JP6299009B2 - Method for evaluating cholesteric liquid crystal composition - Google Patents

Description

  The present invention relates to a cholesteric liquid crystal composition containing cholesteric droplets rotated by a temperature gradient.

  It has been reported that when a temperature gradient is given to the liquid crystal compound along its spiral axis, the director rotates (see Non-Patent Document 1), and this phenomenon has long been known as the Lehmann effect. . Although there was no report about this phenomenon for a long time, it was recently reported that this phenomenon was reproduced (see Non-Patent Document 2).

  On the other hand, liquid crystal display elements have come to be widely used in various measuring instruments, automobile panels, word processors, electronic notebooks, printers, computers, televisions, watches, advertisement display boards, as well as watches and calculators. Various liquid crystal compositions containing a liquid crystal compound have been developed so far.

O. Lehmann, Ann. Phys. Leipzig 2,649 (1900) P. Oswald, Eur. Phys. J. et al. E 28, 377-383 (2009)

  However, the rotation effect of the liquid crystal compound as described above has not been studied any further, and examples in which the rotation phenomenon of the liquid crystal compound is effectively used in the liquid crystal composition have been known so far. Absent. In addition, the relationship between the rotation phenomenon of the liquid crystal compound and the quality of the liquid crystal display element using the liquid crystal compound is not known.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the cholesteric liquid crystal composition which can implement | achieve a high quality display element using the rotation phenomenon of a liquid crystal compound.

  The present inventors have reproduced the cholesteric droplet rotation phenomenon in the cholesteric liquid crystal composition and studied various effective rotation efficiency and control of the rotation direction. As a result, the liquid crystal composition having a high cholesteric droplet rotation speed is It has been found that there is a relationship between the rotational speed of cholesteric droplets and the characteristics of the liquid crystal composition, such as realizing a high-quality display element.

（一般式（ＬＣ）中、Ｒ^ＬＣは炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されていてもよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子に置換されていてもよく、
Ａ^ＬＣ１及びＡ^ＬＣ２は、それぞれ独立して、
（ａ）トランス−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基又は隣接していない２個以上のＣＨ_２基は酸素原子又は硫黄原子で置換されていてもよい。）、
（ｂ）１，４−フェニレン基（この基中に存在する１個のＣＨ基又は隣接していない２個以上のＣＨ基は窒素原子で置換されていてもよい。）、及び
（ｃ）１，４−ビシクロ（２．２．２）オクチレン基、ナフタレン−２，６−ジイル基、ナフタレン−３，７−ジイル基、デカヒドロナフタレン−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、又はクロマン−２，６−ジイル基からなる群より選ばれる基を表すが、上記の基（ａ）、基（ｂ）又は基（ｃ）に含まれる１つ又は２つ以上の水素原子はそれぞれ、フッ素原子、塩素原子、ＣＦ_３又はＯＣＦ_３で置換されていてもよく、
Ｚ^ＬＣは単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、
Ｙ^ＬＣは、水素原子、フッ素原子、塩素原子、シアノ基、及び炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−、−Ｃ≡Ｃ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−で置換されてよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子で置換されていてもよく、
ａは１〜４の整数を表すが、ａが２、３又は４を表し、Ａ^ＬＣ１が複数存在する場合、複数存在するＡ^ＬＣ１は、同一であっても異なっていてもよく、Ｚ^ＬＣが複数存在する場合、複数存在するＺ^ＬＣは、同一であっても異なっていてもよい。）で表される液晶化合物を少なくとも１種含有し、
前記キラル化合物が、下記一般式（Ｃｈ−Ｉ）

（一般式（Ｃｈ−Ｉ）中、Ｒ^１００及びＲ^１０１は互いに独立して、水素原子、又は炭素原子数１〜３０個のキラル若しくはアキラルなアルキル基を含むキラルな基を表すが、該アルキル基中の１個又は２個以上の隣接していないＣＨ_２基は互いに独立して、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯ−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＦ_２−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−又はＣ≡Ｃ−により置換されていてもよく、該アルキル基は直鎖状であっても、分岐していてもよいが、Ｒ^１００及びＲ^１０１の少なくとも一方は、下記式（Ｒａ）、（Ｒｂ）、（Ｒｃ）、（Ｒｆ）、（Ｒｇ）又は（Ｒｈ）

（式中、Ｒ^３は、炭素原子数１〜１０の直鎖状もしくは分岐鎖状のアルキル基、又は水素原子を表し、該アルキル基の１つ又は２つ以上の−ＣＨ_２−基は酸素原子が相互に直接結合しないものとして−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−、−Ｏ−ＣＯ−Ｏ−、−ＣＨ＝ＣＨ−、又は−Ｃ≡Ｃ−で置き換えられてもよく、さらにアルキル基の１つ又はそれ以上の水素原子がフッ素原子で置き換えられていてもよく、
Ｘ^３及びＸ^４は、メチル基、メトキシ基、−ＣＦ_３、又は−ＯＣＦ_３を表し、ただし、Ｘ^４はＸ^３と異なる基を表し、
ｎ_３は０〜２０の整数を表し、
ｎ_４は０又は１を表す。）で表される、ＣＨ_２基が置換されているキラルなアルキル基を表し、
Ｚ^１００及びＺ^１０１は互いに独立して、−Ｏ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−ＣＯＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＨ_２−、−ＣＨ_２ＣＦ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＨ＝ＣＨ−又は単結合を表し、
Ａ^１００及びＡ^１０１は互いに独立して、
（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−ＣＨ_２−又は隣接していない２個以上の−ＣＨ_２−は互いに独立して−Ｏ−に置き換えられてもよい。）、又は
（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。）を表すが、これらの全ての基は、非置換であるか、１個若しくは２個以上の水素原子がＦ若しくはＣｌにより置換されていてもよい炭素原子数１〜７個のアルキル、アルコキシ、アルキルカルボニル若しくはアルコキシカルボニル基で一置換若しくは多置換されていてよく、
ｎ^１１は０を表し、
ｍ^１２は０を表し、
ｍ^１１は０、１、２、３、４又は５を表す。）で表される少なくとも１種の化合物であり、
膜厚がｄである薄膜状の前記コレステリック液晶組成物の膜厚方向に、コレステリック−等方相の共存領域において温度勾配ΔＴを発生させ、コレステリックドロップレットを回転させたときの回転速度ωを規定する、下記式（ｉ）で表される回転指数λを測定する、コレステリック液晶組成物の評価方法を提供する。
λ＝ω（ｄ／ΔＴ） ・・・・（ｉ） The present invention relates to a cholesteric liquid crystal composition comprising a nematic liquid crystal composition exhibiting a liquid crystal phase at room temperature and a chiral compound.
The cholesteric liquid crystal composition has the following general formula (LC)

(In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are- O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— may be substituted, and one or more hydrogen atoms in the alkyl group may be any May be substituted with a halogen atom,
A ^LC1 and A ^LC2 are each independently
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom) ),
(B) 1,4-phenylene group (one CH group present in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom), and (c) 1 , 4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, naphthalene-3,7-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4 -Represents a group selected from the group consisting of a tetrahydronaphthalene-2,6-diyl group or a chroman-2,6-diyl group, but is included in the group (a), group (b) or group (c). One or more hydrogen atoms may each be substituted with a fluorine atom, a chlorine atom, CF ₃ or OCF ₃ ;
Z ^LC is a single bond, —CH═CH—, —CF═CF—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, Represents —OCF ₂ —, —CF ₂ O—, —COO— or —OCO—,
Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are directly bonded to an oxygen atom. May be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ — so as not to be adjacent, One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom,
a represents an integer of 1 to 4, but a represents 2, 3 or 4, and when there are a plurality of A ^LC1 , the plurality of A ^LC1 may be the same or different, and Z ^LC is When there are a plurality of Z ^LCs , the plurality of Z ^LCs may be the same or different. At least one liquid crystal compound represented by
The chiral compound is represented by the following general formula (Ch-I)

(In the general formula (Ch-I), R ¹⁰⁰ and R ¹⁰¹ each independently represents a hydrogen atom or a chiral group containing a chiral or achiral alkyl group having 1 to 30 carbon atoms. One or more non-adjacent CH ₂ groups in the group are independently of each other —O—, —CO—, —COO—, —OCO—, —OCO—O—, —CH═CH—. , —CF ₂ —, —CF═CH—, —CH═CF—, —CF═CF— or C≡C—, the alkyl group may be linear or branched. However, at least one of R ¹⁰⁰ and R ¹⁰¹ may have the following formula (Ra), (Rb), (Rc), (Rf), (Rg) or (Rh)

(In the formula, R ³ represents a linear or branched alkyl group having 1 to 10 carbon atoms or a hydrogen atom, and one or more —CH ₂ — groups of the alkyl group are oxygen atoms. -O-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH = CH-, or -C≡C- as those in which atoms are not directly bonded to each other May be substituted, and further, one or more hydrogen atoms of the alkyl group may be replaced by fluorine atoms,
X ³ and X ⁴ represent a methyl group, a methoxy group, —CF ₃ , or —OCF ₃ , provided that X ⁴ represents a group different from X ³ ;
n ₃ represents an integer of 0 to 20,
n ₄ represents 0 or 1. ), A chiral alkyl group substituted with a CH ₂ group,
Z ¹⁰⁰ and ^{Z 101} are each independently, -O -, - CO -, - COO -, - OCO -, - O-COO -, - OCH 2 -, - CH 2 O -, - CF 2 O-, _{-OCF 2 -, - CH 2 CH} 2 -, - CF 2 CH 2 -, - CH 2 CF 2 -, - CF 2 CF 2 -, - CH = CH -, - CF = CH -, - CH = CF- , -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or a single bond,
A ¹⁰⁰ and A ¹⁰¹ are independent of each other,
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is replaced with independently -O- together Or (b) a 1,4-phenylene group (one —CH═ present in this group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom). All of these groups are unsubstituted or are alkyls of 1 to 7 carbon atoms in which one or more hydrogen atoms may be substituted by F or Cl, May be mono- or polysubstituted by alkoxy, alkylcarbonyl or alkoxycarbonyl groups;
n ¹¹ represents 0;
m ¹² represents 0;
m ¹¹ represents 0, 1, 2, 3, 4 or 5. At least one compound represented by
A temperature gradient ΔT is generated in the coexistence region of the cholesteric-isotropic phase in the film thickness direction of the cholesteric liquid crystal composition having a film thickness of d, and the rotational speed ω when the cholesteric droplet is rotated is defined. A method for evaluating a cholesteric liquid crystal composition, which measures a rotation index λ represented by the following formula (i):
λ = ω (d / ΔT) (i)

  ADVANTAGE OF THE INVENTION According to this invention, the rotational speed of a cholesteric droplet is quick and the cholesteric liquid crystal composition which can implement | achieve a high quality display element is provided.

