Liquid crystal composition and dimming element

Abstract

To provide a liquid crystal composition that achieves protection from sunlight and shielding against blue light, and has a moderate color and excellent design.SOLUTION: A liquid crystal composition contains (A) a liquid crystal component and (B) a dye. Chromaticities (x, y) under the standard light source D65 are in the ranges of 0.3000≤x≤0.3300 and 0.3 200≤y≤0.3500. The maximum optical density in the wavelength range of 380-420 nm is at least 1.5 times higher than the optical density at the wavelength of 550 nm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a guest-host type liquid crystal composition for dimming and a dimming element having a dimming function. . [Background technology]

[0002] A guest-host type liquid crystal composition in which a dichroic dye is dissolved in a liquid crystal exhibits the absorption anisotropy of the dichroic dye. This allows for control of light transmission, and in recent years, it has been used in window glass and room partitions. Applications include dimming elements in building materials, automotive components, and eyewear. It is being considered. Since such dimming elements are also intended for outdoor use, they are used in the aforementioned applications. The guest-host type liquid crystal composition includes anthracite as described in Patent Document 1 and Patent Document 2. Non-dichroic dyes are considered preferable in terms of their stability against light and heat. On the other hand, in recent years, in addition to the fact that ultraviolet rays contained in sunlight cause skin damage, Blue light contained in sunlight can also cause oxidative stress and cell damage, according to an unpatented study. As revealed in reference 1 and other sources, blue light absorption is a measure to protect against blue light. Compounds and filters have been proposed in Patent Document 3, among others. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2010-144041 [Patent Document 2] Japanese Patent Application Publication No. 11-5980 [Patent Document 3] Japanese Patent Publication No. 2018-168140 [Non-patent literature]

[0004] [Non-Patent Document 1] Free Radical Biology and Medicine 108(2017)300-310 [Overview of the project] [Problems that the invention aims to solve]

[0005] Conventionally, the liquid crystal compositions described in Patent Documents 1 and 2 above have very low stability to light. While good in general, it had the problem of not being able to block blue light sufficiently. To improve light shielding properties, the liquid crystals described in Patent Documents 1 and 2 above are used. One possible method is to use the blue light absorbing filter described in Patent Document 3 in combination with the composition. However, this method involves coloring the blue light absorption filter, which affects the design of the liquid crystal dimming element. There was another problem: it could impair performance or function. In other words, the liquid crystal dimming element was affected by voltage application, etc. It is an element that can switch between a high transmittance state and a low transmittance state, but in the high transmittance state... Normally, colorless and transparent is preferred. However, if the liquid crystal dimming element contains blue light absorbing particles... If you use a filter in conjunction with it, it will constantly absorb light in the blue light wavelength range, so it will not transmit The problem is that when the concentration is high, it appears colored yellow. This invention achieves both stability against sunlight and blue light blocking, and has a moderate color tone. To provide a liquid crystal composition with excellent design properties, and to provide a dimming element using the liquid crystal composition. Furthermore, the aim is to provide a dimmable window or smart window equipped with the dimming element. To target. [Means for solving the problem]

[0006] In view of the above problems, the present inventors have conducted diligent studies and have found that the following liquid crystal composition can solve the above problems. The inventors have found a solution to the problem and completed the present invention. That is, the gist of the present invention is as follows.

[0007] [1] A liquid crystal composition containing (A) a liquid crystal component and (B) a dye, wherein the chromaticity (x, y) in a standard light source D65 is in the range of 0.3000 ≦ x ≦ 0.3300 and 0.3 200 ≦ y ≦ 0.3500, and the maximum value of the optical density in the wavelength range of 380 to 420 nm is 1.5 times or more of the optical density at a wavelength of 550 nm. A liquid crystal composition characterized by the above. [2] The liquid crystal composition according to [1], wherein the (B) dye contains at least four or more anthraquinone dyes represented by the following general formula (I) and having four or less aromatic rings.

[0008] [Chemical formula]

[0009] [In formula (I), R 1 represents -NHR 8 or -SR 9 . R 2 , R 3 , and R <00确定]]each independently represents a hydrogen atom, -NHR 8 , -SR 9 , or -OR 10 . R 8 to R 10 each independently represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group optionally having a substituent, an aryl group optionally having a substituent, or a heterocyclic residue optionally having a substituent. However, when one of R 1 to R 4 is -NH2, the other three are not -NH2. Also, R 8 ~R 10 The substituents on the cycloalkyl group, aryl group, and heterocyclic residue are It does not include a connecting ring structure. R 5 , R 6 , and R 7 Each of these is independently a hydrogen atom, a halogen atom, linear or branched. Chain alkyl groups, optionally substituted aryl groups, optionally substituted aryl groups syloxy group, -SR 9 (R 9 The same applies as above. ) or -COYR 11 (Y is acid Elementary atom, sulfur atom, or -NHR 8 (R 8 This is the same as above. ) R 11 is, directly Linear or branched alkyl groups, optionally substituted cycloalkyl groups, substituents An aralkyl group which may have a substituent, an aryl group which may have a substituent, or a substituent This shows the heterocyclic residues that may be present. However, R 1 ~R 4 If one of them is -NH2, then R 5 ~R 7 At least one of them It is not a hydrogen atom. Also, R 5 ~R 7 It does not have a linking ring structure of three or more rings.

