JPWO2018193860A1 - Liquid crystal composition and liquid crystal display device - Google Patents

Abstract

The present invention relates to one or two or more compounds represented by general formula (N-i), and one or two or more compounds represented by general formula (ii); A liquid crystal composition containing one or two or more compounds selected from the group consisting of a compound represented by (IV) and a compound represented by general formula (N-iv), and a liquid crystal display element or light control using the same Provide an element. According to the present invention, it is excellent in high nematic-isotropic transition temperature (TNI) and dissolution stability at low temperature, and further, simultaneously with low birefringence anisotropy (Δn) effective for high light resistance and high heat resistance. It is possible to obtain a liquid crystal composition that satisfies the requirements, and to obtain a liquid crystal display element or a light control element having high reliability and high practicability by using the liquid crystal composition of the present invention.

Description

  The present invention relates to an electro-optical liquid crystal display material, a light guiding liquid crystal composition useful as a light control element material, and a liquid crystal display element or light control element using the same.

  Liquid crystal materials are used not only for various display elements for displaying characters, images and images represented by TVs and smart phones, but also for use as light control elements for controlling the transmission of light.

  When using a liquid crystal material as a light control element, it must exhibit a nematic liquid crystal phase in a wide temperature range, and have light resistance and heat resistance that can withstand use in an outdoor environment.

As a liquid crystal composition for light control elements, the liquid crystal composition for high reliability TV with a negative dielectric anisotropy can be utilized (refer patent document 1, 2). However, in order to be put into practical use as a liquid crystal composition for light control elements, it is excellent in high nematic-isotropic transition temperature (T _NI ) and dissolution stability at low temperature, and further, low compound effective for high light resistance and high heat resistance. There is a shortage of liquid crystal compositions simultaneously satisfying the refractive index anisotropy (Δn), and development of further liquid crystal compositions is required.

JP, 2006-241214, A Unexamined-Japanese-Patent No. 2006-225450

The problems to be solved by the present invention are high nematic-isotropic transition temperature (T _NI ) and excellent dissolution stability at low temperature, and further, low birefringence anisotropy effective for high light resistance and high heat resistance. An object of the present invention is to provide a liquid crystal composition simultaneously satisfying (Δn), and to provide a liquid crystal display element or a light control element using the same.

  As a result of intensive studies by the present inventors, one or two or more compounds represented by General Formula (N-i) and one or two or more compounds represented by General Formula (ii), The liquid crystal composition contains one or two or more compounds selected from the group consisting of compounds represented by general formula (N-iii) and compounds represented by general formula (N-iv). It has been found that the problems can be solved, and the present invention has been completed. .

(Wherein, R ⁱ¹ and R ⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently. -CH = CH-, -C≡C-, -O-, -CO-, -COO- or OCO-, which may be substituted,
A ⁱ¹ and A ⁱ² are each independently
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is -O- and / or -S- May be replaced by)
(B) 1,4-phenylene group (this is present in the group one -CH ₂ - or nonadjacent two or more -CH ₂ - groups may be replaced by a-N-) and ( c) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and It represents a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, but the hydrogen atoms on the above groups (a), (b) and (c) are independent of each other Substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, CN or halogen Well,
Z ⁱ¹ is a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 -, - CF 2 O- , -CH = N-N = CH-, -CH = CH-, -C≡C- or -CF = CF-
m ⁱ¹ represents 0, 1 or 2, but when m ⁱ¹ is 2 and there are a plurality of A ⁱ¹ and Z ⁱ¹ , they may be each independently the same or different. )

( ^Wherein , R ⁱⁱ¹ and R ⁱⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently. It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or OCO-.)

(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is -O- and / or -S- May be replaced by)
(B) 1,4-phenylene group (this is present in the group one -CH ₂ - or nonadjacent two or more -CH ₂ - groups may be replaced by a-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein hydrogen atoms on the above groups (a), (b) and (c) Independently substituted with an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, CN or a fluorine atom May be
Z ⁱⁱⁱ¹ and Z ^iv1 are each independently -COO-, ^-OCO- , -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- , -CH ₂ CH _2- , -CH _{= CH -, - (CH 2} ) 4 -, - CH = CH-CH 2 CH 2 -, - CH 2 CH 2 represents a -CH = CH- or a single bond,
m ^III1 and ^{m iv1} are each represent independently 0, 1 or ^{2, if A III2} and ^{Z III1 m III1} is a 2 there are a ^{plurality, A III2} and ^{Z III1} are identical independently or different even, ^{also, if a iv2} and ^{Z iv1 m iv1} is a 2 there are a ^{plurality, a iv2} and ^{Z iv1} may be different even in the same independently . )
That is, in the present invention, one or two or more compounds represented by the general formula (N-i) and one or two or more compounds represented by the general formula (ii) Provided is a liquid crystal composition containing one or two or more compounds selected from the group consisting of a compound represented by-iii) and a compound represented by the general formula (N-iv), and Provided is a liquid crystal display element or a light control element.

According to the present invention, it is excellent in high nematic-isotropic transition temperature (T _NI ) and dissolution stability at low temperature, and further, low birefringence anisotropy (Δn) effective for high light resistance, high heat resistance and large dielectric It is possible to provide a liquid crystal composition which simultaneously satisfies the absolute value (| Δε |) of the rate anisotropy, and further, by using this liquid crystal composition, a liquid crystal display element or light control element having high reliability and practicability. Can be provided.

The liquid crystal composition of the present invention comprises one or more compounds represented by the general formula (N-i), and one or more compounds represented by the general formula (ii) with the general formula By incorporating one or two or more compounds selected from the group consisting of a compound represented by (N-iii) and a compound represented by general formula (N-iv) into a liquid crystal composition, A liquid crystal composition excellent in high nematic-isotropic transition temperature (T _NI ) and low temperature dissolution stability while satisfying low birefringence anisotropy (Δn) and high dielectric anisotropy (| Δε |) Can be provided.

Hereinafter, each component will be described first.
<Compounds Represented by General Formula (N-i)>
The liquid crystal composition of the present invention contains one or more compounds represented by general formula (Ni).

In the general formula ( ^Ni ), ^Ri1 and ^Ri2 are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or An alkenyloxy group having 2 to 8 carbon atoms is preferable, and 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 2 to 5 carbon atoms An alkenyloxy group is preferable, an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms is further preferable, and an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 3 carbon atoms is further added Preferably, an alkenyl group having 3 carbon atoms (propenyl group) is particularly preferred.

Also, R ^i1, when ring structure R ⁱ¹ is attached is a phenyl group (aromatic) is a linear alkyl group having 1 to 5 carbon atoms, carbon atoms, straight-chain 1-4 Alkoxy groups and alkenyl groups having 4 to 5 carbon atoms are preferred, and in the case where the ring structure to which they are attached is a saturated ring structure such as cyclohexane, pyran and dioxane, a straight chain having 1 to 5 carbon atoms The alkyl group, the linear alkoxy group having 1 to 4 carbon atoms, and the linear alkenyl group having 2 to 5 carbon atoms are preferable. In order to stabilize the nematic phase, the total of carbon atoms and oxygen atoms, if present, is preferably 5 or less, preferably linear. R ⁱ² is preferably a linear alkyl group having 1 to 5 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms, or an alkenyl group having 4 to 5 carbon atoms, and the linear carbon atom number 1-4 alkoxy groups are preferred.

  The alkenyl group is preferably selected from the groups represented by any one of formulas (R1) to (R5). (The black dot in each formula represents a carbon atom in the ring structure.)

A ⁱ¹ and A ⁱ² are preferably independently of each other a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and if it is desired to lower the viscosity, a trans-1,4-cyclohexylene group is more preferred When it is desired to increase birefringence anisotropy, it is more preferable than a 1,4-phenylene group. Each group is preferably unsubstituted.

Z ⁱ¹ is _{-CH 2 O -, - CF 2} O -, - CH 2 CH 2 -, - CF 2 CF 2 - or preferably a single _{bond, -CH 2 O -, - CH} 2 CH 2 - or Single bonds are more preferred, and single bonds are particularly preferred.

m ⁱ¹ is preferably 0, 1 or 2, and if it is desired to lower the viscosity, m ⁱ¹ is preferably 0, and if it is desired to increase the transition temperature, m ⁱ¹ is preferably 1.