The cholesteric liquid crystal composition according to the present invention is a cholesteric liquid crystal composition comprising a nematic liquid crystal composition exhibiting a liquid crystal phase at room temperature and a chiral compound, and the film thickness of the thin cholesteric liquid crystal composition having a film thickness of d. In the direction, a temperature gradient ΔT is generated in the coexistence region of the cholesteric-isotropic phase, and the rotation index λ expressed by the following formula (i) that defines the rotational speed ω when the cholesteric droplet is rotated is 0. 01 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m or more.
λ = ω (d / ΔT) (i)
When such a cholesteric liquid crystal composition is made into a thin film, a cholesteric droplet is rotated by generating a temperature gradient in the film thickness direction, and the rotational efficiency at this time is excellent.

  The cholesteric liquid crystal composition exhibits a liquid crystal phase at room temperature and exhibits a coexistence region of cholesteric and isotropic phases by containing a chiral compound. Here, room temperature typically means a temperature of 15 to 25 ° C.

The cholesteric droplet is an aggregate formed by aggregating liquid crystal compounds, and a specific striped pattern is observed when optically observed using a polarizing microscope or the like. The direction of the stripe pattern differs depending on the direction of the spiral axis of the cholesteric droplet.
In addition, the cholesteric droplet is rotated about the helical axis by the temperature gradient, and the rotation direction generates a temperature gradient such as the direction of the temperature gradient of the liquid crystal composition and the chirality of the chiral compound described later. It can change depending on the state of the liquid crystal composition.

The rotation index λ (degree · sec ⁻¹ · ° C. ⁻¹ · m) is defined as the rotational angular velocity (degree · sec ⁻¹ ) of the cholesteric droplet divided by the temperature gradient (° C. · m ⁻¹ ), and the temperature This is an index of rotational efficiency that can efficiently convert the gradient into rotational motion.

Cholesteric droplets have a higher rotational speed (higher rotational efficiency) as the rotation index λ is larger, and the higher the rotational speed of cholesteric droplets, the faster the liquid crystal display device using such a liquid crystal compound. It will be excellent.
Therefore, the larger the value of the rotation index λ, the better. However, when the rotation index λ is 0.01 × 10 ⁻³ deg · sec ⁻¹ · ° C. ⁻¹ · m or more, a liquid crystal display element sufficiently excellent in high-speed response can be obtained. It is done. In the present invention, the rotation index λ is preferably 0.1 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m or more, and 0.2 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻ It is more preferably ¹ · m or more, and further preferably 0.5 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m or more, and 1.0 × 10 ⁻³ degree · sec ⁻¹ · ° C. still more preferably ^-1 · m or more, and most preferably ^{1.0 × 10 -2 degree · sec -1} · ℃ -1 · m or more.

  Documents “O. Lehmann, Ann. Phys. Leipzig 2,649 (1900)” (Non-Patent Document 1), “P. Oswald, Eur. Phys. J.E 28, 377-383 (2009)”. (Non-Patent Document 2) reports that the director of the liquid crystal compound rotates when a temperature gradient is applied. However, the present inventors have found that when a temperature gradient is applied, the director does not rotate but the cholesteric droplet itself rotates as a whole. The value of the rotation index λ in the present invention is orders of magnitude greater than the value specifically calculated according to the above formula (i) in the same manner from the contents of these two documents, and the rotation speed of the cholesteric droplet is remarkable. Very fast. This is particularly remarkable when a specific liquid crystal compound described later is selected.

The generation of a temperature gradient in the film thickness direction of a thin-film cholesteric liquid crystal composition means that two main surfaces (two opposing surfaces having the largest area or surfaces having the largest area) of the thin-film cholesteric liquid crystal composition. This means that a temperature difference is generated between the surface and the surface having the second largest area, and a known temperature adjusting means can be used to generate the temperature difference.
A thin-film cholesteric liquid crystal composition can be produced, for example, by sandwiching it between two substrates such as a glass plate subjected to an alignment treatment.

  The film thickness of the thin-film cholesteric liquid crystal composition that generates a temperature gradient is preferably 1 μm to 1 cm, more preferably 2 μm to 50 mm, and particularly preferably 3 μm to 10 mm.

The cholesteric liquid crystal composition is excellent in the rotational efficiency of cholesteric droplets, and the temperature gradient showing a rotation index λ of 0.01 × 10 ⁻³ degree · sec ⁻¹ ° C.− ¹ · m or more is Although it will not specifically limit if it is a range which shows the coexistence area | region of a cholesteric-isotropic phase, For example, it adjusts to the range of 0.1-10 degreeC. The rotation index λ is adjusted by the type and amount of components contained in the cholesteric liquid crystal composition.

  In the cholesteric liquid crystal composition, the temperature range at which the cholesteric-isotropic phase coexistence region appears varies depending on the composition, but is, for example, in the range of 0.1 to 10 ° C.

The chiral compound may be a known compound, for example, a compound having an asymmetric atom, a compound having axial asymmetry, a compound having plane asymmetry, or an atropisomer, but a compound having an asymmetric atom. Is preferred. In a compound having an asymmetric atom, it is preferable that the asymmetric atom is an asymmetric carbon atom, since steric inversion hardly occurs, but a hetero atom may be an asymmetric atom. The asymmetric atom may be introduced into a part of the chain structure or may be introduced into a part of the cyclic structure. A compound having axial asymmetry is preferred when a strong helical induction force is particularly required.
The chiral compound may have a polymerizable group or may not have a polymerizable group.
The chiral compound may be used alone or in combination of two or more.

  Examples of the compound having an asymmetric atom include a compound having an asymmetric carbon in a side chain portion, a compound having an asymmetric carbon in a ring structure portion, and a compound satisfying both of them. Specific examples include compounds represented by the following general formula (Ch-I).

一般式（Ｃｈ−Ｉ）中、Ｒ^１００及びＲ^１０１は互いに独立して、水素原子、シアノ基、ＮＯ_２、ハロゲン、ＯＣＮ、ＳＣＮ、ＳＦ_５、炭素原子数１〜３０個のキラル又はアキラルなアルキル基、重合性基又は環構造を含むキラルな基を表すが、該アルキル基中の１個又は２個以上の隣接していないＣＨ_２基は互いに独立して、−Ｏ−、−Ｓ−、−ＮＨ−、−Ｎ（ＣＨ_３）−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯ−Ｏ−、−Ｓ−ＣＯ−、−ＣＯ−Ｓ−、−ＣＨ＝ＣＨ−、−ＣＦ_２−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−又はＣ≡Ｃ−により置換されていてもよく、該アルキル基中の１個又は２個以上の水素原子は互いに独立して、ハロゲン又はシアノ基によって置換されていてもよく、該アルキル基は直鎖状であっても、分岐していても又は環構造を含んでいてもよい。
ＣＨ_２基が置換されているキラルなアルキル基
としては、以下の式（Ｒａ）〜（Ｒｋ）が好ましい。

In the general formula (Ch-I), R ¹⁰⁰ and R ¹⁰¹ are independently of each other a hydrogen atom, a cyano group, NO ₂ , halogen, OCN, SCN, SF ₅ , a chiral or achiral group having 1 to 30 carbon atoms. Represents a chiral group containing an alkyl group, a polymerizable group or a ring structure, wherein one or more non-adjacent CH ₂ groups in the alkyl group are independently of each other —O—, —S—. , —NH—, —N (CH ₃ ) —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —CH═CH—, — One or two or more hydrogen atoms in the alkyl group may be substituted with CF ₂ —, —CF═CH—, —CH═CF—, —CF═CF— or C≡C—. Independently, it may be substituted by a halogen or cyano group, and the alkyl group is linear Even may contain branched even if or ring structure.
As the chiral alkyl group in which the CH ₂ group is substituted, the following formulas (Ra) to (Rk) are preferable.

In the formula, each of R ³ and R ⁵ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, or a hydrogen atom, and one or two or more —CH of the alkyl group _{The 2} -group is defined as a group in which oxygen atoms or sulfur atoms are not directly bonded to each other, —O—, —S—, —NH—, —N (CH ₃ ) —, —CO—, —CO—O—, —O—. CO -, - O-CO- O -, - S-CO -, - CO-S -, - O-SO 2 -, - SO 2 -O -, - CH = CH -, - C≡C-, cycloalkyl May be replaced with a propylene group or —Si (CH ₃ ) ₂ —, and one or more hydrogen atoms of the alkyl group may be replaced with a fluorine atom, a chlorine atom, a bromine atom or a cyano group; It may have a polymerizable group. As the polymerizable group, structures represented by the following formulas (R-1) to (R-15) are preferable.

X ³ and X ⁴ are each a halogen atom (F, Cl, Br, I), a cyano group, a phenyl group (one or more arbitrary hydrogen atoms of the phenyl group are halogen atoms (F, Cl, Br, I), optionally substituted with a methyl group, a methoxy group, —CF ₃ , —OCF ₃ ), a methyl group, a methoxy group, —CF ₃ , or —OCF ₃ . However, in the general formulas (Rc) and (Rh), a group different from X ³ is selected for X ⁴ so that the position marked with an asterisk * becomes an asymmetric atom.

N ₃ is an integer of 0 to 20, n ₄ is 0 or 1,
R ⁵ in the general formulas (Rd) and (Ri) is preferably a hydrogen atom or a methyl group,
Q in the general formulas (Re) and (Rj) includes a divalent hydrocarbon group such as a methylene group, an isopropylidene group, a cyclohexylidene group,
K in the general formula (Rk) is an integer of 0 to 5,
More preferably, a linear or branched alkyl group having 4 to 8 carbon atoms such as R ³ = C ₄ H ₉ , C ₆ H ₁₃ , C ₈ H ₁₇ and the like can be mentioned. X ³ is preferably F, CF ₃ , or CH ₃ .
Among them, as a chiral alkyl group in which the CH ₂ group is substituted,

（式中、ｏは０又は１であり、ｎは２〜１２、好ましくは３〜８、より好ましくは４、５又は６の整数であり、アステリスク＊は、キラルな炭素原子を表す。）が好ましい。

(Wherein, o is 0 or 1, n is an integer of 2 to 12, preferably 3 to 8, more preferably 4, 5 or 6, and an asterisk * represents a chiral carbon atom). preferable.

In the general formula (Ch-I), Z ¹⁰⁰ and Z ¹⁰¹ are independently of each other —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—N. (R ^a ) —, —N (R ^a ) —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 = CH -, - CF = CH-, —CH═CF—, —CF═CF—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or a single bond, —CO—N (R ^a ) — or — N ^(R a) is ^{R a} in -CO- represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, _-CF 2 O-, _{OCF 2 -, - CF 2 CF} 2 -, - CF = CF -, - COO -, - OCO -, - CH 2 -CH 2 -, - C≡C- or is preferably a single bond.

