomer is excessively high, the interfacial interaction with the liquid crystal phase becomes too strong, inhibiting the movement of the liquid crystal and requiring a high driving voltage. Therefore, it is preferable that the polarity of the bifunctional monomer is also low.

[0054] Examples of compounds having a functional group polymerizable by the action of a photopolymerization initiator include compounds having a (meth)acrylate group, compounds having a vinyl group, and compounds having an allyl group. Compounds having a (meth)acrylate group are preferred. That is, it is more preferable to use in combination both a mono(meth)acrylate compound having one (meth)acrylate group in one molecule and a di(meth)acrylate compound having two (meth)acrylate groups in one molecule. In this specification, the term "(meth)acrylate" means "methacrylate and / or acrylate".

[0055] The mono(meth)acrylate compound is preferably a mono(meth)acrylate having a linear, cyclic or branched alkyl group having 5 to 13 carbon atoms. Specific examples thereof include linear alkyl mono(meth)acrylates such as pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, and tridecyl (meth)acrylate; cyclic alkyl mono(meth)acrylates such as isobornyl (meth)acrylate; and branched alkyl mono(meth)acrylates such as 2-methylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-propylhexyl (meth)acrylate, 2-methylheptyl (meth)acrylate, 2-ethylheptyl (meth)acrylate, and 2-propylheptyl (meth)acrylate.

[0056] Suitable examples of the di(meth)acrylate compound include 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,11-undecanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, and 1,13-tridecanediol di(meth)acrylate, as well as trialkylene glycol di(meth)acrylates such as triethylene glycol di(meth)acrylate.

[0057] When a monofunctional monomer and a bifunctional monomer are used in combination, the mass ratio of monofunctional monomer to bifunctional monomer is preferably 10:90 to 97:3, and more preferably 50:50 to 96:4. By using the monofunctional monomer in an amount within the above ratio range, the compatibility with the liquid crystal does not become too high, and therefore separation between the polymer (polymer phase) formed by light irradiation and the liquid crystal phase occurs appropriately, preventing gelation of the monomer alone, and facilitating the formation of a separated phase between the polymer phase and the liquid crystal phase.

[0058] The compatibility of the (C) photocurable compound and the (B) liquid crystal material used in the liquid crystal composition of the present invention can be evaluated by visually observing the phase separation that occurs as the temperature drops after the (C) photocurable compound and the (B) liquid crystal material are dissolved in each other using a polarizing microscope, or by the phase separation temperature obtained by measurements such as DSC. The phase separation temperature between the (C) photocurable compound and the (B) liquid crystal material is preferably in the range of 0 to 50°C, more preferably in the range of 10 to 40°C. By setting the phase separation temperature within this range, the compatibility between the (C) photocurable compound and the (B) liquid crystal material in the liquid crystal composition is good, and phase separation does not occur after polymerization of the (C) photocurable compound proceeds by light irradiation. This prevents the resulting liquid crystal phase from becoming too small, allowing for a lower driving voltage and making it easier to maintain the compatibility of the above components until light irradiation.

[0059] The photopolymerization initiator (D) contained in the liquid crystal composition of the present invention is not particularly limited as long as it is a compound that can polymerize a photocurable compound by irradiation with light. It is preferable that the photopolymerization initiator (D) does not remain in the cured liquid crystal composition after irradiation with light and cause deterioration of the dichroic dye, etc. As the photopolymerization initiator, for example, alkylphenone-based photopolymerization initiators such as Darocur 1173, Irgacure 651, and Irgacure 184, and phosphine oxide-based photopolymerization initiators such as Irgacure TPO are preferably used.

[0060] The content of the (A) dye compound in the liquid crystal composition of the present invention is preferably 1 to 6 parts by mass per 100 parts by mass of the (B) liquid crystal material. Furthermore, the blending ratio of the total of the (A) dye compound and the (B) liquid crystal material to the (C) photocurable compound is preferably 90:10 to 50:50 by mass, and more preferably 80:20 to 50:50. By keeping the blending ratio of the (C) photocurable compound within this range, separation of the (B) liquid crystal material and the (C) photocurable compound before curing by light irradiation and a decrease in the light-blocking properties of the cured product can be prevented. The content of the (D) photopolymerization initiator is preferably about 0.1 to 5 parts by mass relative to 100 parts by mass of the (C) photocurable compound.