  It is preferable to contain general formula (N-i-1) as general formula (N-1).

(Wherein, R ⁱ¹ , R ⁱ² , Z ⁱ¹ and m ⁱ¹ each independently represent the same meaning as R ⁱ¹ , R ⁱ² , Z ⁱ¹ and m ^{i1 in} general formula (N−i).)
The liquid crystal composition of the present invention preferably contains 1% by mass to 50% by mass of the compound represented by the general formula (N-i) based on the total amount of the composition, and the lower limit of the content is 1% by mass The above is preferable, 2% by mass or more is preferable, 3% by mass or more is preferable, 4% by mass or more is preferable, 5% by mass or more is preferable, 8% by mass is preferable, and the upper limit of the content is preferably 30% by mass or less, 25 mass% or less is preferable, 20 mass% or less is preferable, 18 mass% or less is preferable, 15 mass% or less is preferable, 13 mass% or less is preferable, and 10 mass% or less is preferable.
<Compound Represented by General Formula (ii)>
The liquid crystal composition of the present invention contains one or two or more compounds represented by the general formula (ii).

In general formula (ii), R ⁱⁱ¹ is preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and an alkyl group having 1 to 5 carbon atoms or 2 carbon atoms Alkenyl group of 5 is preferred. R ⁱⁱ² is preferably an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, And an alkyl group of 1 to 5 carbon atoms, an alkoxy group of 1 to 5 carbon atoms, an alkenyl group of 2 to 5 carbon atoms or an alkenyloxy group of 2 to 5 carbon atoms is preferable, and an alkyl group of 1 to 5 carbon atoms or carbon atoms is preferable More preferably, it is an alkenyl group having 2 to 5 atoms. In order to obtain particularly high light resistance, UV resistance or heat resistance, at least one of R ⁱⁱ¹ and R ⁱⁱ² is preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, The alkyl group of 1 to 5 is more preferable, and both of R ⁱⁱ¹ and R ⁱⁱ² are preferably an alkyl group having 1 to 5 carbon atoms.

  Among the compounds represented by the general formula (ii), the compounds represented by the general formula (ii-11) and the general formula (II-12) are preferable.

Wherein, although the same meaning as R ⁱⁱ² in R ⁱⁱ² the general formula (ii), there may preferably be an alkyl group or an alkenyl group having 2 to 5 carbon atoms having 1 to 5 carbon atoms, carbon atoms It is preferable that it is an alkyl group of 2 to 5 or an alkenyl group having 2 to 3 carbon atoms.

  The compounds represented by General Formula (ii-11) and / or General Formula (ii-12) are preferably, for example, General Formulas (ii-101) to (ii-110).

  Moreover, it is preferable that the compounds represented by general formula (ii) are general formula (ii-111)-general formula (ii-113).

The liquid crystal composition of the present invention preferably contains the compound represented by the general formula (ii) in an amount of 1% by mass to 80% by mass with respect to the total amount of the composition, and the lower limit of the content is 1% by mass or more 2 mass% or more is preferable, 3 mass% or more is preferable, 4 mass% or more is preferable, 5 mass% or more is preferable, 10 mass% or more is preferable, 15 mass% or more is preferable, 20 mass% or more is preferable 25 mass% or more is preferable, 80 mass% or less is preferable, 75 mass% or less is preferable, 70 mass% or less is preferable, 65 mass% or less is preferable, 60 mass% or less is preferable, 55 mass% or less is preferable % Or less is preferable, 50% by mass or less is preferable, 45% by mass or less is preferable, 40% by mass or less is preferable, 35% by mass or less is preferable, and 30% by mass or less is preferable.
<Compounds Represented by General Formula (N-iii) or General Formula (N-iv)>
The liquid crystal composition of the present invention contains one or more types of compounds represented by General Formula (N-iii) or General Formula (N-iv).

In General Formula (N-iii) or General Formula (N-iv), R ⁱⁱⁱ¹ , R ⁱⁱⁱ² and R ^iv1 and R ^iv2 are each independently an alkyl group having 1 to 8 carbon atoms and 1 to 8 carbon atoms Alkoxy group, alkenyl group having 2 to 8 carbon atoms or alkenyloxy group having 2 to 8 carbon atoms is preferable, and alkyl group having 1 to 5 carbon atoms, alkoxy group having 1 to 5 carbon atoms, and carbon atoms An alkenyl group of 2 to 5 or an alkenyloxy group of 2 to 5 carbon atoms is preferred.

  When the ring structure to which it is bonded is a phenyl group (aromatic), a linear alkyl group having 1 to 5 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms, and carbon Alkenyl group having 4 to 5 atoms is preferable, and when the ring structure to which it is bonded is a saturated ring structure such as cyclohexane, pyran and dioxane, a linear alkyl group having 1 to 5 carbon atoms, a straight chain Preferred is an alkoxy group having 1 to 4 carbon atoms and a linear alkenyl group having 2 to 5 carbon atoms. In order to stabilize the nematic phase, the total of carbon atoms and oxygen atoms, if present, is preferably 5 or less, preferably linear.

  The alkenyl group is preferably selected from the groups represented by any one of formulas (R1) to (R5). (The black dot in each formula represents a carbon atom in the ring structure.)

A ⁱⁱⁱ¹ , A ⁱⁱⁱ² , A ^iv1 and A ^iv2 each independently represent trans-1,4-cyclohexylene group, 1,4-phenylene group or 1,4-cyclohexenylene, but 1,4-phenylene One or more hydrogen atoms present on the group may be independently substituted with each other by halogen, but in the present invention, the trans-1,4-cyclohexylene group, 1, 1 are independently from each other. A 4-phenylene group is preferable, and when it is desired to lower the viscosity, a trans-1,4-cyclohexylene group is preferable, and when it is desired to increase the birefringence, a 1,4-phenylene group is preferable.

Z ^III1 and ^{Z iv1} each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 _{-, - CF 2 O -,} - CH = N-N = CH -, - CH = CH- or represents a -CF = CF-, respectively, in the present invention independently _-CH 2 and O -, - OCH ₂ -Or a single bond is preferred.

m ^III1 and ^{m iv1} are each represent independently 0, 1 or ^{2, if A III2} and ^{Z III1 m III1} is a 2 there are a ^{plurality, A III2} and ^{Z III1} are identical independently or different even, ^{also, if a iv2} and ^{Z iv1 m iv1} is a 2 there are a ^{plurality, a iv2} and ^{Z iv1} may be different even in the same independently . When it is desired to lower the viscosity of the liquid crystal composition, m ⁱⁱⁱ¹ and m ^iv1 are preferably 0. When it is desired to increase the transition temperature, m ⁱⁱⁱ¹ and m ^iv1 are preferably 1 or 2.

  It is preferable to contain general formula (N-1 d) as said general formula (N-iii).

^{(Wherein, R III1} and ^{R III2} each represent a same meaning as ^{R III1} and ^{R III2} in formula ^{(N-iii), n iii1} represents 1 or 2.)
The liquid crystal composition of the present invention preferably contains the compound represented by General Formula (N-iii) and General Formula (N-iv) in an amount of 1% by mass to 80% by mass with respect to the total amount of the composition, 1 mass% or more is preferable, 2 mass% or more is preferable, 3 mass% or more is preferable, 4 mass% or more is preferable, 5 mass% or more is preferable, 10 mass% or more is preferable, and 15 mass% is preferable. The above is preferable, 20% by mass or more is preferable, 25% by mass or more is preferable, 30% by mass or more is preferable, 80% by mass or less is preferable, 75% by mass or less is preferable, 70% by mass or less is preferable 65 mass% or less is preferable, 60 mass% or less is preferable, 55 mass% or less is preferable, and 50 mass% or less is preferable.
<Compound Represented by General Formula (L)>
The liquid crystal composition of the present invention preferably further contains one or more compounds represented by General Formula (L).