In general formula (Ch-I), A ¹⁰⁰ and A ¹⁰¹ are independently of each other,
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - independently of one another are -O- or - May be replaced by S-).
(B) a 1,4-phenylene group (one —CH═ present in the group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom) or (c) 1 , 4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, indan-2,5-diyl, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group And 1,2,3,4-tetrahydronaphthalene-2,6-diyl group (one —CH ₂ — present in the group (c) or two or more —CH ₂ — not adjacent to each other). May be independently replaced with —O— or —S—, and one —CH═ present in the group (c) or two or more non-adjacent —CH═ are nitrogen. Represents a group selected from the group consisting of: All groups of these is unsubstituted halogen, cyano, NO ₂ or the number to seven one or two or more carbon atoms which may hydrogen atoms replaced by F or Cl May be mono- or poly-substituted with an alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl group.

A ¹⁰⁰ and A ¹⁰¹ are preferably 1,4-phenylene or trans-1,4-cyclohexylene, but these rings are unsubstituted, or in the 1-4 position, F, Cl, CN or It is preferably substituted with alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl having 1 to 4 carbon atoms.

In the general formula (Ch-I), n ¹¹ represents 0 or 1, when n ¹¹ is 0, m ¹² is 0, and m ¹¹ is 0, 1, 2, 3, 4 or 5, When n ¹¹ is 1, m ¹¹ and m ¹² are each independently 0, 1, 2, 3, 4 or 5, and when n ¹¹ is 0, at least one of R ¹⁰⁰ and R ¹⁰¹ is chiral. A chiral group containing an alkyl group, a polymerizable group or a ring structure.
When n ¹¹ and m ¹² are 0, m ¹¹ is preferably 1, 2 or 3, and when n ¹¹ is 1, m ¹¹ and m ¹² are each independently preferably 1, 2 or 3. .

  In general formula (Ch-I), D represents the following formulas (D1) to (D3).

（式中、ベンゼン環の任意の１つ又は２つ以上の任意の水素原子はハロゲン原子（Ｆ、Ｃｌ、Ｂｒ、Ｉ）、炭素原子数１〜２０のアルキル基又はアルコキシ基で置換されていてもよく、該アルキル基又はアルコキシ基の水素原子は任意にフッ素原子に置換されていてもよく、また該アルキル基又はアルコキシ基中のメチレン基は、−Ｏ−、−S−、−ＣＯＯ−、−ＯＣＯ−、−ＣＦ_２−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ＝ＣＦ−又はＣ≡Ｃ−により、酸素原子又は硫黄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。）で表される。）で表される置換基である。

(In the formula, any one or two or more arbitrary hydrogen atoms in the benzene ring are substituted with a halogen atom (F, Cl, Br, I), an alkyl group having 1 to 20 carbon atoms, or an alkoxy group. The hydrogen atom of the alkyl group or alkoxy group may be optionally substituted with a fluorine atom, and the methylene group in the alkyl group or alkoxy group may be -O-, -S-, -COO-, _{-OCO -, - CF 2 -,} - CF = CH -, - CH = CF -, - by CF = CF- or C≡C-, be an oxygen atom or a sulfur atom substituted as not linked directly to one another Good)) ).

Partial structure in the general formula ^{(Ch-I), - (} A 100 -Z 100) m 11 - (D) n 11 - (Z 101 -A 101) m 12 - when ^{n 11} in is 0, the The partial structure is preferably the following structure.

(However, in these formulas, any one or two or more arbitrary hydrogen atoms in the benzene ring are halogen atoms (F, Cl, Br, I), methyl groups, methoxy groups, —CF ₃ , —OCF ₃₎ . Any one or more carbon atoms of the benzene ring may be substituted with nitrogen atoms, and the introduction of these substituents and nitrogen atoms may reduce crystallinity and dielectric properties. This is preferable for controlling the direction and size of the directivity.The definition of Z is the same as Z ¹⁰⁰ and Z ¹⁰¹ in the formula (Ch-I). In terms of reliability, a benzene ring or a cyclohexane ring is preferable to a heterocyclic ring such as a pyridine ring or a pyrimidine ring. In terms of increasing the dielectric anisotropy, it is preferable to use a compound having a heterocyclic ring such as a pyridine ring or a pyrimidine ring. In that case, however, the polarizability of the compound is relatively large and the crystallinity is lowered. It is preferable for stabilizing the liquid crystallinity, and when it is a hydrocarbon ring such as a benzene ring or a cyclohexane ring, the polarizability of the compound is low. For this reason, it is preferable to select an appropriate content according to the polarizability of the chiral compound.

When n ¹¹ and m ¹² are 0, preferred forms of the compound represented by the general formula (Ch-I) are as follows.

式中、Ｒ^１００、Ｒ^１０１及びＺ^１００は、一般式（Ｃｈ−Ｉ）におけるＲ^１００、Ｒ^１０１及びＺ^１００と同じ意味を表し、Ｒ^１００及びＲ^１０１の少なくとも一つはキラルな基を表し、Ｌ^１００〜Ｌ^１０５は各々独立に水素原子又はフッ素原子を表す。
中でも、一般式（Ｃｈ−Ｉ）で表される化合物は、下記式で表される化合物が好ましい。

^Wherein, R ^{100, R 101} and ^{Z 100} represents the same meaning as ^{R 100, R 101} and ^{Z 100} in the general formula ^(Ch-I), at least one of ^{R 100} and ^{R 101} represent a chiral group , L ^{100 to} L ¹⁰⁵ each independently represents a hydrogen atom or a fluorine atom.
Among these, the compound represented by the general formula (Ch-I) is preferably a compound represented by the following formula.

When n ¹¹ represents 1, the compound represented by the general formula (Ch-I) has a structure having an asymmetric carbon in the ring structure portion, but the chiral structure D is preferably the formula (D2).
The compound represented by the general formula (Ch-I) when D represents the formula (D2) is specifically the following formulas (D2-1) to (D2-8)

（式中、Ｒ^ｄは各々独立して、炭素原子数３〜１０のアルキルであり、このアルキル中の環に隣接する−ＣＨ_２−は−Ｏ−で置き換えられてもよく、任意の−ＣＨ_２−は、−ＣＨ＝ＣＨ−で置き換えられてもよい。）で表される化合物が好ましい。

(In the formula, each R ^d is independently alkyl having 3 to 10 carbon atoms, and —CH ₂ — adjacent to the ring in this alkyl may be replaced by —O—, and any —CH ₂ — _2- may be replaced by -CH = CH-).

  As the axially asymmetric compound, compounds represented by the following general formulas (IV-d4), (IV-d5), (IV-c1) and (IV-c2) are preferable. Here, in the case of the general formulas (IV-d4), (IV-d5), and (IV-c2), the axially asymmetric axis is a bond connecting the α-positions of the two naphthalene rings, and the general formula (IV-c1 ) Is a single bond connecting two benzene rings.

In the general formulas (IV-d4) and (IV-d5), R ⁷¹ and R ⁷² are each independently a hydrogen atom, a halogen atom, a cyano (CN) group, an isocyanate (NCO) group, or an isothiocyanate (NCS). Represents a group or an alkyl group having 1 to 20 carbon atoms, and one or more of —CH ₂ — in the alkyl group is —O—, —S—, —COO—, —OCO—. , —CH═CH—, —CF═CF—, or —C≡C—, and any hydrogen in the alkyl may be replaced with a halogen atom.

In the general formulas (IV-d4) and (IV-d5), A ⁷¹ and A ⁷² are each independently an aromatic or non-aromatic 3, 6 to 8 membered ring, or having 9 or more carbon atoms. Represents a condensed ring, and any hydrogen atom in these rings may be replaced with a halogen atom, an alkyl group having 1 to 3 carbon atoms or a haloalkyl group, and one or more —CH ₂ — in the ring May be replaced by -O-, -S-, or -NH-, and one or more -CH = in the ring may be replaced by -N =.

In the general formula (IV-d4) and ^(IV-d5), each independently ^{Z 71} and ^{Z 72} is a single bond or represents an alkylene group having 1 to 8 carbon atoms, arbitrary -CH ₂ -, - O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N = N-, -CH = N-, -N = CH-, -N (O) = N-, —N═N (O) —, —CH═CH—, —CF═CF—, or —C≡C— may be substituted, and any hydrogen atom may be substituted with a halogen atom.

In the general formulas (IV-d4) and (IV-d5), X ⁷¹ and X ⁷² are each independently a single bond, —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CF ₂ O. -, - OCF ₂ -, or _-CH 2 CH ₂ - represents a.

In the general formulas (IV-d4) and (IV-d5), m ₇₁ and m ₇₂ each independently represent an integer of 1 to 4. However, either one of m ₇₁ and m ₇₂ in the general formula (IV-d5) may be 0.
R ^k is a hydrogen atom, a halogen atom, or ^X 71 ^- represents the same meaning as ^{(A 71 -Z 71) -R 71} .

In general formulas (IV-c1) and (IV-c2), at least one of X ⁶¹ and Y ⁶¹ , X ⁶² and Y ⁶² exists, and X ⁶¹ , X ⁶² , Y ⁶¹ and Y ⁶² are each , Each independently represents CH ₂ , C═O, O, N, S, P, B, or Si. In the case of N, P, B, and Si, they may be bonded to a substituent such as an alkyl group, an alkoxy group, or an acyl group so as to satisfy a required valence.

In general formulas (IV-c1) and (IV-c2), E ⁶¹ and E ⁶² each independently represent a hydrogen atom, an alkyl group, an aryl group, an allyl group, a benzyl group, an alkenyl group, an alkynyl group, or an alkyl ether group. Represents an alkyl ester group, an alkyl ketone group, a heterocyclic group, or a derivative thereof.
In the general formulas (IV-c1) and (IV-c2),
R ⁶¹ and R ⁶² each independently represent an alkyl group, an alkoxyl group, or a phenyl group, a cyclopentyl group, or a cyclohexyl group that may be substituted with a halogen atom.

In general formula (IV-c1), R ⁶³ , R ⁶⁴ , R ⁶⁵ , R ⁶⁶ , R ⁶⁷ and R ⁶⁸ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, an acyloxy group, a halogen atom, a haloalkyl group, Or a dialkylamino group, and two of R ⁶³ , R ⁶⁴ and R ⁶⁵ may be a methylene chain which may have a substituent, or a mono or polymethylenedioxy which may have a substituent May form a group, and two of R ⁶⁶ , R ⁶⁷ and R ⁶⁸ may have an optionally substituted methylene chain, or may have an optionally substituted mono or polymethylene A dioxy group may be formed. However, it excludes when both ^R65 and ^R66 are hydrogen atoms.

