Liquid crystal composition and liquid crystal element

Abstract

The invention provides a liquid crystal composition and a liquid crystal element containing the liquid crystal composition. The liquid crystal composition satisfies at least one of the following characteristics: a high upper limit temperature of the cholesterol phase, a low lower limit temperature of the cholesterol phase, low viscosity, large optical anisotropy, large dielectric anisotropy, high specific resistance, high stability to light, and high stability to heat. Appropriate spiral pitch length and low temperature dependency of the pitch length. The liquid crystal composition contains a specific compound as a component A, a specific compound as a component B, and an optically active compound as an additive X, and may contain a specific compound as a component C, a specific compound as a component D, or a specific compound as a component E.

Description

Technical Field

[0001] The present invention relates to a liquid crystal composition, a liquid crystal reflective element and a liquid crystal display element containing the composition, and more particularly to a liquid crystal composition having a cholesteric phase and an element for driving the cholesteric liquid crystal composition. Background Art

[0002] In liquid crystal elements, the classification based on the operating mode of liquid crystal molecules is PC (phase change), TN (twisted nematic), STN (super twisted nematic), ECB (electrically controlled birefringence), OCB (optically compensated bend), IPS (in-plane switching), VA (vertical alignment), FFS (fringe field switching), FPA (field-induced photoresistance alignment) and other modes. The classification based on the element driving method is PM (passive matrix) and AM (active matrix). PM is classified as static, multi-tasking, etc., and AM is classified as TFT (thin film transistor), MIM (metal-insulator-metal), etc. TFT is classified into amorphous silicon and polycrystalline silicon. The latter is divided into high-temperature type and low-temperature type according to the manufacturing process. The classification based on the light source is reflective type using natural light, transmissive type using backlight, and semi-transmissive type using both natural light and backlight.

[0003] Liquid crystal compositions containing optically active compounds may sometimes exhibit a "cholesteric phase." This phase is a liquid crystal phase in which the molecular alignment rotates in a helical pattern. The helical axis is perpendicular to the alignment direction. Furthermore, the period of this helical pattern is called the pitch.

[0004] Liquid crystal cells containing liquid crystal compositions exhibiting a "cholesteric phase" are known. These compositions have a helical pitch length in the visible range. Liquid crystal compositions exhibiting a cholesteric phase selectively reflect circularly polarized light, with the direction of rotation of the light vector corresponding to the left-right nature of the cholesteric helix. The reflected wavelength λ can be calculated using Formula (A) using the pitch P of the cholesteric helix and the average complex refractive index n of the cholesteric liquid crystal.

[0005] λ=n×P(A)

[0006] The cholesterol liquid crystal element contains a liquid crystal composition having a cholesterol phase, i.e., a cholesterol liquid crystal composition. This composition has appropriate characteristics. By improving the characteristics of this composition, a liquid crystal element with good characteristics can be obtained. The correlation between the two characteristics is summarized in Table 1 below. The characteristics of the composition are further explained based on commercially available liquid crystal elements. The temperature range of the cholesterol phase is related to the temperature range in which the element can be used. The preferred upper limit temperature of the cholesterol phase is above about 70°C, while the preferred lower limit temperature of the cholesterol phase is below about -10°C. High specific resistance in the composition contributes to high voltage retention of the element. Therefore, a composition having high specific resistance not only at room temperature but also at a temperature close to the upper limit temperature of the cholesterol phase is preferred. After long-term use, a composition having high specific resistance not only at room temperature but also at a temperature close to the upper limit temperature of the cholesterol phase is preferred. The specific resistance of the liquid crystal composition at room temperature is preferably 1×10 10 Ω·cm or more, more preferably 1×10 12 Ω·cm or more, more preferably 1×10 14 Ω·cm or more.