(Wherein, R ^L1 and R ^L2 each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent -CH ₂ -in the alkyl group are independently of each other It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-,
m ^L1 represents 0, 1, 2 or 3 and
A ^L1 , A ^L2 and A ^L3 are each independently (a) 1,4-cyclohexylene group (one -CH _2- present in this group or two or more non-adjacent -CH _2- May be replaced by -O-) and (b) 1,4-phenylene group (one -CH = present in this group or two or more non-adjacent -CH = is -N May be replaced by =.)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and the groups (a), (b) and (c) are each independently a carbon atom It may be substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, a cyano group or a fluorine atom However, A ^L1 , A ^L2 and A ^{4 L 3} are 2,3-difluoro-1,4-phenylene group, 1,7,8-trifluoronaphthalene-2,6-diyl group or 3,4,5-trifluoronaphthalene -2, 6 Not represent a yl group,
Z ^L1 and ^{Z L2} is n each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF _{2 -, - CF 2 O -} , - CH = N-N = CH -, - CH = CH -, - C≡C- or an -CF = CF,
When m ^L1 is 2 or 3 and a plurality of A ^L2 and Z ^L2 exist, A ^L2 and Z ^L2 may be independently identical or different, provided that in general formula (ii) Exclude the compounds represented. )
The compounds represented by formula (L) may be used alone or in combination. There is no particular limitation on the types of compounds that can be combined, but they are used in combination as appropriate depending on the desired properties such as solubility at low temperature, transition temperature, birefringence and the like. The type of compound used is, for example, one type in one embodiment of the present invention. Alternatively, in another embodiment of the present invention, there are two types, three types, four types, and five or more types.

  In the composition of the present invention, the content of the compound represented by the general formula (L) needs to be suitably adjusted according to the required performance such as solubility at low temperature, transition temperature, birefringence and the like.

  The lower limit of the preferable content of the compound represented by the formula (L) to the total amount of the composition of the present invention is 1% or more, 2% or more, 5% or more, 8% or more 10% or more, 13% or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more, 30% or more 40% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more. In addition, when the content is large, the upper limit value of the preferable content is 85% or less, 75% or less, 65% or less, 55% or less, or 45% or less, because problems such as precipitation occur. Yes, 35% or less, 30% or less, 28% or less, 25% or less, 23% or less, 20% or less, 18% or less, 15% or less, 13% or less, 10% or less, 8% or less, and 5% or less.

  When the composition of the present invention is required to keep the viscosity low and have a high response speed, it is preferable that the above lower limit is high and the upper limit is high. Furthermore, the composition of the present invention is a highly reliable composition having a high specific resistance value or VHR, and when the driving voltage is not limited, it is preferable that the above lower limit value is high and the upper limit value is high. When it is desired to increase the dielectric anisotropy in order to keep the drive voltage low, it is preferable that the above lower limit value be low and the upper limit value be low.

When reliability is important, both R ^L1 and R ^L2 are preferably alkyl groups, and when importance is given to reducing the volatility of the compound, alkoxy groups are preferable, and viscosity reduction is important When doing, at least one is preferably an alkenyl group.

  The number of halogen atoms present in the molecule is preferably 0, 1, 2 or 3 and is preferably 0 or 1. When importance is attached to compatibility with other liquid crystal molecules, 1 is preferred.

R ^L1 and R ^L2 are, when the ring structure to which they are bonded is a phenyl group (aromatic), a linear alkyl group of 1 to 5 carbon atoms, or a linear alkyl group of 1 to 4 carbon atoms Alkoxy groups and alkenyl groups having 4 to 5 carbon atoms are preferred, and in the case where the ring structure to which they are attached is a saturated ring structure such as cyclohexane, pyran and dioxane, a straight chain having 1 to 5 carbon atoms The alkyl group, the linear alkoxy group having 1 to 4 carbon atoms, and the linear alkenyl group having 2 to 5 carbon atoms are preferable. In order to stabilize the nematic phase, the total of carbon atoms and oxygen atoms, if present, is preferably 5 or less, preferably linear.

  The alkenyl group is preferably selected from the groups represented by any one of formulas (R1) to (R5). (The black dot in each formula represents a carbon atom in the ring structure.)

When importance is attached to the response speed, m ^L1 is preferably 0, 2 or 3 is preferable to improve the upper limit temperature of the nematic phase, and 1 is preferable to balance them. Moreover, in order to satisfy the characteristics required as a composition, it is preferable to combine compounds of different values.

A ^{L 1} , A ^{L 2} and A ^{L 3} are preferably aromatic when it is required to increase Δn, and are preferably aliphatic to improve the response speed, and each of them is independently trans- 1,4-cyclohexylene group, 1,4-phenylene group, 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] octyrene group piperidine-1,4-diyl group naphthalene-2,6-diyl group decahydronaphthalene-2,6 -Preferably represents a diyl group or 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, more preferably represents the following structure,

More preferably, it represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group.

It is preferable that Z ^L1 and Z ^L2 be a single bond when the response speed is important. The compound represented by formula (L) preferably has 0 or 1 halogen atoms in the molecule.

More specifically as general formula (L), general formula (C1) in which m ^L1 in general formula (L) is 0, general formula (C2) in which m ^L1 in general formula (L) is 1, or it is preferable that the general formula (L) m ^L1 in contains a compound represented by a is formula 2 (C3). As a compound represented by general formula (C1) to (C3), 1 type may be used and it can also be used combining 2 or more types.

In the above formulas, Rd and Pe each independently represent an alkyl group having 1 to 12 carbon atoms, which may be linear or have a methyl or ethyl branch, and has a 3- to 6-membered ring And any —CH ₂ — present in the group is —O—, —CH = CH—, —CH = CF—, —CF = CH—, —CF = CF— Or -C≡C-, and any hydrogen atom present in the group may be substituted by a fluorine atom or a trifluoromethoxy group; An alkyl group, a linear 1-alkenyl group having 2 to 7 carbon atoms, a linear 3-alkenyl group having 4 to 7 carbon atoms, a linear alkoxyl group having 1 to 3 carbon atoms, or a terminal carbon atom A linear alkyl having 1 to 5 carbon atoms substituted with an alkoxy group of 1 to 3 Group is preferable, and further, at least one of them is a linear alkyl group having 1 to 7 carbon atoms, a linear 1-alkenyl group having 2 to 7 carbon atoms, or a linear 3-alkenyl group having 4 to 7 carbon atoms Is particularly preferred. When an asymmetric carbon is generated by branching, the compound may be optically active or racemic.

  Ring G, ring H, ring I and ring J are each independently trans-1,4-cyclohexylene, transdecahydronaphthalene-trans-2,6-diyl, 1-2 fluorine atoms or A 1,4-phenylene group which may be substituted by a methyl group, a naphthalene-2,6-diyl group which may be substituted by one or more fluorine atoms, and one or two fluorine atoms; Tetrahydronaphthalene-2,6-diyl group, 1,4-cyclohexenylene group optionally substituted by 1 to 2 fluorine atoms, 1,3-dioxane-trans-2,5-diyl group, Represents a pyrimidine-2,5-diyl group or a pyridine-2,5-diyl group, and in each compound, trans decahydronaphthalene-trans-2,6-diyl group, one or more A naphthalene-2,6-diyl group which may be substituted by a fluorine atom, a tetrahydronaphthalene-2,6-diyl group which may be substituted by one or two fluorine atoms, a fluorine atom No more than 1 1,4-cyclohexenylene group, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group is also preferable. The other ring is preferably a trans-1,4-cyclohexylene group or a 1,4-phenylene group which may be substituted by one or two fluorine atoms or a methyl group.

L ^g , L ^h and L ^{i each} represents a linking group and each independently represent a single bond, an ethylene group (—CH ₂ CH ₂ —), or a 1,2-propylene group (—CH (CH ₃ ) CH ₂ — and ) -CH ₂ CH (CH ₃ )-), 1,4-butylene group, -COO-, -OCO-, -OCF _2- , -CF ₂ O-, -CH = CH-, -CH = CF-, -CF = CH-, -CF = CF-, -C≡C- or -CH = NN = CH-, but a single bond, ethylene group, 1,4-butylene group, -COO-, -OCO-, _{-OCF 2 -, - CF 2 O} -, - CF = CF -, - C≡C- or -CH = NN = CH- are preferred, and at least one in (C2), the in (C3) It is preferred that at least two represent a single bond.

When the compounds represented by the general formulas (C1) to (C3) are used in combination, different substituents may be selected even if the same options (ring G, L ^{g and the} like) in different molecules represent the same substituent. May be represented.