  When it is particularly required that the helical induction force is strong, the compounds represented by the general formulas (IV-d4) and (IV-d5) are particularly preferable.

  In the cholesteric liquid crystal composition, only one kind of chiral compound may be used, or two or more kinds of chiral compounds may be used, and when there are two or more kinds, the combination and ratio thereof can be arbitrarily adjusted.

  In the cholesteric liquid crystal composition, the content of the chiral compound is preferably 0.05 to 30% by mass, more preferably 0.1 to 5% by mass with respect to the nematic liquid crystal composition. More preferably, it is 0.2-2 mass%. When the content of the chiral compound is in such a range, the rotational speed of the cholesteric droplet is faster (the rotational index λ is larger).

  In the cholesteric liquid crystal composition, the isotropic phase may be a liquid, may contain an isotropic resin, or may be formed of an isotropic resin. When an isotropic resin is included, it is preferable that the resin has a polymer network bonded like a net. By having a polymer network, the cholesteric liquid crystal composition can maintain a shape such as a thin film more stably, and the handleability becomes better.

  The liquid crystal compound in the cholesteric liquid crystal composition only needs to include those capable of forming cholesteric droplets. The liquid crystal compound is any of p-type with positive dielectric anisotropy, n-type with negative dielectric anisotropy, and non-polarized type (not showing any properties of p-type and n-type). But you can.

Hereinafter, preferred liquid crystal compounds in the present invention will be described more specifically.
As a liquid crystal compound, it is preferable to contain the compound represented by the following general formula (LC).

（一般式（ＬＣ）中、Ｒ^ＬＣは炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されていてもよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子に置換されていてもよく、
Ａ^ＬＣ１及びＡ^ＬＣ２は、それぞれ独立して、
（ａ）トランス−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基又は隣接していない２個以上のＣＨ_２基は酸素原子又は硫黄原子で置換されていてもよい。）、
（ｂ）１，４−フェニレン基（この基中に存在する１個のＣＨ基又は隣接していない２個以上のＣＨ基は窒素原子で置換されていてもよい。）、及び
（ｃ）１，４−ビシクロ（２．２．２）オクチレン基、ナフタレン−２，６−ジイル基、ナフタレン−３，７−ジイル基、デカヒドロナフタレン−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、又はクロマン−２，６−ジイル基
からなる群より選ばれる基を表すが、上記の基（ａ）、基（ｂ）又は基（ｃ）に含まれる１つ又は２つ以上の水素原子はそれぞれ、フッ素原子、塩素原子、ＣＦ_３又はＯＣＦ_３で置換されていてもよく、
Ｚ^ＬＣは単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、
Ｙ^ＬＣは、水素原子、フッ素原子、塩素原子、シアノ基、及び炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−、−Ｃ≡Ｃ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−で置換されてよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子で置換されていてもよく、
ａは１〜４の整数を表すが、ａが２、３又は４を表し、Ａ^ＬＣ１が複数存在する場合、複数存在するＡ^ＬＣ１は、同一であっても異なっていてもよく、Ｚ^ＬＣが複数存在する場合、複数存在するＺ^ＬＣは、同一であっても異なっていてもよい。）

(In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are- O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— may be substituted, and one or more hydrogen atoms in the alkyl group may be any May be substituted with a halogen atom,
A ^LC1 and A ^LC2 are each independently
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom) ),
(B) 1,4-phenylene group (one CH group present in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom), and (c) 1 , 4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, naphthalene-3,7-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4 -Represents a group selected from the group consisting of a tetrahydronaphthalene-2,6-diyl group or a chroman-2,6-diyl group, but is included in the group (a), group (b) or group (c). One or more hydrogen atoms may each be substituted with a fluorine atom, a chlorine atom, CF ₃ or OCF ₃ ;
Z ^LC is a single bond, —CH═CH—, —CF═CF—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, Represents —OCF ₂ —, —CF ₂ O—, —COO— or —OCO—,
Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are directly bonded to an oxygen atom. May be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ — so as not to be adjacent, One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom,
a represents an integer of 1 to 4, but a represents 2, 3 or 4, and when there are a plurality of A ^LC1 , the plurality of A ^LC1 may be the same or different, and Z ^LC is When there are a plurality of Z ^LCs , the plurality of Z ^LCs may be the same or different. )

  The compound represented by the general formula (LC) includes the following general formula (LC1) and general formula (LC2).

（式中、Ｒ^ＬＣ１１及びＲ^ＬＣ２１はそれぞれ独立して炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されていてもよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子によって置換されていてもよく、Ａ^ＬＣ１１、及びＡ^ＬＣ２１はそれぞれ独立して下記の何れかの構造

( ^Wherein R ^LC11 and R ^LC21 each independently represents an alkyl group having 1 to 15 carbon atoms, and one or more CH ₂ groups in the alkyl group are not directly adjacent to each other with an oxygen atom. One or more hydrogens in the alkyl group optionally substituted with -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C≡C- atoms may be optionally substituted by a halogen atom, a ^LC11, and a ^LC21 each independently either structure:

（該構造中、シクロヘキシレン基中の１つ又は２つ以上のＣＨ_２基は酸素原子で置換されていてもよく、１，４−フェニレン基中の１つ又は２つ以上のＣＨ基は窒素原子で置換されていてもよく、また、該構造中の１つ又は２つ以上の水素原子はフッ素原子、塩素原子、ＣＦ_３又はＯＣＦ_３で置換されていてもよい。）を表し、
Ｘ^ＬＣ１１、Ｘ^ＬＣ１２、Ｘ^ＬＣ２１〜Ｘ^ＬＣ２３はそれぞれ独立して水素原子、塩素原子、フッ素原子、ＣＦ_３又はＯＣＦ_３を表し、
Ｙ^ＬＣ１１及びＹ^ＬＣ２１はそれぞれ独立して水素原子、塩素原子、フッ素原子、シアノ基、ＣＦ_３、ＯＣＨ_２Ｆ、ＯＣＨＦ_２又はＯＣＦ_３を表し、
Ｚ^ＬＣ１１及びＺ^ＬＣ２１はそれぞれ独立して単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、
ｍ^ＬＣ１１及びｍ^ＬＣ２１はそれぞれ独立して１〜４の整数を表し、Ａ^ＬＣ１１、Ａ^ＬＣ２１、Ｚ^ＬＣ１１及びＺ^ＬＣ２１が複数存在する場合は、それらは同一であっても異なっていてもよい。）
で表される化合物群から選ばれる１種又は２種以上の化合物であることが好ましい。

(In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen. And one or more hydrogen atoms in the structure may be substituted with a fluorine atom, a chlorine atom, CF ₃ or OCF ₃ ).
^{X LC11, X LC12, X LC21} ~X LC23 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, CF ₃ or OCF _3,
Y ^LC11 and Y ^LC21 each independently represent a hydrogen atom, a chlorine atom, a fluorine atom, a cyano group, CF ₃ , OCH ₂ F, OCHF ₂ or OCF ₃ ,
Z ^LC11 and Z ^LC21 are each independently a single bond, —CH═CH—, ^{—CF═CF—, —C≡C—} , —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —. _{, -CH 2 O -, - OCF} 2 -, - CF 2 O -, - COO- or an -OCO-,
m ^LC11 and m ^LC21 each independently represent an integer of 1 to 4, and when there are a plurality of A ^LC11 , A ^LC21 , Z ^LC11 and Z ^LC21 , they may be the same or different. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the compound group represented by these.

R ^LC11 and R ^LC21 are each independently preferably 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. Is more preferably an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms, more preferably a straight chain, and the alkenyl group has the following structure. What is represented is most preferred.

（式中、環構造へは右端で結合するものとする。）

(In the formula, it shall be bonded to the ring structure at the right end.)

A ^LC11 and A ^LC21 each independently preferably have the following structure.

Y ^LC11 and Y ^LC21 are each independently preferably a fluorine atom, a cyano group, CF ₃ or OCF ₃ , preferably a fluorine atom or OCF ₃ , and particularly preferably a fluorine atom.

Z ^LC11 and Z ^LC21 are each independently a single bond, —CH ₂ CH ₂ —, ^{—COO—, —OCO—} , —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—. It is preferably a single bond, —CH ₂ CH ₂ —, —OCH ₂ —, —OCF ₂ — or —CF ₂ O—, more preferably a single bond, —OCH ₂ — or —CF ₂ O—. It is particularly preferred that

m ^LC11 and m ^LC21 are preferably each independently 1, 2 or 3, preferably 1 or 2 when emphasizing storage stability at low temperatures and response speed, and the nematic phase upper limit temperature In order to improve the upper limit, 2 or 3 is preferable.

  The compound represented by the general formula (LC1) is represented by the following general formula (LC1-a) to general formula (LC1-c).

（式中、Ｒ^ＬＣ１１、Ｙ^ＬＣ１１、Ｘ^ＬＣ１１及びＸ^ＬＣ１２はそれぞれ独立して前記一般式（ＬＣ１）におけるＲ^ＬＣ１１、Ｙ^ＬＣ１１、Ｘ^ＬＣ１１及びＸ^ＬＣ１２と同じ意味を表し、
Ａ^{ＬＣ１ａ１}、Ａ^{ＬＣ１ａ２}及びＡ^{ＬＣ１ｂ１}は、トランス−１，４−シクロヘキシレン基、テトラヒドロピラン−２，５−ジイル基、１，３−ジオキサン−２，５−ジイル基を表し、
Ｘ^{ＬＣ１ｂ１}、Ｘ^{ＬＣ１ｂ２}、Ｘ^{ＬＣ１ｃ１}〜Ｘ^{ＬＣ１ｃ４}はそれぞれ独立して水素原子、塩素原子、フッ素原子、ＣＦ_３又はＯＣＦ_３を表す。）
で表される化合物からなる群より選ばれる１種又は２種以上の化合物であることが好ましい。

^{(Wherein, R LC11, Y LC11, X} LC11 and ^{X LC12} each independently represent the same meaning as ^{R LC11,} Y ^{LC11, X} LC11 and ^{X LC12} in the general formula (LC1),
A ^LC1a1 , A ^LC1a2 and A ^LC1b1 represent a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, a 1,3-dioxane-2,5-diyl group,
X ^LC1b1 , X ^LC1b2 , X ^{LC1c1 to} X ^LC1c4 each independently represent a hydrogen atom, a chlorine atom, a fluorine atom, CF ₃ or OCF ₃ . )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these.

R ^LC11 is preferably independently 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, An alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms is more preferable.