[0007] Table 1. Properties of the composition and liquid crystal device

[0008] No Characteristics of the composition Characteristics of liquid crystal components 1 Cholesterol phase has a wide temperature range Components can be used in a wide temperature range 2 Low viscosity Short response time 3 Large optical anisotropy Bright display 4 Large dielectric anisotropy Low threshold voltage and low power consumption 5 High specific resistance High voltage holding rate 6 UV and heat stable Long lifespan

[0009] The optical anisotropy of the composition is related to the brightness displayed by the element. In order to achieve a bright display, a liquid crystal composition with a large optical anisotropy is required. The optical anisotropy measured at a wavelength of 589 nm (measured at 25°C) is preferably in the range of 0.10 to 0.40, more preferably in the range of 0.12 to 0.35, and further preferably in the range of 0.15 to 0.30. The dielectric anisotropy in the composition contributes to the low driving voltage of the element, so a high dielectric anisotropy is preferred. The dielectric anisotropy measured at a frequency of 1 kHz (measured at 25°C) is preferably in the range of 10 to 100, more preferably in the range of 15 to 80, and further preferably in the range of 25 to 60. The viscosity of the composition is related to the response time of the element. In order to display animation on the element, a shorter response time is preferred. Even if it is 1 millisecond, a shorter response time is desired. Therefore, a smaller viscosity in the composition is preferred. The viscosity at 20°C is preferably 120 mPa·s or less, more preferably 80 mPa·s or less. A lower viscosity at low temperatures is more preferred. The helical pitch length in the composition is preferably such that the reflection wavelength in the visible region can be adjusted with as little added optically active compound as possible, so as not to impair the properties of the host nematic liquid crystal composition. Furthermore, to prevent degradation of display quality due to changes in ambient temperature, the helical pitch length preferably has little or no temperature dependence.

[0010] The most common cholesteric liquid crystal elements are SSCT (surface-stabilized cholesterol structure) and PSCT (polymer-stabilized cholesterol structure) elements. SSCT and PSCT elements typically contain a cholesteric liquid crystal composition that, for example, initially exhibits a planar structure that reflects light of a specific wavelength. However, by applying an AC current pulse, they can be switched to a focal conic light-scattering structure, or vice versa.

[0011] These liquid crystal elements are bistable, meaning that after the electric field is switched off, each state is maintained and can only be reversed back to the initial state by reapplying the electric field. When a higher voltage pulse is applied, the cholesterol liquid crystal composition transitions to an isotropic, transparent state. From this state, it relaxes to a planar state when the voltage is quickly switched to zero, or to a focal conic state when the voltage is slowly switched. The minimum drive voltage required to return from the planar state (reflection) to the isotropic phase (transmission) is called the Vreset voltage. The lower this drive voltage, the less power is consumed.

[0012] Cholesterol liquid crystal elements generally do not require a backlight. In a planar state, the cholesterol liquid crystal composition in the pixel will display selective reflection of light of a specific wavelength according to the above formula (A), with the result that, for example, the pixel will show a corresponding reflection color on a black background. When it is converted to a scattering state caused by a focal conic structure or an isotropic transparent state, the reflection color disappears. For the above reasons, the power consumption of cholesterol liquid crystal elements is quite low. In addition, even if these elements have viewing angle dependence in the scattering state, it is very small. Therefore, these displays do not require active matrix addressing and can operate in a simpler multiple or passive matrix mode. On the other hand, since the display quality is relatively inferior, in order to improve this, there are also reports of elements combining it with an active matrix (Patent Documents 1, 2).

[0013] [Prior art literature]

[0014] [Patent Document]

[0015] [Patent Document 1] Japanese Patent Application Laid-Open No. 7-140440

[0016] [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-275463 Summary of the Invention

[0017] [Problems to be solved by the invention]

[0018] The present invention aims to provide a liquid crystal composition that satisfies at least one of the following characteristics: a high upper temperature limit of the cholesteric phase, a low lower temperature limit of the cholesteric phase, low viscosity, large optical anisotropy, positive and large dielectric anisotropy, high resistivity, high stability to light, high stability to heat, an appropriate helical pitch length, and low temperature dependence of the pitch length. Another object is to provide a liquid crystal composition that has an appropriate balance between at least two of these characteristics. Another object is to provide a liquid crystal element comprising such a composition. Another object is to provide a cholesteric liquid crystal element having the following characteristics: short response time, high voltage holding ratio, low Vreset voltage (voltage for switching from an initial reflective state to a transmissive state), high contrast ratio, and long life.