  In the general formulas (C1) to (C3), the number of halogen atoms in the molecule is preferably 0 or 1.

  The lower limit value of the preferable content of the compounds represented by the general formulas (C1) to (C3) with respect to the total amount of the composition of the present invention is 1% or more, 2% or more, 5% or more Yes, 8% or more, 10% or more, 13% or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more, 30% or more, 40% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% It is above. The upper limit value of the preferable content is 85% or less, 75% or less, 65% or less, 55% or less, 45% or less, 35% or less, 30% or less, 28% or less, 25% or less, 23% or less, 20% or less, 18% or less, 15% or less, 13% or less, 10% or less, 8% It is below and 5% or less.

  It is preferable to keep the viscosity of the composition of the present invention low and to lower the above lower limit value and to raise the upper limit value when a composition having a high response speed is required. Furthermore, when the composition of the present invention has a high specific resistance value or VHR and requires a highly reliable composition, it is preferable to make the above lower limit value higher and the upper limit value higher. When it is desired to increase the dielectric anisotropy in order to keep the drive voltage low, it is preferable to lower the above lower limit and lower the upper limit.

  More preferred forms of (C1) can be represented by the following general formulas (C1a) to (C1h).

In each of the above formulas, R f and R g each independently represent a linear alkyl group having 1 to 7 carbon atoms, a linear 1-alkenyl group having 2 to 7 carbon atoms, or a linear chain having 4 to 7 carbon atoms Represents a linear 3-alkenyl group, a linear alkoxyl group having 1 to 3 carbon atoms, or a linear alkyl group having 1 to 5 carbon atoms, the terminal of which is substituted by an alkoxyl group having 1 to 3 carbon atoms, At least one of them represents a linear alkyl group having 1 to 7 carbon atoms, a linear 1-alkenyl group having 2 to 7 carbon atoms, or a linear 3-alkenyl group having 4 to 7 carbon atoms. However, when ring G1 to ring G3 is an aromatic ring, the corresponding R ^f excludes 1-alkenyl group and alkoxyl group, and when ring H1 to ring H3 is an aromatic ring, corresponding R ^g is 1-alkenyl group and alkoxyl Remove the group.

  Ring G1 and ring H1 are each independently substituted by a trans-1,4-cyclohexylene group, a trans decahydronaphthalene-trans-2,6-diyl group, one or two fluorine atoms or a methyl group A 1,4-phenylene group, a naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, a tetrahydronaphthalene-2 optionally substituted by 1 to 2 fluorine atoms, 6-diyl group, 1,4-cyclohexenylene group optionally substituted by 1 to 2 fluorine atoms, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group Group or a pyridine-2,5-diyl group, but in each compound, trans decahydronaphthalene-trans-2,6-diyl group, one or more fluorine atoms Naphthalene-2,6-diyl group which may be substituted, tetrahydronaphthalene-2,6-diyl group which may be substituted by 1 to 2 fluorine atoms, 1 optionally substituted by a fluorine atom The number of 3,4-cyclohexenylene group, 1,3-dioxane-trans-2,5-diyl group, pyrimidine-2,5-diyl group or pyridine-2,5-diyl group is preferably 1 or less, In that case, the other ring is a trans-1,4-cyclohexylene group or a 1,4-phenylene group which may be substituted by one or two fluorine atoms or a methyl group. Provided that the ring G1 and the ring H1 both represent a trans-1,4-cyclohexylene group.

  Ring G2 and ring H2 are each independently substituted by a trans-1,4-cyclohexylene group, a trans decahydronaphthalene-trans-2,6-diyl group, one or two fluorine atoms or a methyl group A 1,4-phenylene group, a naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, a tetrahydronaphthalene-2 optionally substituted by 1 to 2 fluorine atoms, 6-diyl group is represented, but in each compound, trans decahydronaphthalene-trans-2,6-diyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, 1 to 4 The number of tetrahydronaphthalene-2,6-diyl groups which may be substituted by two fluorine atoms is preferably one or less. One ring is a trans-1,4-cyclohexylene group or a 1,4-phenylene group which may be substituted by 1 to 2 fluorine atoms or a methyl group. Ring G 3 and ring H 3 are each independently a 1,4-phenylene group which may be substituted by 1 to 2 fluorine atoms or methyl groups, or a naphthalene-2 which may be substituted by one or more fluorine atoms , A 6-diyl group, a tetrahydronaphthalene-2,6-diyl group optionally substituted by 1 to 2 fluorine atoms, and a naphthalene group optionally substituted by one or more fluorine atoms in each compound It is preferable that it is less than 1 piece of tetrahydro naphthalene- 2, 6- diyl group which may be substituted by the 2, 6- diyl group and the 1-2 fluorine atom.

  More preferably, they are the following compounds.

  More preferred embodiments of (C2) can be represented by the following general formulas (C2a) to (C2m).

  In the above formulas, ring G1, ring G2, ring G3, ring H1, ring H2 and ring H3 have the same meanings as described above, ring I1 is the same as ring G1, ring I2 is ring G2, and ring I3 is ring G3. Represents the meaning. In each of the above compounds, trans decahydronaphthalene-trans-2,6-diyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, 1-2 fluorine atoms Tetrahydronaphthalene-2,6-diyl group which may be substituted, 1,4-cyclohexenylene group which may be substituted by fluorine atom, 1,3-dioxane-trans-2,5-diyl group, The pyrimidine-2,5-diyl group or the pyridine-2,5-diyl group is preferably within one, in which case the other ring is a trans-1,4-cyclohexylene group or one to two. It is a 1,4-phenylene group which may be substituted by a fluorine atom or a methyl group.

  More preferably, they are the following compounds.

  Next, more preferable forms in (C3) can be represented by the following general formulas (C3a) to (C3f).

  In the above formulas, ring G1, ring G2, ring H1, ring H2, ring I1 and ring I2 have the same meanings as described above, ring J1 has the same meaning as ring G1 and ring J2 has ring G2, respectively. In each of the above compounds, trans decahydronaphthalene-trans-2,6-diyl group, naphthalene-2,6-diyl group optionally substituted by one or more fluorine atoms, 1-2 fluorine atoms Tetrahydronaphthalene-2,6-diyl group which may be substituted, 1,4-cyclohexenylene group which may be substituted by fluorine atom, 1,3-dioxane-trans-2,5-diyl group, The pyrimidine-2,5-diyl group or the pyridine-2,5-diyl group is preferably within one, in which case the other ring is a trans-1,4-cyclohexylene group or one to two. It is a 1,4-phenylene group which may be substituted by a fluorine atom or a methyl group.

  More preferably, they are the following compounds.

<Compound Represented by General Formula (N)>
The liquid crystal composition of the present invention preferably further contains one or more compounds represented by General Formula (N).

(Wherein, R ^N1 and R ^N2 each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent -CH ₂ -in the alkyl group are each independently. It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-,
m ^N1 represents 0, 1, 2 or 3 and
A ^N1 , A ^N2 and A ^N3 are each independently (a) 1,4-cyclohexylene group (one -CH _2- present in this group or two or more non-adjacent -CH _2- May be replaced by -O-) and (b) 1,4-phenylene group (one -CH = present in this group or two or more non-adjacent -CH = is -N May be replaced by =.)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and the groups (a), (b) and (c) are each independently a carbon atom It may be substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, a cyano group or a fluorine atom However, at least one of A ^N1 , A ^N2 and A ^N3 is a 2,3-difluoro-1,4-phenylene group, 1,7,8-trifluoronaphthalene-2,6-diyl group or 3,4,4, 5-trifluorona It represents the array type-2,6-diyl group,
Z ^N1 and ^{Z N2} each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 _{-, - CF 2 O -,} - CH = N-N = CH -, - CH = CH- or an -CF = CF-,
When m ^N1 is 2 or 3 and A ^N2 and Z ^N2 are present, A ^N2 and Z ^N2 may be independently the same or different, provided that the general formula (N-i And the compounds represented by formulas (N-iii) and (N-iv). )
In the general formula (N), ^RN1 and ^RN2 are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or a carbon atom An alkenyloxy group having 2 to 8 carbon atoms is preferable, and 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 an alkenyloxy having 2 to 5 carbon atoms Group is preferable, an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms is more preferable, and an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 3 carbon atoms is more preferable. An alkenyl group having 3 carbon atoms (propenyl group) is particularly preferred.