X ^{LC11 to} X ^LC1c4 are preferably each independently a hydrogen atom or a fluorine atom.
Y ^LC11 is preferably each independently a fluorine atom, CF ₃ or OCF ₃ .

  The compound represented by the general formula (LC1) is represented by the following general formula (LC1-d) to general formula (LC1-m).

（式中、Ｒ^ＬＣ１１、Ｙ^ＬＣ１１、Ｘ^ＬＣ１１及びＸ^ＬＣ１２はそれぞれ独立して前記一般式（ＬＣ１）におけるＲ^ＬＣ１１、Ｙ^ＬＣ１１、Ｘ^ＬＣ１１及びＸ^ＬＣ１２と同じ意味を表し、
Ａ^{ＬＣ１ｄ１}、Ａ^{ＬＣ１ｆ１}、Ａ^{ＬＣ１ｇ１}、Ａ^{ＬＣ１ｊ１}、Ａ^{ＬＣ１ｋ１}、Ａ^{ＬＣ１ｋ２}、Ａ^{ＬＣ１ｍ１}〜Ａ^{ＬＣ１ｍ３}は、それぞれ独立して１，４−フェニレン基、トランス−１，４−シクロヘキシレン基、テトラヒドロピラン−２，５−ジイル基、又は１，３−ジオキサン−２，５−ジイル基を表し、
Ｘ^{ＬＣ１ｄ１}、Ｘ^{ＬＣ１ｄ２}、Ｘ^{ＬＣ１ｆ１}、Ｘ^{ＬＣ１ｆ２}、Ｘ^{ＬＣ１ｇ１}、Ｘ^{ＬＣ１ｇ２}、Ｘ^{ＬＣ１ｈ１}、Ｘ^{ＬＣ１ｈ２}、Ｘ^{ＬＣ１ｉ１}、Ｘ^{ＬＣ１ｉ２}、Ｘ^{ＬＣ１ｊ１}〜Ｘ^{ＬＣ１ｊ４}、Ｘ^{ＬＣ１ｋ１}、Ｘ^{ＬＣ１ｋ２}、Ｘ^{ＬＣ１ｍ１}及びＸ^{ＬＣ１ｍ２}は、それぞれ独立して水素原子、塩素原子、フッ素原子、ＣＦ_３又はＯＣＦ_３を表し、
Ｚ^{ＬＣ１ｄ１}、Ｚ^{ＬＣ１ｅ１}、Ｚ^{ＬＣ１ｊ１}、Ｚ^{ＬＣ１ｋ１}、及びＺ^{ＬＣ１ｍ１}は、それぞれ独立して単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表す。）
で表される化合物からなる群より選ばれる１種又は２種以上の化合物であることが好ましい。

^{(Wherein, R LC11, Y LC11, X} LC11 and ^{X LC12} each independently represent the same meaning as ^{R LC11,} Y ^{LC11, X} LC11 and ^{X LC12} in the general formula (LC1),
^ALC1d1 , ^ALC1f1 , ^ALC1g1 , ^ALC1j1 , ^ALC1k1 , ^ALC1k2 , ^{ALC1m1 to ALC1m3} are each independently 1,4-phenylene group, trans-1,4-cyclohexylene group, tetrahydropyran-2 , 5-diyl group or 1,3-dioxane-2,5-diyl group,
^{X LC1d1, X LC1d2, X LC1f1} , X LC1f2, X LC1g1, X LC1g2, X LC1h1, X LC1h2, X LC1i1, X LC1i2, X LC1j1 ~X LC1j4, X LC1k1, X LC1k2, X LC1m1 and ^{X LC1m2} each Independently represents a hydrogen atom, a chlorine atom, a fluorine atom, CF ₃ or OCF ₃ ;
Z ^LC1d1 , Z ^LC1e1 , Z ^LC1j1 , Z ^LC1k1 , and Z ^LC1m1 are each independently a single bond, —CH═CH—, ^{—CF═CF—} , ^—C≡C— , —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO— is represented. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these.

R ^LC11 is preferably 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, an alkyl group having 1 to 5 carbon atoms, carbon It is more preferably an alkoxy group having 1 to 5 atoms or an alkenyl group having 2 to 5 carbon atoms.

X ^{LC11 to} X ^LC1m2 are preferably each independently a hydrogen atom or a fluorine atom.
Y ^LC11 is ^preferably a fluorine atom, CF ₃ or OCF ₃ .
Z ^{LC1d1 to} Z ^LC1m1 are each preferably independently —CF ₂ O— or —OCH ₂ —.

  The compound represented by the general formula (LC2) is represented by the following general formula (LC2-a) to general formula (LC2-g).

（式中、Ｒ^ＬＣ２１、Ｙ^ＬＣ２１及びＸ^ＬＣ２１〜Ｘ^ＬＣ２３は、それぞれ独立して前記一般式（ＬＣ２）におけるＲ^ＬＣ２１、Ｙ^ＬＣ２１及びＸ^ＬＣ２１〜Ｘ^ＬＣ２３と同じ意味を表し、
Ｘ^{ＬＣ２ｄ１}〜Ｘ^{ＬＣ２ｄ４}、Ｘ^{ＬＣ２ｅ１}〜Ｘ^{ＬＣ２ｅ４}、Ｘ^{ＬＣ２ｆ１}〜Ｘ^{ＬＣ２ｆ４}及びＸ^{ＬＣ２ｇ１}〜Ｘ^{ＬＣ２ｇ４}は、それぞれ独立して水素原子、塩素原子、フッ素原子、ＣＦ_３又はＯＣＦ_３を表し、
Ｚ^{ＬＣ２ａ１}、Ｚ^{ＬＣ２ｂ１}、Ｚ^{ＬＣ２ｃ１}、Ｚ^{ＬＣ２ｄ１}、Ｚ^{ＬＣ２ｅ１}、Ｚ^{ＬＣ２ｆ１}及びＺ^{ＬＣ２ｇ１}は、それぞれ独立して単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表す。）
で表される化合物からなる群より選ばれる１種又は２種以上の化合物であることが好ましい。

( ^Wherein R ^LC21 , Y ^LC21 and X ^{LC21 to} X ^LC23 each independently represent the same meaning as R ^LC21 , Y ^LC21 and X ^{LC21 to} X ^LC23 in the general formula (LC2),
^{X LC2d1 ~X LC2d4, X LC2e1 ~X} LC2e4, X LC2f1 ~X LC2f4 and ^X LC2g1 ^{~X LC2g4} each independently represent a hydrogen atom, a chlorine atom, a fluorine atom, CF ₃ or OCF _3,
Z ^LC2a1 , Z ^LC2b1 , Z ^LC2c1 , Z ^LC2d1 , Z ^LC2e1 , Z ^LC2f1 and Z ^LC2g1 are each independently a single bond, —CH═CH—, ^{—CF═CF—} , ^{—CF═CF—} , ^—C≡C— , —CH _2. It represents CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO—. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these.

R ^LC21 is preferably independently 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, An alkyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms is more preferable.

X ^{LC21 to} X ^LC2g4 are preferably each independently a hydrogen atom or a fluorine atom.
Y ^LC21 is ^preferably a fluorine atom, CF ₃ or OCF ₃ .
Z ^{LC2a1 to} Z ^LC2g4 are preferably each independently —CF ₂ O— or —OCH ₂ —.

  The compound represented by the general formula (LC) includes the following general formula (LC3), general formula (LC4), general formula (LC4 ') and general formula (LC5).

（式中、Ｒ^ＬＣ３１、Ｒ^ＬＣ３２、Ｒ^ＬＣ４１、Ｒ^ＬＣ４２、Ｒ^ＬＣ５１及びＲ^ＬＣ５２はそれぞれ独立して炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されていてもよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子で置換されていてもよく、
Ａ^ＬＣ３１、Ａ^ＬＣ３２、Ａ^ＬＣ４１、Ａ^ＬＣ４２、Ａ^ＬＣ５１及びＡ^ＬＣ５２はそれぞれ独立して下記の何れかの構造

^(Wherein represents ^{R LC31, R LC32, R LC41} , R LC42, alkyl groups ^{R LC51} and ^{R LC52} is 1-15 carbon atoms independently, one in the alkyl group or two or more The CH ₂ group may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent, One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom,
^{A LC31, A LC32, A LC41} , A LC42, A LC51 and ^{A LC52} each independently either the following structures

（該構造中、シクロヘキシレン基中の１つ又は２つ以上のＣＨ_２基は酸素原子で置換されていてもよく、１，４−フェニレン基中の１つ又は２つ以上のＣＨ基は窒素原子で置換されていてもよく、また、該構造中の１つ又は２つ以上の水素原子は塩素原子、ＣＦ_３又はＯＣＦ_３で置換されていてもよい。）のいずれかを表し、
Ｚ^ＬＣ３１、Ｚ^ＬＣ３２、Ｚ^ＬＣ４１、Ｚ^ＬＣ４２、Ｚ^ＬＣ５１及びＺ^ＬＣ５２はそれぞれ独立して単結合、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＣＯＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２Ｏ−、−ＯＣＦ_２−又は−ＣＦ_２Ｏ−を表し、
Ｚ^５はＣＨ_２基又は酸素原子を表し、
Ｘ^ＬＣ４１は水素原子又はフッ素原子を表し、
ｍ^ＬＣ３１、ｍ^ＬＣ３２、ｍ^ＬＣ４１、ｍ^ＬＣ４２、ｍ^ＬＣ５１及びｍ^ＬＣ５２はそれぞれ独立して０〜３を表し、ただし、ｍ^ＬＣ３１＋ｍ^ＬＣ３２、ｍ^ＬＣ４１＋ｍ^ＬＣ４２及びｍ^ＬＣ５１＋ｍ^ＬＣ５２は１、２又は３であり、Ａ^ＬＣ３１〜Ａ^ＬＣ５２、及びＺ^ＬＣ３１〜Ｚ^ＬＣ５２が複数存在する場合は、それらは同一であっても異なっていてもよい。）
で表される化合物群から選ばれる１種又は２種以上の化合物であることが好ましい。

(In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen. And one or more hydrogen atoms in the structure may be substituted with a chlorine atom, CF ₃ or OCF ₃ ).
^{Z LC31, Z LC32, Z LC41} , Z LC42, Z LC51 and ^{Z LC52} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 _{-, - COO -, - OCH} 2 -, - CH 2 O -, - OCH 2 CH 2 -, - CH 2 CH 2 O -, - OCF 2 - or _-CF 2 O-,
Z ⁵ represents a CH ₂ group or an oxygen atom,
X ^LC41 represents a hydrogen atom or a fluorine atom,
^{m LC31, m LC32, m LC41} , m LC42, m LC51 and ^{m LC52} represent each independently 0 to 3, provided ^{that, m LC31 + m LC32, m} LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or 3 ^And when there are a plurality of A ^{LC31 to} A ^LC52 and Z ^{LC31 to} Z ^LC52 , they may be the same or different. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the compound group represented by these.

