JP2021105662A - Liquid crystal display - Google Patents

Abstract

To provide a liquid crystal display that uses a cholesteric liquid crystal composition, the liquid crystal display reducing a difference in hue due to a difference in environmental temperature and having high reflectance of incident light.SOLUTION: A liquid crystal display 10 has a first cholesteric liquid crystal layer 1 and a second cholesteric liquid crystal layer 2 that is laminated with the first cholesteric liquid crystal layer 1. The first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 include a cholesteric liquid crystal composition that contains two or more types of optically active compounds selected such that temperature dependency of a selected reflection wavelength becomes zero. The first cholesteric liquid crystal layer 1 and a second cholesteric liquid crystal layer 2 are different in spiral twist direction of the cholesteric liquid crystal composition.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid crystal display device.

Conventionally, there are cholesteric (chiral nematic) liquid crystal compositions that form a spiral molecular arrangement. A liquid crystal display device using a cholesteric liquid crystal composition has bistability in which two states, a planar state that reflects incident light and a focal conic state that transmits incident light, are stably held under no electric field. .. Therefore, it is particularly preferably used for electronic books, electronic price tags, presentation panels, etc., which require low power consumption.

When the liquid crystal display device using the cholesteric liquid crystal composition is in the planar state, the spiral axis of the cholesteric liquid crystal composition is in a state perpendicular to the substrate sandwiching the cholesteric liquid crystal composition. Then, of the incident light incident on the liquid crystal display device, only the light having a circularly polarized light component that coincides with the spiral twisting direction of the cholesteric liquid crystal composition and having the same wavelength as the spiral period is reflected (selective reflection).

The wavelength (λ) that is selectively reflected is determined by the product of the average refractive index (n) of the cholesteric liquid crystal composition and the liquid crystal pitch length (P), which is the spiral period of the cholesteric liquid crystal composition. Therefore, the wavelength (λ) that is selectively reflected changes depending on the liquid crystal pitch length (P). The liquid crystal pitch length (P) can be adjusted by changing the type and concentration of the chiral dopant in the cholesteric liquid crystal composition. Therefore, the selective reflection wavelength can be adjusted by changing the type and concentration of the chiral dopant in the cholesteric liquid crystal composition.

Examples of the liquid crystal composition used in the liquid crystal display device include those described in Patent Documents 1 to 5.

JP-A-2018-95668 Japanese Unexamined Patent Publication No. 2004-83568 Japanese Unexamined Patent Publication No. 2003-105338 Japanese Unexamined Patent Publication No. 2010-275463 Japanese Unexamined Patent Publication No. 2019-123822

The selective reflection wavelength of the liquid crystal display device using the cholesteric liquid crystal composition has a temperature dependence. This is because the spiral winding strength (spiral period (chiral pitch length)) of the cholesteric liquid crystal composition changes depending on the temperature. Therefore, the conventional liquid crystal display device using the cholesteric liquid crystal composition has a disadvantage that the selective reflection wavelength changes and the displayed color changes when the temperature of the use environment changes.

Further, in a liquid crystal display device using the cholesteric liquid crystal composition, in the planar state, among the incident light having a wavelength corresponding to the product of the pitch length of the liquid crystal and the average refractive index of the liquid crystal, the spiral twist of the cholesteric liquid crystal composition The circularly polarized light component in the direction of rotation opposite to the direction passes through as it is. That is, in a liquid crystal display device using a cholesteric liquid crystal composition, circularly polarized light having a wavelength corresponding to the product of the pitch length of the liquid crystal and the average refractive index of the liquid crystal, which coincides with the spiral twist direction of the cholesteric liquid crystal composition. Only the components can be extracted as reflected light. As a result, in the liquid crystal display device using the cholesteric liquid crystal composition, the brightness may be insufficient, and it is required to improve the brightness.

The present invention has been made in view of the above circumstances, and is a liquid crystal display device using a cholesteric liquid crystal composition, in which the difference in color due to different environmental temperatures is small and the reflectance of incident light is high. An object of the present invention is to provide a liquid crystal display device.

[1] It has a first cholesteric liquid crystal layer and a second cholesteric liquid crystal layer laminated with the first cholesteric liquid crystal layer.
The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer contain a cholesteric liquid crystal composition containing two or more optically active compounds selected so that the temperature dependence of the selective reflection wavelength becomes zero.
The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are liquid crystal display devices in which the spiral twist direction of the cholesteric liquid crystal composition is different.

[2] The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are formed by sandwiching the cholesteric liquid crystal composition between two transparent substrates facing each other.
The transparent adhesive layer is in contact with the transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer and the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer. Provided,
The liquid crystal display device according to [1], wherein the difference in refractive index between the transparent adhesive layer and the transparent substrate in contact with the transparent adhesive layer at 25 ° C. is 0.12 or less.

[3] The cholesteric liquid crystal composition is sandwiched between two transparent substrates facing each other in the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer, respectively.
The transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer and the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer are in contact with each other [1]. ] The liquid crystal display device described in.

[4] The cholesteric liquid crystal composition is sandwiched between two transparent substrates facing each other in the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer, respectively.
The transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer also serves as the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer [1]. The liquid crystal display device described.

[5] The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are a pixel electrode substrate made of a transparent substrate provided with pixel electrodes on a surface in contact with the cholesteric liquid crystal composition, and the cholesteric liquid crystal composition, respectively. The cholesteric liquid crystal composition is sandwiched between a common electrode substrate made of a transparent substrate provided with a common electrode on the surface in contact with the cholesteric liquid crystal composition.
The pixel electrodes of the first cholesteric liquid crystal layer and the pixel electrodes of the second cholesteric liquid crystal layer are the sum of the positional deviation in the first direction and the positional deviation in the second direction orthogonal to the first direction in a plan view. However, the liquid crystal display device according to any one of [1] to [4], which is 60 μm or less.

[6] The difference between the center wavelength of the selective reflection wavelength of the first cholesteric liquid crystal layer at 25 ° C. and the center wavelength of the selective reflection wavelength of the second cholesteric liquid crystal layer at 25 ° C. is within the range of 0 to 30 nm. The liquid crystal display device according to any one of [1] to [5].

[7] The liquid crystal display device according to any one of [1] to [6], wherein the cholesteric liquid crystal composition contains a dielectrically positive liquid crystal compound.
[8] The liquid crystal display device according to any one of [1] to [7], wherein the cholesteric liquid crystal composition contains a dielectrically neutral liquid crystal compound.
[9] The liquid crystal display device according to any one of [1] to [8], wherein the optically active compound is a binaphthyl chiral compound.

The liquid crystal display device of the present invention has a first cholesteric liquid crystal layer and a second cholesteric liquid crystal layer laminated with the first cholesteric liquid crystal layer, and the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are selective reflection. It contains a cholesteric liquid crystal composition containing two or more optically active compounds selected so that the temperature dependence of wavelength becomes zero. Therefore, in the liquid crystal display device of the present invention, the difference in color due to the difference in environmental temperature is small.

Further, in the liquid crystal display device of the present invention, the spiral twist direction of the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer is different. Therefore, in the planar state, of the incident light incident on the liquid crystal display device, the circularly polarized light component that coincides with the spiral twist direction of the cholesteric liquid crystal composition of the first cholesteric liquid crystal layer is reflected by the first cholesteric liquid crystal layer. NS. Then, the circularly polarized light component in the rotation direction opposite to the spiral twisting direction of the cholesteric liquid crystal composition of the first cholesteric liquid crystal layer is reflected by the second cholesteric liquid crystal layer. Therefore, in the liquid crystal display device of the present invention, not only the circularly polarized light component that coincides with the spiral twisting direction of the cholesteric liquid crystal composition but also the circularly polarized light component in the opposite rotation direction can be extracted as reflected light. As a result, the liquid crystal display device of the present invention has a higher reflectance of incident light than, for example, as compared with the case where only one or more of the first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer is provided. ..

FIG. 1 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the first embodiment. FIG. 2 is an enlarged plan view showing only the pixel electrodes of the liquid crystal display device shown in FIG. FIG. 3 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the second embodiment. FIG. 4 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the third embodiment.

Hereinafter, the liquid crystal display device of the present invention will be described in detail with reference to the drawings. In addition, in the drawing used in the following description, in order to make the feature of the present invention easy to understand, the feature portion may be enlarged and shown for convenience. Therefore, the dimensional ratio of each component may differ from the actual one.

<First Embodiment>
[Liquid crystal display device]
FIG. 1 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the first embodiment. FIG. 2 is an enlarged plan view showing only the pixel electrodes of the liquid crystal display device shown in FIG.
As shown in FIG. 1, the liquid crystal display device 10 of the present embodiment has a first cholesteric liquid crystal layer 1 and a second cholesteric liquid crystal layer 2 laminated with the first cholesteric liquid crystal layer 1.

The first cholesteric liquid crystal layer 1 is formed by sandwiching the first cholesteric liquid crystal composition 21 (hereinafter, may be referred to as “first liquid crystal composition”) between two transparent substrates 31a and 31b facing each other. Of the two transparent substrates 31a and 31b, the transparent substrate 31a arranged on the upper side in FIG. 1 is a common electrode substrate provided with a common electrode 41a on the surface on the side in contact with the first liquid crystal composition 21. Further, of the two transparent substrates 31a and 31b, the transparent substrate 31b arranged on the lower side in FIG. 1 is a pixel electrode provided with a plurality of pixel electrodes 41b on the surface on the side in contact with the first liquid crystal composition 21. It is a substrate. An alignment film (not shown) is provided on the first liquid crystal composition 21 side of the pixel electrode 41b.

The second cholesteric liquid crystal layer 2 is formed by sandwiching the second cholesteric liquid crystal composition 22 (hereinafter, may be referred to as “second liquid crystal composition”) between two transparent substrates 32a and 32b facing each other. Of the two transparent substrates 32a and 32b, the transparent substrate 32a arranged on the upper side in FIG. 1 is a common electrode substrate provided with a common electrode 42a on the surface on the side in contact with the second liquid crystal composition 22. Further, of the two transparent substrates 32a and 32b, the transparent substrate 32b arranged on the lower side in FIG. 1 is a pixel electrode provided with a plurality of pixel electrodes 42b on the surface on the side in contact with the second liquid crystal composition 22. It is a substrate. An alignment film (not shown) is provided on the second liquid crystal composition 22 side of the pixel electrode 42b.

As the transparent substrates 31a, 31b, 32a, 32b included in the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2, conventionally known ones can be used. For example, as the transparent substrates 31a, 31b, 32a, 32b, a transparent sheet made of a resin film such as polyethylene terephthalate, glass, or the like can be used.

Conventionally known common electrodes 41a and 42a of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 include metals such as silver, copper and aluminum, and metal oxides such as indium tin oxide (ITO) and indium oxide. Those made of materials can be used.
Conventionally known pixel electrodes 41b and 42b of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 include metals such as silver, copper and aluminum, and metal oxides such as indium tin oxide (ITO) and indium oxide. Those made of materials can be used.

As the alignment film of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2, conventionally known ones formed of a polyimide film or the like can be used. The alignment film may be a homogenius alignment film, a homeotropic alignment film, or a combination of a homogenius alignment film and a homeotropic alignment film. Specifically, for example, a homeotropic alignment film is provided on the common electrode 41a of the first cholesteric liquid crystal layer 1 in the liquid crystal display device 10 of the present embodiment, and a homogenius alignment film is provided on the transparent substrate 31b and the pixel electrode 41b. It may be provided. Further, a homeotropic alignment film may be provided on the common electrode 42a of the second cholesteric liquid crystal layer 2, and a homogenius alignment film may be provided on the transparent substrate 32b and the pixel electrode 42b.

As shown in FIG. 2, in the plan view of the liquid crystal display device 10, the pixel electrodes 41b of the first cholesteric liquid crystal layer 1 and the pixel electrodes 42b of the second cholesteric liquid crystal layer 2 have a quadrangular shape, and their dimensions are , Can be appropriately determined according to the screen size and resolution.
For example, when the screen size is 8 inches diagonally and the resolution is 162 ppi, the lengths of the pixel electrodes 41b and 42 are preferably 122 μm to 147 μm and the width is preferably 122 μm to 147 μm, and the pixel electrodes 41b and 42 are square. The length of one side is preferably 122 μm to 147 μm.
For example, when the screen size is 12 inches diagonally and the resolution is 106 ppi, the lengths of the pixel electrodes 41b and 42 are preferably 205 μm to 225 μm, the width is preferably 205 μm to 225 μm, and the pixel electrodes 41b and 42 are square. The length of one side is preferably 205 μm to 225 μm.
For example, when the screen size is 4 inches diagonally and the resolution is 318 ppi, the lengths of the pixel electrodes 41b and 42 are preferably 70 μm to 90 μm and the width is preferably 70 μm to 90 μm, and the pixel electrodes 41b and 42 are square. The length of one side is preferably 70 μm to 90 μm.

As shown in FIG. 2, the pixel electrode 41b of the first cholesteric liquid crystal layer 1 and the pixel electrode 42b of the second cholesteric liquid crystal layer 2 are displaced from each other in the X direction (first direction) in a plan view, and the Xth X. The total (dx + dy) with the misalignment dy in the Y direction (second direction) orthogonal to the direction is preferably 60 μm or less, preferably 50 μm or less, preferably 45 μm or less, and 30 μm or less. It is more preferable that there is, and the smaller the total (dx + dy) is, the more preferable. When the total of the above misalignments (dx + dy) is 60 μm or less, the liquid crystal display device 10 can suppress the deterioration of visibility due to the above misalignments and can display with good visibility.

A transparent substrate 31b (pixel electrode substrate) arranged on the second cholesteric liquid crystal layer 2 side (lower side in FIG. 1) of the first cholesteric liquid crystal layer 1 and the first cholesteric liquid crystal layer 1 side of the second cholesteric liquid crystal layer 2. The transparent adhesive layer 5 is provided in contact with the transparent substrate 32a (common electrode substrate) arranged in the above.
Examples of the transparent adhesive layer 5 include a cured product of a pressure-sensitive adhesive containing a transparent resin (OCR (Optical Clear Resin)) such as a silicone elastomer, an epoxy resin, and a urethane resin, and a transparent adhesive such as a silicone elastomer on both sides of the transparent resin film. A transparent sheet-like material provided with an (OCA (Optical Clear Adhesive)) layer can be used.

The transparent adhesive layer 5 preferably has a refractive index difference of 0.12 or less, preferably 0.10 or less, from the transparent substrates 31b and 32a in contact with the transparent adhesive layer 5 at 25 ° C. More preferred. When the difference in refractive index is 0.12 or less, the light passing through the first cholesteric liquid crystal layer 1 and incident on the second cholesteric liquid crystal layer 2 via the transparent adhesive layer 5 and the second liquid crystal composition 22. Light that is reflected by the transparent adhesive layer 5 and enters the first cholesteric liquid crystal layer 1 through the transparent adhesive layer 5 is likely to enter and exit the transparent adhesive layer 5. As a result, the proportion of the light incident on the liquid crystal display device 10 that cannot be taken out from the liquid crystal display device 10 by passing through the transparent adhesive layer 5 is reduced, and the reflectance of the incident light is further increased.

On the other hand, for example, the transparent substrate 31b, which is not provided with the transparent adhesive layer 5 and is arranged on the second cholesteric liquid crystal layer 2 side of the first cholesteric liquid crystal layer 1, and the first cholesteric of the second cholesteric liquid crystal layer 2. When the transparent substrate 32a arranged on the liquid crystal layer 1 side is in contact with the transparent substrate 32a, a part of the transparent substrate 31b and the transparent substrate 32a do not adhere to each other, and a gap is formed between the transparent substrate 31b and the transparent substrate 32a. May be done. In the gap, there is air (refractive index of about 1.0 at 25 ° C.), which is a substance having a large difference in refractive index from the transparent substrates 31b and 32a. Therefore, there is a risk that the light that can be extracted from the liquid crystal display device 10 will be reduced due to refraction at the interface between the transparent substrates 31b and 32a and the gap (air), and the reflectance of the liquid crystal display device 10 will be lowered.