[0061] In addition to the (A) dye compound through (D) photopolymerization initiator, the liquid crystal composition of the present invention may contain, for example, 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, or the like may be added to control the cell gap of the light-control element. In this case, the cell gap can be set in the range of 2 to 100 μm.

[0062] The liquid crystal composition of the present invention can be obtained by mixing and stirring the essential components (A) the dye compound and (B) the liquid crystal material, as well as any optional components added as needed. The simplest way to mix and stir is to simply place all of the components in a container and stir them manually, but it is more effective to use a device such as a magnetic stirrer for stirring.

[0063] By irradiating the liquid crystal composition of the present invention with light, a cured product of the liquid crystal composition is obtained in which the photocurable compound (C) is cured (polymerized). Note that the term "cured product" in the present invention refers to a state in which the functional groups of the photocurable compound are polymerized or copolymerized by light irradiation, and does not necessarily refer to a cured product in which the dye compound (A) and the liquid crystal material (B) have contributed to the curing reaction. The light source for irradiating light is not particularly limited as long as it is capable of irradiating light of a wavelength absorbed by the (D) photopolymerization initiator. Preferred light sources include high-pressure mercury lamps, metal halide lamps, xenon lamps, and halogen lamps capable of irradiating ultraviolet light. The temperature during light irradiation is preferably a temperature at which the liquid crystal composition can maintain a uniformly dissolved state, i.e., a temperature higher than the phase separation temperature, and more preferably maintained in a range of 1 to 5°C higher than the phase separation temperature. When the temperature during light irradiation is higher than the phase separation temperature, separation of the photocurable compound and the liquid crystal material before light irradiation is prevented, and a more uniform cured product can be obtained. On the other hand, when the temperature during light irradiation is not significantly higher than the phase separation temperature, the domain size formed by the liquid crystal material can be prevented from becoming excessively small when the polymer of the photocurable compound obtained by photocuring separates from the liquid crystal material.

[0064] The light-adjusting element of the present invention comprises a pair of substrates arranged facing each other, at least one of which is a transparent substrate having a transparent electrode, and a thin film layer made of the liquid crystal composition of the present invention or a cured product of the liquid crystal composition of the present invention sandwiched between them. Examples of materials for the substrate include glass, quartz, metal, metal oxide, semiconductor, ceramic, and organic polymer materials. Composite materials obtained by combining these materials with fillers, reinforcing fibers, etc. may also be used, and the substrate may be in the form of a plate or a film.

[0065] The electrode is a conductive thin film formed on the entire surface or part of the substrate by coating, printing, vapor deposition such as sputtering, or the like using, for example, a metal oxide, metal, semiconductor, or organic conductive substance. The electrode formed on the substrate can also be partially etched. To efficiently produce large-area light-control elements, it is preferable to use an electrode substrate in which an ITO (indium oxide, tin oxide) electrode is formed on a transparent polymer film such as PET by vapor deposition such as sputtering, printing, or the like. The substrate may be provided with wiring for connecting the electrodes or for connecting the electrodes to an external device. For example, a segment driving electrode substrate, a matrix driving electrode substrate, or an active matrix driving electrode substrate may be used. Furthermore, a protective film or an alignment film made of an organic compound such as polyimide, polyamide, silicon, or a cyanide compound, an inorganic compound such as SiO2, TiO2, or ZrO2, or a mixture thereof, may be provided on the electrode surface of the substrate.

[0066] In the light-controlling element of the present invention, the hue a obtained according to JIS Z 8781 * When the transmittance is measured with a voltage applied between the pair of substrates, a value of 5.0 or less means that the residual color in the red region has been sufficiently reduced. A value of 3.0 or less is even more preferable. The method for displaying object colors specified in JIS Z 8781 corresponds to the method for displaying object colors specified by the International Commission on Illumination (CIE).

[0067] In the photochromic element of the present invention, when a voltage is applied between a pair of substrates, the difference between the smallest and largest minimum transmittance values ​​in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less, which can be said to be sufficient reduction in color retention in the red region. Furthermore, when no voltage is applied, the difference between the smallest and largest minimum transmittance values ​​in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less, which can be said to be sufficient reduction in color retention in the red region. It is preferable that any one of these conditions is satisfied, and it is even more preferable that both conditions are satisfied. When both of these conditions are satisfied, a good black photochromic element with sufficient reduction in color retention in the red region can be obtained. [Example]

[0068] The present invention will be described in more detail below with reference to examples. In the text, "parts" and "%" are by mass unless otherwise specified. The maximum absorption wavelength in the examples is a value measured using a spectrophotometer "UV-3150" (manufactured by Shimadzu Corporation).