[0010] [3] A dimming element comprising a layer made of the liquid crystal composition described in [1] or [2]. [4] A pair of transparent electrode substrates arranged so that the transparent electrodes face each other, and the pair of transparent electrodes A dimming element according to [3], wherein a layer made of a liquid crystal composition is sandwiched between substrates with light electrodes. . [5] The dimming element described in [3] for automotive use. [6] The dimming element described in [3] for use in building materials. A dimmable window equipped with the dimming element described in [7] [3]. [8] [3] A smart window equipped with a dimming element as described above. [Effects of the Invention]

[0011] According to the present invention, it is possible to achieve both stability against sunlight and blue light blocking, and a moderate A liquid crystal composition with excellent design qualities in terms of color tone can be provided. Furthermore, the liquid crystal composition of the present invention The present invention provides a liquid crystal element, a dimmable window equipped with the liquid crystal element, and a smart window. It is possible. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a spectral diagram of Example 1. [Figure 2] Figure 2 is the spectral diagram of Comparative Example 1. [Figure 3] Figure 3 is the spectral diagram of Comparative Example 2. [Modes for carrying out the invention]

[0013] The present invention will be described in detail below, but the following description is an example of an embodiment of the present invention. In fact, the present invention is not limited to the following description unless it exceeds the gist of the present invention. The invention can be modified and implemented as desired, without departing from the spirit of the invention.

[0014] [1] Liquid crystal composition The liquid crystal composition of the present invention contains (A) a liquid crystal component and (B) a dye, and is exposed to a standard light source D65. The chromaticity (x, y) is 0.3000 ≤ x ≤ 0.3300 and 0.3200 ≤ y ≤ 0.35 It is within the range of 00, and the maximum optical density in the wavelength range of 380-420 nm is at wavelength 5 It is more than 1.5 times the optical density at 50 nm. The following provides a detailed description of each component of the liquid crystal composition.

[0015] [1-1] (A) Liquid crystal component In the present invention, (A) when a known liquid crystalline substance is used as the liquid crystal component, for example, Japan Edited by the 142nd Committee of the Japan Society for the Promotion of Science; "Liquid Crystal Device Handbook," Japan Industrial Newspaper Co., Ltd. (1989) (Year) Pages 152-192 and edited by the LCD Handbook Editorial Committee; "LCD Handbook" Maruzen Co., Ltd. (20 Biphenyl-based, phenylcycline-based, as described on pages 260-330 (2000) hydroxyhexane-based, cyclohexylcyclohexane-based, alkyl halogen-based, tran-based, etc. Various low-molecular-weight compounds or mixtures can be used.

[0016] In the present invention, (A) the nematic isotropic phase transition temperature (Tni) of the liquid crystal component The temperature is preferably 80°C or higher. If the phase transition temperature is too low, the usable temperature range will be limited. At very high temperatures, the dimming function is lost, and if the temperature is too high, the viscosity increases near room temperature. Driving tends to become difficult. Furthermore, the phase transition temperature is determined using a phase transition temperature measuring device, and the phase transition occurs with respect to the phase transition. This can be evaluated by measuring changes in transmitted light intensity, etc.

[0017] In the present invention, (A) the value of the dielectric anisotropy of the liquid crystal component (Δε) can be either positive or negative. However, from the viewpoint of reducing the driving voltage of the dimming element, it is preferable that its absolute value be 3 or more. It is more preferable that the value be 5 or higher.

[0018] In the present invention, (A) if the liquid crystal component contains a chiral agent, the liquid crystal component after dye formulation The twist pitch length (p) is preferably 1 to 5 μm. Specifically, the twist pitch length ( It is preferable that the d / p value, which is the relationship between p) and the cell thickness (d) of the dimming element, satisfies 1 to 5. .

[0019] As for chiral agents that may contain liquid crystal components, the product name is CB-15 (CAS RN: 63 799-11-1), S-1011(CAS RN:165660-09-3), R-1 011(CAS RN:154102-21-3), S-2011(CAS RN:18 5207-90-3), R-2011(CAS RN:159077-75-5), S- 5011(CAS RN:693227-30-4), R-5011(CAS RN:9 Examples include 44537-61-5). In particular, S-1 has a large torsional twisting force (HTP). 011, R-1011, S-5011, and R-5011 produce a large amount of twisting with a small amount of formulation. It is preferable because it can be obtained.