  When the ring structure to which it is bonded is a phenyl group (aromatic), a linear alkyl group having 1 to 5 carbon atoms, a linear alkoxy group having 1 to 4 carbon atoms, and carbon Alkenyl group having 4 to 5 atoms is preferable, and when the ring structure to which it is bonded is a saturated ring structure such as cyclohexane, pyran and dioxane, a linear alkyl group having 1 to 5 carbon atoms, a straight chain Preferred is an alkoxy group having 1 to 4 carbon atoms and a linear alkenyl group having 2 to 5 carbon atoms. In order to stabilize the nematic phase, the total of carbon atoms and oxygen atoms, if present, is preferably 5 or less, preferably linear.

  The alkenyl group is preferably selected from the groups represented by any one of formulas (R1) to (R5). (The black dot in each formula represents a carbon atom in the ring structure.)

It is preferable that A ^N1 , A ^N2 , A ^N21 and A ²³ be each independently aromatic when it is required to increase Δn, and in order to improve the response speed, it is preferably aliphatic. Trans-1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, 3,5-difluoro-1,4 -Phenylene group, 2,3-difluoro-1,4-phenylene group, 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, It is preferable to represent a naphthalene-2,6-diyl group, a decahydronaphthalene-2,6-diyl group or a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the following structure And still more preferably,

More preferably, it represents a trans-1,4-cyclohexylene group, a 1,4-cyclohexenylene group or a 1,4-phenylene group.

Z ^N11 and ^{Z N12} are each _{independently -CH 2 O -, - CF 2} O -, - CH 2 CH 2 -, - CF 2 CF 2 - or preferably a single bond, _-CH 2 O-, -CH ₂ CH ₂ - or a single bond is more preferable, _-CH 2 O-or a single bond is particularly preferred.

m ^N1 is preferably 0, 1 or 2, ^{m N1} is 0 preferably in order to decrease the viscosity, if it is desired to increase the transition temperature ^{m N1} is 1 are preferred.

  The lower limit of the preferable content of the compound represented by the formula (N) with respect to the total amount of the composition of the present invention is 1% or more, 10% or more, 20% or more, 30% or more , 40% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more . The upper limit value of the preferable content is 95% or less, 85% or less, 75% or less, 65% or less, 55% or less, 45% or less, 35% or less, 25% or less and 20% or less.

When it is necessary to keep the viscosity of the composition of the present invention low and have a high response speed, it is preferable that the above lower limit is low and the upper limit is low. Furthermore, when the specific resistance value or VHR of the composition of the present invention is high and a highly reliable composition is required, it is preferable that the above lower limit value is low and the upper limit value is low. When it is desired to increase the dielectric anisotropy in order to keep the driving voltage low, it is preferable that the above lower limit value be high and the upper limit value be high.
As general formula (N), any one or more of a compound group represented by the following general formulas (N-1a) to (N-1g) can be contained.

(Wherein, R ^N1 and R ^N2 represent the same meaning as R ^N1 and R ^N1 in the general formula (N), n ^Na11 represents 0 or 1, n ^Nb11 represents 1 or 2, and n ^Nc11 is 0 or 1 represents n ^Ne11 represents 1 or 2; n ^Nf11 represents 1 or 2; n ^Ng11 represents 1 or 2; A ^Ne11 represents a trans-1,4-cyclohexylene group or 1,4-phenylene And A ^Ng11 represents a trans-1,4-cyclohexylene group, a 1,4-cyclohexenylene group or a 1,4-phenylene group, but at least one represents a 1,4-cyclohexenylene group. , Z ^{Ne 11} represents a single bond or ethylene, but at least one represents ethylene)
The liquid crystal composition of the present invention comprises the compound represented by the general formula (N-i), the compound represented by the general formula (ii), and the compound represented by the general formula (N-iii) and / or the general formula It is preferable to simultaneously contain the compound represented by Formula (N-iv) and the compound represented by General Formula (L), and the compound represented by General Formula (N-i), and General Formula (ii) And a compound represented by General Formula (N-iii) and / or a compound represented by General Formula (N-iv) and a compound represented by General Formula (N) at the same time The compound represented by the general formula (N-i), the compound represented by the general formula (ii), and the compound represented by the general formula (N-iii) and / or the general formula (N- a compound represented by iv), a compound represented by General Formula (L), and a compound represented by General Formula (N) Preferably it contains simultaneously.

  Compound Represented by General Formula (N-i), Compound Represented by General Formula (ii), Compound Represented by General Formula (N-iii), and / or Total Amount of Liquid Crystal Composition The lower limit of the preferable content of the total of the compounds represented by the general formula (N-iv) is 30% or more, 40% or more, 45% or more, 50% or more, 55% or more 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more. The upper limit value of the preferable content is 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, It is 65% or less, 60% or less, 55% or less, and 50% or less.

  Compound Represented by General Formula (N-i), Compound Represented by General Formula (ii), Compound Represented by General Formula (N-iii), and / or Total Amount of Liquid Crystal Composition The lower limit of the preferable content of the total of the compound represented by the general formula (N-iv) and the compound represented by the general formula (L) is 30% or more, 40% or more, and 45% or more Yes, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, It is 90% or more, 95% or more, and 98% or more. The upper limit value of the preferable content is 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, It is 65% or less, 60% or less, 55% or less, and 50% or less.

  Compound Represented by General Formula (N-i), Compound Represented by General Formula (ii), Compound Represented by General Formula (N-iii), and / or Total Amount of Liquid Crystal Composition The lower limit of the preferable content of the total of the compound represented by formula (N-iv) and the formula (N) is 30% or more, 40% or more, 45% or more, 50% or more , 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more , 95% or more and 98% or more. The upper limit value of the preferable content is 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, It is 65% or less, 60% or less, 55% or less, and 50% or less.

  Compound Represented by General Formula (N-i), Compound Represented by General Formula (ii), Compound Represented by General Formula (N-iii), and / or Total Amount of Liquid Crystal Composition The lower limit of the preferable content of the total of the compound represented by the general formula (N-iv), the compound represented by the general formula (L), and the compound represented by the general formula (N) is 30% or more Yes, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, It is 80% or more, 85% or more, 90% or more, 95% or more, and 98% or more. The upper limit value of the preferable content is 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, It is 65% or less, 60% or less, 55% or less, and 50% or less.

  The lower limit of the preferable content of the total of the compounds represented by the general formula (L) and the general formula (N) with respect to the total amount of the liquid crystal composition is 1% or more, 2% or more, and 5% Or more, 8% or more, 10% or more, 13% or more, 15% or more, 18% or more, 20% or more, 22% or more, 25% or more Yes, 30% or more, 40% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, 75% or more, 80% or more. The upper limit value of the preferable content is 85% or less, 75% or less, 65% or less, 55% or less, 45% or less, 35% or less, 30% or less, 28% or less, 25% or less, 23% or less, 20% or less, 18% or less, 15% or less, 13% or less, 10% or less, 8% It is below and 5% or less.

  It is preferable that the composition of this invention does not contain the compound which has a structure which hetero atoms, such as oxygen atoms, such as a peracid (-CO-OO-) structure, couple | bonded in a molecule | numerator.

  Also, in the composition of the present invention,

It is preferable that the compound which has 1 or 2 or more groups represented by these, does not have a group represented by -CH (zeta) CH- in this compound. Moreover, it is more preferable not to contain the compound which has a group represented by -CH (zeta) CH- in the composition of this invention.

  When importance is placed on the reliability and long-term stability of the composition, the content of the compound having a carbonyl group is preferably 5% or less, more preferably 3% or less, based on the total mass of the composition. Preferably, it is more preferably 1% or less, and most preferably substantially free.

  When importance is placed on stability due to UV irradiation, the content of the compound substituted with chlorine atoms is preferably 15% or less, preferably 10% or less, based on the total mass of the composition. % Is preferable, 5% or less is more preferable, 3% or less is preferable, and substantially no content is further preferable.