In the liquid crystal display device 10 shown in FIG. 1, a light absorption layer 6 is arranged on the opposite side of the second cholesteric liquid crystal layer 2 from the first cholesteric liquid crystal layer 1. The light absorption layer 6 absorbs light that has passed through the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2. Since the light absorption layer 6 is provided, the light that has passed through the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 is absorbed, so that better visibility can be obtained. The light absorption layer 6 can be formed by a conventionally known method using a conventionally known material.

In the liquid crystal display device 10 shown in FIG. 1, the difference between the center wavelength of the selective reflection wavelength of the first cholesteric liquid crystal layer 1 at 25 ° C. and the center wavelength of the selective reflection wavelength of the second cholesteric liquid crystal layer 2 at 25 ° C. is , It is preferably in the range of 0 to 30 nm, and more preferably in the range of 0 to 20 nm. In other words, it is preferable that the first liquid crystal composition 21 and the second liquid crystal composition 22 have similar product values of the average refractive index (n) and the liquid crystal pitch length (P).
In the present embodiment, the central wavelength of the selective reflection wavelength of the first cholesteric liquid crystal layer 1 (or the second cholesteric liquid crystal layer 2) at 25 ° C. is the reflection between the maximum reflectance and the minimum reflectance of the selective reflection wavelength. It means the average value of the maximum wavelength and the minimum wavelength showing the rate.

When the difference between the center wavelengths of the selective reflection wavelengths at 25 ° C. is 30 nm or less, the light incident on the liquid crystal display device 10 and reflected by the first liquid crystal composition 21 and the second liquid crystal composition 22 The difference in color from the light reflected by is small, and the reflected light with a narrow wavelength distribution and high color purity can be obtained with high reflectance.

In the liquid crystal display device 10 shown in FIG. 1, the spiral twist direction of the cholesteric liquid crystal composition is opposite between the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2.
The spiral twisting direction of the first liquid crystal composition 21 of the first cholesteric liquid crystal layer 1 and the spiral twisting direction of the second liquid crystal composition 22 of the second cholesteric liquid crystal layer 2 are the first liquid crystal composition 21 and the second liquid crystal composition. It is determined by the type of optically active compound contained in each of 22.

In the liquid crystal display device 10 of the present embodiment, the first liquid crystal composition 21 contained in the first cholesteric liquid crystal layer 1 and the second liquid crystal composition 22 contained in the second cholesteric liquid crystal layer 2 have a liquid crystal pitch length (chiral pitch length). ) Contains two or more optically active compounds selected so that the temperature dependence (wavelength change) of the reflection wavelength becomes zero. Therefore, in the liquid crystal display device 10 of the present embodiment, the difference in color due to the difference in the environmental temperature is small.

In the liquid crystal display device 10 of the present embodiment, the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 contain two or more kinds of optically active compounds selected so that the temperature dependence of the selective reflection wavelength becomes zero. Therefore, the temperature dependence of the selective reflection wavelength in the temperature range of 0 to 50 ° C. is preferably 0.3 nm / ° C. or less, and more preferably 0.25 nm / ° C. or less. It is more preferably 0.2 nm / ° C. or lower, and the smaller the better. Here, the temperature dependence of the selective reflection wavelength in the temperature range of 0 to 50 ° C. is the difference between the maximum value and the minimum value of the wavelength of the selective reflection light in the temperature range of 0 to 50 ° C. divided by the temperature range. Means a value.

In the liquid crystal display device 10 of the present embodiment, the difference between the temperature dependence of the selective reflection wavelength in the first cholesteric liquid crystal layer 1 and the temperature dependence of the selective reflection wavelength in the second cholesteric liquid crystal layer 2 is 0. It is preferably .15 nm / ° C. or lower, more preferably 0.125 nm / ° C. or lower, further preferably 0.1 nm / ° C. or lower, and the smaller the better. When the difference in temperature dependence of the selective reflection wavelength between the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 is small, the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 have similar wavelengths regardless of the environmental temperature. Expresses selective reflected light. Therefore, reflected light having high reflectance of incident light and high color purity can be obtained.

In the liquid crystal display device 10 of the present embodiment, for example, it is clear that the surface on the first cholesteric liquid crystal layer 1 side is the display surface, and the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 are in a planar state. The case where the state is used as the dark state and the state is used as the focal conic state will be described as an example. The liquid crystal display device 10 shown in FIG. 1 can stably hold two states, a planar state and a focal conic state, under no electric field. Therefore, the liquid crystal display device 10 of the present embodiment has a memory property.

In the liquid crystal display device 10 of the present embodiment, the planar state and the focal conic state are switched by using common electrodes 41a and 42a and pixel electrodes 41b and 42b for the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2, respectively. This is performed by setting a state in which a voltage is applied or a state in which a voltage is not applied. The energization of the common electrodes 41a and 42a and the pixel electrodes 41b and 42b is controlled by a drive circuit (not shown).

In the present embodiment, switching between the planar state and the focal conic state in the first cholesteric liquid crystal layer 1 and switching between the planar state and the focal conic state in the second cholesteric liquid crystal layer 2 are performed at the same time. That is, when the first cholesteric liquid crystal layer 1 is in the planar state, the second cholesteric liquid crystal layer 2 is also in the planar state, and when the first cholesteric liquid crystal layer 1 is in the focal conic state, the second cholesteric liquid crystal layer 2 is also in the planar state. Control to be in the focal conic state.

Next, the optical characteristics when the liquid crystal display device 10 of the present embodiment is in the planar state and in the focal conic state will be described in detail.
Hereinafter, the first liquid crystal composition 21 of the first cholesteric liquid crystal layer 1 and the second liquid crystal composition 22 of the second cholesteric liquid crystal layer 2 have substantially the same average refractive index (n) and liquid crystal pitch length (P) ( Therefore, the case where the selective reflection wavelength (λ) is substantially the same) will be described as an example.

(Planer state)
When the liquid crystal display device 10 is in the planar state (the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2), the first liquid crystal composition 21 of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 The spiral axis of the two liquid crystal compositions 22 is substantially perpendicular to the transparent substrates 31a, 31b, 32a, and 32b.

At this time, as shown in FIG. 1, when the incident light L0 is incident on the liquid crystal display device 10 from the first cholesteric liquid crystal layer 1 side, a part of the incident light L0 is light L1 (indicated by an arrow L1 in FIG. 1). Is selectively reflected (selective reflection) by the first liquid crystal composition 21 of the first cholesteric liquid crystal layer 1. The light L1 selectively reflected by the first liquid crystal composition 21 is a circularly polarized light component that coincides with the spiral twist direction of the first liquid crystal composition 21. The light L1 reflected by the first liquid crystal composition 21 is taken out from the liquid crystal display device 10 as shown in FIG.

Further, of the incident light L0 incident on the liquid crystal display device 10, the light not reflected by the first liquid crystal composition 21 passes through the first cholesteric liquid crystal layer 1. The light that has passed through the first cholesteric liquid crystal layer 1 has the same wavelength as L1 selectively reflected by the first liquid crystal composition 21 and has the opposite spiral twisting direction (indicated by arrow L2 in FIG. 1).

In the present embodiment, the first liquid crystal composition 21 and the second liquid crystal composition 22 have substantially the same average refractive index (n) and liquid crystal pitch length (P). Therefore, as shown in FIG. 1, the light L2 having the same wavelength as L1 selectively reflected by the first liquid crystal composition 21 and having the opposite spiral twist direction is reflected (selectively reflected) by the second liquid crystal composition 22. ).

As shown in FIG. 1, the light L3 reflected by the second liquid crystal composition 22 enters the first cholesteric liquid crystal layer 1 via the transparent adhesive layer 5, passes through the first cholesteric liquid crystal layer 1, and passes through the first cholesteric liquid crystal layer 1. It is taken out from the liquid crystal display device 10.
As described above, in the liquid crystal display device 10 shown in FIG. 1, among the incident light L0, not only the circularly polarized light component corresponding to the spiral twist direction of the first liquid crystal composition 21 indicated by the arrow L1 but also the circularly polarized light component indicated by the arrow L3. The circularly polarized light component in the rotation direction opposite to the spiral twisting direction of the first liquid crystal composition 21 is also selectively reflected by the second liquid crystal composition 22 and is taken out as reflected light.

(Focal conic state)
When the liquid crystal display device 10 is in a focal conic state (the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2), the first liquid crystal composition 21 of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 The spiral axis of the second liquid crystal composition 22 is substantially horizontal to the transparent substrates 31a, 31b, 32a, 32b.

At this time, as shown in FIG. 1, when the incident light L0 is incident on the liquid crystal display device 10 from the first cholesteric liquid crystal layer 1 side, most of the incident light L0 is the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2. Pass through.

[Liquid crystal composition]
Next, the compositions of the first liquid crystal composition 21 and the second liquid crystal composition 22 in the liquid crystal display device 10 of the present embodiment will be described in detail.
The first liquid crystal composition 21 and the second liquid crystal composition 22 include an optically active compound as a chiral dopant and a liquid crystal compound other than the optically active compound. In the present embodiment, the following can be used as the optically active compound and the liquid crystal compound other than the optically active compound.

The mixture of all liquid crystal compositions other than the optically active compound preferably has a refractive index anisotropy Δn of 0.15 to 0.40, more preferably 0.2 to 0.35. It is more preferably 23 to 0.35, and particularly preferably 0.24 to 0.35. By setting the refractive index anisotropy Δn to the above range, the reflectance becomes large and a bright screen can be obtained.
The mixture of all liquid crystal compositions other than the optically active compound preferably has a dielectric anisotropy Δε of preferably 10 to 50, more preferably 15 to 45, and particularly preferably 20 to 40. .. By setting the dielectric anisotropy Δε in the above range, low voltage drive can be realized.

The melting point of all the liquid crystal compositions other than the optically active compound, that is, the temperature at which the solid phase is restored to the cholesteric phase is preferably −20 ° C. or lower, more preferably −30 ° C. or lower, −. It is particularly preferably 40 ° C. or lower. By setting the melting point in the above range, a wide operating temperature range can be obtained.
In a mixture of all the liquid crystal composition other than the optically active compounds, the phase transition temperature change an isotropic liquid phase from the cholesteric phase (T _NI) of preferably at 60 to 120 ° C., is 70 to 110 ° C. Is more preferable, and 80 to 110 ° C. is particularly preferable. By setting the phase transition temperature ( _TNI ) in the above range, a wide operating temperature range can be obtained.
The viscosity η showing the flow viscosity in the mixture of all the liquid crystal compositions other than the optically active compound is preferably as small as possible, and the lower limit thereof is not particularly limited, but a practically sufficient response speed can be achieved if it is 100 mPa · s or less.

(Liquid crystal compounds other than optically active compounds)
As the liquid crystal compound other than the optically active compound, only one kind of compound showing a liquid crystal phase alone may be used, or a compound showing a liquid crystal phase by using a mixture of two or more kinds may be used. When two or more kinds of compounds are mixed and used as the liquid crystal compound, various combinations are possible.

The liquid crystal compound preferably contains a dielectrically positive liquid crystal compound, and preferably contains a dielectrically neutral liquid crystal compound together with the dielectrically positive liquid crystal compound. Only one kind of each of the dielectrically positive liquid crystal compound and the dielectrically neutral liquid crystal compound may be used, or two or more kinds may be used.

(Dielectrically positive liquid crystal compound)
Examples of the dielectrically positive liquid crystal compound include compounds represented by the general formula (A) and the general formula (B). The compounds represented by the general formula (A) and the general formula (B) correspond to a compound having a dielectric anisotropy Δε larger than 2 and being dielectrically positive. The compounds represented by the general formula (A) and the general formula (B) may be used alone or in combination.

The compounds represented by the general formula (A) and the general formula (B) may be used alone or in combination of two or more. The compounds represented by the general formula (A) and the general formula (B) can be appropriately selected according to the characteristics required for the liquid crystal display device 10, and a plurality of types can be used in combination as necessary. It is preferable to use 1 to 12 kinds of compounds represented by the general formula (A) and the general formula (B).

（式（Ａ）および（Ｂ）中、Ｒ^２Ａ１及びＲ^２Ｂ１は、相互に独立して、炭素原子数１から７のアルキル基、炭素原子数１から７のアルコキシ基、炭素原子数２から７のアルケニル基又は炭素原子数２から７のアルケニルオキシ基である。Ｒ^２Ａ１及びＲ^２Ｂ１上の１個又は２個以上の水素原子は、相互に独立して、フッ素原子又は塩素原子で置換されていてもよい。Ｃ^２Ａ１及びＣ^２Ｂ１は、相互に独立して、（ａ）１，４−シクロヘキシレン基（この基中に存在する１個の−ＣＨ_２−又は隣接していない２個以上の−ＣＨ_２−は−Ｏ−に置き換えられてもよい。）（ｂ）１，４−フェニレン基（この基中に存在する１個の−ＣＨ＝又は隣接していない２個以上の−ＣＨ＝は−Ｎ＝に置き換えられてもよい。）（ｃ）ナフタレン−２，６−ジイル基、１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基、デカヒドロナフタレン−２，６−ジイル基又はインダン−２，５−ジイル基（ナフタレン−２，６−ジイル基又は１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基中に存在する１個の−ＣＨ＝又は隣接していない２個以上の−ＣＨ＝は−Ｎ＝に置き換えられても良い。）及び（ｄ）１，４−シクロヘキセニレン基からなる群より選ばれる基を表し、上記の基（ａ）、基（ｂ）、基（ｃ）及び基（ｄ）は、相互に独立してシアノ基、フッ素原子又は塩素原子で置換されていても良い。Ｌ^２Ａ１及びＬ^２Ｂ１は、相互に独立して、単結合、−Ｃ_２Ｈ_４−、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＦ_２Ｏ−又は−ＯＣＦ_２−を表す。Ｘ^２Ａ１及びＸ^２Ｂ１は、相互に独立して、−Ｆ、−Ｃｌ、−ＣＮ、−ＮＣＳ、−ＣＦ_３、−ＯＣＦ_３、少なくとも１つの水素原子がハロゲン原子で置換された炭素原子数1〜６のアルキル基又は少なくとも１つの水素原子がハロゲン原子で置換された炭素原子数1〜６のアルコキシ基を表す。Ｙ^２Ａ１、Ｙ^２Ａ２、Ｙ^２Ｂ１及びＹ^２Ｂ２は、相互に独立して、水素原子又はフッ素原子を表す。ｂ^２Ａ１及びｂ^２Ｂ１は、相互に独立して、１、２、３又は４を表す。）

(In formulas (A) and (B), R ^2A1 and R ^2B1 are independent of each other, an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and 2 to 7 carbon atoms. An alkoxy group or an alkoxyoxy group having 2 to 7 carbon atoms. ^{One or more hydrogen atoms on R 2A1} and R ^2B1 are independently substituted with a fluorine atom or a chlorine atom. ^{C 2A1} and C ^2B1 may be independent of each other (a) a 1,4-cyclohexylene group (one −CH ₂₋ present in this group or two or more non-adjacent groups). -CH _2- may be replaced with -O-.) (B) 1,4-phenylene group (one -CH = existing in this group or two or more non-adjacent -CH = May be replaced with -N =.) (C) Naphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, decahydronaphthalene-2,6- One -CH = or adjacent to a diyl group or an indan-2,5-diyl group (naphthalen-2,6-diyl group or 1,2,3,4-tetrahydronaphthalene-2,6-diyl group) Two or more -CH = which are not used may be replaced with -N =) and (d) represent a group selected from the group consisting of 1,4-cyclohexenylene groups, and the above group (a). , Group (b), group (c) and group (d) may be substituted independently of each other with a cyano group, a fluorine atom or a chlorine atom. L ^2A1 and L ^2B1 are independent of each other. a single _{bond, -C 2 H 4 -, -} CH = CH -, - C≡C -, - COO -, - OCO -, - CH 2 O -, - OCH 2 -, - CF 2 O- or -OCF Represents _2- ^{X 2A1} and X ^2B1 are independent of each other, with -F, -Cl, -CN, -NCS, -CF ₃ , -OCF ₃ , and at least one hydrogen atom substituted with a halogen atom. Represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms in which at least one hydrogen atom is replaced with a halogen atom. Y ^2A1 , Y ^2A2 , Y ^2B1 and Y ^2B2 are independent of each other. Then, it represents a hydrogen atom or a fluorine atom. ^{B 2A1} and b 2B1 represent 1, 2, 3 or 4 independently of each other.)