[0019] [Technical means to solve the problem]

[0020] The present invention relates to a liquid crystal composition comprising: as component A, at least one compound selected from the compounds represented by formula (1); as component B, at least one compound selected from the compounds represented by formula (2); and as an additive X, an optically active compound; the liquid crystal composition having a cholesteric phase; and a liquid crystal cell comprising the composition.

[0021]

[0022] In formula (1), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; 1 is a single bond, a carbonyloxy group, or a difluoromethyleneoxy group; X 1 and X 2 is hydrogen or fluorine; a is 1 or 2; in formula (2), R 2 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Z 2 is a carbonyloxy group or a difluoromethyleneoxy group; X 3 、X 4 、X 5 、X 6 、X 7 and X 8 is hydrogen or fluorine; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

[0023] [Effects of the Invention]

[0024] The present invention has the advantage of providing a liquid crystal composition that satisfies at least one of the following properties: a high upper temperature limit of the cholesteric phase, a low lower temperature limit of the cholesteric phase, low viscosity, large optical anisotropy, positive and large dielectric anisotropy, high specific resistance, high stability to light, high stability to heat, an appropriate helical pitch length, and low temperature dependence of the pitch length. Another advantage is providing a liquid crystal composition that has an appropriate balance between at least two of these properties. Another advantage is providing a liquid crystal cell containing such a composition. Another advantage is providing a cholesteric liquid crystal cell having characteristics such as a short response time, a high voltage holding ratio, a low threshold voltage, a high contrast ratio, and a long life. DETAILED DESCRIPTION

[0025] The terms used in this specification are as follows. The terms "liquid crystal composition" and "liquid crystal display element" may be referred to as "composition" and "element" for short. "Liquid crystal display element" is a general term for liquid crystal display panels and liquid crystal display modules. "Liquid crystal compound" is a general term for compounds having liquid crystal phases such as nematic phase, cholesteric phase, smectic phase, and compounds that do not have a liquid crystal phase but are mixed into the composition in order to adjust the temperature range, viscosity, dielectric anisotropy and other properties of the liquid crystal phase. Such compounds have six-membered rings such as 1,4-cyclohexylene or 1,4-cyclohexenylene (1,4-phenylene), and their molecules (liquid crystal molecules) are rod-like. "Polymerizable compound" is a compound added to generate a polymer in a composition. Liquid crystal compounds having alkenyl groups are not classified as polymerizable compounds in this sense.

[0026] Liquid crystal compositions are prepared by mixing multiple liquid crystal compounds. Additives such as optically active compounds may be added to these liquid crystal compositions as needed. The proportion of the liquid crystal compound, even when additives are added, is expressed as a mass percentage (mass %) based on the mass of the liquid crystal composition without the additives. The proportion of the additive is expressed as a mass percentage (mass %) based on the mass of the liquid crystal composition without the additives. In other words, the ratio of the liquid crystal compound to the additive is calculated based on the total mass of the liquid crystal compound.

[0027] A liquid crystal composition before the addition of additives such as optically active compounds may be referred to as a "host liquid crystal composition." A liquid crystal composition to which an optically active compound is added to exhibit a cholesteric phase may be referred to as a "cholesteric liquid crystal" or "cholesteric liquid crystal composition."

[0028] “The upper limit temperature of the nematic phase or the cholesterol phase” may be referred to as the “upper limit temperature” for short. “The lower limit temperature of the nematic phase or the cholesterol phase” may be referred to as the “lower limit temperature” for short. The expression “increasing the dielectric anisotropy” means that its value increases in the positive direction when the dielectric anisotropy of the composition is positive, and means that its value increases in the negative direction when the dielectric anisotropy of the composition is negative. “High specific resistance” means that the composition has a higher specific resistance not only at room temperature but also when it is close to the upper limit temperature of the cholesterol phase in the initial stage, and has a higher specific resistance not only at room temperature but also when it is close to the upper limit temperature of the cholesterol phase after long-term use. “High voltage holding ratio” means that the element has a higher voltage holding ratio not only at room temperature but also when it is close to the upper limit temperature of the cholesterol phase in the initial stage, and has a higher voltage holding ratio not only at room temperature but also when it is close to the upper limit temperature of the cholesterol phase after long-term use.