[0020] From these perspectives, examples of liquid crystal components include those described in Japanese Patent Publication No. 2018-28655 and the National Patent Publication No. The liquid crystal material for dimming elements described in International Publication No. 2020 / 158038 is particularly preferred.

[0021] [1-2](B) Pigment In the present invention, (B) dye is not particularly limited, but is a dye used for blocking blue light. It is preferable that it contains (B-1). The dye (B-1) is the following general formula (Ia) Anthraquinone-based dyes expressed, edited by the 142nd Committee of the Japan Society for the Promotion of Science; "Liquid Crystal Devices "Dobook," Japan Industrial Newspaper Co., Ltd. (1989), p. 728, Japanese Patent Publication No. 61-98768, and Azo dyes as described in Japanese Patent Publication No. 61-145285, Japanese Patent Publication No. 61-53 Quinophthalone-based dyes as described in Patent Publication No. 361, Japanese Patent Publication No. 57-63377 Use perylene-based dye compounds or mixtures thereof as described in the report. It is possible. Among these, azo dyes and quinophthalone dyes, which have a high molecular extinction coefficient, are preferred.

[0022] [ka]

[0023] In formula (Ia), R 12 This is a linear or branched alkyl group having 1 to 5 carbon atoms, or This refers to a cycloalkyl group having a linear alkyl group with 1 to 6 carbon atoms as a substituent. R 2 a , R 3 a , R 4 a , R 5 a , R 6 a , and R 7 a Each of them is independently a hydrogen atom, carbon Linear alkyl groups with 1 to 5 prime numbers, and linear or branched alkyl groups with 1 to 6 carbon atoms. A phenylthio group, pyridylthio group, or a group having 1 to 6 carbon atoms, which may have a substituent. This represents a cyclohexylcarboxyl group having a linear alkyl group as a substituent.

[0024] In the above formula (Ia), from the viewpoint of blue light shielding and dissolution in the host liquid crystal, Ra, R 12 The group consists of an ethyl group, a propyl group, an n-butyl group, a t-butyl group, and a 4-methylcyclohexyl group. A xyl group or a 4-n-butylcyclohexyl group is preferred, R 3 a is a hydrogen atom, phen A ruthio group, a 4-methylphenylthio group, or a pyridylthio group is preferred, R 2 a , R 4 a , R 5 a , R6 a and R 7 a A hydrogen atom is preferred.

[0025] A suitable anthraquinone-based yellow pigment represented by the general formula (Ia) is, specifically The following are some examples:

[0026] [ka]

[0027] In the present invention, (B) dye may also contain dye (B-2) other than dye (B-1). preferable. As for pigments (B-2), for example, they are represented by the following general formula (I) and have four or fewer aromatic rings. Anthraquinone-based pigments are one example.

[0028] [ka]

[0029] In formula (I), R 1 -NHR 8 , or -SR 9 Show, R 2 , R 3 and R 4 Each is independent Standing upright, hydrogen atom, -NHR 8 , -SR 9 , or -OR 10 This indicates R 8 ~R 10 Each Independently, a hydrogen atom, a linear or branched alkyl group, and a substituent which may be present. A chloroalkyl group, an optionally substituted aryl group, or an optionally substituted group. This shows a heterocyclic residue. However, R 1 ~R 4 If one of them is -NH2, then the other three are not -NH2. Also, the substituents of the cycloalkyl group, aryl group, and heterocyclic residue of R 8 ~R 10 do not contain a linked ring structure. R 5 , R 6 and R 7 are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group, an aryl group which may have a substituent, an aryloxy group which may have a substituent, -SR (R 9 is the same as described above.), or -COYR 9 (Y represents an oxygen 11 atom, a sulfur atom, or -NHR (R 8 is the same as described above.). R 8 represents a hydrogen 11 ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​An amino group that may be present or a phenylthio group that may have a substituent is preferred. R 5 , R 6 and R 7 are each independently a hydrogen atom, a carbonyl group that may have a substituent, or a carboxy group that may have a substituent is preferred.

[0031] In the anthraquinone-based dye represented by the general formula (I) and having 4 or fewer aromatic rings, More preferred red dyes include those represented by the following general formulas (Ib), (Ic), and (Id). Such are exemplified.

[0032]

Chemical formula

[0033] In formula (Ib), R 2 b is a hydrogen atom, a phenylthio group having a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, or a phenylthio group having a cyclohexyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent. [[ID=ID=39]]is shown. R 5 b is a carboxy group having a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, a cyclohexyl carboxy group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, a phenylcarbo xy group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, or a phenoxy group having a linear alkyl group having 1 to 8 carbon atoms as a substituent. is shown. is shown. R 7 b is a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, A carboxyl group having a carboxyl group and a linear alkyl group having 1 to 8 carbon atoms as substituents. A hexyl carboxyl group having a linear alkyl group with 1 to 8 carbon atoms as a substituent. Cyclocarboxyl groups having a ylcarboxyl group or a linear alkyl group having 1 to 8 carbon atoms as substituents This shows a phenylcarboxyl group having a hexyl group as a substituent.