In the general formula (A) and the general formula (B), R ^2A1 and R ^2B1 are independent of each other and have an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, and 2 carbon atoms. An alkenyl group of ~ 8 or an alkenyloxy group having 2 to 8 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms or carbon. An alkenyloxy group having 2 to 5 atoms is preferable, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 2 to 5 carbon atoms is more preferable, and an alkyl group having 2 to 5 carbon atoms or an alkyl group having 2 to 5 carbon atoms is preferable. An alkenyl group of 3 is more preferable, and an alkoxy group having 3 carbon atoms (propenyl group) is particularly preferable.

^{R 2A1} and R ^2B1 are preferably alkyl groups when reliability is important, and alkenyl groups when reduction in viscosity is important.

When ^{the ring structure to which R 2A1} and R ^2B1 are bonded is a phenyl group (aromatic), R ^2A1 and R ^2B1 are linear alkyl groups having 1 to 5 carbon atoms and linear carbon atoms of 1. Alkoxy groups of ~ 4 and alkenyl groups of 4-5 carbon atoms are preferred.
When ^{the ring structure to which R 2A1} and R ^2B1 are bonded is a saturated ring structure such as cyclohexane, pyran and dioxane, R ^2A1 and R ^2B1 are linear alkyl groups having 1 to 5 carbon atoms and linear. An alkoxy group having 1 to 4 carbon atoms and a linear alkenyl group having 2 to 5 carbon atoms are preferable. In order to stabilize the liquid crystal composition, the total of carbon atoms and oxygen atoms, if present, is preferably 5 or less, and is preferably linear.

When R ^2A1 and R ^2B1 are alkenyl groups, it is preferably selected from the groups represented by any of the following formulas (R1) to (R5).

（式（Ｒ１）〜（Ｒ５）中の黒点は結合手を表す。）

(Black dots in equations (R1) to (R5) represent bonds.)

In the general formula (A) and the general formula (B), C ^2A1 and C ^2B1 are aromatic when it is required to increase the refractive index anisotropy (Δn) independently of each other. Preferably, it is aliphatic in order to improve the response speed.
It is more preferable that C ^2A1 and C ^2B1 are selected from the groups represented by any of the following formulas (C1) to (C8).

L ^2A1 and ^{L 2B1,} independently of one another, a single _{bond, -CH 2 O -, - OCH} 2 -, - CF 2 O- or -OCF ₂ -, more preferably a single bond, _-CH 2 O-or - CF ₂ O-it is preferably a single bond or _-CF 2 O-are Konomashikui.
^{L 2A1} sandwiched between C ^2A1 is preferably a single bond. Further, ^{it is preferable that L 2B1} sandwiched between ^{C 2B} 1 is a single bond.

X ^2A1 and X ^2B1 are independent of each other, _{preferably -F, -Cl, -CF 3} or -OCF ₃ , preferably -F or -OCF ₃ , and preferably -F. preferable.
It is preferable that Y ^2A1 , Y ^2A2 , Y ^2B1 and Y ^2B2 are all fluorine atoms, or one in the same molecule is a fluorine atom and the other is a hydrogen atom.

b ^2A1 and b ^2B1 are preferably 1, 2 or 3 independently of each other, and preferably 2 or 3 when the upper limit temperature of the liquid crystal phase of the liquid crystal composition is important. When the viscosity and dielectric anisotropy of the product are emphasized, it is preferably 1 or 2.

As the compound represented by the general formula (A), for example, a compound represented by the general formula (A1) or the general formula (A2) is preferable.

（一般式（Ａ１）において、Ｒ^７は炭素原子数１〜７個のアルキル基、炭素原子数１〜７個のアルコキシ基又は炭素原子数２〜７個のアルケニル基を表す。Ｙ^１２〜Ｙ^２３は相互に独立して水素原子又はフッ素原子を表す。）
（一般式（Ａ２）において、Ｒ^１は炭素原子数１〜７のアルキル基、炭素原子数１〜７のアルコキシ基、炭素原子数２〜７のアルケニル基、炭素原子数３〜７のアルケニルオキシ基を表す。Ｙ^４０〜Ｙ^４４は、それぞれ独立して水素原子又はフッ素原子を表す。）

(In the general formula (A1), R ⁷ represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. Y ^{12 to} Y. ²³ represents a hydrogen atom or a fluorine atom independently of each other.)
(In the general formula (A2), R ¹ is an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, and an alkenyloxy having 3 to 7 carbon atoms. Represents a group. Y ^{40 to Y 44} independently represent a hydrogen atom or a fluorine atom.)

More specifically, the compound represented by the general formula (A) is preferably a compound represented by the general formulas (A-1) to (A-31).

（式（Ａ−１）〜（Ａ−３１）中、Ｒ^２Ａ１は、炭素原子数１から７のアルキル基、炭素原子数１から７のアルコキシ基又は炭素原子数２から７のアルケニル基又は炭素原子数２から７のアルケニルオキシ基である。Ｒ^２Ａ１上の１個又は２個以上の水素原子は、相互に独立して、フッ素原子又は塩素原子で置換されていてもよい。）

(In formulas (A-1) to (A-31), R ^2A1 is an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group or carbon having 2 to 7 carbon atoms. ^{It is an alkoxyoxy} group having 2 to 7 atoms. One or two or more hydrogen atoms on R 2A1 may be independently substituted with a fluorine atom or a chlorine atom.)

Further, the compound represented by the general formula (A) may be, for example, any compound represented by the general formulas (A3), (A4) and (A5).

（一般式（Ａ３）（Ａ４）及び（Ａ５）において、Ｒ^１、Ｒ^２及びＲ^３は相互に独立して炭素原子数１〜７個のアルキル基、炭素原子数１〜７個のアルコキシ基又は炭素原子数２〜７個のアルケニル基を表す。Ｙ^１〜Ｙ^５、Ｙ^２４〜Ｙ^３５は相互に独立して水素原子又はフッ素原子を表す。一般式（Ａ３）（Ａ４）において、Ｃ^２Ａ１は一般式（Ａ）のＣ^２Ａ１と同じ意味を表す。ａ、ｂは相互に独立して０又は１を表す。）

(In the general formula (A3) (A4) and ^{(A5), R 1, R} 2 and ^{R 3} independently of one another carbon atom 1-7 alkyl groups, 1 to 7 carbon atoms alkoxy groups Alternatively, it represents an alkoxy group having 2 to 7 carbon atoms. Y ^{1 to Y 5} and Y ^{24 to Y 35} represent hydrogen atoms or fluorine atoms independently of each other. In the general formulas (A3) and (A4), C ^2A1 is .a representing the same meaning as ^{C 2A1} of the general formula (a), b represents 0 or 1 independently of each other.)

More specifically, as the compound represented by the general formula (A), it is preferable to use one or more selected from the compounds represented by the formulas (A-32) to (A-47).

（式（Ａ−３２）〜式（Ａ−４７）において、Ｒ^２Ａ１は一般式（Ａ）のＲ^２ａ１と同じ意味を表す。）

(In formulas (A-32) to (A-47), R ^2A1 has the same meaning as ^{R 2a1 in the} general formula (A).)

The compound represented by the general formula (B) is preferably a compound represented by the general formulas (B-1) to (B-6).

（一般式（Ｂ−１）〜（Ｂ−６）において、Ｒ^２Ｂ１は、炭素原子数１から７のアルキル基、炭素原子数１から７のアルコキシ基、炭素原子数２から７のアルケニル基又は炭素原子数２から７のアルケニルオキシ基である。Ｒ^２Ｂ１上の１個又は２個以上の水素原子は、相互に独立して、フッ素原子又は塩素原子で置換されていてもよい。）

(In the general formulas (B-1) to (B-6), R ^2B1 is an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. It is an alkoxyoxy group having 2 to 7 carbon atoms. ^{One or two or more hydrogen atoms on R 2B1} may be independently substituted with a fluorine atom or a chlorine atom.)

When the reliability of the liquid crystal composition is emphasized, the general formulas (A-1) to (A-11), (A-16) to (A-20) and the general formulas (B-1) to (B-4) It is preferable to use a compound selected from the group represented by), among which the general formulas (A-1), (A-2), (A-4), (A-17) and (A-20) are used. It is more preferable to select from the represented group.
When importance is attached to low viscosity, the groups represented by the general formulas (A-12) to (A-15), (A-21) to (A-28) and (B-5) to (B-6). It is preferable to use a compound selected from, and among them, select from the group represented by (A-12), (A-13), (A-22), (A-23) and (A-26). Is more preferable.

In the present embodiment, the content of the compound represented by the general formula (A) and / or the general formula (B) contained in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is at a low temperature. It is appropriately adjusted according to the required performance such as solubility, transition temperature, electrical reliability, birefringence, and dielectric anisotropy.

The lower limit of the preferable content of the compounds represented by the general formulas (A) and (B) with respect to the total mass of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is, for example, 1% by mass. Yes, it is more preferably 10% by mass, and more preferably 20% by mass. The upper limit of the preferable content is, for example, 95% by mass, preferably 80% by mass, preferably 70% by mass, based on the total mass of the first liquid crystal composition 21 and / or the second liquid crystal composition 22. 60% by mass is preferable, and 50% by mass is more preferable.

In the first liquid crystal composition 21 and / or the second liquid crystal composition 22, when it is necessary to keep the viscosity low and increase the response speed, it is preferable to lower the above lower limit value and upper limit value. _{Further, when it is necessary to keep the phase transition temperature (TNI} ) of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 high and to have good temperature stability, the above lower limit value and upper limit value are set. It is preferable to lower it. Further, when it is desired to increase the dielectric anisotropy (Δε) in order to keep the drive voltage low, it is preferable to increase the above lower limit value and upper limit value.

(Dielectrically neutral liquid crystal compound)
Examples of the dielectrically neutral liquid crystal compound include a compound represented by the general formula (L). The liquid crystal compound represented by the general formula (L) has a dielectric anisotropy (Δε) value of -2 to 2, and corresponds to a dielectrically neutral compound.
The compound represented by the general formula (L) preferably contains at least 1 type, preferably 1 type to 10 types, and particularly preferably 2 to 8 types.

（式（Ｌ）中、Ｒ^２１及びＲ^２２はお互い独立して炭素原子数１から１０のアルキル基又は炭素原子数２から１０のアルケニル基を表す。これらの基中に存在する１個のメチレン基又は隣接していない２個以上のメチレン基は−Ｏ−又は−Ｓ−に置換されても良く、またこれらの基中に存在する１個又は２個以上の水素原子はフッ素原子又は塩素原子に置換されても良い。Ｍ^２１、Ｍ^２２及びＭ^２３はお互い独立して（ａ）トランス−１，４−シクロへキシレン基（この基中に存在する１個のメチレン基又は隣接していない２個以上のメチレン基は−Ｏ−又は−Ｓ−に置き換えられてもよい）、（ｂ）１，４−フェニレン基（この基中に存在する１個の−ＣＨ＝又は隣接していない２個以上の−ＣＨ＝は窒素原子に置き換えられてもよい）、２−フルオロ−１，４−フェニレン基、３−フルオロ−１，４−フェニレン基、３，５−ジフルオロ−１，４−フェニレン基及び（ｃ）１，４−シクロヘキセニレン基、１，４−ビシクロ［２．２．２］オクチレン基、ピペリジン−２，５−ジイル基、ナフタレン−２，６−ジイル基、デカヒドロナフタレン−２，６−ジイル基及び１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基からなる群より選ばれる基を表す。上記の基（ａ）、基（ｂ）及び基（ｃ）はそれぞれ独立してシアノ基、フッ素原子又は塩素原子で置換されていても良い。ｐは０、１又は２を表す。Ｌ^２１及びＬ^２２はお互い独立して単結合、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＨ＝ＣＨ−、−ＣＨ＝Ｎ−Ｎ＝ＣＨ−又は−Ｃ≡Ｃ−を表す。Ｌ^２２が複数存在する場合は、それらは同一でも良く異なっていても良い。Ｍ^２３が複数存在する場合は、それらは同一でも良く異なっていても良い。）

(In the formula (L), R ²¹ and R ²² independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. One methylene present in these groups. Two or more methylene groups that are group or non-adjacent may be substituted with -O- or -S-, and one or more hydrogen atoms present in these groups are fluorine or chlorine atoms. ^{M 21} , M ²² and M ²³ may be substituted with (a) a trans-1,4-cyclohexylene group (one methylene group present in this group or not adjacent to each other) independently of each other. Two or more methylene groups may be replaced with -O- or -S-), (b) 1,4-phenylene group (one -CH = or non-adjacent 2 present in this group). More than one -CH = may be replaced with a nitrogen atom), 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 3,5-difluoro-1,4-phenylene Group and (c) 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-2,5-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene Represents a group selected from the group consisting of -2,6-diyl group and 1,2,3,4-tetrahydronaphthalene-2,6-diyl group. The above groups (a), group (b) and group (c). ) May be independently substituted with a cyano group, a fluorine atom or a chlorine atom. P represents 0, 1 or 2. L ²¹ and L ²² are independent of each other and are single-bonded, −CH ₂ CH _{2 -, - (CH 2) 4} -, - OCH 2 -, - CH 2 O -, - OCF 2 -, - CF 2 O -, - CH = CH -, - CH = N-N = CH- or -C If .L ²² representing the ≡C- there are multiple, if they where good .M ²³ be different may be the same there are two or more, they may be different may be the same.)

In the compound represented by the general formula (L), R ²¹ and R ²² are independent of each other as an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms (1 existing in these groups). One methylene group or two or more non-adjacent methylene groups are substituted with -O- or -S-, and one or more hydrogen atoms present in these groups are fluorine atoms or It also includes those substituted with chlorine atoms), preferably an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or 3 to 6 carbon atoms. The alkenyloxy group is more preferable, and an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms is particularly preferable.

When reliability is important, it is preferable that both ^RL1 and ^{RL2 are alkyl groups.} When it is important to reduce the volatility of the compound, it is preferable that both ^RL1 and ^{RL2 are alkoxy groups.} It is preferred when emphasizing a reduction in viscosity is at least one of R ^L1 and R ^L2 is an alkenyl group.
In the general formula (L), the number of halogen atoms present in the molecule is preferably 0, 1, 2 or 3, preferably 0 or 1, and 1 is preferable when compatibility with other liquid crystal molecules is important. ..