R ^{LC31 to} R ^LC52 are each independently preferably 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. Is most preferably the following structure:

（式中、環構造へは右端で結合するものとする。）
Ａ^ＬＣ３１〜Ａ^ＬＣ５２は、それぞれ独立して下記の構造が好ましく、

(In the formula, it shall be bonded to the ring structure at the right end.)
A ^{LC31 to} A ^LC52 each independently preferably have the following structure:

Ｚ^ＬＣ３１〜Ｚ^ＬＣ５１は、それぞれ独立して単結合、−ＣＨ_２Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−又は−ＯＣＨ_２−であることが好ましい。

Z ^{LC31 to} Z ^LC51 are each independently a single bond, —CH ₂ O—, —COO—, ^—OCO— , —CH ₂ CH ₂ —, —CF ₂ O—, —OCF ₂ — or —OCH ₂ —. It is preferable that

  The compound represented by the general formula (LC3) includes the following general formula (LC3-a) and general formula (LC3-b).

（式中、Ｒ^ＬＣ３１、Ｒ^ＬＣ３２、Ａ^ＬＣ３１及びＺ^ＬＣ３１は、それぞれ独立して前記一般式（ＬＣ３）におけるＲ^ＬＣ３１、Ｒ^ＬＣ３２、Ａ^ＬＣ３１及びＺ^ＬＣ３１と同じ意味を表し、
Ｘ^{ＬＣ３ｂ１}〜Ｘ^{ＬＣ３ｂ６}はそれぞれ独立して水素原子又はフッ素原子を表すが、Ｘ^{ＬＣ３ｂ１}及びＸ^{ＬＣ３ｂ２}又はＸ^{ＬＣ３ｂ３}及びＸ^{ＬＣ３ｂ４}のうちの少なくとも一方の組み合わせは共にフッ素原子を表し、
ｍ^{ＬＣ３ａ１}は１、２又は３を表し、ｍ^{ＬＣ３ｂ１}は０又は１を表し、Ａ^ＬＣ３１及びＺ^ＬＣ３１が複数存在する場合は、それらは同一であっても異なっていてもよい。）
で表される化合物群から選ばれる１種又は２種以上の化合物であることが好ましい。

(Wherein R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 each independently represent the same meaning as R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 in the general formula (LC3);
X ^{LC3b1 to} X ^LC3b6 each independently represent a hydrogen atom or a fluorine atom, but at least one combination of X ^LC3b1 and X ^LC3b2 or X ^LC3b3 and X ^LC3b4 both represents a fluorine atom,
m ^LC3a1 represents 1, 2 or 3, m ^LC3b1 represents 0 or 1, and when a plurality of A ^LC31 and Z ^LC31 are present, they may be the same or different. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the compound group represented by these.

R ^LC31 and R ^LC32 are each independently 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 alkenyloxy having 2 to 7 carbon atoms. It is preferably a group.

A ^LC31 is preferably a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, or a 1,3-dioxane-2,5-diyl group, A 1,4-phenylene group or a trans-1,4-cyclohexylene group is more preferable.

Z ^LC31 is preferably a single bond, —CH ₂ O—, —COO—, —OCO—, or —CH ₂ CH ₂ —, and more preferably a single bond.

  The general formula (LC3-a) preferably represents the following general formula (LC3-a1) to general formula (LC3-a4).

（式中、Ｒ^ＬＣ３１及びＲ^ＬＣ３２は、それぞれ独立して前記一般式（ＬＣ３）におけるＲ^ＬＣ３１及びＲ^ＬＣ３２と同じ意味を表す。）

(In the formula, R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in General Formula (LC3).)

R ^LC31 and ^{R LC32} are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or is preferably an alkenyl group having 2 to 7 carbon ^{atoms, R LC31} is More preferably, it is an alkyl group having 1 to 7 carbon atoms, and R ^LC32 is an alkoxy group having 1 to 7 carbon atoms.

  As general formula (LC3-b), it is preferable to represent the following general formula (LC3-b1) to general formula (LC3-b12), and general formula (LC3-b1), general formula (LC3-b6), and general formula (LC3-b8) or general formula (LC3-b11) is more preferable, general formula (LC3-b1) or general formula (LC3-b6) is more preferable, and general formula (LC3-b1) Most preferably, is represented.

（式中、Ｒ^ＬＣ３１及びＲ^ＬＣ３２は、それぞれ独立して前記一般式（ＬＣ３）におけるＲ^ＬＣ３１及びＲ^ＬＣ３２と同じ意味を表す。）

(In the formula, R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in General Formula (LC3).)

R ^LC31 and ^{R LC32} are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or is preferably an alkenyl group having 2 to 7 carbon ^{atoms, R LC31} is More preferably, it is an alkyl group having 2 or 3 carbon atoms, and R ^LC32 is an alkyl group having 2 carbon atoms.

  The compounds represented by general formula (LC4) and general formula (LC4 ′) are represented by the following general formula (LC4-a) to general formula (LC4-c), general formula (LC4′-d), and general formula (LC5). The compounds represented by general formula (LC5-a) to general formula (LC5-c)

（式中、Ｒ^ＬＣ４１、Ｒ^ＬＣ４２及びＸ^ＬＣ４１は、それぞれ独立して前記一般式（ＬＣ４）及び一般式（ＬＣ４’）におけるＲ^ＬＣ４１、Ｒ^ＬＣ４２及びＸ^ＬＣ４１と同じ意味を表し、
Ｒ^ＬＣ５１及びＲ^ＬＣ５２は、それぞれ独立して前記一般式（ＬＣ５）におけるＲ^ＬＣ５１及びＲ^ＬＣ５２と同じ意味を表し、
Ｚ^{ＬＣ４ａ１}、Ｚ^{ＬＣ４ｂ１}、Ｚ^{ＬＣ４ｃ１}、Ｚ^{ＬＣ４ｄ１}、Ｚ^{ＬＣ５ａ１}、Ｚ^{ＬＣ５ｂ１}及びＺ^{ＬＣ５ｃ１}は、それぞれ独立して単結合、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＣＯＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２Ｏ−、−ＯＣＦ_２−又は−ＣＦ_２Ｏ−を表す。）
で表される化合物からなる群より選ばれる１種又は２種以上の化合物であることがより好ましい。

( ^Wherein R ^LC41 , R ^LC42 and X ^LC41 each independently represent the same meaning as R ^LC41 , R ^LC42 and X ^{LC41 in the} general formula (LC4) and general formula (LC4 ′),
R ^LC51 and ^{R LC52} each independently represents the same meaning as ^{R LC51} and ^{R LC52} in the general formula (LC5),
^{Z LC4a1, Z LC4b1, Z LC4c1} , Z LC4d1, Z LC5a1, Z LC5b1 and ^{Z LC5c1} are each independently a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - ( _{CH 2) 4 -, - COO} -, - OCH 2 -, - CH 2 O -, - OCH 2 CH 2 -, - CH 2 CH 2 O -, - OCF 2 - or an _-CF 2 O-. )
It is more preferable that it is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these.

^{R LC41,} R LC42, R ^LC51 and ^{R LC52} are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group, or number of carbon atoms of 2 to 7 carbon atoms 2 to 7 alkenyloxy groups are preferred.

Z ^{LC4a1 to} Z ^LC5c1 are each independently ^preferably a single bond, —CH ₂ O—, ^—COO— , ^—OCO— , or —CH ₂ CH ₂ —, and more preferably a single bond.

  The compound represented by the general formula (LC) is represented by the following general formula (LC6).

（式中、Ｒ^ＬＣ６１及びＲ^ＬＣ６２は、それぞれ独立して炭素原子数１〜１５のアルキル基を表し、該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されていてもよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子で置換されていてもよく、
Ａ^ＬＣ６１〜Ａ^ＬＣ６３はそれぞれ独立して下記のいずれかの構造

( ^Wherein R ^LC61 and R ^LC62 each independently represent an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are not directly adjacent to each other with an oxygen atom. And may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C—, wherein one or more of the alkyl groups are The hydrogen atom may be optionally substituted with a halogen atom,
A ^{LC61 to} A ^LC63 are each independently one of the following structures

（該構造中、シクロヘキシレン基中の１つ又は２つ以上のＣＨ_２ＣＨ_２基は、−ＣＨ＝ＣＨ−、−ＣＦ_２Ｏ−、又は−ＯＣＦ_２−で置換されていてもよく、１，４−フェニレン基中の１つ又は２つ以上のＣＨ基は窒素原子で置換されていてもよい。）
を表し、
Ｚ^ＬＣ６１及びＺ^ＬＣ６２は、それぞれ独立して単結合、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＣＯＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−又は−ＣＦ_２Ｏ−を表し、
ｍＬＣ６１は０〜３を表す。ただし、前記一般式（ＬＣ１）〜一般式（ＬＣ５）で表される化合物を除く。）
で表される化合物群から選ばれる１種又は２種以上の化合物であることが好ましい。

(In the structure, one or more CH ₂ CH ₂ groups in the cyclohexylene group may be substituted with —CH═CH—, —CF ₂ O—, or —OCF ₂ —. , 4-phenylene group, one or more CH groups may be substituted with nitrogen atoms.)
Represents
Z ^LC61 and Z ^LC62 each independently represent a single bond, —CH═CH—, ^—C≡C— , —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCH ₂ —, Represents —CH ₂ O—, —OCF ₂ — or —CF ₂ O—,
mLC61 represents 0-3. However, the compound represented by the general formula (LC1) to the general formula (LC5) is excluded. )
It is preferable that it is 1 type, or 2 or more types of compounds chosen from the compound group represented by these.

R ^LC61 and R ^LC62 are preferably each independently 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. Most preferably represents the following structure.

（式中、環構造へは右端で結合するものとする。）
Ａ^ＬＣ６１〜Ａ^ＬＣ６３はそれぞれ独立して下記の構造が好ましく、

(In the formula, it shall be bonded to the ring structure at the right end.)
A ^{LC61 to} A ^LC63 each independently preferably have the following structure:

Ｚ^ＬＣ６１及びＺ^ＬＣ６２はそれぞれ独立して単結合、−ＣＨ_２ＣＨ_２−、−ＣＯＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−又は−ＣＦ_２Ｏ−が好ましい。
一般式（ＬＣ６）で表される化合物は、下記一般式（ＬＣ６−ａ）〜一般式（ＬＣ６−ｍ）

Z ^LC61 and Z ^LC62 are each independently ^preferably a single bond, —CH ₂ CH ₂ —, ^—COO— , —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—.
The compound represented by the general formula (LC6) is represented by the following general formula (LC6-a) to general formula (LC6-m).