[0029]

[0030] The above compound (1z) is used as an example for explanation. In formula (1z), the α and β symbols surrounded by a hexagon correspond to ring α and ring β, respectively, indicating a six-membered ring, a condensed ring, or the like. When the subscript "x" is 2, there are two rings α. The two groups representing the two rings α can be the same or different. When the subscript "x" is greater than 2, this rule applies to any two rings α. This rule also applies to other symbols, such as the bonding group Z. The slash passing through one side of ring β indicates that any hydrogen on ring β can be replaced by a substituent (-Sp-P). The subscript "y" indicates the number of substituents replaced. When the subscript "y" is 0, there is no such substitution. When the subscript "y" is 2 or more, there are multiple substituents (-Sp-P) on ring β. In this case, the "may be the same or different" rule also applies. In addition, this rule also applies when the Ra symbol is used in multiple compounds.

[0031] In formula (1z), for example, the expression "Ra and Rb are alkyl, alkoxy, or alkenyl" means that Ra and Rb are independently selected from the group consisting of alkyl, alkoxy, and alkenyl. Here, the group represented by Ra and the group represented by Rb may be the same or different.

[0032] At least one compound among the compounds represented by formula (1z) may be simply referred to as "compound (1z)". "Compound (1z)" means one compound, a mixture of two compounds, or a mixture of three or more compounds represented by formula (1z). The same applies to compounds represented by other formulae. The expression "at least one compound among the compounds represented by formula (1z) and formula (2z)" means at least one compound selected from the group consisting of compound (1z) and compound (2z).

[0033] The expression "at least one 'A'" means that the number of 'A's' is arbitrary. The expression "at least one 'A' may be substituted with 'B'" means that when there is one 'A', the position of 'A' is arbitrary, and when there are two or more 'A's, their positions can also be selected without restriction. The expression "at least one -CH2- may be substituted with -O-" is sometimes used. In this case, -CH2-CH2-CH2- can be converted to -O-CH2-O- by replacing non-adjacent -CH2- with -O-. However, adjacent -CH2- cannot be replaced with -O- because such substitution would produce -OO-CH2- (peroxide).

[0034] The alkyl group of the liquid crystal compound is linear or branched and does not include cyclic alkyl groups. Linear alkyl groups are preferred over branched alkyl groups. This also applies to terminal groups such as alkoxy and alkenyl groups. Regarding the stereo configuration of 1,4-cyclohexenylene, the trans form is preferred over the cis form to increase the upper temperature limit. 2-fluoro-1,4-phenylene is bilaterally asymmetric, so it exists in the left-hand (L) and right-hand (R) directions.

[0035]

[0036] The same applies to divalent groups such as tetrahydropyran-2,5-diyl and bonding groups such as carbonyloxy (-COO- or -OCO-).

[0037] The present invention is as follows, etc.

[0038] Item 1. A liquid crystal composition comprising: at least one compound selected from the compounds represented by formula (1) as component A, at least one compound selected from the compounds represented by formula (2) as component B, and an optically active compound as an additive X, wherein the liquid crystal composition has a cholesteric phase.

[0039]

[0040] In formula (1), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; 1 is a single bond, a carbonyloxy group, or a difluoromethyleneoxy group; X 1 and X 2 is hydrogen or fluorine; a is 1 or 2;

[0041] In formula (2), R 2is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Z 2 is a carbonyloxy group or a difluoromethyleneoxy group; X 3 、X 4 、X 5 、X 6 、X 7 and X 8 is hydrogen or fluorine; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

[0042] Item 2. The liquid crystal composition according to Item 1, comprising at least one compound selected from the group consisting of compounds represented by Formula (1-1) to Formula (1-9) as Component A,

[0043]

[0044] In formula (1-1) to formula (1-9), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; X 1 and X 2 is hydrogen or fluorine.

[0045] Item 3. The liquid crystal composition according to Item 1 or 2, wherein the ratio of Component A is in the range of 5% by mass to 50% by mass.

[0046] Item 4. The liquid crystal composition according to any one of Items 1 to 3, comprising at least one compound selected from the group consisting of compounds represented by Formula (2-1) to Formula (2-8) as Component B,

[0047]

[0048] In formula (2-1) to formula (2-8), R 2 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

[0049] Item 5. The liquid crystal composition according to any one of Items 1 to 4, wherein the ratio of Component B is in the range of 5% by mass to 50% by mass.