R ²¹ and R ²² are linear alkyl groups having 1 to 5 carbon atoms and linear carbon atoms 1 to 4 when the ring structure to which they are bonded is a phenyl group (aromatic). Alkoxy group and alkenyl group having 4 to 5 carbon atoms are preferable.
R ²¹ and R ²² are linear alkyl groups having 1 to 5 carbon atoms and linear carbon atoms when the ring structure to which they are bonded is a saturated ring structure such as cyclohexane, pyran, or dioxane. Alkoxy groups having a number of 1 to 4 and linear alkenyl groups having 2 to 5 carbon atoms are preferable.
In ^{order to stabilize the liquid crystal composition, R 21} and R ²² preferably have a total of 5 or less carbon atoms and oxygen atoms if present, and are preferably linear.

When ^RL1 and ^RL2 are alkenyl groups, it is preferably selected from the groups represented by any of the formulas (R11) to (R15).

（各式中の黒点は環構造中の炭素原子を表す。）

(The black dots in each equation represent carbon atoms in the ring structure.)

M ²¹ , M ²² and M ²³ are independently trans-1,4-cyclohexylene groups (one CH ₂ group existing in this group or two non-adjacent CH ₂ groups are oxygen atoms. 1,4-phenylene group (including one in which one or more CH groups present in this group are substituted with a nitrogen atom), 3-fluoro-1 , 4-phenylene group, 3,5-difluoro-1,4-phenylene group, 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl Group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2,3,4-tetrahydronaphthalene-2,6-diyl group is preferable, and trans-1,4-cyclohexylene. A group, a 1,4-phenylene group or a 1,4-bicyclo [2.2.2] octylene group is more preferable, and a trans-1,4-cyclohexylene group or a 1,4-phenylene group is particularly preferable.

M ²¹ , M ²² and M ²³ are preferably aromatic when it is required to increase the refractive index anisotropy (Δn). M ²¹ , M ²² and M ²³ are preferably aliphatic in order to improve the response rate, and are independently trans-1,4-cyclohexylene group, 1,4-phenylene group and 2-. Fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 3,5-difluoro-1,4-phenylene group, 1,4-cyclohexenylene group, 1,4-bicyclo [2. 2.2] Octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group or 1,2,3,4-tetrahydronaphthalene-2,6 -It is preferably any of the diyl groups, more preferably the structure represented by any of the following formulas (M1) to (M8), and the trans-1,4-cyclohexylene group or 1, It is more preferable to represent a 4-phenylene group.

In the general formula (L), p is preferably 0, 1 or 2, and more preferably 0 or 1.
L ²¹ and ^{L 22} are each independently a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - OCF 2 -, - CF 2 O- , -CH = CH -, - CH = N-N = CH- or -C≡C-, more preferably a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH ₂ O- or -C ≡ C- is more preferred, and single bond, -CH ₂ CH _2- or -C ≡ C- is even more preferred.

Among the structures formed by the combination of the above options, -CH = CH-CH = CH-, -C≡C-C≡C- and -CH = CH-C≡C- are preferable from the viewpoint of chemical stability. do not have. Further, it is also not preferable that the hydrogen atom in these structures is replaced with the fluorine atom. Further, a structure in which oxygen is bonded to each other, a structure in which sulfur atoms are bonded to each other, and a structure in which sulfur atoms and oxygen atoms are bonded are also not preferable. Further, a structure in which nitrogen atoms are bonded to each other, a structure in which a nitrogen atom and an oxygen atom are bonded, and a structure in which a nitrogen atom and a sulfur atom are bonded are also not preferable.

Specifically, the general formula (L) is preferably a compound represented by the following general formulas (L-1) to (L-25).

（式（Ｌ−１）〜式（Ｌ−２５）で表される化合物において、Ｒ^２３及びＲ^２４は、それぞれ独立的に炭素数１から１０のアルキル基、炭素数１から１０のアルコキシ基、炭素数２から１０のアルケニル基又は炭素数３から１０のアルケニルオキシ基を表す。）

(In the compounds represented by the formulas (L-1) to (L-25), R ²³ and R ²⁴ are independently alkyl groups having 1 to 10 carbon atoms and alkoxy groups having 1 to 10 carbon atoms, respectively. Represents an alkenyl group having 2 to 10 carbon atoms or an alkenyloxy group having 3 to 10 carbon atoms.

In the compounds represented by the formulas (L-1) to (L-25), R ²³ and R ²⁴ independently have an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or carbon. An alkenyl group having 2 to 10 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 10 carbon atoms is more preferable.

Among the compounds represented by the general formulas (L-1) to (L-25), the general formula (L-1), the general formula (L-2), the general formula (L-3), and the general formula (L). -5), the compound represented by the general formula (L-12), the general formula (L-13), the general formula (L-17), the general formula (L-19) or the general formula (L-25) is preferable. , The compound represented by the general formula (L-1), the general formula (L-3), the general formula (L-5), the general formula (L-12) or the general formula (L-13) is more preferable.

Further, the general formula (L) is preferably a compound represented by the following general formula (L1).

（式（Ｌ１）中、Ｒ^３３及びＲ^３４は、相互に独立して炭素原子数１〜７個のアルキル基、炭素原子数１〜７個のアルコキシ基又は炭素原子数２〜７個のアルケニル基を表す。環Ａは１，４−シクロへキシレン基又は１，４−フェニレン基を表す。Ｙ^６〜Ｙ^１２は相互に独立して水素原子、フッ素原子又はメチル基を表す。Ｚ^１は、単結合、−ＣＯＯ−又は−ＣＨ_２ＣＨ_２−を表し、ｃは相互に独立して０又は１を表す。）

(In the formula (L1), R ³³ and R ³⁴ are independent of each other as an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl having 2 to 7 carbon atoms. The ring A represents a 1,4-cyclohexylene group or a 1,4-phenylene group. Y ^{6 to Y 12} represent a hydrogen atom, a fluorine atom or a methyl group independently of each other. Z ^{1 represents a group.} , Single bond, -COO- or -CH ₂ CH _2- , and c represents 0 or 1 independently of each other.)

More specifically, as the compound represented by the general formula (L1), it is preferable to use one or more selected from the compounds represented by the formulas (L-26) to (L-34).

（式（Ｌ−２６）〜式（Ｌ−３４）表される化合物において、Ｒ^３３及びＲ^３４は、相互に独立して炭素原子数１〜７個のアルキル基、炭素原子数１〜７個のアルコキシ基又は炭素原子数２〜７個のアルケニル基を表す。）

(In the compounds represented by the formulas (L-26) to (L-34), R ³³ and R ³⁴ are mutually independent alkyl groups having 1 to 7 carbon atoms and 1 to 7 carbon atoms. Represents an alkoxy group or an alkenyl group having 2 to 7 carbon atoms.

In the present embodiment, the content of the liquid crystal compound represented by the general formula (L) contained in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is solubility at low temperature, transition temperature, and electricity. The appropriate adjustment is made according to the required performance such as reliability, birefringence, process compatibility, dripping marks, seizure, and dielectric anisotropy (Δε).
The lower limit of the content of the compound represented by the formula (L) with respect to the total mass of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is preferably, for example, 1% by mass, preferably 50% by mass. Is more preferable. The upper limit of the content of the compound represented by the formula (L) with respect to the total mass of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is preferably 85% by mass, preferably 65% by mass. Is more preferable.

When a composition that keeps the viscosity of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 low and has a high response speed is required, it is preferable that the above lower limit value and upper limit value are high. _{Further, when it is necessary to keep the phase transition temperature (TNI} ) of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 high to obtain a composition having good temperature stability, the above lower limit value and upper limit value are obtained. It is preferable to increase the temperature. Further, when it is desired to increase the dielectric anisotropy (Δε) in order to keep the drive voltage low, it is preferable that the above lower limit value and upper limit value are low.

(Optically active compound)
As the optically active compound, two or more kinds selected so that the temperature dependence of the chiral pitch length is different and the temperature dependence of the chiral pitch length is zero are used.
In the present embodiment, the optically active compound is one or more in which the chiral pitch length becomes shorter as the temperature rises in the temperature range of 0 to 50 ° C., which is preferable as the normal temperature of the liquid crystal display device, and the chiral pitch length rises in temperature. Use one or more things that become longer with.

In the liquid crystal display device 10 of the present embodiment, the first liquid crystal composition 21 contains one or more optically active compounds having the spiral twisting direction as the first direction (for example, the right direction). Further, the second liquid crystal composition 22 contains one or more optically active compounds having a second direction (for example, a left direction) different from the first direction in the spiral twist direction. That is, in the liquid crystal display device 10 of the present embodiment, the first liquid crystal composition 21 and the second liquid crystal composition 22 selectively contain optically active compounds that induce different spiral twist directions. As a result, in the liquid crystal display device 10 of the present embodiment, the spiral twist directions of the first liquid crystal composition 21 and the second liquid crystal composition 22 are different.

As the optically active compound, for example, compounds represented by the following formulas (D-1) to (D-6) can be used.

（式中、Ｒ^９は、炭素原子数１〜１６のアルキル基、炭素原子数１〜１６のアルコキシ基、炭素原子数２〜１６のアルケニル基、炭素原子数３〜１６のアルケニルオキシ基、又は炭素原子数１〜１０のアルコキシ基で置換された炭素原子数１〜１２のアルキル基を表す。Ｒ^１０は、炭素原子数１〜１６のアルキル基、炭素原子数１〜１６のアルコキシ基、炭素原子数２〜１６のアルケニル基、炭素原子数３〜１６のアルケニルオキシ基、炭素原子数１〜１０のアルコキシ基で置換された炭素原子数１〜１２のアルキル基、水素原子、フッ素原子、基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基が酸素原子により置き換えられても良いトランス−１，４−シクロへキシレン基又は基中に存在する１個の炭素原子又は隣接していない２個以上の炭素原子が窒素原子に置き換えられてもよい１，４−フェニレン基を表し、該１，４−フェニレン基はフッ素原子により置換されていても良い。Ａ^８、Ａ^１０及びＡ^１１は、基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基が酸素原子により置き換えられても良いトランス−１，４−シクロへキシレン基又は基中に存在する１個の炭素原子又は隣接していない２個以上の炭素原子が窒素原子に置き換えられてもよい１，４−フェニレン基を表し、該１，４−フェニレン基はフッ素原子により置換されていても良い。Ａ^８、Ａ^１０及びＡ^１１は単結合を表していても良い。Ｚ^７、Ｚ^８、Ｚ^９及びＺ^１０はそれぞれ独立的して−ＣＨ_２ＣＨ_２−、−ＣＨ（ＣＨ_３）ＣＨ_２−、−ＣＨ_２ＣＨ（ＣＨ_３）−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ=ＣＨ−、−ＣＦ=ＣＦ−、−Ｃ≡Ｃ−、−Ｏ（ＣＨ_２）_３−、−（ＣＨ_２）_３Ｏ−、−（ＣＨ_２）_４−又は単結合を表す。）

(In the formula, R ⁹ is an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkenyloxy group having 3 to 16 carbon atoms, or Represents an alkyl group having 1 to 12 carbon atoms substituted with an alkoxy group having 1 to 10 carbon atoms. R ¹⁰ is an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, and carbon. An alkenyl group having 2 to 16 atoms, an alkenyloxy group having 3 to 16 carbon atoms, an alkyl group having 1 to 12 carbon atoms substituted with an alkoxy group having 1 to 10 carbon atoms, a hydrogen atom, a fluorine atom, and a group. two or more CH ₂ groups not one CH ₂ group or adjacent present in the one present in the xylene group or groups to be trans-1,4-cyclohexylene be replaced by an oxygen atom A carbon atom or two or more non-adjacent carbon atoms may be substituted with a nitrogen atom to represent a 1,4-phenylene group, and the 1,4-phenylene group may be substituted with a fluorine atom. ⁸ , A ¹⁰ and A ¹¹ _{are trans-1,4-cyclohexylene in which one CH 2} group existing in the group or two or more CH ₂ groups not adjacent to each other may be replaced by an oxygen atom. A group or a 1,4-phenylene group in which one carbon atom existing in the group or two or more carbon atoms not adjacent to each other may be replaced with a nitrogen atom, and the 1,4-phenylene group is fluorine. It may be substituted by an atom. A ⁸ , A ¹⁰ and A ¹¹ may represent a single bond. Z ⁷ , Z ⁸ , Z ⁹ and Z ¹⁰ are independently −CH ₂ CH ₂ −. , -CH (CH ₃ ) CH _{2- , -CH 2} CH (CH ₃ )-, -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- , -COO-, -OCO- , -CH = CH -, - CF = CF -, - C≡C -, - O (CH 2) 3 -, - (CH 2) 3 O -, - (CH 2) 4 - or a single bond. )

As the optically active compound, it is preferable to use a binaphthyl chiral compound having a binaphthyl skeleton in which the 1-positions of two naphthalene rings are covalently bonded to each other.
The binaphthyl chiral compound is an optically active compound having a large liquid crystal twisting force. Therefore, by using the binaphthyl chiral compound as the optically active compound, the content of the optically active compound in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 can be reduced. As a result, it is possible to suppress an increase in viscosity, a decrease in phase transition temperature and a decrease in storage stability of the first liquid crystal composition 21 and / or the second liquid crystal composition 22 due to the inclusion of the optically active compound, which is preferable.
As the binaphthyl chiral compound, for example, a compound represented by the following formula (D-7) is preferable.

（式（Ｄ−７）中、Ｒ^８及びＲ^９は相互に独立して炭素原子数１〜７個のアルキル基、炭素原子数１〜７個のアルコキシ基又は炭素原子数２〜７個のアルケニル基を表す。環Ｄ、Ｅ、Ｆ、Ｇは相互に独立して１，４−シクロへキシレン基又は１，４−フェニレン基を表す。Ｚ^５及びＺ^６は相互に独立して単結合又は−ＣＯＯ−を表し、ｅ及びｆは相互に独立して０又は１を表す。）

(In the formula (D-7), R ⁸ and R ⁹ are independent of each other and have an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkoxy group having 2 to 7 carbon atoms. an alkenyl group. ring D, E, F, G are .Z ⁵ and ^{Z 6} represents a cyclohexylene group or 1,4-phenylene group independently of one another 1,4-cyclohexylene is a single bond, independently of one another Or -COO-, and e and f represent 0 or 1 independently of each other.)

As the binaphthyl chiral compound represented by the formula (D-7), for example, the compounds represented by the following formulas (3-1) to (3-4) are preferable.

The compounds represented by the formulas (3-1) and (3-3) induce a right-handed spiral twisting direction. Further, the compounds represented by the formulas (3-2) and (3-4) induce a left-handed spiral twisting direction.

As the optically active compound, for example, a compound represented by the following formula (E1) may be used.