[0034] In the above formula (Ib), from the viewpoint of moderate color tone and dissolution in the host liquid crystal, R 2 b The phenylthio group having a hydroxyl group or a methyl group as a substituent is preferred, R 5 b A phenylcarboxyl group having a linear alkyl group with 1 to 8 carbon atoms as a substituent is preferred. Shii. R 7 b It has a hydrogen atom or a linear alkyl group having 1 to 8 carbon atoms as a substituent. A cyclohexylcarboxyl group is preferred.

[0035] [ka]

[0036] In formula (Ic), R 13 This is a methyl group, a linear or branched alkyl group having 1 to 8 carbon atoms. A cyclohexyl group having a C1-C8 linear alkyl group as a substituent. Show, R 14 This is a phenyl group having a linear alkyl group with 1 to 8 carbon atoms as a substituent. or a cyclohexylphenyl group having a linear alkyl group with 1 to 8 carbon atoms as a substituent. This indicates.

[0037] In the above formula (Ic), from the viewpoint of moderate color tone and dissolution in the host liquid crystal, R 13 The cyclohexyl group having a linear alkyl group with 1 to 8 carbon atoms is preferred, R 14 is charcoal A phenyl group having a linear alkyl group with a prime number of 1 to 8 as a substituent is preferred.

[0038] [ka]

[0039] In formula (Id), R 15 , R 16 , R 17 and R 18 Each of these is an independent hydrogen atom, and the number of carbon atoms A linear or branched alkyl group with 1 to 8 carbon atoms, or a linear alkyl group with 1 to 8 carbon atoms. This shows the cyclohexyl group that is present as a substituent.

[0040] In the above formula (Id), from the viewpoint of a moderate color tone and dissolution in the host liquid crystal, R 15 , R 16 , R 17 and R 18 Each of these is independently a hydrogen atom, a methyl group, a propyl group, and a pentyl group. , or a t-butyl group is preferred.

[0041] Preferred anthraquinone-based red pigments represented by the general formulas (Ib), (Ic), and (Id) Specifically, the following can be cited as examples.

[0042] [ka]

[0043] In an anthraquinone-based pigment represented by the above general formula (I) and having four or fewer aromatic rings, A more preferred pigment is one represented by the following general formula (Ie).

[0044] [ka]

[0045] In equation (Ie), R 2 e This includes an amino group, a linear alkylthio group with 1 to 8 carbon atoms, and a carbon number a phenylamino group having 1 to 8 linear alkyl groups or fluorine atoms as substituents, Alternatively, it represents a phenylthio group having a linear alkyl group with 1 to 8 carbon atoms as a substituent, R 3 e , R 4 e , and R 7 e Each of these independently consists of a hydrogen atom, a hydroxyl group, and a group with 1 to 8 carbon atoms. A linear alkylthio group, or a linear or branched alkyl group having 1 to 13 carbon atoms, is placed therein. It shows the phenylthio group as the substitution group, R 5 e It consists of hydrogen atoms and a linear chain with 1 to 8 carbon atoms. Alternatively, a carboxyl group having a branched alkyl group as a substituent, or a linear group having 1 to 8 carbon atoms. A cyclohexylcarboxyl group having an alkyl group as a substituent, or a group having 1 to 8 carbon atoms It represents a phenylcarboxyl group having a linear alkyl group or a fluorine atom as a substituent, R 19 This includes hydrogen atoms, linear or branched alkyl groups having 1 to 8 carbon atoms, or fluorine atoms. This indicates a phenyl group having a chlorine atom or a phenyl atom as a substituent.

[0046] In the above formula (Ie), from the viewpoint of moderate color tone and dissolution in the host liquid crystal, R 2 e These are amino groups, linear alkylthio groups with 1 to 8 carbon atoms, and linear alkylthio groups with 1 to 8 carbon atoms. A phenylamino group having a fluorine atom or a phenyl group as a substituent, or a linear group having 1 to 8 carbon atoms. A phenylthio group having an alkyl group as a substituent is preferred, R 3 e is a hydrogen atom or carbon A linear alkylthio group having 1 to 8 units is preferred. 4 e , R 7 e and R 19 is a hydrogen atom Preferably, R 5 e This has a linear alkyl group with 1 to 8 carbon atoms or a fluorine atom as a substituent. It has a phenylcarboxyl group and a linear alkyl group having 1 to 8 carbon atoms as substituents. A cyclohexylcarboxyl group is preferred.