  It is preferable to increase the content of compounds in which all ring structures in the molecule are six-membered rings, and the content of compounds in which all ring structures in the molecule are six-membered rings is 80 based on the total mass of the composition. % Or more is preferable, 90% or more is more preferable, 95% or more is more preferable, and the composition is composed only of compounds in which all ring structures in the molecule are substantially 6-membered rings. Most preferred.

  In order to suppress deterioration due to oxidation of the composition, it is preferable to reduce the content of the compound having a cyclohexenylene group as a ring structure, and the content of the compound having a cyclohexenylene group is the total mass of the composition. On the other hand, it is preferably 10% or less, preferably 8% or less, more preferably 5% or less, preferably 3% or less, and even more preferably substantially non-containing.

  In the case of focusing on the improvement of the viscosity and the improvement of Tni, the content of the compound having a 2-methylbenzene-1,4-diyl group in which the hydrogen atom may be substituted by halogen in the molecule may be reduced. Preferably, the content of the compound having the 2-methylbenzene-1,4-diyl group in the molecule is preferably 10% or less, and more preferably 8% or less, based on the total mass of the composition. And 5% or less is more preferable, 3% or less is preferable, and substantially no content is more preferable.

In the present application, "not substantially contained" means that it is not contained except for unintentionally contained substances.
When the compound contained in the composition of the present invention has an alkenyl group as a side chain, the number of carbon atoms of the alkenyl group is preferably 2 to 5 when the alkenyl group is bonded to cyclohexane. When the alkenyl group is bonded to benzene, the number of carbon atoms of the alkenyl group is preferably 4 to 5, and the unsaturated bond of the alkenyl group and benzene are preferably not directly bonded.

  In order to enhance the stability of the liquid crystal composition in the present invention, it is preferable to add a stabilizer such as an antioxidant, an ultraviolet (UV) absorber, a light stabilizer or an infrared absorber. Examples of the antioxidant include hydroquinone derivatives, nitrosamine type polymerization inhibitors, hindered phenol type antioxidants, etc. More specifically, tert-butyl hydroquinone, methyl hydroquinone, manufactured by Wako Pure Chemical Industries, Ltd. Q-1300 "," Q-1301 ", BASF's" IRGANOX 1010 "," IRGANOX 1035 "," IRGANOX 1076 "," IRGANOX 1098 "," IRGANOX 1135 "," IRGANOX 1330 "," IRGANOX 1425 "," IRGANOX 1520 "," IRGANOX17 ", "IRGANOX 245", "IRGANOX 259", "IRGANOX 3114", "IRGANOX 3790", "IRGANOX 5057", "IRGANOX 565", etc. Can be mentioned.

  As the UV absorber, it is preferable to have excellent ability to absorb ultraviolet light with a wavelength of 370 nm or less, and from the viewpoint of good liquid crystal display properties, a compound that absorbs less visible light with a wavelength of 400 nm or more. More specifically, for example, hindered phenol compounds, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salts compounds, triazine compounds and the like can be mentioned. As the dophenol compounds, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-) 4-hydroxybenzyl) benzene, tris- (3,5-di-) ert- butyl-4-hydroxybenzyl) - isocyanurate. Examples of benzotriazole compounds include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H) -Benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, Triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N'-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy- Hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2- (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5 -Chlorobenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], and BASF TINUVIN 109, TINUVIN 171, TINUVIN 171, TINUVIN 326, TINUVIN 327, TINUVIN 328, TINUVIN 770, TINUVIN 900, TINUVIN 928, manufactured by Japan KK, KEMISORB 71, KEMISORB 73, KEMISORB 74, manufactured by Chemi-Pro Chemical Co., Ltd. are also preferable. It is possible to have.

  The addition amount of the stabilizer is preferably 0.01 to 2.0% by mass, 0.05 to 1.0% by mass, and 0.05 to 0.5% by mass with respect to the polymerizable liquid crystal composition. Is more preferable, 0.1 to 1.0% by mass is more preferable, and 0.1 to 0.5% by mass is more preferable.

  The liquid crystal composition of the present invention may contain, in addition to the above-mentioned compounds, compounds selected from ordinary nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, chiral agents and polymerizable compounds.

  The liquid crystal composition of the present invention may use a compound having an asymmetric atom, an axially asymmetric compound, or a mixture thereof as a chiral agent for inducing a pitch. A compound having an asymmetric carbon atom is preferred as a chiral agent for inducing pitch, and a 1,4-phenylene group (one or two of hydrogen atoms in this group may be substituted by fluorine, methyl or methoxy) It is preferable that it is a molecular structure which has one or two or more. In order to improve or adjust the temperature dependency of pitch, a plurality of chiral agents may be mixed and used.

    The liquid crystal composition of the present invention may contain, as a polymerizable compound, a polymerizable compound used for PS type, PSA type, PSVA type, etc. For example, two or three 1,4-phenylene groups may be used. The polymerizable compound to be constituted is preferable, and the polymerizing group is preferably acrylate or methacrylate. Specifically, the polymerizable compounds represented by formulas (RM-001) to (RM-007) can be suitably contained in the range of 0% by mass to 5% by mass.

The polymerizable compound represented by may be suitably contained in the range of 0 mass% to 5 mass%.
The hydrogen atom or fluorine atom in the 1,4-phenyl group constituting the molecular structure of the polymerizable compound may be optionally substituted by a fluorine atom or a methyl group or a methoxy group. The polymerizable compound used in the present invention may contain an alkylene group generally called a spacer between the ring and the polymerizing group as in RM-005, and the alkylene group has 1 to 10 carbon atoms. Is preferred.
When the liquid crystal composition of the present invention contains 1% by mass to 5% by mass of a polymerizable compound, the above-mentioned spacer is preferably an alkylene group having 1 to 6 carbon atoms, and plural kinds of polymerizable compounds Is more preferable from the viewpoint of better solubility. When the liquid crystal composition of the present invention contains 0.1% by mass to 1% by mass of the polymerizable compound, one or more of the polymerizable compounds represented by formulas (RM-001) to (RM-007) are used. It is preferable to contain 2 or more types.

  The liquid crystal composition of the present invention is a nematic liquid crystal composition having a negative dielectric anisotropy (Δε). When the liquid crystal composition has negative dielectric anisotropy, although the dielectric anisotropy (Δε) at 25 ° C. is −2.0 to −6.0, −2.0 to −5.0 is More preferably, -2.5 to -5.0 is particularly preferred.

  The liquid crystal composition of the present invention has a birefringence anisotropy (Δn) at 25 ° C. of 0.070 to 0.200, preferably 0.07 to 0.13, more preferably 0.09 to 0.12. Is particularly preferred.

  The liquid crystal composition of the present invention has a viscosity (η) at 10 ° C. of 10 to 100 mPa · s, preferably 10 to 90 mPa · s, more preferably 10 to 80 mPa · s, and 10 to 70 mPas. S is preferable, 10 to 60 mPa · s is preferable, 10 to 50 mPa · s is more preferable, 10 to 40 mPa · s is preferable, and 10 to 30 mPa · s Is particularly preferred.

The liquid crystal composition of the present invention has a rotational viscosity (γ ₁ ) at 25 ° C. of 40 to 250 mPa · s, preferably 40 to 200 mPa · s, and more preferably 40 to 160 mPa · s, Of from 140 to 140 mPa · s, preferably from 40 to 140 mPa · s, preferably from 40 to 130 mPa · s, preferably from 40 to 125 mPa · s, and preferably from 40 to 120 mPa · s. Is more preferably 40 to 115 mPa · s, more preferably 40 to 110 mPa · s, and particularly preferably 40 to 100 mPa · s.

The liquid crystal composition of the present invention preferably has a nematic phase-isotropic liquid phase transition temperature (T _ni ) of 80 ° C. or higher, preferably 90 ° C. or higher, and more preferably 100 ° C. or higher, The temperature is preferably 110 ° C. or more, more preferably 120 ° C. or more, and particularly preferably adjusted to 90 ° C. to 115 ° C.

  The liquid crystal composition of the present invention may be used as a guest-host liquid crystal composition. As the guest compound, for example, one or more dichroic dyes such as an azo compound can be contained.