（式（Ｅ１）中、Ｋ^１−４は、互いに独立して、アネレートされたベンゼン、シクロヘキサンまたはシクロヘキセンであり、ここで、１つまたは２つ以上のＣＨ基は、随意に、Ｎにより置換されており、１つまたは２つ以上のＣＨ_２基は、随意に、Ｏおよび／またはＳにより、Ｏおよび／またはＳ原子が互いに直接結合しないように置換されており、
Ｕ^１−４は、互いに独立して、ＣＨ_２、Ｏ、Ｓ、ＣＯ、ＮＨまたはＣＦ_２であり、
Ｖ^１−４は、互いに独立して、Ｕ^１の意味の１つを有し、ただし、Ｏ、ＳおよびＮＨは、互いに直接隣接していないか、または単結合を示し、
Ｚは、Ｃ、Ｓｉ、Ｇｅ、ＳｎまたはＴｉであり、
Ｘ_１−１２は、互いに独立して、Ｒ、Ｐ−Ｓｐまたは−Ｗ^１−Ａ^１−（Ｗ^２−Ａ^２）_ｍ−Ｒであり、
Ｒは、各々の存在において、独立して、Ｈ、Ｆ、Ｃｌ、Ｂｒ、Ｉ、ＣＮ、ＮＯ_２、ＯＨ、ＮＣＳ、ＳＦ_５、１〜４０個のＣ原子を有し、非置換であるか、Ｆ、Ｃｌ、Ｂｒ、ＩもしくはＣＮにより単置換または多置換されている直鎖状もしくは分枝状アルキルであり、ここで、１つもしくは２つ以上のＣＨ_２基は、随意に、各々の場合において、互いに独立して、−Ｏ−、−Ｓ−、−ＮＨ−、−ＮＲ０−、−ＳｉＲ^０Ｒ^００−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯ−Ｏ−、−Ｓ−ＣＯ−、−ＣＯ−Ｓ−、−ＳＯ_２−、−ＣＧ^１＝ＣＧ^２−もしくは−Ｃ≡Ｃ−により、２個のＯもしくは２個のＳ原子が互いに直接結合しないように置換されているか、またはＰ−Ｓｐ−を示し、
Ｒ^０およびＲ^００は、互いに独立して、Ｈまたは１〜１２個のＣ原子を有するアルキルであり、
Ｇ^１およびＧ^２は、互いに独立して、Ｈ、Ｆ、ＣｌまたはＣＮであり、
Ｐは、反応性の基であり、
Ｓｐは、スペーサー基または単結合であり、
Ａ^１およびＡ^２は、各々の存在において、独立して、置換もしくは非置換芳香族もしくは脂環式環、または２つもしくは３つ以上の縮合した芳香族もしくは脂環式環を含む基であり、ここで、これらの環は、随意に、Ｎ、ＯおよびＳから選択された１個または２個以上のヘテロ原子を含み、
Ｗ^１およびＷ^２は、各々の存在において、独立して、−Ｏ−、−Ｓ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｓ−ＣＯ−、−ＣＯ−Ｓ−、−Ｏ−ＣＯＯ−、−ＣＯ−ＮＲ^０−、−ＮＲ^０−ＣＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＳＣＨ_２−、−ＣＨ_２Ｓ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｓ−、−ＳＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＨ_２−、−ＣＨ_２ＣＦ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝Ｎ−、−Ｎ＝ＣＨ−、−Ｎ＝Ｎ−、−ＣＨ＝ＣＨ−、−ＣＨ＝ＣＲ^０−、−ＣＲ^０＝ＣＲ^００−、−ＣＧ^１＝ＣＧ^２−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−または単結合であり、ｍは、各々の存在において、独立して、０、１、２または３である。）

(In formula (E1), K ^1-4 are benzene, cyclohexane or cyclohexene annealed independently of each other, where one or more CH groups are optionally substituted with N. and, one or more CH ₂ groups may optionally by O and / or S, O and / or S atoms are substituted so as not linked directly to one another,
U ^1-4 are independent of each other and are CH ₂ , O, S, CO, NH or CF ₂ .
V ^1-4 are independent of each other and have ^one of the meanings of U 1, where O, S and NH are not directly adjacent to each other or indicate a single bond.
Z is C, Si, Ge, Sn or Ti,
X _1-12 are R, P-Sp or -W ^1- A ^1- (W ^2- A ² ) _m -R independently of each other.
Does R, in each presence, independently have H, F, Cl, Br, I, CN, NO ₂ , OH, NCS, SF ₅ , 1 to 40 C atoms and are unsubstituted? , F, Cl, Br, I or CN mono- or poly-substituted linear or branched alkyl, where one or more CH ₂ groups are optionally each. in case, independently of one another, -O -, - S -, - NH -, - NR0 -, - SiR 0 R 00 -, - CO -, - COO -, - OCO -, - OCO-O -, - S-CO-, -CO-S-, -SO _2- , -CG ¹ = CG ^2- or -C ≡ C- are substituted so that two O or two S atoms are not directly bonded to each other. Or indicates P-Sp-,
R ⁰ and R ⁰⁰ are alkyl having H or 1 to 12 C atoms, independent of each other.
G ¹ and G ² are independent of each other and are H, F, Cl or CN.
P is the basis of reactivity,
Sp is a spacer group or a single bond,
A ¹ and A ² are groups that, in their respective presence, independently contain a substituted or unsubstituted aromatic or alicyclic ring, or two or more condensed aromatic or alicyclic rings. Here, these rings optionally contain one or more heteroatoms selected from N, O and S.
W ¹ and W ² independently in their respective existence are -O-, -S-, -CO-, -COO-, -OCO-, -S-CO-, -CO-S-, -O. -COO-, ^{-CO-NR 0-} , -NR ^0- CO-, -OCH _2- , -CH ₂ O-, -SCH _2- , -CH ₂ S-, -CF ₂ O-, -OCF _{2- , -CF 2 S -, - SCF} 2 -, - CH 2 CH 2 -, - CF 2 CH 2 -, - CH 2 CF 2 -, - CF 2 CF 2 -, - CH = N -, - N = CH -, -N = N-, -CH = CH-, -CH = CR ^0- , -CR ⁰ = CR ^00- , -CG ¹ = CG ^2- , -C≡C-, -CH = CH-COO- , -OCO-CH = CH- or single bond, where m is 0, 1, 2 or 3 independently in each presence. )

As the compound represented by the formula (E1), for example, the compounds represented by the following formulas (E1-1) to (E1-3) are preferable.

As the optically active compound, for example, a compound represented by the following formula (E2) may be used.

（式（Ｅ２）中、Ｘ^１、Ｘ^２、Ｙ^１およびＹ^２は、互いに独立して、Ｈ、Ｆ、Ｃｌ、Ｂｒ、Ｉ、ＣＮ、ＳＣＮ、ＳＦ_５、２５個までのＣ原子を有する直鎖状または分枝状アルキルであって、非置換であるか、あるいはＦ、Ｃｌ、Ｂｒ、ＩまたはＣＮにより一置換または多置換されていてもよく、また、１つまたは２つ以上の非隣接ＣＨ_２基が、各々の場合において互いに独立して、−Ｏ−、−Ｓ−、−ＮＨ−、−ＮＲ^０−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯ−Ｏ−、−Ｓ−ＣＯ−、−ＣＯ−Ｓ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−によって、Ｏ原子および／またはＳ原子が互いに直接結合しないように置換されていてもよい前記アルキル、あるいは任意選択でＬであり、
Ｒ^０は、Ｈまたは、１個から４個のＣ原子を有するアルキルであり、
ｘ１およびｘ２は、互いに独立して、０、１または２であり、
ｙ１およびｙ２は、互いに独立して、０、１、２、３または４であり、
ＢおよびＣは、互いに独立して、芳香族または部分飽和もしくは全飽和脂肪族の６員環であり、１つまたは２つ以上のＣＨ基がＮで置換され、かつ１つまたは２つ以上のＣＨ_２基がＯおよび／またはＳで置換されていてもよく、
Ｗ^１およびＷ^２の一方が−Ｚ^１−Ａ^１−（Ｚ^２−Ａ^２）_ｍ−Ｒであり他方がＲ^１またはＡ^３であるか、あるいはＷ^１およびＷ^２の両方が−Ｚ^１−Ａ^１−（Ｚ^２−Ａ^２）_ｍ−Ｒであり、かつＷ^１およびＷ^２が同時にＨではなく、または、
Ｃ−Ｗ^１−（−Ｗ^２−）が下記式（Ｅ２−１）または下記（Ｅ２−２）であり、
Ｕ^１およびＵ^２は、互いに独立して、ＣＨ_２、Ｏ、Ｓ、ＣＯまたはＣＳであり、
Ｖ^１およびＶ^２は、互いに独立して、(ＣＨ_２）ｎであり、４つまでの非隣接ＣＨ_２基がＯおよび／またはＳで置換されていてもよく、かつＶ^１およびＶ^２の１つ、または
Ｃ−Ｗ^１−（−Ｗ^２−）が下記式（Ｅ２−３）の場合には、Ｖ^１およびＶ^２の一方または両方ともが単結合を意味し、
ｎは１〜７の整数であり、
Ｚ^１およびＺ^２は、互いに独立して、−Ｏ−、−Ｓ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−ＣＯＯ−、−ＣＯ−ＮＲ^０−、−ＮＲ^０−ＣＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＳＣＨ_２−、−ＣＨ_２Ｓ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｓ−、−ＳＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＨ_２−、−ＣＨ_２ＣＦ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝Ｎ−、−Ｎ＝ＣＨ−、−Ｎ＝Ｎ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−または単結合であり、
Ａ^１、Ａ^２およびＡ^３が、互いに独立して、さらに１つまたは２つ以上のＣＨ基がＮで置換されていてもよい１，４−フェニレン、さらに１つまたは２つの非隣接ＣＨ_２基がＯおよび／またはＳで置換されていてもよい１，４−シクロヘキシレン、１，３−ジオキソラン−４，５−ジイル、１，４−シクロヘキセニレン、１，４−ビシクロ−（２，２，２）−オクチレン、ピペリジン−１，４−ジイル、ナフタレン−２，６−ジイル、デカヒドロナフタレン−２，６−ジイル、または１，２，３，４−テトラヒドロナフタレン−２，６−ジイルであり、これらのすべての基は非置換であるか、またはＬによって一置換または多置換されていてもよく、またＡ^１は単結合でもよく、
Ｌは、ハロゲンまたは、１〜７個のＣ原子を有する、シアノ、ニトロアルキル、アルコキシ、アルキルカルボニルまたはアルコキシカルボニル基であって、ここで１つまたは２つ以上のＨ原子がＦまたはＣｌで置換されていてもよく、
ｍは、それぞれの場合に独立して、０、１、２または３であり、ならびに
ＲおよびＲ^１は、互いに独立して、Ｈ、Ｆ、Ｃｌ、Ｂｒ、Ｉ、ＣＮ、ＳＣＮ、ＯＨ、ＳＦ_５、２５個までのＣ原子を有する直鎖状または分枝状アルキルであって、非置換であるか、またはＦ、Ｃｌ、Ｂｒ、ＩもしくはＣＮで一置換または多置換されていてもよく、また、１つまたは２つ以上の非隣接ＣＨ_２基が、各々の場合において互いに独立して、−Ｏ−、−Ｓ−、−ＮＨ−、−ＮＲ^０−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯ−Ｏ−、−Ｓ−ＣＯ−、−ＣＯ−Ｓ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−によって、Ｏ原子および／またはＳ原子が互いに直接結合しないように置換されていることも可能である、前記アルキル基である。）

(In formula (E2), X ¹ , X ² , Y ¹ and Y ² have up to 25 C atoms, H, F, Cl, Br, I, CN, SCN, SF _{5, independent of each other.} It may be a linear or branched alkyl, unsubstituted, or mono- or poly-substituted with F, Cl, Br, I or CN, and one or more non-substituted. _Two adjacent CHs are independent of each other in each case, -O-, -S-, -NH-, -NR ^0- , -CO-, -COO-, -OCO-, -OCO-O-, The alkyl, or optionally, which may be substituted by -S-CO-, -CO-S-, -CH = CH- or -C≡C- so that the O and / or S atoms do not bond directly to each other. L in selection,
R ⁰ is an alkyl having H or 1 to 4 C atoms.
x1 and x2 are 0, 1 or 2 independently of each other.
y1 and y2 are 0, 1, 2, 3 or 4, independent of each other.
B and C are independently aromatic or partially saturated or fully saturated aliphatic 6-membered rings, with one or more CH groups substituted with N and one or more CH groups. _Two CH groups may be substituted with O and / or S,
One of W ¹ and W ² is −Z ¹ −A ¹ − (Z ² −A ² ) _m −R and the other is R ¹ or A ³ , or ^{both W 1} and W ² are −Z ¹ −A ¹ − (Z ² −A ² ) _m −R, and W ¹ and W ² are not H at the same time, or
C-W ^1- (-W ^2- ) is the following formula (E2-1) or the following (E2-2).
U ¹ and U ² _{are CH 2} , O, S, CO or CS, independent of each other.
V ¹ and ^{V 2} independently of one another, _(CH 2) n, and may be non-adjacent CH ₂ groups of up to four substituted with O and / or S, and the ^{V 1} and ^{V 2} When one or C-W ^1- (-W ^2- ) is the following formula (E2-3), one or both of ^{V 1} and V ^{2 mean a single bond.}
n is an integer from 1 to 7
Z ¹ and Z ² are independent of each other, -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, ^{-CO-NR 0-} , -NR ^0- CO. -, -OCH _2- , -CH ₂ O-, -SCH _2- , -CH ₂ S-, -CF ₂ O-, -OCF _2- , -CF ₂ S-, -SCF _2- , -CH ₂ CH _2- , -CF ₂ CH _2- , -CH ₂ CF _2- , -CF ₂ CF _2- , -CH = N-, -N = CH-, -N = N-, -CH = CH-, -CF = CH-, -CH = CF-, -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or single bond.
A ¹ , A ² and A ³ are independent of each other, with 1,4-phenylene in which one or more CH groups may be substituted with N, and one or two non-adjacent CH ₂ 1,4-Cyclohexylene, 1,3-dioxolane-4,5-diyl, 1,4-cyclohexenylene, 1,4-bicyclo- (2, whose groups may be substituted with O and / or S) 2,2) -octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, or 1,2,3,4-tetrahydronaphthalene-2,6-diyl All of these groups may be unsubstituted or mono- or poly-substituted by L, and A ¹ may be single-bonded.
L is a halogen or a cyano, nitroalkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group having 1 to 7 C atoms, where one or more H atoms are substituted with F or Cl. May have been
m is 0, 1, 2 or 3 independently in each case, and R and R ¹ are independent of each other, H, F, Cl, Br, I, CN, SCN, OH, SF. _A linear or branched alkyl having up to 5 or 25 C atoms, which may be unsubstituted or mono- or poly-substituted with F, Cl, Br, I or CN. also, one or more non-adjacent CH ₂ groups, in each case independently of one another, -O -, - S -, - NH -, - NR 0 -, - CO -, - COO-, -OCO-, -OCO-O-, -S-CO-, -CO-S-, -CH = CH- or -C≡C- are used to replace the O and / or S atoms so that they do not bond directly to each other. The alkyl group, which can also be. )

As the compound represented by the formula (E2), for example, the compounds represented by the following formulas (E2-4) to (E2-7) are preferable.

As the optically active compound, for example, a compound represented by the following formula (E3) may be used.