[0047] A suitable anthraquinone-based blue dye represented by the general formula (Ie) is, specifically, The following are some examples:

[0048] [ka]

[0049] In this invention, from the viewpoint of moderate color tone and dimming dynamic range, a wavelength of 500n Since it is preferable that the absorbance characteristics from m to 800 nm be flat, (B) dye is dye It is preferable that (B-2) contains at least four types, is represented by general formula (I), and has an aromatic ring. It is more preferable to include at least four types of anthraquinone-based dyes, each containing four or fewer of these dyes.

[0050] The anthraquinone dye represented by the general formula (I) is, for example, as described in Japanese Patent Publication No. 56-5547. By combining the conventionally known methods described in Japanese Patent Publication No. 9, Japanese Patent Publication No. 58-53954, etc. It can be synthesized.

[0051] In the present invention, (B) the dye may be a UV absorbing dye or a near-infrared absorbing dye, if necessary. Element (B-1), other than anthraquinone pigments represented by formula (I) above and having four or fewer aromatic rings. It may contain the following pigments.

[0052] The liquid crystal composition of the present invention has a chromaticity (x, y) of 0.3000 ≤ x ≤ 0.3000 in standard light source D65. The range is 0.3300 and 0.3200 ≤ y ≤ 0.3500, and the wavelength is 380-420. The maximum optical density in the nm range is 1.5 times or more the optical density at a wavelength of 550 nm. That is the case.

[0053] The chromaticity (x, y) of the standard light source D65 is 0.3000 ≤ x ≤ 0.3400 and 0. The range is 3200 ≤ y ≤ 0.3600, and 0.3000 ≤ x ≤ 0.3400 and 0. Preferably, 3200 ≤ y ≤ 0.3500, and 0.3200 ≤ x ≤ 0.3400 and 0.33 00≦y≦0.3500 is more preferable. Within the above range, a moderate color tone can be achieved.

[0054] The maximum optical density in the wavelength range of 380-420 nm is the same as the light at a wavelength of 550 nm. The concentration should be 1.5 times or more of the normal concentration, preferably 1.6 times or more. Furthermore, there is no particular limit to the upper limit. However, it is preferable that it be 1.8 times or less. If the value is above the lower limit, it offers excellent blue light blocking; if it is below the upper limit, it offers moderate protection. This makes it possible to achieve a wide range of color tones.

[0055] In order to satisfy the aforementioned chromaticity range and optical density ratio, for example, a dye (B-1), The color can be adjusted by combining it with pigment (B-2) as appropriate.

[0056] The content of (B) dye in the liquid crystal composition of the present invention is, per 100 parts by mass of (A) liquid crystal component Preferably, it is 3 parts by mass or more, and more preferably 5 parts by mass or more. Also, 20 parts by mass or less is preferable. It is preferable to have 15 parts by mass or less. The upper and lower limits can be combined as desired. For example, (A) 100 parts by mass of liquid crystal component, (B) the content of the dye is 3 to 20 (B) The amount of dye is preferably in parts by mass, and particularly preferably in parts by weight of 5 to 15 parts by weight. If the value is above the lower limit, sufficient blue light blocking effect tends to be obtained. Also, If the value is below the upper limit, the deposition of dyes in the liquid crystal composition tends to be suppressed.

[0057] The liquid crystal composition of the present invention comprises (A) a liquid crystal component and (B) a dye, as well as other components as needed. It may contain additives.

[0058] The liquid crystal composition of the present invention is obtained by mixing (A) liquid crystal components and (B) dyes in a known manner. A liquid crystal composition can be prepared by this. Specifically, for example, (A) liquid crystal component and ( B) The dye can be prepared by shaking and mixing the container in which it is placed.

[0059] [2] Dimming element The dimming element of the present invention comprises a layer made of the liquid crystal composition of the present invention, and the transparent electrode is A pair of transparent electrode substrates arranged facing each other, and between the pair of transparent electrode substrates It is preferable that the configuration includes a layer made of the liquid crystal composition of the present invention sandwiched between two layers.

[0060] The operating temperature range of the dimming element of the present invention is preferably 0°C to 60°C, and more preferably -10°C to 80°C. Preferred. The transmittance of visible light (wavelength 380-780nm) of the dimming element is determined by the driving voltage. It is preferable that it be adjustable as desired, and the range is preferably 1% to 40% in terms of visible light transmittance. A range of 1% to 70% is more preferable. Haze of 10% or less is preferable, and 5% or less is more preferable. These element characteristics depend on the physical properties of the liquid crystal components used in the liquid crystal composition, the cell thickness of the dimming element, and the dimming element itself. The appropriate option can be selected depending on the number of layers stacked, etc.