[0050] Item 6. The liquid crystal composition according to any one of Items 1 to 5, comprising at least one compound selected from the group consisting of compounds represented by Formula (3-1) to Formula (3-7) as the additive X,

[0051]

[0052] In formula (3-1) to formula (3-7), R 3 and R 4 It is hydrogen, halogen, -C≡N, -N=C=O, -N=C=S, -SF5, or an alkyl group having 1 to 10 carbon atoms, in which at least one -CH2- group may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups, at least one hydrogen group may be replaced by fluorine or chlorine.

[0053] Item 7. The liquid crystal composition according to any one of Items 1 to 6, wherein the ratio of the additive X is in the range of 0.1% by mass to 10% by mass.

[0054] Item 8. The liquid crystal composition according to any one of Items 1 to 7, comprising at least one compound selected from the group consisting of compounds represented by formula (4) as component C,

[0055]

[0056] In formula (4), R 5 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Ring B is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; 3 is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethyleneoxy; X 9 and X 10 is hydrogen or fluorine; Y 2 is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; b is 1, 2, 3, or 4.

[0057] Item 9. The liquid crystal composition according to any one of Items 1 to 8, comprising at least one compound selected from the group consisting of compounds represented by Formula (4-1) to Formula (4-26) as Component C,

[0058]

[0059]

[0060]

[0061] In formula (4-1) to formula (4-26), R 5 It is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms.

[0062] Item 10. The liquid crystal composition according to Item 8 or 9, wherein the ratio of Component C is in the range of 1% by mass to 50% by mass.

[0063] Item 11. The liquid crystal composition according to any one of Items 1 to 10, comprising at least one compound selected from the group consisting of compounds represented by formula (5) as component D,

[0064]

[0065] In formula (5), R 6 and R 7 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine; Ring C and Ring D are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 4 is a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy; c is 1, 2, or 3.

[0066] Item 12. The liquid crystal composition according to any one of Items 1 to 11, comprising at least one compound selected from the group consisting of compounds represented by Formula (5-1) to Formula (5-20) as Component D,

[0067]

[0068]

[0069] In formula (5-1) to formula (5-20), R 6 and R 7 It is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine.

[0070] Item 13. The liquid crystal composition according to Item 11 or 12, wherein the ratio of Component D is in the range of 10% by mass to 90% by mass.

[0071] Item 14. The liquid crystal composition according to any one of Items 1 to 13, comprising at least one compound selected from the group consisting of compounds represented by formula (6) as component E,

[0072]

[0073] In formula (6), R 8 and R 9 is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, alkenyloxy having 2 to 12 carbon atoms, or alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; Ring E and Ring G are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chromane-2,6-diyl, or at least one hydrogen is replaced by fluorine or chlorine. Chromane-2,6-diyl; Ring F is 2,3-difluoro-1,4-phenylene, 1,8-difluorophenanthrene-2,7-diyl, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochromane-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, 4,6-difluorodibenzofuran-3,7-diyl, 4,6-difluorodibenzothiophene-3,7-diyl, or 1,1,6,7-tetrafluoroindene-2,5-diyl; Z 5 and Z 6 is a single bond, ethylene, vinylene, methyleneoxy, or carbonyloxy; d is 0, 1, 2, or 3; e is 0 or 1; and the sum of d and e is 3 or less.

[0074] Item 15. The liquid crystal composition according to any one of Items 1 to 14, comprising at least one compound selected from the group consisting of compounds represented by Formula (6-1) to Formula (6-36) as Component E,

[0075]

[0076]

[0077]

[0078]

[0079] In formula (6-1) to formula (6-36), R 8 and R 9 It is hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine.

[0080] Item 16. The liquid crystal composition according to Item 14 or 15, wherein the proportion of Component E is in the range of 1% by mass to 10% by mass.

[0081] Item 17. The liquid crystal composition according to any one of Items 1 to 16, further comprising at least one compound selected from the polymerizable compounds represented by formula (7) as the additive Y.