（式（Ｅ３）中、Ｌ^１１、Ｌ^２１は、各々、同一にまたは異なって、Ｆ、Ｃｌ、Ｂｒ、Ｉ、ＣＮ、ＳＣＮ、ＳＦ_５、非置換であっても、Ｆ、Ｃｌ、Ｂｒ、ＩもしくはＣＮによって単置換もしくは多置換されていてもよい２５個までのＣ原子を有する直鎖状もしくは分枝状アルキルであって、それは、１以上の非隣接ＣＨ_２基が各々の場合において互いに独立して、−Ｏ−、−Ｓ−、−ＮＨ−、−ＮＲ^０−、−ＣＯ−、−Ｃ（Ｏ）Ｏ−、−ＯＣ（Ｏ）−、−ＯＣ（Ｏ）−Ｏ−、−ＳＣ（Ｏ）−、−Ｃ（Ｏ）Ｓ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−によりＯおよび／またはＳ原子が互いに直接結合しないように置き換えられていることもまた可能である該アルキル、または、Ｌ^３１によって、任意に単置換もしくは多置換されていてもよい２０個までのＣ原子を有するシクロアルキルもしくはアリールであり、
Ｒ^０は、Ｈまたは１〜４個のＣ原子を有するアルキルであり、
Ｍ^１およびＭ^２の一方は−Ｚ^３１−Ａ^３１−（Ｚ^３２−Ａ^３２）ｍ−Ｒ^３１であり、他方はＲ^４１もしくはＡ^４１であり、または、
Ｍ^１およびＭ^２の両方は、同一にまたは異なって、−Ｚ^３１−Ａ^３１−（Ｚ^３２−Ａ^３２）_ｍ−Ｒ^３１であるか、または、
下記式（Ｅ３−１）は、下記式（Ｅ３−２）もしくは下記式（Ｅ３−３）であり、
Ｕ^１およびＵ^２は、各々、同一にまたは異なって、−ＣＨ_２−、−ＣＦ_２−、−Ｏ−、−Ｓ−、−ＣＯ−または−ＣＳ−を示し、
Ｖ^１およびＶ^２は、各々、同一にまたは異なって、単結合または（ＣＨ_２）ｎを示し、ここで３つまでの非隣接ＣＨ_２−基が−Ｏ−および／または−Ｓ−によって置き換えられていてもよく、
Ｚ^１１、Ｚ^１２、Ｚ^２１、Ｚ^２２、Ｚ^３１およびＺ^３２は、各々、同一にまたは異なって、−Ｏ−、−Ｓ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−ＣＯＯ−、−ＣＯ−ＮＲ^０−、−ＮＲ^０−ＣＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＳＣＨ_２−、−ＣＨ_２Ｓ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｓ−、−ＳＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＨ_２−、−ＣＨ_２ＣＦ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝Ｎ−、−Ｎ＝ＣＨ−、−Ｎ＝Ｎ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−または単結合を示し、
Ａ^１１、Ａ^１２、Ａ^２１、Ａ^２２、Ａ^３１、Ａ^３２、およびＡ^４１は、各々、同一にまたは異なって、１，４−フェニレンを示し、ここでさらに、１以上のＣＨ基がＮ、１，４−シクロヘキシレンによって置き換えられていてもよく、ここでさらに、１以上の非隣接ＣＨ_２基が−Ｏ−および／または−Ｓ−、１，３−ジオキソラン−４，５−ジイル、１，４−シクロヘキセニレン、１，４−ビシクロ［２，２，２］オクチレン、ピペリジン−１，４−ジイル、ナフタレン−２，６−ジイル、デカヒドロナフタレン−２，６−ジイル、もしくは１，２，３，４−テトラヒドロナフタレン−２，６−ジイルによって置き換えられていてもよく、これら全ての基が非置換であるか、Ｌ^３１によって単置換または多置換されていることが可能であり、
Ｌ^３１は、各々、独立して、または異なって、ハロゲンまたは１〜７個のＣ原子を有するシアノ、ニトロ、アルキル、アルコキシ、アルキルカルボニルもしくはアルコキシカルボニル基であり、ここで１個以上のＨ原子がＦまたはＣｌによって置き換えられていてもよく、
Ｒ^１１、Ｒ^２１、Ｒ^３１およびＲ^４１は、各々、同一にまたは異なって、Ｈ、Ｆ、Ｃｌ、Ｂｒ、Ｉ、ＣＮ、ＳＣＮ、ＯＨ、ＳＦ_５、非置換であっても、Ｆ、Ｃｌ、Ｂｒ、ＩもしくはＣＮによって単置換もしくは多置換されていてもよい２５個までのＣ原子を有する直鎖状もしくは分枝状アルキルであって、それは、１以上の非隣接ＣＨ_２基が各々の場合において互いに独立して−Ｏ−、−Ｓ−、−ＮＨ−、−ＮＲ^０−、−ＣＯ−、−Ｃ（Ｏ）Ｏ−、−ＯＣ（Ｏ）−、−ＯＣ（Ｏ）Ｏ−、−ＳＣ（Ｏ）−、−Ｃ（Ｏ）Ｓ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−によって−Ｏ−および／または−Ｓ−原子が互いに直接結合されないように置き換えられていることもまた可能である該アルキルを示し、
ｍは、０、１または２であり、
ｍ１、ｍ２は、各々、同一にまたは異なって、０、１、２または３であり、
ｎは、１〜７の整数であり、
ｒ１、ｒ２は、各々、同一にまたは異なって、０、１、２、３、４または５を示し、ならびに
ｓは、０または１を示す。）

(In formula (E3), L ¹¹ , L ²¹ are the same or different, respectively, F, Cl, Br, I, CN, SCN, SF ₅ , F, Cl, Br, even if they are unsubstituted. a straight-chain or branched alkyl having up to 25 C atoms which may be mono- or polysubstituted by I or CN, it may comprise one or more non-adjacent CH ₂ groups with each other in each case Independently, -O-, -S-, -NH-, -NR ^0- , -CO-, -C (O) O-, -OC (O)-, -OC (O) -O-,- It is also possible that SC (O)-, -C (O) S-, -CH = CH- or -C≡C- have replaced the O and / or S atoms so that they do not bond directly to each other. alkyl, or by L ^31, cycloalkyl or aryl having optionally C up to 20 atoms which may be mono- or polysubstituted,
R ⁰ is an alkyl having H or 1 to 4 C atoms.
One of M ¹ and ^{M 2 -Z} 31 ^-A 31 ^- is ^{(Z 32 -A 32) m-} R 31, the other is ^{R 41} or ^{A 41,} or,
Both M ¹ and ^{M 2} are identical or ^different, -Z ³¹ -A ³¹ - or a _{^{(Z 32 -A 32) m -R}} 31, or,
The following formula (E3-1) is the following formula (E3-2) or the following formula (E3-3).
U ¹ and ^{U 2} are each a or the same or _{different, -CH 2 -, - CF 2} -, - O -, - S -, - CO- or -CS- indicates,
V ¹ and V ² represent a single bond or (CH ₂ ) n, respectively, identically or differently, where up to three non-adjacent CH ₂ -groups are replaced by -O- and / or -S-. May be
Z ¹¹ , Z ¹² , Z ²¹ , Z ²² , Z ³¹ and Z ³² are the same or different, respectively, -O-, -S-, -CO-, -COO-, -OCO-, -O-. COO-, ^{-CO-NR 0-} , -NR ^0- CO-, -OCH _2- , -CH ₂ O-, -SCH _2- , -CH ₂ S-, -CF ₂ O-, -OCF _2- , -CF ₂ S-, -SCF _2- , -CH ₂ CH _2- , -CF ₂ CH _2- , -CH ₂ CF _2- , -CF ₂ CF _2- , -CH = N-, -N = CH- , -N = N-, -CH = CH-, -CF = CH-, -CH = CF-, -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = Indicates CH- or single bond,
A ¹¹ , A ¹² , A ²¹ , A ²² , A ³¹ , A ³² , and A ⁴¹ each exhibit 1,4-phenylene, either identically or differently, where one or more CH groups are N. , may be replaced by 1,4-cyclohexylene, wherein further one or more non-adjacent CH ₂ groups are -O- and / or -S-, 1,3-dioxolane-4,5-diyl, 1,4-Cyclohexenylene, 1,4-bicyclo [2,2,2] octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, or 1 , may be replaced by 2,3,4-tetrahydronaphthalene-2,6-diyl, wherein all groups they are unsubstituted, it is possible which are mono- or polysubstituted by L ³¹ ,
L ³¹ is a cyano, nitro, alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group, each independently or differently, having a halogen or 1-7 C atoms, wherein one or more H atoms. May be replaced by F or Cl,
R ¹¹ , R ²¹ , R ³¹ and R ⁴¹ are the same or different, respectively, H, F, Cl, Br, I, CN, SCN, OH, SF ₅ , even if not substituted, F, Cl. , Br, I or CN, which is a linear or branched alkyl having up to 25 C atoms which may be mono- or poly-substituted, each of which has one or more non-adjacent CH ₂ groups. In some cases, -O-, -S-, -NH-, -NR ^0- , -CO-, -C (O) O-, -OC (O)-, -OC (O) O-, independently of each other. -SC (O)-, -C (O) S-, -CH = CH- or -C≡C- may replace the -O- and / or -S- atoms so that they are not directly bonded to each other. Also showing the alkyl that is possible,
m is 0, 1 or 2
m1 and m2 are 0, 1, 2 or 3, respectively, the same or different.
n is an integer of 1 to 7 and
r1 and r2 are the same or different, respectively, indicating 0, 1, 2, 3, 4 or 5, and s indicates 0 or 1. )

As the compound represented by the formula (E3), for example, the compounds represented by the following formulas (E3-4) to (E3-13) are preferable.

As the optically active compound, for example, a compound represented by the following formula (E4-1) or formula (E4-2) may be used.

（式（Ｅ４−１）および（Ｅ４−２）中、Ｒ^ｋ１はそれぞれ独立して、水素、ハロゲン、シアノ、−ＳＦ_５、または炭素数１〜５のアルキルであり、このアルキル中の少なくとも１つの−ＣＨ_２−は、−Ｏ−、−ＣＯＯ−または−ＯＣＯ−、で置き換えられてもよく、少なくともひとつの−ＣＨ_２−ＣＨ_２−は、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよいが、２つの連続する−ＣＨ_２−が−Ｏ−で置き換えられることはなく、このアルキル中の少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ｒ^ｋ２はそれぞれ独立して水素、ハロゲン、シアノ、−ＳＦ_５、または炭素数１〜２０のアルキルであり、このアルキル中の少なくとも１つの−ＣＨ_２−は、−Ｏ−、−ＣＯＯ−または−ＯＣＯ−、で置き換えられてもよく、少なくともひとつの−ＣＨ_２−ＣＨ_２−は、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよいが、２つの連続する−ＣＨ_２−が−Ｏ−で置き換えられることはなく、このアルキル中の少なくとも１つの水素はハロゲンで置き換えられてもよく；
環Ａはそれぞれ独立して、フェニレン環と連結して多環構造を構成する環であり、１，２−フェニレンあるいは１，２−シクロヘキシレンを示し；
環Ａ^ｋ１はそれぞれ独立して２個の結合部位を有する環構造であり、１，４−フェニレン、１，４−シクロヘキシレン、１，３−ジオキサン−２，５−ジイル、テトラヒドロピラン−２，５−ジイル、テトラヒドロピラン−３，５−ジイル、ピリミジン−２，５−ジイル、ピリジン−２，５−ジイル、または１，４−ビシクロ−（２，２，２）−オクチレンであり、これらの環中の少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ｘ^ｋ１はそれぞれ独立して、単結合、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＨ＝ＣＨ−、−ＣＦ_２ＣＦ_２−、−ＣＦ＝ＣＦ−、または−Ｃ≡Ｃ−であり；
Ｙ^ｋ１はそれぞれ独立して、単結合、または−（ＣＨ_２）_n−であり、ｎは１〜２０の整数であり；
Ｚ^ｋ１はそれぞれ独立して、単結合、または炭素数１〜１０のアルキレンであり、このアルキレン中の少なくとも１つの−ＣＨ_２−は、−Ｏ−、−ＣＯＯ−または−ＯＣＯ−、で置き換えられてもよく、少なくともひとつの−ＣＨ_２−ＣＨ_２−は、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−または−Ｃ≡Ｃ−で置き換えられてもよく、このアルキレン中の少なくとも１つの水素はハロゲンで置き換えられてもよく（ただし、Ｚ^ｋ１中に−Ｏ−Ｏ−があるものを除く）；
ｍｋ１はそれぞれ独立して、２〜４の整数であり；
ｎｋ１、およびｎｋ２はそれぞれ独立して、０〜２の整数である。）

(In formulas (E4-1) and (E4-2), R ^k1 is independently hydrogen, halogen, cyano, -SF ₅ , or an alkyl having 1 to 5 carbon atoms, and at least 1 in the alkyl. one of the _-CH 2 - can, -O -, - COO- or -OCO-, in may be replaced, at least one _-CH 2 -CH ₂ - is, -CH = CH- or -C≡C- in Although they may be replaced, the two contiguous −CH _2−s may not be replaced by −O− and at least one hydrogen in this alkyl may be replaced by a halogen;
R ^k2 is each independently hydrogen, halogen, cyano, -SF ₅ , or an alkyl having 1 to 20 carbon atoms, and at least one -CH _2- in this alkyl is -O-, -COO- or-. OCO-, in may be replaced, at least one _-CH 2 -CH ₂ - is, -CH = CH- or may be replaced by -C≡C-, but two consecutive -CH ₂ - is It is not replaced by —O— and at least one hydrogen in this alkyl may be replaced by a halogen;
Ring A is a ring that independently connects with a phenylene ring to form a polycyclic structure, and represents 1,2-phenylene or 1,2-cyclohexylene;
Ring ^Ak1 is a ring structure having two binding sites independently, and is 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, tetrahydropyran-2, These are 5-diyl, tetrahydropyran-3,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, or 1,4-bicyclo- (2,2,2) -octylene. At least one hydrogen in the ring may be replaced with a halogen;
X ^k1 is independently single-bonded, -O-, -CO-, -COO-, -OCO-, -OCH _2- , -CH ₂ O-, -CF ₂ O-, -OCF ₂ -,- CH = CH-, -CF ₂ CF _2- , -CF = CF-, or -C≡C-;
Y ^k1 are independently single bonds, or − (CH ₂ ) _n −, and n is an integer from 1 to 20;
Each Z ^k1 is independently a single bond or an alkylene having 1 to 10 carbon atoms, and at least one -CH _2- in this alkylene is replaced with -O-, -COO- or -OCO-. Alternatively, at least one −CH ₂ −CH ₂₋ may be replaced by −CH = CH−, −CF = CF− or −C≡C−, and at least one hydrogen in this alkylene is a halogen. May be replaced with (except for those with -O-O- in ^{Z k1);}
Each mk1 is independently an integer of 2-4;
nk1 and nk2 are independently integers of 0 to 2. )

As the optically active compound, for example, a compound represented by the following formula (E5-1) or formula (E5-2) may be used.

（式（Ｅ５−１）および（Ｅ５−２）中、Ｒ^１、Ｒ^２およびＲ^３は独立して、水素、ハロゲン、シアノ、−ＳＦ_５、または炭素数１から１０のアルキルであり、このアルキルにおいて、少なくとも１つの−ＣＨ_２−は、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ＝ＣＨ−、または−Ｃ≡Ｃ−で置き換えられてもよく、これらの基において、少なくとも１つの水素は、フッ素または塩素で置き換えられてもよく；環Ａ、環Ｂ、環Ｅ、および環Ｆは独立して、５，６，７，８−テトラヒドロナフタレン−１，２−ジイルまたはナフタレン−１，２−ジイルであり；環Ｃ、環Ｄ、および環Ｇは独立して、１，４−シクロヘキシレン、１，４−フェニレン、１，３−ジオキサン−２，５−ジイル、テトラヒドロピラン−２，５−ジイル、テトラヒドロピラン−３，５−ジイル、ピリミジン−２，５−ジイル、ピリジン−２，５−ジイル、または１，４−ビシクロ−（２，２，２）−オクチレンであり、これらの環において、少なくとも１つの水素は、フッ素または塩素で置き換えられてもよく；Ｚ^１、Ｚ^２、Ｚ^３、Ｚ^４、およびＺ^５は独立して、単結合または炭素数１から２０のアルキレンであり、このアルキレンにおいて、少なくとも１つの−ＣＨ_２−は、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ＝ＣＨ−、または−Ｃ≡Ｃ−で置き換えられてもよく、これらの基において、少なくとも１つの水素は、フッ素または塩素で置き換えられてもよく；ａ、ｂ、およびｃは独立して、２、３、または４である。）

(In the formula (E5-1) and ^{(E5-2), R 1, R} 2 and ^{R 3} are independently hydrogen, halogen, cyano, alkyl of -SF _5, or 1 to 10 carbon atoms, this In alkyl, at least one −CH ₂ − may be replaced by −O−, −COO−, −OCO−, −CH = CH−, or −C≡C−, and at least 1 in these groups. One hydrogen may be replaced with fluorine or chlorine; ring A, ring B, ring E, and ring F independently, 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene-. 1,2-Diyl; Ring C, Ring D, and Ring G are independently 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, tetrahydropyran- 2,5-diyl, tetrahydropyran-3,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, or 1,4-bicyclo- (2,2,2) -octylene. In these rings, at least one hydrogen may be replaced with fluorine or chlorine; Z ¹ , Z ² , Z ³ , Z ⁴ , and Z ⁵ are independently single-bonded or 1 to 20 carbon atoms. It is an alkylene, in which at least one −CH ₂₋ may be replaced by −O−, −CO−, −COO−, −OCO−, −CH = CH−, or −C≡C−. Well, in these groups, at least one hydrogen may be replaced with fluorine or chlorine; a, b, and c are independently 2, 3, or 4).