  The liquid crystal composition of the present invention is a liquid crystal composition having a negative dielectric anisotropy and is preferably an APL (antiparallel) and VA (vertical alignment) liquid crystal display element, but the addition of a chiral agent The alignment axes of the upper and lower substrates may be shifted so that the liquid crystal molecules are twisted when the voltage is turned on. When it is desired to add a dichroic dye to the liquid crystal composition and adjust the amount of transmitted light as a guest-host type liquid crystal composition without a polarizing plate, the alignment axis may be twisted 90 ° to obtain high contrast. More preferably, 240 ° twist is more preferable, and if it is desired to obtain a higher contrast, technically more difficult 250 ° twist or 260 ° twist or 270 ° twist is preferable, and 360 ° twist is also preferable. preferable.

When the liquid crystal composition is a liquid crystal composition having negative dielectric anisotropy, the pretilt angle is preferably 80 ° to 90 °.
The liquid crystal composition of the present invention can be used for a liquid crystal display element or a light control element.

  In addition, a liquid crystal display device using the liquid crystal composition of the present invention is useful for a passive matrix drive system and a liquid crystal display device for active matrix drive, and is a PSA mode, PSVA mode, VA mode, PS-IPS mode, TN mode And a liquid crystal display element for STN mode, IPS mode or PS-FFS mode.

  The two substrates of the liquid crystal cell used in the device may be a flexible transparent material such as glass or plastic, and one may be an opaque material such as silicon. A transparent substrate having a transparent electrode layer can be obtained, for example, by sputtering indium tin oxide (ITO) on a transparent substrate such as a glass plate. In order to improve the contrast of the device, it is preferable to use a substrate subjected to antiglare treatment such as AR coating.

  The color filter can be produced, for example, by a pigment dispersion method, a printing method, an electrodeposition method, a dyeing method or the like. A method of producing a color filter by the pigment dispersion method will be described by way of example. A curable coloring composition for a color filter is applied on the transparent substrate, subjected to a patterning treatment, and cured by heating or light irradiation. By performing this process for each of three colors of red, green, and blue, it is possible to create a pixel portion for a color filter. In addition, on the substrate, a pixel electrode provided with an active element such as a TFT, a thin film diode, or a metal insulator metal specific resistance element can be provided.

  The substrate is opposed with the transparent electrode layer on the inside. At this time, the distance between the substrates may be adjusted through the spacer. At this time, it is preferable to adjust the thickness of the obtained light control layer to 1 to 100 μm. The thickness is more preferably 1.5 to 10 μm, and in the case of using a polarizing plate, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so as to maximize the contrast.

  When the liquid crystal composition contains a chiral agent, the twist pitch (p) of the liquid crystal composition is, for example, 10 μm to 120 μm, preferably 2 μm to 20 μm. More specifically, the twisting pitch (p) is appropriately adjusted in accordance with the mode of the liquid crystal display device such as the TN mode or STN mode.

  When the liquid crystal composition contains a chiral agent, the d / p value, which is the relationship between the twist pitch (p) and the cell thickness d, preferably satisfies 0.5 to 2.2. Specifically, according to the twist angle, the relationship d / p value between the twist pitch (p) and the cell thickness (d) is adjusted to be optimum. The optimum d / p value is a region where there is no orientation defect such as reverse twist domain or stripe domain. For example, for a 240 ° twist, the optimal d / p value is in the range of 0.45 to 0.66. It is preferable that the domain be observed by visual observation or a microscope to adjust so as not to cause alignment defects.

  When two polarizing plates are provided, the polarizing axis of each polarizing plate can be adjusted to adjust the viewing angle and contrast to be good. Furthermore, retardation films for widening the viewing angle can also be used. Examples of the spacer include glass particles, plastic particles, alumina particles, and photoresist materials. Thereafter, a sealing agent such as an epoxy-based thermosetting composition is screen-printed on the substrate in a form provided with a liquid crystal injection port, the substrates are adhered to each other, and the sealing agent is thermally cured.

  As a method of holding the liquid crystal composition between the two substrates, a normal vacuum injection method or an ODF method can be used.

  The element of the present invention may be used by laminating a film that cuts light of a wavelength of 400 nm or less, for example, as a UV cut film on a liquid crystal cell.

  The element of the present invention may be used in a single-layer liquid crystal cell, or may be used by laminating a plurality of liquid crystal cells in two or three or more layers. When it is desired to add a dichroic dye to a liquid crystal composition and to control the amount of transmitted light as a guest-host type liquid crystal composition without a polarizing plate, vertical alignment of antiparallel alignment processing is performed from the viewpoint of contrast improvement. It is preferable to stack the cells by 90 ° at right angles.

The present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. Moreover, "%" in the composition of the following example and a comparative example means "mass%."
The following abbreviations are used for the description of the liquid crystal compounds in the examples.
(Ring structure)

(Side chain structure and linked structure)

  The characteristics measured in the examples are as follows.

T _ni : Nematic phase-isotropic liquid phase transition temperature (° C.)
It measured with a Nikon polarization microscope using a Mettler make hot stage.

Δn: refractive index anisotropy at 25 ° C
It measured using an Abbe refractometer.

Δε: dielectric anisotropy at 25 ° C
It measured using the LCR meter made from Agilent.

η: Bulk flow viscosity [mPa · s] (20 ° C)
It was measured using an E-type viscometer.

  Solubility: About 0.5 g of the liquid crystal composition was placed in a test tube, degassed, filled with nitrogen and then capped, and stored in a thermostat, and after 240 hours, the presence or absence of precipitation was visually observed. When there was no precipitation, it was "○", and when precipitation was confirmed, it was "×". The storage temperature was -30 ° C, -25 ° C and -15 ° C, respectively.

Light resistance (VHR (UV)): Voltage holding ratio (%) to initial applied voltage after irradiating UV for 10 days (240 hours) with xenon lamp, measurement conditions are 1V, 60 Hz, 25 ° C., illuminance is 300 The cell thickness of the test panel is 3.5 μm at 500 W / m ^{2 at} ̃800 nm.
Heat resistance (VHR (HEAT)): Voltage holding ratio (%) with respect to initial applied voltage after heating at 80 ° C. for 10 days (240 hours), measurement condition is 1V, 60 Hz, 25 ° C., cell of test panel The thickness is 3.5 μm.
(Examples 1 to 6 and Comparative Examples 1 to 3)
The liquid crystal compositions of Examples 1 to 6 and Comparative Examples 1 to 3 shown in the following table were prepared, and their physical properties and characteristics were measured. The proportion of the liquid crystal composition in the table is indicated by mass%. Moreover, the liquid crystal cell for test panels was produced using these liquid crystal compositions, and the light resistance and heat resistance test were done. Physical properties, properties and test results are as shown in Table 2.

From the results of Example 1 and 2 and Comparative Example 1, and Example 6 and Comparative Example 3, viscosity, dielectric anisotropy and refractive index can be obtained by containing the compound corresponding to the general formula (N-i). The value of T _ni could be increased without affecting the anisotropy, and the low temperature storage characteristics could be improved. Further, it is understood from Examples 1 and 2 and Comparative Example 2 that the low temperature storage characteristics can be improved by containing the compound represented by General Formula (ii). From the results of the light resistance test and the heat resistance test of Examples 1, 2 and 6, it was confirmed that the liquid crystal composition of the present invention can obtain a sufficient reliability result.
(Example 7, Example 8, Comparative Example 4, Comparative Example 5)
The liquid crystal compositions of Example 7, Example 8, Comparative Example 4 and Comparative Example 5 shown in the following table were prepared, and their physical properties and characteristics were measured. The proportion of the liquid crystal composition in the table is indicated by mass%. Moreover, the liquid crystal cell for test panels was produced using these liquid crystal compositions, and the light resistance and heat resistance test were done. Physical properties, properties and test results are as shown in Table 3.

From the results of Examples 7 and 8 and Comparative Example 4 and Comparative Example 5, a compound corresponding to General Formula (N-i) is contained, and a compound represented by General Formula (ii) is contained. It can be seen that the value of T _ni can be increased without affecting the viscosity, dielectric anisotropy and refractive index anisotropy. From the results of the light resistance and heat resistance tests of Examples 7 and 8, it was confirmed that the liquid crystal composition of the present invention can obtain sufficient reliability results.
(Examples 9 to 12, Comparative Example 6, Comparative Example 7)
The liquid crystal compositions of Examples 9 to 12 and Comparative Examples 6 and 7 shown in the following table were prepared, and their physical properties and characteristics were measured. The proportion of the liquid crystal composition in the table is indicated by mass%. Moreover, the liquid crystal cell for test panels was produced using these liquid crystal compositions, and the light resistance and heat resistance test were done. Physical properties, properties and test results are as shown in Table 4.