[0082]

[0083] In formula (7), ring I and ring K are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidin-2-yl, or pyridin-2-yl, in which at least one hydrogen is substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine; ring J is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene Z is selected from the group consisting of 1,4-diyl, 1,5-diyl, 1,6-diyl, 1,7-diyl, 1,8-diyl, 2,3-diyl, 2,6-diyl, 2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 2,5-pyrimidine-2,5-diyl and 2,5-pyridine-2,5-diyl, wherein at least one hydrogen in the ring may be substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine; 7 and Z 8 is a single bond or an alkylene group having 1 to 10 carbon atoms, wherein at least one -CH2- in the alkylene group may be substituted by -O-, -CO-, -COO-, or -OCO-, and at least one -CH2CH2- may be substituted by -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)-, or -C(CH3)=C(CH3)-, and at least one hydrogen in these groups may be substituted by fluorine; 1 To P 3 is a polymerizing group; Sp 1 To Sp 3 is a single bond or an alkylene group with 1 to 10 carbon atoms, wherein Sp 1 To Sp 3 In the formula (a), at least one -CH2- may be replaced by -O-, -COO-, -OCO-, or -OCOO-, at least one -CH2CH2- may be replaced by -CH=CH- or -C≡C-, and at least one hydrogen may be replaced by fluorine; i is 0, 1, or 2; f, g, and h are 0, 1, 2, 3, or 4; and the sum of f, g, and h is 1 or greater.

[0084] Item 18. The liquid crystal composition according to Item 17, wherein in formula (7), P 1 To P 3is a group selected from the polymerizable groups represented by formula (P-1) to formula (P-5),

[0085]

[0086] In formula (P-1) to formula (P-5), M 1 To M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is replaced by fluorine. 1 To M 3 In the alkyl group, at least one -CH2- group may be substituted by -O-.

[0087] Item 19. The liquid crystal composition according to any one of Items 1 to 18, further comprising at least one compound selected from the group consisting of polymerizable compounds represented by Formula (7-1) to Formula (7-29) as the additive Y.

[0088]

[0089]

[0090]

[0091] In formula (7-1) to formula (7-29), Sp 1 To Sp 3 is a single bond or an alkylene group with 1 to 10 carbon atoms, wherein Sp 1 To Sp 3 wherein at least one -CH2- may be replaced by -O-, -COO-, -OCO-, or -OCOO-, at least one -CH2CH2- may be replaced by -CH=CH- or -C≡C-, and at least one hydrogen may be replaced by fluorine; 4 To P 6 is a polymerizable group selected from the groups represented by formula (P-1) to formula (P-3);

[0092]

[0093] In formula (P-1) to formula (P-3), M 1 To M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is replaced by fluorine, wherein M 1 To M 3 In the alkyl group, at least one -CH2- group may be substituted by -O-.

[0094] Item 20. The liquid crystal composition according to any one of Items 17 to 19, wherein the ratio of the additive Y is in the range of 0.1% by mass to 5% by mass.

[0095] Item 21. The liquid crystal composition according to any one of Items 1 to 20, wherein the optical anisotropy at a wavelength of 589 nm (measured at 25° C.) is 0.16 or more.

[0096] Item 22. A liquid crystal element comprising the liquid crystal composition as described in any one of Items 1 to 21

[0097] Item 23. The liquid crystal element according to Item 22, which is a liquid crystal display element or a liquid crystal reflection element.

[0098] The present invention further includes the following items: (a) the above-mentioned composition comprising one, two, or three or more compounds selected from additives such as antioxidants, UV absorbers, matting agents, pigments, defoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, and polar compounds. (b) an AM device comprising the above-mentioned composition. (e) a device comprising the above-mentioned composition and having a PC, TN, STN, ECB, OCB, IPS, VA, FFS, or FPA mode. (f) a transmissive device comprising the above-mentioned composition. (g) using the above-mentioned composition as a composition having a cholesterol phase.

[0099] The composition of the present invention will be described in the following order. First, the composition's composition will be described. Second, the main characteristics of the component compounds and the main effects of the compounds on the composition and device will be described. Third, the combination of the component compounds in the composition, the preferred ratio, and the basis therefor will be described. Fourth, the preferred form of the component compounds will be described. Fifth, preferred component compounds will be identified. Sixth, additives that can be added to the composition will be described. Seventh, the synthesis method of the component compounds will be described. Finally, the use of the composition will be described.