As the compound represented by the formula (E5-1), for example, the compound represented by the formula (E5-3) shown below is preferable.
As the compound represented by the formula (E5-2), for example, the compound represented by the following formula (E5-2) is preferable.

As the optically active compound, for example, compounds represented by the following formulas (E6-1) to (E6-7) may be used.

（式（Ｅ６−１）〜（Ｅ６−７）中、Ｒ^Ｋはそれぞれ独立して、炭素数３〜１０のアルキルまたは炭素数３〜１０のアルコキシであり、アルキル中またはアルコキシ中の少なくとも１つの−ＣＨ_２−ＣＨ_２−は、−ＣＨ＝ＣＨ−で置き換えられてもよく；
Ｒ^Ｋ０はそれぞれ独立して、水素または炭素数１〜１０のアルキルであり；
Ａ^Ｋはそれぞれ独立して、芳香族性あるいは非芳香族性の３〜８員環または炭素数９以上の縮合環であり、これらの環の任意の水素がハロゲン、炭素数１〜３のアルキルまたはハロアルキルで置き換えられてもよく、環の−ＣＨ_２−は−Ｏ−、−Ｓ−または−ＮＨ−で置き換えられてもよく、−ＣＨ＝は−Ｎ＝で置き換えられてもよく；
Ｙ^Ｋは独立して、水素、ハロゲン、炭素数１〜３のアルキル、炭素数１〜３のハロアルキル、芳香族性または非芳香族性の３から８員環、または、炭素数９以上の縮合環であり、これらの環の任意の水素がハロゲン、炭素数１〜３のアルキルまたはハロアルキルで置き換えられてもよく、−ＣＨ_２−は−Ｏ−、−Ｓ−または−ＮＨ−で置き換えられてもよく、−ＣＨ＝は−Ｎ＝で置き換えられてもよく；
Ｚ^Ｋは独立して、単結合、炭素数１〜８のアルキレンであるが、任意の−ＣＨ_２−は、−Ｏ−、−Ｓ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＳＯ−、−ＯＣＳ−、−Ｎ＝Ｎ−、−ＣＨ＝Ｎ−、−Ｎ＝ＣＨ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−または−Ｃ≡Ｃ−で置き換えられてもよく、任意の水素はハロゲンで置き換えられてもよく；
Ｘ^Ｋは単結合、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−または−ＣＨ_２ＣＨ_２−であり；
ｍＫは１〜４の整数である。）

(In the formula (E6-1) ~ (E6-7), R K is independently an alkoxy alkyl or 3-10 carbon atoms having 3 to 10 carbon atoms, at least one of the alkyl or a an alkoxy −CH ₂ −CH ₂₋ may be replaced by −CH = CH−;
^{Each RK0} is independently hydrogen or an alkyl having 1 to 10 carbon atoms;
^AK are independently aromatic or non-aromatic 3- to 8-membered rings or condensed rings having 9 or more carbon atoms, and any hydrogen in these rings is a halogen and an alkyl having 1 to 3 carbon atoms. Alternatively, it may be replaced with a haloalkyl, the -CH _{2- of} the ring may be replaced with -O-, -S- or -NH-, and -CH = may be replaced with -N =;
Y ^K is independently hydrogen, halogen, alkyl of 1 to 3 carbon atoms, haloalkyl of 1 to 3 carbon atoms, an aromatic or nonaromatic 3 to 8-membered ring, or having 9 or more fused carbocyclic Rings, any hydrogen in these rings may be replaced with halogen, alkyl or haloalkyl having 1-3 carbon atoms, with -CH _2- being replaced with -O-, -S- or -NH-. Also, -CH = may be replaced by -N =;
Z ^K is independently a single bond, alkylene with 1 to 8 carbon atoms, but any -CH _2- can be -O-, -S-, -COO-, -OCO-, -CSO-,-. It may be replaced by OCS-, -N = N-, -CH = N-, -N = CH-, -CH = CH-, -CF = CF- or -C≡C-, and any hydrogen is a halogen. May be replaced by;
X ^K is single bond, -COO-, -OCO-, -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- or -CH ₂ CH _2- ;
mK is an integer of 1 to 4. )

As the compound represented by the formula (E6-4), for example, the compound represented by the following formulas (E6-9) and (E6-10) is preferable.
As the compound represented by the formula (E6-6), for example, the compound represented by the following formula (E6-8) is preferable.

As the optically active compound, for example, a compound represented by the following formula (E7) may be used.

（式（Ｅ７）中、Ｌは置換基を有してもよい炭素数１〜１５の連結基を示し、Ｒ¹〜Ｒ¹⁰は、それぞれ独立して、水素原子、又は１価の置換基を示す。）

(In the formula (E7), L represents a linking group having 1 to 15 carbon atoms which may have a substituent, and R ^{1 to} R ¹⁰ each independently have a hydrogen atom or a monovalent substituent. show.)

As the compound represented by the formula (E7), for example, the compound represented by the formula (E7-1) shown below is preferable.

As the optically active compound, for example, a compound represented by the following formula (E8) may be used.

As the optically active compound, for example, a compound represented by the following formula (E9-1) may be used.

（式（Ｅ９−１）において、Ｙ^２は独立して、水素、ハロゲンまたは式（Ｅ９−２）で表される基であり、ただし、Ｙ^２中で少なくとも２つは式（Ｅ９−２）で表される基である。
式（Ｅ９−２）において、Ｒ^１は独立してハロゲン、シアノ、炭素数２〜２０のアルケニルまたは炭素数１〜２０のアルキルであり、この基中の少なくとも１つの−ＣＨ_２−は、−Ｏ−が隣接する場合を除いて−Ｏ−で置き換えられてもよく、この基中の少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ａ^２は独立して、１，４−シクロへキシレン、１，４−フェニレン、４，４’−ビフェニレン、ナフタレン−２，６−ジイル、デカヒドロナフタレン−２，６−ジイル、１，２，３，４−テトラヒドロナフタレン−２，６−ジイルまたは少なくとも１つの水素がハロゲンで置き換えられた１，４−フェニレンであり；
Ｚ^１は独立して、単結合、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−、−ＣＨ_２ＣＨ_２−ＣＯＯ−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＯＣＦ_２−または−(ＣＨ_２)_ｐ−であり、−(ＣＨ_２)_ｐ−の１つの−ＣＨ_２−は、−Ｏ−で置き換えられてもよく；
ｐは独立して１〜２０の整数であり；
ｒは独立して１〜３の整数である。）

(In formula (E9-1), Y ² is independently a hydrogen, halogen or group represented by formula (E9-2), provided ^{that at least two of Y 2} are in formula (E9-2). It is a group represented by.
In formula (E9-2), R ¹ is independently a halogen, cyano, an alkenyl having 2 to 20 carbon atoms or an alkyl having 1 to 20 carbon atoms, and at least one −CH ₂ − in this group is − It may be replaced with -O- unless the O- are adjacent; at least one hydrogen in this group may be replaced with a halogen;
A ² is independently 1,4-cyclohexylene, 1,4-phenylene, 4,4'-biphenylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2, 3,4-Tetrahydronaphthalene-2,6-diyl or 1,4-phenylene in which at least one hydrogen is replaced with halogen;
Z ¹ is independent, single bond, -O-, -COO-, -OCO-, -CH = CH-COO-, -OCO-CH = CH-, -CH ₂ CH _{2-COO-, -OCO- CH 2 CH 2 -, - OCF} 2 - or - (CH _{2) p} - in and, - (CH _{2) p} - in one -CH ₂ - may be replaced by -O-;
p is an independently integer from 1 to 20;
r is independently an integer of 1-3. )

As the optically active compound, for example, a compound represented by the following formula (E10-1) may be used.

（式（Ｅ１０−１）中、Ａｒ^２は、炭素数６乃至１２のアリーレン基、炭素数３乃至１２のシクロアルキレン基、又は炭素数３乃至１２のシクロアルケニレン基を表し、ｍは０乃至３である。また、Ｒ^３は、水素、炭素数１乃至１２のアルキル基、又は炭素数１乃至１２のアルコキシ基を表す。また、Ｒ及びＲ^１のうちの一方は、下記式（Ｅ１０−２）で表される置換基を表し、他方は水素を表す。）
（式（Ｅ１０−２）中、Ａｒ^１は、炭素数６乃至１２のアリーレン基、炭素数３乃至１２のシクロアルキレン基、又は炭素数３乃至１２のシクロアルケニレン基を表し、ｋは１乃至３である。また、Ｒ^２は、水素、炭素数１乃至１２のアルキル基、又は炭素数１乃至１２のアルコキシ基を表す。）

(In the formula (E10-1), Ar ² represents an arylene group having 6 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a cycloalkenylene group having 3 to 12 carbon atoms, and m is 0 to 3. Further, R ³ represents hydrogen, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. ^One of R and R 1 represents the following formula (E10-2). ) Represents a substituent, and the other represents hydrogen.)
(In the formula (E10-2), Ar ¹ represents an arylene group having 6 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a cycloalkoxylene group having 3 to 12 carbon atoms, and k represents 1 to 3 carbon atoms. R ² represents hydrogen, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.)

As the compound represented by the formula (E10-1), for example, the compounds represented by the following formulas (E10-3) to (E10-10) are preferable.

As the optically active compound, for example, a compound represented by the following formula (E11) may be used.

（式（Ｅ１１）中、Ｂは、Ｌにより一置換、二置換または三置換されていてもよい１，４−フェニレン、または、１，４−シクロヘキシレンであり、
Ｌは、Ｈ、Ｆ、Ｃｌ、ＣＮ、または、１〜７個の炭素原子を有しハロゲン化されていてもよいアルキル、アルコキシ、アルキルカルボニル、アルコキシカルボニル、アルキルカルボニルオキシまたはアルコキシカルボニルオキシであり、
ｂは、０、１または２であり、
Ｚ^５は、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ２ＣＨ２−または単結合であり、および
Ｒ^５は、１〜１２個の炭素原子を有するアルキル、アルコキシ、アルキルカルボニル、アルコキシカルボニルまたはアルキルカルボニルオキシである。）

(In formula (E11), B is 1,4-phenylene or 1,4-cyclohexylene, which may be mono-substituted, di- or tri-substituted by L.
L is H, F, Cl, CN, or alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 7 carbon atoms and may be halogenated.
b is 0, 1 or 2,
Z ⁵ is -COO-, -OCO-, -CH2CH2- or a single bond, and R ⁵ is an alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having 1-12 carbon atoms. .. )

As the compound represented by the formula (E11), for example, the compound represented by the formula (E11-1) shown below is preferable.

As the optically active compound, for example, a compound represented by the following formula (E12) may be used.

When a binaphthyl chiral compound is used as the optically active compound, the content of the optically active compound in the first liquid crystal composition 21 and the second liquid crystal composition 22 can be appropriately determined depending on the intended selective reflection wavelength. Specifically, the content of the optically active compound in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 can be 0.1 to 10% by mass, respectively, and 1 to 8% by mass. Is preferable.

When the content of the optically active compound in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is 0.1% by mass or more, a high weighing is easily performed regardless of the production scale when preparing the optically active compound. The optically active compound can be weighed with high accuracy, and the concentration of the optically active compound tends to be prepared with high accuracy. Therefore, because the concentration of the optically active compound in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 is not in the desired concentration range, the first cholesteric liquid crystal layer 1 and / or the second cholesteric liquid crystal layer 2 It is possible to prevent the selective reflection wavelength and the temperature dependence from being out of the predetermined range. Therefore, it is easy to obtain the first cholesteric liquid crystal layer 1 and / or the second cholesteric liquid crystal layer 2 having a desired spiral twist direction and selective reflection wavelength.
When the content of the optically active compound is 10% by mass or less, the increase in viscosity, the phase transition temperature, and the decrease in storage stability of the first liquid crystal composition 21 and the second liquid crystal composition 22 due to the inclusion of the optically active compound are suppressed. can.

It is preferable that the first liquid crystal composition 21 and the second liquid crystal composition 22 do not contain a compound having a structure in which oxygen atoms are bonded to each other, such as a peracid (-CO-OO-) structure, in the molecule.

The first liquid crystal composition 21 and / or the second liquid crystal composition 22 preferably has a high content of a compound having a 6-membered ring structure in the molecule. The content of the compound in which the ring structure in the molecule is all 6-membered rings is preferably 80% by mass or more with respect to the total mass of the first liquid crystal composition 21 and / or the second liquid crystal composition 22. It is more preferably 90% by mass or more, further preferably 95% by mass or more, and most preferably only a compound having a substantially all 6-membered ring structure in the molecule.

In order to suppress deterioration due to oxidation, it is preferable to reduce the content of the compound having a cyclohexenylene group as a ring structure, and set the content of the compound having a cyclohexenylene group to the first liquid crystal composition 21 and / or It is preferably 10% by mass or less, preferably 8% by mass or less, more preferably 5% or less, and 3% by mass or less with respect to the total mass of the second liquid crystal composition 22. Is preferable, and it is more preferable that it is not substantially contained.

Substantially not contained in the present application means that it is not contained except for an unintentionally contained substance.
When the liquid crystal compound contained in the first liquid crystal composition 21 and / or the second liquid crystal composition 22 has an alkenyl group as a side chain, and when the alkenyl group is bonded to cyclohexane, the alkenyl group is used. The number of carbon atoms is preferably 2-5. When the alkenyl group is bonded to benzene, the alkenyl group preferably has 4 to 5 carbon atoms, and the unsaturated bond of the alkenyl group and benzene are preferably not directly bonded.

The liquid crystal display device 10 of the present embodiment has a first cholesteric liquid crystal layer 1 and a second cholesteric liquid crystal layer 2 laminated with the first cholesteric liquid crystal layer 1. The first cholesteric liquid crystal layer 1 comprises a first liquid crystal composition 21 containing two or more kinds of optically active compounds selected so that the temperature dependence of the chiral pitch length is different and the temperature dependence of the chiral pitch length is zero. include.
Further, the second cholesteric liquid crystal layer 2 also contains a second liquid crystal composition containing two or more kinds of optically active compounds selected so that the temperature dependence of the chiral pitch length is different and the temperature dependence of the chiral pitch length is zero. 22 is included. Therefore, in the liquid crystal display device 10 of the present embodiment, the difference in color due to the difference in the environmental temperature is small.

Further, in the liquid crystal display device 10 of the present embodiment, the spiral twist direction of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 is different. Therefore, the liquid crystal display device 10 of the present embodiment reflects not only the circularly polarized light component that coincides with the spiral twisting direction of the first liquid crystal composition 21 or the second liquid crystal composition 22, but also the circularly polarized light component in the opposite rotation direction. It can be taken out as light. As a result, the liquid crystal display device 10 of the present embodiment has a reflectance of incident light as compared with the case where, for example, only one of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 is provided with one or more layers. It will be expensive.