[0069] Example 1 (Preparation of Liquid Crystal Composition of the Present Invention) (C) 0.362 parts of isobornyl acrylate (Osaka Organic Chemical Industry Co., Ltd.) as a monofunctional monomer of the photocurable compound, (C) 0.018 parts of triethylene glycol dimethacrylate (Shin-Nakamura Chemical Co., Ltd.) as a bifunctional monomer of the photocurable compound, (B) 0.297 parts of 1-cyano-4'-n-pentylbiphenyl, 0.146 parts of 1-cyano-4'-n-heptylbiphenyl, 0.093 parts of 1-cyano-4'-n-octyloxybiphenyl, and 0.047 parts of 1-cyano-4''-n-pentylterphenyl as liquid crystal materials, (D) Irgacure TPO ( A mixture of 0.004 parts of BASF's (manufactured by BASF) and 0.004 parts of Irgacure 184 (manufactured by BASF), 0.0102 parts of the compound represented by specific example No. 2 as an (A) dye compound, 0.0135 parts of the compound represented by specific example No. 102, and 0.0063 parts of the compound represented by specific example No. 213 as an (A) dye compound, was stirred on a hot plate at 70°C for 1 hour to prepare a liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio (mass ratio) of No. 2 to No. 102 was 2:2.6).

[0070] Example 2 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of No. 2 to No. 102 was 2:1.4) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0126 parts of the compound represented by Specific Example No. 2, 0.0090 parts of the compound represented by Specific Example No. 102, and 0.0069 parts of the compound represented by Specific Example No. 202.

[0071] Example 3 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of No. 1 to No. 102 was 2:2.6) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0093 parts of the compound represented by Specific Example No. 1, 0.0122 parts of the compound represented by Specific Example No. 102, and 0.0085 parts of the compound represented by Specific Example No. 215.

[0072] Example 4 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 25 to No. 107 was 2:2.9) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0105 parts of the compound represented by Specific Example No. 25, 0.0150 parts of the compound represented by Specific Example No. 107, and 0.0045 parts of the compound represented by Specific Example No. 205.

[0073] Example 5 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 19 to No. 101 was 2:2.6) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0093 parts of the compound represented by Specific Example No. 19, 0.0122 parts of the compound represented by Specific Example No. 101, and 0.0085 parts of the compound represented by Specific Example No. 216.

[0074] Example 6 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of No. 1 to No. 102 was 2:2.6) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0102 parts of the compound represented by Specific Example No. 1, 0.0135 parts of the compound represented by Specific Example No. 102, and 0.0065 parts of the compound represented by Specific Example No. 213.

[0075] Example 7 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 16 to No. 102 was 2:2.8) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0108 parts of the compound represented by Specific Example No. 16, 0.0152 parts of the compound represented by Specific Example No. 102, and 0.0039 parts of the compound represented by Specific Example No. 205.

[0076] Example 8 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 18 to No. 101 was 2:2.8) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0081 parts of the compound represented by Specific Example No. 18, 0.0114 parts of the compound represented by Specific Example No. 101, and 0.0100 parts of the compound represented by Specific Example No. 216.

[0077] Example 9 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 23 to No. 102 was 2:2.2) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0105 parts of the compound represented by Specific Example No. 23, 0.0115 parts of the compound represented by Specific Example No. 102, and 0.0080 parts of the compound represented by Specific Example No. 215.

[0078] Example 10 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %; the content ratio of No. 1 to No. 101 was 2:2.8) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0108 parts of the compound represented by Specific Example No. 1, 0.0153 parts of the compound represented by Specific Example No. 101, and 0.0039 parts of the compound represented by Specific Example No. 205.

[0079] Example 11 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of No. 19 to No. 101 was 2:2.6) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0125 parts of the compound represented by Specific Example No. 19, 0.0162 parts of the compound represented by Specific Example No. 101, and 0.0014 parts of the compound represented by Specific Example No. 301.