[0100] First, the composition of the composition is described. This composition contains a plurality of liquid crystal compounds. This composition may contain additives. Additives include optically active compounds, antioxidants, ultraviolet absorbers, matting agents, pigments, defoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. From the perspective of liquid crystal compounds, this composition can be classified into composition A and composition B. In addition to compounds selected from compound (1), compound (2), additive X, compound (4), compound (5), and compound (6), composition A may further contain other liquid crystal compounds, other additives, and the like. "Other liquid crystal compounds" refers to liquid crystal compounds different from compound (1), compound (2), compound (4), compound (5), and compound (6). These compounds are mixed into the composition for the purpose of further adjusting the properties.

[0101] Composition B is essentially composed only of compounds selected from compound (1), compound (2), additive X, compound (4), compound (5), and compound (6). "Essentially" means that composition B may contain other additives but does not contain other liquid crystal compounds. Compared with composition A, composition B has fewer components. From the perspective of cost reduction, composition B is more preferred than composition A. From the perspective of further adjusting properties by mixing other liquid crystal compounds, composition A is more preferred than composition B.

[0102] Second, we describe the main properties of the component compounds and their primary effects on the composition and device. The main properties of the component compounds are summarized in Table 2. In Table 2, the symbols L represent large or high, M represents medium, and S represents small or low. The symbols L, M, and S are based on qualitative comparisons of the component compounds, with the symbol 0 (zero) representing a value smaller than S.

[0103] Table 2. Properties of liquid crystal compounds

[0104] characteristic Compound (1) Compound (2) Compound (4) Compound (5) Compound (6) Upper limit temperature S~L M~L S~L S~L S~L Viscosity M~L L M~L S~M M~L Optical anisotropy M~L M~L M~L S~L M~L Dielectric anisotropy L L M~L 0 <![CDATA[M~L 1) ]]> Specific resistance L L L L L

[0105] 1) The dielectric anisotropy is negative, and the sign indicates the magnitude of the absolute value.

[0106] The main effects of the component compounds are as follows. Compound (1) increases dielectric anisotropy. Compound (2) increases dielectric anisotropy and lowers the minimum temperature. Additive X is an optically active compound that exhibits a cholesteric phase by being added to a liquid crystal composition having a nematic phase, and can be adjusted to a desired reflection wavelength by adjusting the amount added. Compound (4) increases dielectric anisotropy or increases optical anisotropy. Compound (5) reduces viscosity or increases optical anisotropy. Compound (6) increases optical anisotropy or lowers the minimum temperature.

[0107] Third, the combination of the component compounds in the composition, the preferred ratio, and the basis thereof will be described. Preferred combinations of the component compounds in the composition are compound (1) + compound (2) + additive X, compound (1) + compound (2) + additive X + compound (4), compound (1) + compound (2) + additive X + compound (5), compound (1) + compound (2) + additive X + compound (6), compound (1) + compound (2) + additive X + compound (4) + compound (5), compound (1) + compound (2) + additive X + compound (4) + compound (6), compound (1) + compound (2) + additive X + compound (5) + compound (6), or compound (1) + compound (2) + additive X + compound (4) + compound (5) + compound (6). A particularly preferred combination is compound (1) + compound (2) + additive X + compound (4) + compound (5).

[0108] The preferred ratio of compound (1) is about 5% by mass or more in order to improve dielectric anisotropy, and about 50% by mass or less in order to lower the minimum temperature. A more preferred ratio is in the range of about 10% by mass to about 40% by mass. A particularly preferred ratio is in the range of about 15% by mass to about 40% by mass.

[0109] The preferred ratio of compound (2) is about 5% by mass or more in order to improve dielectric anisotropy, and about 50% by mass or less in order to lower the minimum temperature. A more preferred ratio is in the range of about 5% by mass to about 30% by mass. A particularly preferred ratio is in the range of about 10% by mass to about 25% by mass.