From the results of Examples 9 to 12 and Comparative Example 6 and Comparative Example 7, the compound corresponding to the general formula (N-i) is contained, and the compound represented by the general formula (ii) is contained. It can be seen that the value of T _ni can be increased without affecting the viscosity, dielectric anisotropy and refractive index anisotropy. From the results of the light resistance test and the heat resistance test of Examples 9 to 12, it can be confirmed that the liquid crystal composition of the present invention can obtain a sufficient reliability result.
From the above results, the liquid crystal composition of the present invention simultaneously satisfies the low birefringence anisotropy (Δn) effective for light resistance and high heat resistance and the absolute value (| Δε |) of large dielectric anisotropy simultaneously. The liquid crystal display device or light control device of the present invention has excellent characteristics which are practically required because a liquid crystal composition excellent in high nematic-isotropic transition temperature (T _NI ) and dissolution stability at low temperature can be obtained. Is satisfied.

Claims (12)

One or two or more compounds represented by the general formula (N-i), one or two or more compounds represented by the general formula (ii), and a compound represented by the general formula (N-iii) The liquid crystal composition which contains 1 type, or 2 or more types of compounds chosen from the group which consists of a compound and the compound represented by general formula (N-iv).

(Wherein, R ⁱ¹ and R ⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently. -CH = CH-, -C≡C-, -O-, -CO-, -COO- or OCO-, which may be substituted,
A ⁱ¹ and A ⁱ² are each independently
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is -O- and / or -S- May be replaced by)
(B) 1,4-phenylene group (this is present in the group one -CH ₂ - or nonadjacent two or more -CH ₂ - groups may be replaced by a-N-) and ( c) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and It represents a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, but the hydrogen atoms on the above groups (a), (b) and (c) are independent of each other Substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, CN or halogen Well,
Z ⁱ¹ is a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 -, - CF 2 O- , -CH = N-N = CH-, -CH = CH-, -C≡C- or -CF = CF-
m ⁱ¹ represents 0, 1 or 2, but when m ⁱ¹ is 2 and there are a plurality of A ⁱ¹ and Z ⁱ¹ , they may be each independently the same or different. )

( ^Wherein , R ⁱⁱ¹ and R ⁱⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently. It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or OCO-.)

( ^Wherein , R ⁱⁱⁱ¹ , R ⁱⁱⁱ² , R ^iv1 and R ^iv2 each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH _{2 s in the} alkyl group) -May be each independently substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or OCO-,
A ⁱⁱⁱ¹ , A ⁱⁱⁱ² , A ^iv1 and A ^iv2 are each independently
(A) trans-1,4-cyclohexylene group (the one present in the group -CH ₂ - or nonadjacent two or more -CH ₂ - is -O- and / or -S- May be replaced by)
(B) 1,4-phenylene group (this is present in the group one -CH ₂ - or nonadjacent two or more -CH ₂ - groups may be replaced by a-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein hydrogen atoms on the above groups (a), (b) and (c) Independently substituted with an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, CN or a fluorine atom May be
Z ⁱⁱⁱ¹ and Z ^iv1 are each independently -COO-, ^-OCO- , -CH ₂ O-, -OCH _2- , -CF ₂ O-, -OCF _2- , -CH ₂ CH _2- , -CH _{= CH -, - (CH 2} ) 4 -, - CH = CH-CH 2 CH 2 -, - CH 2 CH 2 represents a -CH = CH- or a single bond,
m ^III1 and ^{m iv1} are each represent independently 0, 1 or ^{2, if A III2} and ^{Z III1 m III1} is a 2 there are a ^{plurality, A III2} and ^{Z III1} are identical independently or different even, ^{also, if a iv2} and ^{Z iv1 m iv1} is a 2 there are a ^{plurality, a iv2} and ^{Z iv1} may be different even in the same independently . ) The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula (L).

(Wherein, R ^L1 and R ^L2 each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent -CH ₂ -in the alkyl group are independently of each other It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-,
m ^L1 represents 0, 1, 2 or 3 and
A ^L1 , A ^L2 and A ^L3 are each independently (a) 1,4-cyclohexylene group (one -CH _2- present in this group or two or more non-adjacent -CH _2- May be replaced by -O-) and (b) 1,4-phenylene group (one -CH = present in this group or two or more non-adjacent -CH = is -N May be replaced by =.)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and the groups (a), (b) and (c) are each independently a carbon atom It may be substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, a cyano group or a fluorine atom However, A ^L1 , A ^L2 and A ^{4 L 3} are 2,3-difluoro-1,4-phenylene group, 1,7,8-trifluoronaphthalene-2,6-diyl group or 3,4,5-trifluoronaphthalene -2, 6 Not represent a yl group,
Z ^L1 and ^{Z L2} is n each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF _{2 -, - CF 2 O -} , - CH = N-N = CH -, - CH = CH -, - CH≡CH- or an -CF = CF,
When m ^L1 is 2 or 3 and a plurality of A ^L2 and Z ^L2 exist, A ^L2 and Z ^L2 may be independently identical or different, provided that in general formula (ii) Exclude the compounds represented. ) The liquid crystal composition according to claim 2, wherein m ^L1 in the general formula (L) is 1. The liquid crystal composition according to any one of claims 1 to 3, further comprising one or more compounds represented by general formula (N).

(Wherein, R ^N1 and R ^N2 each independently represent an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent -CH ₂ -in the alkyl group are each independently. It may be substituted by -CH = CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-,
m ^N1 represents 0, 1, 2 or 3 and
A ^N1 , A ^N2 and A ^N3 are each independently (a) 1,4-cyclohexylene group (one -CH _2- present in this group or two or more non-adjacent -CH _2- May be replaced by -O-) and (b) 1,4-phenylene group (one -CH = present in this group or two or more non-adjacent -CH = is -N May be replaced by =.)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And a group selected from the group consisting of 1,2,3,4-tetrahydronaphthalene-2,6-diyl, and the groups (a), (b) and (c) are each independently a carbon atom It may be substituted by an alkyl group of 1 to 3 carbon atoms, an alkenyl group of 2 to 3 carbon atoms, an alkoxyl of 1 to 3 carbon atoms, an alkenyloxy group of 1 to 3 carbon atoms, a cyano group or a fluorine atom However, at least one of A ^N1 , A ^N2 and A ^N3 is a 2,3-difluoro-1,4-phenylene group, 1,7,8-trifluoronaphthalene-2,6-diyl group or 3,4,4, 5-trifluorona It represents the array type-2,6-diyl group,
Z ^N1 and ^{Z N2} each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 _{-, - CF 2 O -,} - CH = N-N = CH -, - CH = CH- or an -CF = CF-,
When m ^N1 is 2 or 3 and a plurality of A ^N2 and Z ^N2 exist, A ^N2 and Z ^N2 may be independently the same or different, provided that general formula (i), The compounds represented by the general formula (iii) and the general formula (iv) are excluded. )   The liquid crystal composition according to any one of claims 1 to 4, further comprising a monomer.   The liquid crystal composition according to claim 1, further comprising 0.05 to 0.5% by weight of a stabilizer.   The liquid crystal composition according to any one of claims 1 to 6, further comprising one or more dichroic dyes.   The liquid crystal composition according to any one of claims 1 to 7, wherein a chiral agent is further added, and the twist pitch is adjusted to 10 μm to 120 μm.   The nematic-isotropic transition temperature is 80 ° C to 120 ° C, the dielectric anisotropy is -2.0 to -6.0, and the birefringence is 0.070 to 0.130. The liquid crystal composition according to item 1.   The liquid crystal display element using the liquid crystal composition of any one of Claims 1-9.   The liquid crystal display element according to claim 10, wherein the pretilt angle is 80 ° to 90 °.   The light control element using the liquid crystal composition of any one of Claims 1-9.