[0061] The substrate for the transparent electrode of the dimming element of the present invention is not particularly limited, but can be a glass plate, acrylic glass plate, or acrylic glass plate. Various synthetic resin sheets such as polycarbonate resin and polyethylene terephthalate resin. Suitable for use. The transparent electrode layer formed on the substrate is not particularly limited, but oxidation Materials consisting of metal oxides such as indium and indium tin oxide (ITO, IZO), and PE Conductive polymers such as DOT / PSS are preferably used. Surface of the transparent electrode layer in contact with the liquid crystal. Orientation processing can be applied as needed. For example, the orientation processing method is oc Tadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride, etc. Known methods include coating and vertical orientation, coating polyimide and parallel orientation, and photoalignment films. The method can be used as appropriate. The two electrode substrates are arranged so that their orientation-treated surfaces face each other, and spacers are used to connect them. By integrating them, the gap between the two electrode-equipped substrates becomes, for example, 1 to 30 μm, preferably A cell is formed with a space of 3 to 10 μm, and liquid crystal is sealed within this space. Enter.

[0062] [3] Dimmable windows, smart windows The applications of the dimming element of the present invention are not particularly limited, but it is possible to efficiently dim visible light. Therefore, it is suitable for use as dimmable windows and smart windows for automobiles and building materials, for example. The dimming element of the present invention is described in Japanese Patent Publication No. 6-18856 and Japanese Patent Publication No. 2007-102210. Laminated glass and It can be processed into dimmable windows and smart windows, such as curved glass. [Examples]

[0063] The present invention will be described in detail below with reference to examples, but the present invention will not exceed its gist. The embodiments described below are not the only ones.

[0064] [Example 1] As the host liquid crystal component, a nematic liquid crystal (Shan) with a twist pitch length adjusted to 4 μm is used. Manufactured by Benz, Sb-412010 Nematic isotropic phase transition temperature: 96°C, induction Electrical anisotropy Δε: +10.77) 1g, dichroism as the pigment component -1 of the blue light blocking component. Pigment (manufactured by Mitsui Chemicals Fine, S-428) 20.5 mg, and further as pigment component-2, The following general formula (Id 38.5 mg of a mixture of red anthraquinone dyes represented by '),

[0065] [ka]

[0066] In the formula (Id'), R 15 , R 16 , R 17 and R 18 Of these, n are hydrogen atoms, (4-n) elements represent tert-butyl groups. n is an integer from 0 to 4.

[0067] 6.0 mg of red anthraquinone dye represented by the following general formula (III),

[0068] [ka]

[0069] 18.6 mg of red anthraquinone dye represented by the following general formula (IV),

[0070] [ka]

[0071] 48.4 mg of blue anthraquinone dye represented by the following general formula (V),

[0072] [ka]

[0073] A total of four types of anthraquinone dyes were mixed and dissolved to prepare liquid crystal composition-I. This liquid crystal composition-I is coated and cured with a polyimide resin and then rubbed to achieve homogeneous orientation. It consists of a glass plate with a processed transparent electrode, and is configured so that its orientation-treated surfaces face each other. A dimming element-I was fabricated by encapsulating it in a cell with a 12 μm gap. The transmission and absorption of the fabricated cell were measured. The spectrum was measured using a spectrophotometer (Hitachi High-Technologies Corporation U-4100) and standard light The chromaticity x and y values ​​were calculated at source D65. Figure 1 shows the spectral distribution, and Table 1 shows the chromaticity measurement results. This indicates. Furthermore, the surface of the fabricated cells is covered with triacetylcellulose, which has a transmission limit wavelength of 380 nm. Equipped with a sharp-cut filter, and a xenon weather resistance tester (Atlas Corporation, Ci400) 0) Light irradiation test (xenon exposure test) (irradiation intensity 0.55 W / m²) 2 Wavelength 340n After performing step (m) for 240 hours, the transmission absorption spectrum was measured again. The measurement results are shown in Table 2. vinegar.

[0074] The composition described in Example 1, as shown in Figure 1, is in the blue light wavelength range of 380 nm. The maximum optical density at 420 nm is 1.71 times that at a wavelength of 550 nm. It has high blue light blocking properties, and as shown in Table 1, the chromaticity x and y are 0.300. The color tone was moderate when 0 ≤ x ≤ 0.3300 and 0.3200 ≤ y ≤ 0.3500. Furthermore, as shown in Table 2, the chromaticity after the xenon exposure test also showed high fastness, and the color before and after the exposure test Difference (ΔE * The score was 0.265, which is very good. Note that the color difference (ΔE) before and after the exposure test * ) can be calculated from the following formula, and the smaller the color difference, the firmer it is. This indicates high durability and excellent light resistance.

[0075]

number

[0076] Here, L * 240 a * 240 , b * 240 This is the CI after 240 hours of xenon exposure testing. E(1976) indicates chromaticity, L * 0、 a * 0, b * 0 is CIE(1 976) Indicates chromaticity.