[0080] Example 12 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 17 to No. 102 was 2:3.4) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0102 parts of the compound represented by Specific Example No. 17, 0.0171 parts of the compound represented by Specific Example No. 102, and 0.0027 parts of the compound represented by Specific Example No. 412.

[0081] Example 13 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of No. 22 to No. 101 was 2:2.7) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0090 parts of the compound represented by Specific Example No. 22, 0.0120 parts of the compound represented by Specific Example No. 101, and 0.0090 parts of the compound represented by Specific Example No. 216.

[0082] Comparative Example 1 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, the (B) liquid crystal material, and the (D) photopolymerization initiator was approximately 3.0 mass%, and the content ratio of (X) to (Y) was 2:1.8) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0135 parts of a compound represented by the following formula (X), 0.0120 parts of a compound represented by the following formula (Y), and 0.0045 parts of compound represented by Specific Example No. 202.

[0083] [ka]

[0084] Comparative Example 2 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, (B) liquid crystal material, and (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of (Z) to No. 102 was 2:2.7) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.0090 parts of a compound represented by the following formula (Z), 0.0120 parts of a compound represented by Specific Example No. 102, and 0.0090 parts of a compound represented by Specific Example No. 213.

[0085] [ka]

[0086] Comparative Example 3 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the total amount of the (C) photocurable compound, the (B) liquid crystal material, and the (D) photopolymerization initiator was approximately 3.0 mass %, and the content ratio of No. 2 to No. 102 was 2:6) was prepared in the same manner as in Example 1, except that the (A) dye compound was changed to 0.006 parts of the compound represented by Specific Example No. 2, 0.018 parts of the compound represented by Specific Example No. 102, and 0.006 parts of the compound represented by Specific Example No. 213.

[0087] Example 14 (Fabrication of the light-adjusting element of the present invention) The liquid crystal composition obtained in Example 1 was mixed with 0.010 parts of a spacer agent (Micropearl (registered trademark) SP220 manufactured by Sekisui Chemical Co., Ltd.) having a diameter of 20 μm at room temperature. Using an applicator, the liquid crystal composition containing the spacer agent was applied onto the ITO film of a 5 cm square PET film having an ITO film formed thereon, to form a liquid crystal composition layer. Next, this film and another 5 cm square PET film having the same ITO film formed thereon were superimposed so that the liquid crystal composition layer faced the ITO film. The thus obtained laminate of the two films and the liquid crystal composition layer was heated to 23°C on a thermoplate while being heated to 200°C under a light intensity of 9 mW / cm at 365 nm from an LED lamp. 2 The photo-curable compound was photo-cured by irradiating it with light for 1 minute, thereby obtaining a light-adjusting element of the present invention.

[0088] Examples 15 to 26 (Fabrication of the light-adjusting element of the present invention) A light-adjusting element of the present invention was prepared in the same manner as in Example 14, except that the liquid crystal composition obtained in Examples 2 to 13 was used instead of the liquid crystal composition obtained in Example 1.

[0089] Comparative Examples 4 to 6 (Fabrication of Comparative Light-Controlling Devices) Comparative light-controlling elements were prepared in the same manner as in Example 14, except that the liquid crystal compositions obtained in Comparative Examples 1 to 3 were used instead of the liquid crystal composition obtained in Example 1.

[0090] (Spectral characteristics of dimming element) For the dimming elements obtained in Examples 14 to 26 and Comparative Examples 4 to 6, the transmittance was measured using a spectrophotometer when no voltage was applied and when a voltage (100 V) was applied. Table 11 shows the differences between the smallest and largest minimum transmittance values ​​in the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm.

[0091] [Table 11]

[0092] (Hue a when voltage is applied to the dimming element * value) For the light-control devices obtained in Examples 14 to 26 and Comparative Examples 4 to 6, the transmittance when a voltage (100 V) was applied was measured using a spectrophotometer, and the hue a was calculated according to JIS Z 8781-4:2013. * The values ​​are shown in Table 12.