（式中、Ｒ^ＬＣ６１及びＲ^ＬＣ６２は、それぞれ独立して炭素原子数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のアルケニル基又は炭素原子数２〜７のアルケニルオキシ基を表す。）
で表される化合物からなる群より選ばれる１種又は２種以上の化合物であるのがより好ましい。

(In the formula, R ^LC61 and R ^LC62 are each independently 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 2 to 2 carbon atoms. 7 represents an alkenyloxy group.)
It is more preferable that it is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these.

  As described above, in the present invention, various compounds can be used as the liquid crystal compound. Among these, a liquid crystal compound having a fluorine atom is preferable, and the liquid crystal composition includes at least a liquid crystal compound having a fluorine atom. It is preferable to contain 1 type. By using such a specific liquid crystal compound, the rotational speed of the cholesteric droplet is faster (rotational efficiency is higher).

  When the cholesteric liquid crystal composition contains a liquid crystal compound having a fluorine atom, the ratio of the content of the liquid crystal compound having a fluorine atom to the total content of the liquid crystal compound is preferably 5% by mass or more. % Or more is more preferable, and 15% by mass or more is particularly preferable. The upper limit value of the ratio is not particularly limited, but is preferably 80% by mass, and more preferably 70% by mass.

  Among the liquid crystal compounds represented by the general formula (LC), the liquid crystal compound having a fluorine atom includes the following general formula (1F)

（式中、Ｒ^１Ｆ及びＲ^２Ｆはそれぞれ独立して炭素数１〜１８の直鎖状若しくは分岐鎖状のアルキル基、フッ素原子、塩素原子、ジフルオロメチル基、トリフルオロメチル基、ジフルオロメトキシ基、トリフルオロメトキシ基又はシアノ基を表し、ただし、Ｒ^１Ｆ及びＲ^２Ｆの少なくとも一方は前記アルキル基を表し、前記アルキル基中の１つ以上の−ＣＨ_２−は、酸素原子と硫黄原子が直接隣接しないように−Ｏ−、−Ｓ−、−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−、−ＣＯ−Ｓ−、−Ｓ−ＣＯ−、−Ｏ−ＳＯ_２−、−ＳＯ_２−Ｏ−、−Ｏ−ＣＯ−Ｏ−、−ＣＯ−Ｎ（Ｒ^ａ）−又は−Ｎ（Ｒ^ａ）−ＣＯ−で置換されていてもよく、前記アルキル基中の１つ以上の水素原子は、シアノ基又は水酸基で置換されていてもよく、前記−ＣＯ−Ｎ（Ｒ^ａ）−及び−Ｎ（Ｒ^ａ）−ＣＯ−におけるＲ^ａは水素原子又は炭素原子数１〜４の直鎖状若しくは分岐鎖状のアルキル基を表し、前記炭素原子数１〜４のアルキル基中の１つ以上の−ＣＨ_２−は、−ＣＨ＝ＣＨ−又は−Ｃ≡Ｃ−で置換されていてもよく、前記炭素原子数１〜４のアルキル基中の１つ以上の水素原子は、ハロゲン原子で置換されていてもよく、
Ａ^１Ｆ、Ａ^２Ｆ、Ａ^３Ｆ及びＡ^４Ｆは、それぞれ独立して下記式

Wherein R ^1F and R ^2F are each independently a linear or branched alkyl group having 1 to 18 carbon atoms, a fluorine atom, a chlorine atom, a difluoromethyl group, a trifluoromethyl group, a difluoromethoxy group, Represents a trifluoromethoxy group or a cyano group, provided that at least one of R ^1F and R ^2F represents the alkyl group, and one or more —CH ₂ — in the alkyl group has an oxygen atom and a sulfur atom directly adjacent to each other. , - - -O so as not to S -, - CO -, - CO-O -, - O-CO -, - CO-S -, - S-CO -, - O-sO 2 -, - sO 2 - O—, —O—CO—O—, —CO—N (R ^a ) — or —N (R ^a ) —CO— may be substituted, and one or more hydrogen atoms in the alkyl group may be , May be substituted with a cyano group or a hydroxyl group, O-N ^{(R a)} - and ^-N (R a) is ^{R a} in -CO- represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, the carbon atoms 1 One or more —CH ₂ — in the alkyl group of ˜4 may be substituted with —CH═CH— or —C≡C—, and is one of the alkyl groups of 1 to 4 carbon atoms. The above hydrogen atoms may be substituted with halogen atoms,
A ^1F , A ^2F , A ^3F and A ^4F are each independently represented by the following formula:

（式中、シクロヘキサン環の１つ以上の−ＣＨ_２−は、酸素原子で置換されていてもよく、ベンゼン環の１つ以上の−ＣＨ＝は、窒素原子で置換されていてもよく、前記式中の１つ以上の水素原子は、塩素原子、トリフルオロメチル基又はトリフルオロメトキシ基で置換されていてもよい。）のいずれかの基を表し、
Ｘ^１Ｆ、Ｘ^２Ｆ及びＸ^３Ｆは、それぞれ独立して単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−Ｎ＝Ｎ−、−ＣＨ＝Ｎ−Ｎ＝ＣＨ−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＦ_２−、−（ＣＨ_２）_４−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯ−Ｎ（Ｒ^ｂ）−、−Ｎ（Ｒ^ｂ）−ＣＯ−、−ＣＨ＝ＣＨ−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−ＣＨ＝ＣＨ−を表し、前記−ＣＯ−Ｎ（Ｒ^ｂ）−及び−Ｎ（Ｒ^ｂ）−ＣＯ−におけるＲ^ｂは、水素原子又は炭素原子数１〜４の直鎖状若しくは分岐鎖状のアルキル基を表し、
ｎ_Ｆ及びｍ_Ｆはそれぞれ独立して０又は１を表し、
ただし、Ｒ^１Ｆ、Ｒ^２Ｆ、Ａ^１Ｆ、Ａ^２Ｆ、Ａ^３Ｆ、Ａ^４Ｆ、Ｘ^１Ｆ、Ｘ^２Ｆ及びＸ^３のいずれか１つ以上は、フッ素原子を有する基を表す。）
で表される化合物が例示できる。
一般式（１Ｆ）で表される化合物は、本発明で用いる液晶化合物として、特に好ましいものである。

(In the formula, one or more —CH ₂ — of the cyclohexane ring may be substituted with an oxygen atom, and one or more —CH═ of the benzene ring may be substituted with a nitrogen atom, One or more hydrogen atoms in the formula may be substituted with a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group)
X ^1F , X ^2F and X ^3F are each independently a single bond, —CH═CH—, —CF═CF—, —C≡C—, —N═N—, —CH═N—N═CH— , —CH ₂ CH ₂ —, —CF ₂ CF ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, —CH ₂ O—, —OCH ₂ CH ₂ —, — CH ₂ CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —CO—N (R ^b ) —, —N (R ^b ) —CO—, —CH═CH—CO—O— or —O It represents -CO-CH = CH-, wherein the ^{-CO-N (R b) -} R b in and ^-N (R b) -CO- represents a linear or branched hydrogen atom or 1 to 4 carbon atoms Represents a chain alkyl group,
n _F and m _F each independently represent 0 or 1,
However, one or more of R ^1F , R ^2F , A ^1F , A ^2F , A ^3F , A ^4F , X ^1F , X ^2F and X ³ represent a group having a fluorine atom. )
The compound represented by these can be illustrated.
The compound represented by the general formula (1F) is particularly preferable as the liquid crystal compound used in the present invention.

  In the cholesteric liquid crystal composition, only one type of liquid crystal compound may be used, or two or more types may be used, and when there are two or more types, the combination and ratio thereof can be arbitrarily adjusted.

  In the cholesteric liquid crystal composition, the content of the chiral compound is not particularly limited as long as the rotation index λ becomes a predetermined value, but from the viewpoint of performing high-speed response evaluation of the liquid crystal display element described later with higher accuracy, It is preferable that it is 0.05-10.0 mass%, and it is more preferable that it is 0.1-5.0 mass%.

  When the cholesteric liquid crystal composition is formed into a thin film, a cholesteric droplet is rotated by generating a temperature gradient in the film thickness direction. The rotation efficiency (rotation speed, ease of rotation, rotation index λ) at this time is the rotation efficiency of the liquid crystal compound when a voltage is applied with a liquid crystal composition containing the same liquid crystal compound sandwiched between the electrodes. And have a correlation. Therefore, from the value of the rotation index λ of the cholesteric liquid crystal composition according to the present invention, it is possible to evaluate high-speed response when a liquid crystal composition containing the same liquid crystal compound is applied to a liquid crystal display element. The cholesteric liquid crystal composition according to the present invention has a large rotation index λ, and a liquid crystal display device manufactured using a liquid crystal composition containing the same liquid crystal compound has excellent high-speed response.

The liquid crystal composition to be evaluated only needs to contain the same liquid crystal compound as the cholesteric liquid crystal composition according to the present invention, and the composition may be the same as or different from the cholesteric liquid crystal composition according to the present invention. However, as the other components other than the liquid crystal compound, those containing the same components as the liquid crystal composition according to the present invention are preferable. The content ratio of each component is preferably within 20%, more preferably within 10%, between the liquid crystal composition to be evaluated and the cholesteric liquid crystal composition according to the present invention. Particularly preferably, it is within 5%.
The shape of the liquid crystal composition to be evaluated at the time of evaluation may be the same as or different from that of the cholesteric liquid crystal composition according to the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples at all. In the following examples and comparative examples, “wt%” means mass%.

<Manufacture of cholesteric liquid crystal composition, measurement of rotation index λ of cholesteric droplets>
[Example 1]
A nematic liquid crystal composition containing liquid crystal compounds represented by the following formulas in the following ratios was prepared, and a chiral dopant (chiral compound) represented by the following formula was further added in an amount of 1% by mass with respect to the nematic liquid crystal composition. A cholesteric liquid crystal composition was prepared by addition.