[0077] [Comparative Example 1] The host liquid crystal of Example 1 is the same as Example 1 except that it does not contain the blue light blocking pigment component -1. Liquid crystal composition-II was prepared with the same composition ratio as the components and dye component-2. This liquid crystal composition- Dimming element-II was fabricated by sealing II in a cell using the same method as in Example 1. Figure 2 shows the result. The light spectrum and chromaticity measurement results are shown in Table 1. Furthermore, dimming was performed using the same method as in Example 1. Table 2 shows the results of measuring the characteristics of element-II after the light irradiation test.

[0078] The composition described in Comparative Example 1, as shown in Figure 2, is in the blue light wavelength range of 380 nm. The maximum optical density at 420 nm is 0.43 times higher than the optical density at 550 nm. Because the ratio is low, or less than 1.0 times, the blue light blocking effect is low, as shown in Table 1. Furthermore, the chromaticity x and y also showed a bluish tint. Additionally, the chromaticity after the xenon exposure test is shown in Table 2. Color difference (ΔE) before and after exposure test * The result was 0.635, which is inferior to that of Example 1.

[0079] [Comparative Example 2] The host liquid crystal component is a nematic liquid crystal with a twist pitch length of 4 μm (manufactured by Shanben). Mix 1g of Sb-412010 with the following 6 types of dyes described in Japanese Patent Publication No. 11-5980. The mixture was dissolved to prepare liquid crystal composition-III. This liquid crystal composition-III was prepared in the same manner as in Example 1. The dimming element-III was fabricated by encapsulating it in a cell using various methods. Figure 3 shows the spectral distribution and table. Figure 1 shows the chromaticity measurement results. Furthermore, the light of the dimming element-III was measured using the same method as in Example 1. Table 2 shows the results of measuring the characteristics after the irradiation test. In the following equations (VI) and (VII), C8H 17 The octyl group is C7H 15 is hep The chill group is C5H 11 This represents a pentyl group.

[0080] 10.0 mg of yellow azo dye represented by the following general formula (VI)

[0081] [ka]

[0082] 10.0 mg of yellow azo dye represented by the following general formula (VII)

[0083] [ka]

[0084] 15.0 mg of red anthraquinone dye represented by the following general formula (VIII).

[0085] [ka]

[0086] A mixture of red anthraquinone dyes represented by the general formula (Id') used in Example 1 20 0mg 18.0 mg of red anthraquinone dye represented by the above general formula (IV) 40.0 mg of blue anthraquinone dye represented by the general formula (V) mentioned above.

[0087] The composition described in Comparative Example 2, as shown in Figure 3, is in the blue light wavelength range of 380 nm. The maximum optical density at 420 nm is 0.81 times higher than the optical density at 550 nm. The effect was low, approximately 1.0 times, meaning it was insufficient to block blue light. As shown in Tables 1 and 2, the chromaticity after the xenon exposure test was initially moderate, but , the color difference (ΔE) before and after the exposure test * The result was 0.711, which is inferior to that of Example 1.

[0088] [Table 1]

[0089] [Table 2]

[0090] As described above, the present invention provides a guest host liquid crystal assembly with excellent blue light shielding properties. This enables the creation of dimming elements using molded materials and also improves light resistance.

Claims

1. A liquid crystal composition containing (A) a liquid crystal component and (B) a dye, The aforementioned (B) pigment comprises pigment (B-1) and pigment (B-2), The aforementioned dye (B-1) is a compound selected from the group consisting of anthraquinone dyes, azo dyes, quinophthalone dyes, and perylene dyes represented by the following general formula (Ia): The aforementioned pigment (B-2) is an anthraquinone-based pigment represented by the following general formula (I), having four or fewer aromatic rings. The chromaticity (x, y) in the standard light source D65 is within the range of 0.3000 ≤ x ≤ 0.3300 and 0.3200 ≤ y ≤ 0.3500. A liquid crystal composition characterized in that the maximum optical density in the wavelength range of 380 to 420 nm is 1.5 times or more the optical density at a wavelength of 550 nm. 【Chemistry 1】 [In formula (Ia), R 12 represents a linear or branched alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having a linear alkyl group having 1 to 6 carbon atoms as a substituent. R2a, R3a, R4a, R5a, R6a, and R7a each independently represent a hydrogen atom, a linear alkyl group having 1 to 5 carbon atoms, a phenylthio group or pyridylthio group which may have a linear or branched alkyl group having 1 to 6 carbon atoms as a substituent, or a cyclohexylcarboxyl group which has a linear alkyl group having 1 to 6 carbon atoms as a substituent. 【Chemistry 2】 [In formula (I), R1 represents -NHR8 or -SR9, and R2, R3, and R4 each independently represent a hydrogen atom, -NHR8, -SR9, or -OR10. R8 to R10 each independently represent a hydrogen atom, a linear or branched alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, or an optionally substituted heterocyclic residue. However, if one of R1 to R4 is -NH2, then the other three are not -NH2. Furthermore, the substituents on the cycloalkyl groups, aryl groups, and heterocyclic residues of R8 to R10 do not contain linking ring structures. R5, R6, and R7 each independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group, an optionally substituted aryl group, an optionally substituted aryloxy group, -SR9 (where R9 is the same as above), or -COYR11 (where Y is an oxygen atom, a sulfur atom, or -NHR8 (where R8 is the same as above)). R11 represents a linear or branched alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aralkyl group, an optionally substituted aryl group, or an optionally substituted heterocyclic residue. However, if one of R1 to R4 is -NH2, then at least one of R5 to R7 is not a hydrogen atom. Also, R5 to R7 do not have a linking ring structure of three or more rings.