[0093] [Table 12]

[0094] From the results of Tables 11 and 12, the light-controlling elements of the present invention obtained in Examples 14 to 26 have a small difference between the smallest and largest transmittance values ​​of 6% or less among the minimum transmittance values ​​in the wavelength range of 420 to 460 nm, the wavelength range of 520 to 590 nm, and the wavelength range of 600 to 640 nm when an applied voltage is applied, and a hue of * On the other hand, the comparative light-controlling elements obtained in Comparative Examples 4 and 5 have a minimum transmittance in the wavelength range of 420 to 460 nm, the wavelength range of 520 to 590 nm, and the wavelength range of 600 to 640 nm, respectively, in which the difference between the smallest transmittance and the largest transmittance is greater than 6%, and the hue a *The value exceeded 5, indicating that the red region remained colored during transmission. Furthermore, in Comparative Example 6, in which the contents of the compound of formula (1) and the compound of formula (2) were changed, the difference between the smallest and largest transmittance values ​​among the minimum transmittance values ​​in the wavelength region of 420 to 460 nm, the wavelength region of 520 to 590 nm, and the wavelength region of 600 to 640 nm when no voltage was applied was greater than 6%, and the hue a * The value exceeded 5, and the red color remained in the transmitted light, making it impossible to create a black dimming element.

[0095] The present invention will be described in more detail below with reference to further examples. As in the above examples, "parts" and "%" in the text are by mass unless otherwise specified, and the maximum absorption wavelength is a value measured using a spectrophotometer "UV-3150" (manufactured by Shimadzu Corporation).

[0096] Example 27 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention was prepared by mixing 0.0085 parts of the compound represented by Specific Example No. 2, 0.0100 parts of the compound represented by Specific Example No. 102, and 0.0065 parts of the compound represented by Specific Example No. 213 as (A) dye compounds, and (B) liquid crystal materials (0.242 parts of 1-cyano-4'-n-pentylbiphenyl, 0.118 parts of 1-cyano-4'-n-heptylbiphenyl, 0.076 parts of 1-cyano-4'-n-octyloxybiphenyl, and 0.038 parts of 1-cyano-4''-n-pentylterphenyl) at room temperature. The content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0% by mass, and the mass ratio of No. 2 to No. 102 was 2:2.4.

[0097] Example 28 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 2 to No. 102 was 2:1.2) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0105 parts of the compound represented by Specific Example No. 2, 0.0062 parts of the compound represented by Specific Example No. 102, and 0.0070 parts of the compound represented by Specific Example No. 202.

[0098] Example 29 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 1 to No. 102 was 2:2.5) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0070 parts of the compound represented by Specific Example No. 1, 0.0089 parts of the compound represented by Specific Example No. 102, and 0.0091 parts of the compound represented by Specific Example No. 215.

[0099] Example 30 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 19 to No. 101 was 2:2.3) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0078 parts of the compound represented by Specific Example No. 19, 0.0089 parts of the compound represented by Specific Example No. 101, and 0.0083 parts of the compound represented by Specific Example No. 216.

[0100] Example 31 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 1 to No. 102 was 2:2.7) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0079 parts of the compound represented by Specific Example No. 1, 0.0106 parts of the compound represented by Specific Example No. 102, and 0.0065 parts of the compound represented by Specific Example No. 213.

[0101] Example 32 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 23 to No. 102 was 2:1.6) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0096 parts of the compound represented by Specific Example No. 23, 0.0079 parts of the compound represented by Specific Example No. 102, and 0.0075 parts of the compound represented by Specific Example No. 215.

[0102] Example 33 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 19 to No. 101 was 2:2.2) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0110 parts of the compound represented by Specific Example No. 19, 0.0122 parts of the compound represented by Specific Example No. 101, and 0.0018 parts of the compound represented by Specific Example No. 301.

[0103] Example 34 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 17 to No. 102 was 2:3.0) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0085 parts of the compound represented by Specific Example No. 17, 0.0130 parts of the compound represented by Specific Example No. 102, and 0.0035 parts of the compound represented by Specific Example No. 412.

[0104] Example 35 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 22 to No. 101 was 2:2.3) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0075 parts of the compound represented by Specific Example No. 22, 0.0088 parts of the compound represented by Specific Example No. 101, and 0.0088 parts of the compound represented by Specific Example No. 216.

[0105] Example 36 (Preparation of Liquid Crystal Composition of the Present Invention) A liquid crystal composition of the present invention (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of Nos. 17 to 107 was 2:2.8) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0072 parts of the compound represented by Specific Example No. 17, 0.0102 parts of the compound represented by Specific Example No. 107, and 0.0075 parts of the compound represented by Specific Example No. 213.