<Second Embodiment>
FIG. 3 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the second embodiment. The difference between the liquid crystal display device 20 shown in FIG. 3 and the liquid crystal display device 10 shown in FIG. 1 is that the liquid crystal display device 20 shown in FIG. 3 has the transparent adhesive layer 5 in the liquid crystal display device 10 shown in FIG. There is no place. Therefore, in the liquid crystal display device 20 shown in FIG. 3, the same members as those of the liquid crystal display device 10 shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 3, in the liquid crystal display device 20 of the present embodiment, the transparent substrate 31b arranged on the second cholesteric liquid crystal layer 2 side of the first cholesteric liquid crystal layer 1 and the first cholesteric of the second cholesteric liquid crystal layer 2 It is in contact with the transparent substrate 32a arranged on the liquid crystal layer 1 side.

<Third Embodiment>
FIG. 4 is a schematic cross-sectional view for explaining a main part of the liquid crystal display device of the third embodiment. The difference between the liquid crystal display device 30 shown in FIG. 4 and the liquid crystal display device 20 shown in FIG. 3 is that in the liquid crystal display device 30 shown in FIG. 4, the liquid crystal display device 30 is arranged on the second cholesteric liquid crystal layer 2 side of the first cholesteric liquid crystal layer 1. The transparent substrate 33 is also serving as the transparent substrate 33 arranged on the first cholesteric liquid crystal layer 1 side of the second cholesteric liquid crystal layer 2. Therefore, in the liquid crystal display device 30 shown in FIG. 4, the same members as those of the liquid crystal display device 20 shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

Also in the liquid crystal display devices 20 and 30 of the second embodiment and the third embodiment, the first cholesteric liquid crystal layer 1 and the first cholesteric liquid crystal layer are similar to the liquid crystal display device 10 of the first embodiment shown in FIG. It has a second cholesteric liquid crystal layer 2 laminated with 1. The first cholesteric liquid crystal layer 1 is a first liquid crystal composition containing two or more kinds of optically active compounds selected so that the temperature dependence of the chiral pitch length is different and the temperature dependence of the chiral pitch length is zero. 21 is included. Further, the second cholesteric liquid crystal layer 2 also contains a second liquid crystal composition containing two or more kinds of optically active compounds selected so that the temperature dependence of the chiral pitch length is different and the temperature dependence of the chiral pitch length is zero. 22 is included. Therefore, the difference in color due to the difference in environmental temperature is small.

Further, also in the liquid crystal display devices 20 and 30 of the second embodiment and the third embodiment, the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer are similar to the liquid crystal display device 10 of the first embodiment shown in FIG. The spiral twist direction of 2 is different. Therefore, for example, the reflectance of the incident light is higher than that in the case where only one of the first cholesteric liquid crystal layer 1 and the second cholesteric liquid crystal layer 2 is provided with one or more layers.

Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited to the following examples.
(Liquid crystal compounds 1 to 4 other than optically active compounds)
The liquid crystal compounds of the following formulas (1) to (20) were mixed at the ratio shown in Table 1 to prepare liquid crystal compounds 1 to 5 other than the optically active compound.
The liquid crystal compounds of the formulas (1) to (9) and (16) to (20) are dielectrically positive liquid crystal compounds.
The liquid crystal compounds of the formulas (10) to (15) are dielectrically neutral liquid crystal compounds.

For liquid crystal compounds 1 to 5 other than optically active compounds, the phase transition temperature ( _TNI ), which is the temperature at which the liquid crystal phase transitions to the isotropic phase, the melting point, which is the temperature at which the solid crystal phase is restored to the liquid crystal phase, and the temperature of 25 ° C. The refractive anisotropy (Δn) at a wavelength of 589 nm, the dielectric anisotropy (Δε) at a temperature of 25 ° C. and a frequency of 1 kHz, and the viscosity, which is the flow viscosity at a temperature of 20 ° C., were measured. The results are shown in Table 1.

(Cholesteric liquid crystal layers 1-4, 6, 7)
An empty panel was prepared by using two glass substrates having a homogeneous alignment film and not subjected to a rubbing treatment and having a refractive index of 1.52 at 25 ° C. In the obtained empty panel, any one of the liquid crystal compounds 1 to 5 other than the optically active compounds shown in Table 1 and the optically active compounds of the above formulas (3-1) to (3-4) at the ratio shown in Table 2 were added. A liquid crystal panel was formed by injecting a cholesteric liquid crystal composition containing the mixture and sealing the injection port. The obtained liquid crystal panel _{was heated to a temperature equal to} or higher than the phase transition temperature (TNI), and then slowly cooled to room temperature. Then, the surface of the liquid crystal panel was repeatedly pressed with tweezers to obtain cholesteric liquid crystal layers 1 to 4, 6 and 7 having a homogeneous orientation and a thickness of 6 μm.

(Cholesteric liquid crystal layer 5)
An empty panel was produced using the same two glass substrates used in producing the cholesteric liquid crystal layer 1. A cholesteric liquid crystal composition containing a liquid crystal compound 1 other than the optically active compound shown in Table 1 and an optically active compound of the above formulas (3-1) and (3-3) in the proportion shown in Table 2 in the obtained empty panel. Was injected and the injection port was sealed to form a liquid crystal panel. The obtained liquid crystal panel _{was heated to a temperature equal to} or higher than the phase transition temperature (TNI), and then slowly cooled to room temperature. Then, the surface of the liquid crystal panel was repeatedly pressed with tweezers to obtain a cholesteric liquid crystal layer 5 having a homogeneous orientation and a thickness of 12 μm.

The selective reflection wavelengths of the obtained cholesteric liquid crystal layers 1 to 7 were measured at 0 ° C., 25 ° C., and 50 ° C., respectively, by the methods shown below. In addition, the temperature dependence of the selective reflection wavelength was calculated for each of the cholesteric liquid crystal layers 1 to 7. The results are shown in Table 2.

"Temperature dependence of selective reflection wavelength (0 to 50 ° C)"
Light is incident on the cholesteric liquid crystal layer at an incident angle of 30 ° from the normal of the panel, and the wavelength of the light reflected in the normal direction of the liquid crystal panel at each temperature of 0 ° C, 25 ° C, and 50 ° C is set to the liquid crystal display. Measurement was performed using a panel evaluation device (trade name; LCD-5200 (manufactured by Otsuka Electronics Co., Ltd.)), and the selective reflection wavelength at each temperature was determined. Then, by dividing the difference between the maximum value and the minimum value of the selective reflected light in the temperature range of 0 to 50 ° C. by the temperature range (50 ° C.), the temperature depends on the selective reflection wavelength in the temperature range of 0 to 50 ° C. The sex was calculated.

(Example 1 (liquid crystal display device))
The cholesteric liquid crystal layer 1 shown in Table 2 and the cholesteric liquid crystal layer 2 were laminated so as to be in contact with each other to obtain the liquid crystal display device of Example 1.

(Comparative Example 1 (Liquid Crystal Display Device))
Two cholesteric liquid crystal layers 1 shown in Table 2 were used and laminated so as to be in contact with each other to obtain a liquid crystal display device of Comparative Example 1.
(Comparative Example 2 (Liquid Crystal Display Device))
The cholesteric liquid crystal layer 5 shown in Table 2 was used as the liquid crystal display device of Comparative Example 2.

(Example 2 (liquid crystal display device))
The cholesteric liquid crystal layer 1 and the cholesteric liquid crystal layer 2 shown in Table 2 are bonded together using an adhesive (trade name: LUMISIL203UV; manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), and have a refractive index of 1.41 at 25 ° C. and a thickness of about 100 μm. The liquid crystal display device of Example 2 in which the cholesteric liquid crystal layer 1 and the cholesteric liquid crystal layer 2 were laminated via the transparent adhesive layer of the above was obtained.

(Comparative Example 3 (Liquid Crystal Display Device))
The cholesteric liquid crystal layer 3 shown in Table 2 and the cholesteric liquid crystal layer 4 were laminated so as to be in contact with each other to obtain a liquid crystal display device of Comparative Example 3.
(Comparative Example 4 (Liquid Crystal Display Device))
The cholesteric liquid crystal layer 3 and the cholesteric liquid crystal layer 4 shown in Table 2 are bonded together using an adhesive (trade name: LUMISIL203UV; manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), and have a refractive index of 1.41 at 25 ° C. and a thickness of about 100 μm. The liquid crystal display device of Comparative Example 4 in which the cholesteric liquid crystal layer 3 and the cholesteric liquid crystal layer 4 were laminated via the transparent adhesive layer of the above was obtained.

(Example 3 (liquid crystal display device))
The cholesteric liquid crystal layer 6 and the cholesteric liquid crystal layer 7 shown in Table 2 are bonded together using an adhesive (trade name: LUMISIL203UV; manufactured by Asahi Kasei Wacker Silicone Co., Ltd.), and have a refractive index of 1.41 at 25 ° C. and a thickness of about 100 μm. The liquid crystal display device of Example 3 in which the cholesteric liquid crystal layer 6 and the cholesteric liquid crystal layer 7 were laminated via the transparent adhesive layer of the above was obtained.

For each of the obtained liquid crystal display devices of Examples 1 to 3 and Comparative Examples 1 to 4, the cholesteric liquid crystal layer shown in Table 3 was arranged on the upper side (light incident side). Then, for each liquid crystal display device, the selective reflection wavelengths at 0 ° C., 25 ° C., and 50 ° C. were measured in the same manner as in the cholesteric liquid crystal layer 1, and the temperature dependence of the selective reflection wavelength was calculated. Further, for the liquid crystal display devices of Examples 1 to 3 and Comparative Examples 1 to 4, the cholesteric liquid crystal layer shown in Table 3 is arranged on the upper side (light incident side), and the reflection of each wavelength of the standard white plate is performed. The maximum reflectance in the temperature range of 0 to 50 ° C. when the rate was 100% was determined. The results are shown in Table 3.

As shown in Table 3, in each of Examples 1 to 3, the maximum reflectance was 80% or more, and the reflectance of the incident light was high. In particular, in Examples 2 and 3 in which the upper and lower cholesteric liquid crystal layers are laminated via a transparent adhesive layer having a refractive index of 1.41, the maximum reflectance is 85% or more, and the reflectance of incident light is high. rice field.
Further, in each of Examples 1 to 3, the value of the temperature dependence of the selective reflection wavelength at 0 ° C. to 50 ° C. was small, and the difference in color due to the difference in the environmental temperature was small.

On the other hand, in Comparative Example 1 in which the upper and lower cholesteric liquid crystal layers are the same and the spiral twist direction is the right direction, the maximum reflectance is less than 50% and the reflectance of the incident light is low. ..
Further, also in Comparative Example 2 composed of a single cholesteric liquid crystal layer, the maximum reflectance was less than 50%, and the reflectance of the incident light was low.

Further, in Comparative Example 3 and Comparative Example 4 in which the upper and lower cholesteric liquid crystal layers each contain only one optically active compound, the value of the temperature dependence of the selective reflection wavelength at 0 ° C. to 50 ° C. is large, and the environmental temperature is different. There was a large difference in color due to this.

(Example 4 (liquid crystal display device))
One of the two glass substrates was a glass substrate in which a pixel electrode having a length of 150 μm and a width of 80 μm and a homogeneous alignment film were provided in this order, and the other was a glass substrate provided with a common electrode. A liquid crystal display device of Example 4 was obtained in the same manner as in Example 2.
With respect to the obtained liquid crystal display device, the pixel electrode of the cholesteric liquid crystal layer 1 and the pixel electrode of the cholesteric liquid crystal layer 2 are measured in the vertical direction in a plan view by a method of measuring the pixel deviation using an optical microscope manufactured by Olympus Corporation. And the horizontal misalignment was measured, and the total of the vertical misalignment and the horizontal misalignment was calculated. As a result, it was about 45 μm.

(Example 5 (liquid crystal display device))
In the same manner as in Example 4, the pixel electrodes of the cholesteric liquid crystal layer 1 and the pixel electrodes of the cholesteric liquid crystal layer 2 were laminated so as to have a larger positional deviation in a plan view than in the fourth embodiment. The liquid crystal display device of Example 5 was obtained.
For the obtained liquid crystal display device, the total of the vertical misalignment and the horizontal misalignment was calculated in the same manner as in Example 4. As a result, it was 90 μm.

Characters were displayed on the liquid crystal display devices of Examples 4 and 5 thus obtained, and the display surface was observed. As a result, in Example 4, a display having high definition and good visibility was obtained as compared with Example 5.

1: 1st cholesteric liquid crystal layer, 2: 2nd cholesteric liquid crystal layer, 5: transparent adhesive layer, 10, 20, 30: liquid crystal display device, 21: 1st cholesteric liquid crystal composition (1st liquid crystal composition), 22: Second cholesteric liquid crystal composition (second liquid crystal composition), 31a, 31b, 32a, 32b, 33: transparent substrate, 41a, 42a: common electrode, 41b, 42b: pixel electrode, L0: incident light, L1, L2: light.

Claims (9)

It has a first cholesteric liquid crystal layer and a second cholesteric liquid crystal layer laminated with the first cholesteric liquid crystal layer.
The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer contain a cholesteric liquid crystal composition containing two or more optically active compounds selected so that the temperature dependence of the selective reflection wavelength becomes zero.
The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are liquid crystal display devices in which the spiral twist direction of the cholesteric liquid crystal composition is different. The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are formed by sandwiching the cholesteric liquid crystal composition between two transparent substrates facing each other.
The transparent adhesive layer is in contact with the transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer and the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer. Provided,
The liquid crystal display device according to claim 1, wherein the difference in refractive index between the transparent adhesive layer and the transparent substrate in contact with the transparent adhesive layer at 25 ° C. is 0.12 or less. The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are formed by sandwiching the cholesteric liquid crystal composition between two transparent substrates facing each other.
The claim that the transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer and the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer are in contact with each other. The liquid crystal display device according to 1. The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are formed by sandwiching the cholesteric liquid crystal composition between two transparent substrates facing each other.
The first aspect of claim 1, wherein the transparent substrate arranged on the second cholesteric liquid crystal layer side of the first cholesteric liquid crystal layer also serves as the transparent substrate arranged on the first cholesteric liquid crystal layer side of the second cholesteric liquid crystal layer. The liquid crystal display device described. The first cholesteric liquid crystal layer and the second cholesteric liquid crystal layer are a pixel electrode substrate made of a transparent substrate having pixel electrodes on a surface in contact with the cholesteric liquid crystal composition, and a side in contact with the cholesteric liquid crystal composition, respectively. The cholesteric liquid crystal composition is sandwiched between a common electrode substrate made of a transparent substrate provided with a common electrode on the surface of the cholesteric liquid crystal composition.
The pixel electrodes of the first cholesteric liquid crystal layer and the pixel electrodes of the second cholesteric liquid crystal layer are the sum of the positional deviation in the first direction and the positional deviation in the second direction orthogonal to the first direction in a plan view. However, the liquid crystal display device according to any one of claims 1 to 4, wherein the liquid crystal display device is 60 μm or less. Claim that the difference between the center wavelength of the selective reflection wavelength of the first cholesteric liquid crystal layer at 25 ° C. and the center wavelength of the selective reflection wavelength of the second cholesteric liquid crystal layer at 25 ° C. is in the range of 0 to 30 nm. The liquid crystal display device according to any one of 1 to 5. The liquid crystal display device according to any one of claims 1 to 6, wherein the cholesteric liquid crystal composition contains a dielectrically positive liquid crystal compound. The liquid crystal display device according to any one of claims 1 to 7, wherein the cholesteric liquid crystal composition contains a dielectrically neutral liquid crystal compound. The liquid crystal display device according to any one of claims 1 to 8, wherein the optically active compound is a binaphthyl chiral compound.

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