2. The liquid crystal composition according to claim 1, comprising at least four anthraquinone-based dyes represented by the following general formula (I) and having four or fewer aromatic rings, as the (B) dye. 【Transformation 3】 〔In formula (I), R １ represents -NHR ８ , or -SR ９ . R ２ , R ３ , and R ４ each independently represent a hydrogen atom, -NHR ８ , -SR ９ , or -OR １０ . R ８ to R １０ each independently represent a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic residue which may have a substituent. However, R １ ~R ４ One of them is -NH ２ If so, the other three are -NH ２ isn't it. Also, R ８ ~R １０ The substituents on the cycloalkyl groups, aryl groups, and heterocyclic residues do not contain linking ring structures. R ５ , R ６ , and R ７ Each of these independently comprises a hydrogen atom, a halogen atom, a linear or branched alkyl group, an optionally substituted aryl group, an optionally substituted aryloxy group, and -SR ９ (R ９ The same applies as above. ), or -COYR １１ (Y is an oxygen atom, a sulfur atom, or -NHR) ８ (R ８ This is the same as above. ) R １１ This represents a linear or branched alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aralkyl group, an optionally substituted aryl group, or an optionally substituted heterocyclic residue. However, R １ ~R ４ One of them is -NH ２ If R ５ ~R ７ At least one of them is not a hydrogen atom. Also, R ５ ~R ７ It does not have a linking ring structure of three or more rings.

3. The liquid crystal composition according to claim 1, wherein the dye (B-2) comprises at least one red dye represented by the following general formula (Ib), (Ic), or (Id), and at least one blue dye represented by the following general formula (Ie). 【Chemistry 4】 [In formula (Ib), R2b represents a hydrogen atom, a hydroxyl group, a phenylthio group substituted with a linear or branched alkyl group having 1 to 8 carbon atoms, or a phenylthio group substituted with a cyclohexyl group substituted with a linear alkyl group having 1 to 8 carbon atoms. R5b represents a carboxyl group having a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, a cyclohexylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, a phenylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, or a phenoxy group having a linear alkyl group having 1 to 8 carbon atoms as a substituent. R7b represents a hydrogen atom, a carboxyl group having a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, a cyclohexylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, a phenylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, or a phenylcarboxyl group having a cyclohexyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent. 【Transformation 5】 [In formula (Ic), R 13 represents a methyl group, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cyclohexyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent; R 14 represents a phenyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, or a cyclohexylphenyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent.] 【Transformation 6】 [In formula (Id), R15, R16, R17, and R18 each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cyclohexyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent.] 【Transformation 7】 [In formula (Ie), R2e represents an amino group, a linear alkylthio group having 1 to 8 carbon atoms, a phenylamino group having a linear alkyl group having 1 to 8 carbon atoms or a fluorine atom as a substituent, or a phenylthio group having a linear alkyl group having 1 to 8 carbon atoms; R3e, R4e, and R7e each independently represent a hydrogen atom, a hydroxyl group, a linear alkylthio group having 1 to 8 carbon atoms, or a phenylthio group having a linear or branched alkyl group having 1 to 13 carbon atoms as a substituent; R5e represents a hydrogen atom, a carboxyl group having a linear or branched alkyl group having 1 to 8 carbon atoms as a substituent, a cyclohexylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms as a substituent, or a phenylcarboxyl group having a linear alkyl group having 1 to 8 carbon atoms or a fluorine atom as a substituent; R19 This represents a phenyl group having a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a fluorine atom or a chlorine atom as a substituent.

4. A dimming element comprising a layer made of the liquid crystal composition according to claim 1 or claim 2.

5. The dimming element according to claim 4, comprising a pair of substrates with transparent electrodes arranged facing each other, and a layer made of a liquid crystal composition sandwiched between the pair of substrates with transparent electrodes.

6. The dimming element according to claim 4, which is for use in automobiles.

7. A dimming element according to claim 4, which is for use in building materials.

8. A dimmable window comprising the dimming element described in claim 4.

9. A smart window comprising the dimming element described in claim 4.

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