[0106] Comparative Example 7 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of (X) to (Y) was 2:2.0) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0075 parts of the compound represented by formula (X) above, 0.0075 parts of the compound represented by formula (Y) above, and 0.0100 parts of specific example compound No. 213.

[0107] Comparative Example 8 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of No. 2 to No. 102 was 2:6.0) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0050 parts of the compound represented by Specific Example No. 2, 0.0150 parts of the compound represented by Specific Example No. 102, and 0.0050 parts of the compound represented by Specific Example No. 213.

[0108] Comparative Example 9 (Preparation of Comparative Liquid Crystal Composition) A comparative liquid crystal composition (the content of the (A) dye compound relative to the (B) liquid crystal material was approximately 5.0 mass %, and the content ratio (mass ratio) of (Z) to No. 102 was 2:2.7) was prepared in the same manner as in Example 27, except that the (A) dye compound was changed to 0.0075 parts of the compound represented by formula (Z), 0.0100 parts of the compound represented by specific example No. 102, and 0.0075 parts of the compound represented by specific example No. 213.

[0109] Examples 37 to 46 and Comparative Examples 10 to 12 (Preparation of light-controlling elements of the present invention and comparative examples) The liquid crystal compositions obtained in Examples 27 to 36 and Comparative Examples 7 to 9 were sealed in elements having transparent electrodes and two glass substrates, top and bottom, that had been subjected to a homogeneous alignment treatment by rubbing a polyamide resin on the surface in contact with the liquid crystal composition, with a gap of 30 μm between the substrates, to prepare light control elements of the present invention and for comparison.When no voltage was applied, the liquid crystal material in the liquid crystal composition in the element that had been subjected to the above alignment treatment was in a homogeneous alignment state, and the molecules of the dye compound also took on a similar alignment according to the host liquid crystal.

[0110] (Spectral characteristics of the dimming element and hue when voltage is applied a * value) For the light-control devices obtained in Examples 37 to 46 and Comparative Examples 10 to 12, the transmittance was measured with a spectrophotometer when no voltage was applied and when a voltage (100 V) was applied, and the difference between the smallest and largest transmittance values ​​among the minimum transmittances in the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is shown in Table 13. In addition, for the light-control devices obtained in Examples 37 to 46 and Comparative Examples 10 to 12, the transmittance was measured with a spectrophotometer when a voltage (100 V) was applied, and the hue a obtained in accordance with JIS Z 8781-4:2013 was * The values ​​are shown in Table 13.

[0111] [Table 13]

[0112] From the results in Table 13, the light-controlling elements of the present invention obtained in Examples 37 to 46 had a small difference of 6% or less between the smallest and largest minimum transmittances in the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm when no voltage was applied and when a voltage was applied, and a hue of *The values ​​were 5 or less, and there was little color retention in the red region during transmission. On the other hand, the comparative light control devices obtained in Comparative Examples 10 and 11 had a difference between the smallest and largest minimum transmittance values ​​in the 420 to 460 nm wavelength region, the 520 to 590 nm wavelength region, and the 600 to 640 nm wavelength region with and without voltage applied, respectively, of more than 6%, and the comparative light control device obtained in Comparative Example 12 had a difference between the smallest and largest minimum transmittance values ​​in the 420 to 460 nm wavelength region, the 520 to 590 nm wavelength region, and the 600 to 640 nm wavelength region with and without voltage applied, respectively, of more than 6%. Furthermore, the comparative light control devices obtained in Comparative Examples 11 and 12 had a hue a * The value was much greater than 5, and color remained in the red region during transmission, making it impossible to create a black dimming element. [Industrial Applicability]

[0113] The liquid crystal composition of the present invention and its cured product each have excellent spectral characteristics when a voltage is applied, and therefore, by using the composition, a light-controlling device having excellent contrast and suppressed coloration when a voltage is applied can be obtained. Such a light-controlling device can be applied to a wide range of objects, such as vehicles such as trains and automobiles, and windows, doors, and partitions in buildings such as business buildings and hospitals.