The obtained cholesteric liquid crystal composition was sandwiched between two glass plates subjected to a free horizontal alignment treatment to produce a cell having a cell thickness of 20 μm.
Using a polarizing microscope, confirm that the cholesteric liquid crystal composition has a cholesteric-isotropic phase coexistence region in the region of 55-57 ° C., and further presents a stripe pattern with a diameter of about 20 μm in the isotropic phase Was observed, confirming the presence of cholesteric droplets.
Cholesteric droplets rotate when one of the glass plates is heated to a high temperature (71 ° C.) and the other glass plate is set to a low temperature (40 ° C.) to generate a temperature gradient. The state was confirmed, and the rotation speed was 3 degrees / second. This rotation was considered to be rotation of the cholesteric droplet itself. The same applies to the following embodiments.
When the rotation index λ represented by the formula (i) was determined, it was 0.3 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 2]
A cell was prepared in the same manner as in Example 1 except that the nematic liquid crystal composition was replaced with the liquid crystal compound represented by the following formula in the following ratio instead of the above, and a cholesteric drop was prepared. The lett's rotation index λ was determined to be 1.0 × 10 ⁻³ degrees · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 3]
A cell was prepared in the same manner as in Example 2 except that the addition amount of the chiral dopant was changed to 0.2% by mass instead of 1% by mass, and the rotation index λ of the cholesteric droplet was determined. It was 5 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 4]
A cell was prepared in the same manner as in Example 2 except that the addition amount of the chiral dopant was changed to 2% by mass instead of 1% by mass, and the rotation index λ of the cholesteric droplet was determined. 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 5]
A cell was prepared in the same manner as in Example 1 except that a liquid crystal compound represented by the following formula was used in place of the nematic liquid crystal composition, and the rotation index λ of the cholesteric droplet was determined. 25 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 6]
A cell was prepared in the same manner as in Example 1 except that the nematic liquid crystal composition was replaced with the liquid crystal compound represented by the following formula in the following ratio instead of the above, and a cholesteric drop was prepared. The lett's rotation index λ was determined to be 0.2 × 10 ⁻³ degrees · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 7]
A cell was prepared in the same manner as in Example 1 except that a liquid crystal compound represented by the following formula was used in place of the nematic liquid crystal composition, and the rotation index λ of the cholesteric droplet was determined. 25 × 10 ⁻³ degree · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 8]
A cell was prepared in the same manner as in Example 1 except that the nematic liquid crystal composition was replaced with the liquid crystal compound represented by the following formula in the following ratio instead of the above, and a cholesteric drop was prepared. The lett's rotation index λ was found to be 2.6 × 10 ⁻³ degrees · sec ⁻¹ · ° C. ⁻¹ · m.

[Example 9]
A cell was prepared in the same manner as in Example 1 except that the nematic liquid crystal composition was replaced with the liquid crystal compound represented by the following formula in the following ratio instead of the above, and a cholesteric drop was prepared. The lett's rotation index λ was determined to be 2.5 × 10 ⁻³ degrees · sec ⁻¹ · ° C. ⁻¹ · m.

[Comparative Example 1]
A cell was prepared in the same manner as in Example 1 except that a liquid crystal compound represented by the following formula was used in place of the nematic liquid crystal composition, and the rotation index λ of the cholesteric droplet was determined. 0.001 × 10 ⁻³ degree · sec ⁻¹ ° C. ⁻¹ · m.

<Manufacture of liquid crystal display element and evaluation of response time>
[Example 10]
The response time of the liquid crystal display element using the cholesteric liquid crystal composition in Example 2 was measured at 25 ° C. using a test cell (“SE-5300” manufactured by Nissan Chemical Industries, Ltd., cell thickness 3.5 μm) (τd, 4 Measured from 0.5 V to 1 V), it was 6 ms, and the response was extremely fast. Thus, it was confirmed that the liquid crystal composition in which the rotation speed of the cholesteric droplet is fast (the rotation index λ is large) exhibits high-speed response.

[Comparative Example 2]
The response time of the liquid crystal display device was measured in the same manner as in Example 10 except that the cholesteric liquid crystal composition in Comparative Example 1 was used. The response time was 12 ms and the response was slow.

Claims (4)

In a cholesteric liquid crystal composition comprising a nematic liquid crystal composition exhibiting a liquid crystal phase at room temperature and a chiral compound,
The cholesteric liquid crystal composition has the following general formula (LC)

(In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are- O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— may be substituted, and one or more hydrogen atoms in the alkyl group may be any May be substituted with a halogen atom,
A ^LC1 and A ^LC2 are each independently
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom) ),
(B) 1,4-phenylene group (one CH group present in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom), and (c) 1 , 4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, naphthalene-3,7-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4 -Represents a group selected from the group consisting of a tetrahydronaphthalene-2,6-diyl group or a chroman-2,6-diyl group, but is included in the group (a), group (b) or group (c). One or more hydrogen atoms may each be substituted with a fluorine atom, a chlorine atom, CF ₃ or OCF ₃ ;
Z ^LC is a single bond, —CH═CH—, —CF═CF—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, Represents —OCF ₂ —, —CF ₂ O—, —COO— or —OCO—,
Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, or an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are directly bonded to an oxygen atom. May be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ — so as not to be adjacent, One or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom,
a represents an integer of 1 to 4, but a represents 2, 3 or 4, and when there are a plurality of A ^LC1 , the plurality of A ^LC1 may be the same or different, and Z ^LC is When there are a plurality of Z ^LCs , the plurality of Z ^LCs may be the same or different. At least one liquid crystal compound represented by
The chiral compound is represented by the following general formula (Ch-I)

(In the general formula (Ch-I), R ¹⁰⁰ and R ¹⁰¹ each independently represents a hydrogen atom or a chiral group containing a chiral or achiral alkyl group having 1 to 30 carbon atoms. One or more non-adjacent CH ₂ groups in the group are independently of each other —O—, —CO—, —COO—, —OCO—, —OCO—O—, —CH═CH—. , —CF ₂ —, —CF═CH—, —CH═CF—, —CF═CF— or C≡C—, the alkyl group may be linear or branched. However, at least one of R ¹⁰⁰ and R ¹⁰¹ may have the following formula (Ra), (Rb), (Rc), (Rf), (Rg) or (Rh)

(In the formula, R ³ represents a linear or branched alkyl group having 1 to 10 carbon atoms or a hydrogen atom, and one or more —CH ₂ — groups of the alkyl group are oxygen atoms. -O-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH = CH-, or -C≡C- as those in which atoms are not directly bonded to each other May be substituted, and further, one or more hydrogen atoms of the alkyl group may be replaced by fluorine atoms,
X ³ and X ⁴ represent a methyl group, a methoxy group, —CF ₃ , or —OCF ₃ , provided that X ⁴ represents a group different from X ³ ;
n ₃ represents an integer of 0 to 20,
n ₄ represents 0 or 1. ), A chiral alkyl group substituted with a CH ₂ group,
Z ¹⁰⁰ and ^{Z 101} are each independently, -O -, - CO -, - COO -, - OCO -, - O-COO -, - OCH 2 -, - CH 2 O -, - CF 2 O-, _{-OCF 2 -, - CH 2 CH} 2 -, - CF 2 CH 2 -, - CH 2 CF 2 -, - CF 2 CF 2 -, - CH = CH -, - CF = CH -, - CH = CF- , -CF = CF-, -C≡C-, -CH = CH-COO-, -OCO-CH = CH- or a single bond,
A ¹⁰⁰ and A ¹⁰¹ are independent of each other,
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is replaced with independently -O- together Or (b) a 1,4-phenylene group (one —CH═ present in this group or two or more non-adjacent —CH═ may be replaced by a nitrogen atom). All of these groups are unsubstituted or are alkyls of 1 to 7 carbon atoms in which one or more hydrogen atoms may be substituted by F or Cl, May be mono- or polysubstituted by alkoxy, alkylcarbonyl or alkoxycarbonyl groups;
n ¹¹ represents 0;
m ¹² represents 0;
m ¹¹ represents 0, 1, 2, 3, 4 or 5. At least one compound represented by
A temperature gradient ΔT is generated in the coexistence region of the cholesteric-isotropic phase in the film thickness direction of the cholesteric liquid crystal composition having a film thickness of d, and the rotational speed ω when the cholesteric droplet is rotated is defined. A method for evaluating a cholesteric liquid crystal composition, comprising measuring a rotation index λ represented by the following formula (i) :
λ = ω (d / ΔT) (i) The method according to claim 1, wherein the temperature gradient indicating the rotation index λ is 10 ° C. or less. The method according to claim 1 or 2, wherein a temperature range in which a cholesteric-isotropic phase coexistence region is expressed is 0.1 ° C or more. The following general formula (1F)

Wherein R ^1F and R ^2F are each independently a linear or branched alkyl group having 1 to 18 carbon atoms, a fluorine atom, a chlorine atom, a difluoromethyl group, a trifluoromethyl group, a difluoromethoxy group, Represents a trifluoromethoxy group or a cyano group, provided that at least one of R ^1F and R ^2F represents the alkyl group, and one or more —CH ₂ — in the alkyl group has an oxygen atom and a sulfur atom directly adjacent to each other. , - - -O so as not to S -, - CO -, - CO-O -, - O-CO -, - CO-S -, - S-CO -, - O-sO 2 -, - sO 2 - O—, —O—CO—O—, —CO—N (R ^a ) — or —N (R ^a ) —CO— may be substituted, and one or more hydrogen atoms in the alkyl group may be , May be substituted with a cyano group or a hydroxyl group, O-N ^{(R a)} - and ^-N (R a) is ^{R a} in -CO- represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, the carbon atoms 1 One or more —CH ₂ — in the alkyl group of ˜4 may be substituted with —CH═CH— or —C≡C—, and is one of the alkyl groups of 1 to 4 carbon atoms. The above hydrogen atoms may be substituted with halogen atoms,
A ^1F , A ^2F , A ^3F and A ^4F are each independently represented by the following formula:

(In the formula, one or more —CH ₂ — of the cyclohexane ring may be substituted with an oxygen atom, and one or more —CH═ of the benzene ring may be substituted with a nitrogen atom, One or more hydrogen atoms in the formula may be substituted with a chlorine atom, a trifluoromethyl group or a trifluoromethoxy group)
X ^1F , X ^2F and X ^3F are each independently a single bond, —CH═CH—, —CF═CF—, —C≡C—, —N═N—, —CH═N—N═CH— , —CH ₂ CH ₂ —, —CF ₂ CF ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, —CH ₂ O—, —OCH ₂ CH ₂ —, — CH ₂ CH ₂ O—, —OCF ₂ —, —CF ₂ O—, —CO—N (R ^b ) —, —N (R ^b ) —CO—, —CH═CH—CO—O— or —O It represents -CO-CH = CH-, wherein the ^{-CO-N (R b) -} R b in and ^-N (R b) -CO- represents a linear or branched hydrogen atom or 1 to 4 carbon atoms Represents a chain alkyl group,
n _F and m _F each independently represent 0 or 1,
However, one or more of R ^1F , R ^2F , A ^1F , A ^2F , A ^3F , A ^4F , X ^1F , X ^2F and X ³ represent a group having a fluorine atom. The method as described in any one of Claims 1-3 which contains at least 1 sort (s) of liquid crystal compounds represented by this.