Claims

1. A liquid crystal composition containing (A) a dye compound and (B) a liquid crystal material, The dye compound (A) is (i) a compound represented by the following general formula (1): 【Chemistry 1】 (In formula (1), one of X and Y represents a hydroxy group, and the other of X and Y represents a hydrogen atom, a hydroxy group, or an amino group. R １ and R ２ represents a hydrogen atom, and R １ and R ２ The other is represented by the following formula (a): 【Chemistry 2】 (In formula (a), R ７ is a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a group represented by the following formula (b): 【Transformation 3】 (In formula (b), R ８ represents a linear or branched alkyl group having 1 to 12 carbon atoms; １ represents an oxygen atom or a sulfur atom. However, when X is a hydroxy group and Y is a hydrogen atom or an amino group, R １ represents a substituent represented by formula (a) as R ２ represents a hydrogen atom, and when X is a hydrogen atom or an amino group and Y is a hydroxy group, R １ represents a hydrogen atom, R ２ represents a substituent represented by formula (a). R ３ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or a substituent represented by the above formula (b); R ４ represents a linear or branched alkyl group having 4 to 12 carbon atoms, a linear or branched alkoxy group having 4 to 12 carbon atoms, or a substituent represented by the above formula (b). an anthraquinone compound represented by (ii) the following general formula (2): 【Chemistry 4】 (In formula (2), R ５ represents a linear or branched alkyl group having 1 to 18 carbon atoms or a linear or branched alkoxy group having 1 to 18 carbon atoms; R ６ represents a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched alkoxy group having 1 to 18 carbon atoms, or a substituent represented by the above formula (b). An anthraquinone compound represented by the formula: (iii) Dye compounds other than the anthraquinone compounds represented by the general formula (1) or the anthraquinone compounds represented by the general formula (2) Including, the mass ratio of the anthraquinone compound represented by the general formula (1) to the anthraquinone compound represented by the general formula (2) is 2:1 to 1:2; Liquid crystal composition.

2. X is a hydroxy group, Y is an amino group, and R １ is a substituent represented by formula (a), and Z １ The liquid crystal composition according to claim 1 , wherein is an oxygen atom.

3. R ４ and R ７ 3. The liquid crystal composition according to claim 2, wherein each of the groups independently represents a linear or branched alkyl group having 6 to 12 carbon atoms or a linear or branched alkoxy group having 6 to 12 carbon atoms.

4. R ３ 4. The liquid crystal composition according to claim 3, wherein is a linear or branched alkyl group having 4 to 7 carbon atoms or a linear or branched alkoxy group having 4 to 7 carbon atoms.

5. R ４ and R ７ are each independently a substituent represented by the above formula (b), and R ３ 3. The liquid crystal composition according to claim 2, wherein is a linear or branched alkyl group having 1 to 8 carbon atoms or a linear or branched alkoxy group having 1 to 8 carbon atoms.

6. R ４ and R ７ are each independently a substituent represented by the above formula (b), and R ８ 6. The liquid crystal composition according to claim 5, wherein is a linear or branched alkyl group having 3 to 8 carbon atoms.

7. The liquid crystal composition according to claim 1 , further comprising (C) a photocurable compound and (D) a photopolymerization initiator.

8. The liquid crystal composition according to claim 7 , wherein the photocurable compound (C) contains a monofunctional monomer having one polymerizable functional group and a bifunctional monomer having two polymerizable functional groups.

9. The liquid crystal composition according to claim 8 , wherein the photocurable compound (C) contains a mono(meth)acrylate compound and a di(meth)acrylate compound.

10. A cured product of the liquid crystal composition according to claim 7 .

11. A light-adjusting element comprising a pair of substrates arranged opposite each other, at least one of which is a transparent substrate having a transparent electrode, and a liquid crystal composition according to any one of claims 1 to 6 or a cured product according to claim 10 sandwiched between the pair of substrates.

12. With a voltage applied between the pair of substrates, the hue a was determined by the method specified in JIS Z 8781-4:2013. ＊ The photochromic element according to claim 11 , wherein the value is 5.0 or less.

13. When a voltage is applied between the pair of substrates, the difference between the smallest transmittance value and the largest transmittance value among the minimum transmittance values ​​in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less, and 13. The light-controlling element according to claim 11, wherein, when no voltage is applied, a difference between the smallest transmittance value and the largest transmittance value in each of the wavelength ranges of 420 to 460 nm, 520 to 590 nm, and 600 to 640 nm is 6% or less.

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