[0110] The preferred ratio of additive X is about 0.1% by mass or greater to develop a cholesterol phase, and about 10% by mass or less to lower the minimum temperature. A more preferred ratio is in the range of about 0.5% by mass to about 7% by mass. A particularly preferred ratio is in the range of about 1% by mass to about 6% by mass.

[0111] The preferred ratio of compound (4) is about 1% by mass or more in order to improve dielectric anisotropy, and about 50% by mass or less in order to lower the minimum temperature. A more preferred ratio is in the range of about 5% by mass to about 30% by mass. A particularly preferred ratio is in the range of about 10% by mass to about 25% by mass.

[0112] The preferred proportion of compound (5) is about 10% by mass or more in order to increase optical anisotropy or reduce viscosity, and about 90% by mass or less in order to increase dielectric anisotropy. A further preferred proportion is in the range of about 15% by mass to about 60% by mass. A particularly preferred proportion is in the range of about 20% by mass to about 50% by mass.

[0113] The preferred ratio of compound (6) is about 1% by mass or more in order to increase optical anisotropy, and about 10% by mass or less in order to increase dielectric anisotropy. A further preferred ratio is in the range of about 2% by mass to about 8% by mass. A particularly preferred ratio is in the range of about 2% by mass to about 6% by mass.

[0114] Fourth, preferred forms of the component compounds are described. In formula (1), formula (2), formula (3-1) to formula (3-7), formula (4), formula (5), and formula (6), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. 1 In order to improve stability, it is an alkyl group having 1 to 12 carbon atoms, and in order to lower the minimum temperature, it is an alkenyl group having 2 to 12 carbon atoms. 2 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. 2 In order to improve stability, R is an alkyl group having 1 to 12 carbon atoms. 3 and R 4 is hydrogen, halogen, -C≡N, -N=C=O, -N=C=S, -SF5, or an alkyl group having 1 to 10 carbon atoms, wherein at least one -CH2- in the alkyl group may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups, at least one hydrogen group may be replaced by fluorine or chlorine. 3 or R 4 In order to improve stability, R is an alkyl group having 1 to 12 carbon atoms. 5 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. 5 In order to improve stability, R is an alkyl group having 1 to 12 carbon atoms. 6 and R 7 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. 6 or R 7 In order to improve stability, it is an alkyl group having 1 to 12 carbon atoms, and in order to reduce viscosity, it is an alkenyl group having 2 to 12 carbon atoms. 8 and R 9 is hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. 8 or R 9The alkyl group may be an alkyl group having 1 to 12 carbon atoms to improve stability, the alkenyl group may be an alkenyl group having 2 to 12 carbon atoms to reduce viscosity, and the alkoxy group may be an alkoxy group having 1 to 12 carbon atoms to increase the dielectric constant in the short axis direction.

[0115] Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl. More preferred alkyl groups are methyl, ethyl, propyl, butyl, or pentyl in order to reduce the viscosity.

[0116] Preferred alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, and heptyloxy groups. In order to reduce the viscosity, further preferred alkoxy groups include methoxy and ethoxy groups.

[0117] Preferred alkenyl groups include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl. Further preferred alkenyl groups are vinyl, 1-propenyl, 3-butenyl, or 3-pentenyl to reduce viscosity. The preferred stereo configuration of -CH=CH- in these alkenyl groups depends on the position of the double bond. To reduce viscosity, etc., the trans form is preferred for alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, and 3-hexenyl. The cis form is preferred for alkenyl groups such as 2-butenyl, 2-pentenyl, and 2-hexenyl.

[0118] Preferred alkenyloxy groups include vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy, and 4-pentenyloxy. In order to reduce the viscosity, further preferred alkenyloxy groups include allyloxy and 3-butenyloxy.

[0119] Preferred examples of the alkyl group in which at least one hydrogen is replaced by fluorine or chlorine include fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl, or 8-fluorooctyl. Further preferred examples for improving dielectric anisotropy include 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, or 5-fluoropentyl.

[0120] Preferred examples of alkenyl groups in which at least one hydrogen atom is replaced by fluorine or chlorine include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl, or 6,6-difluoro-5-hexenyl. Further preferred examples for reducing viscosity include 2,2-difluorovinyl or 4,4-difluoro-3-butenyl.

[0121] Ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl. In order to increase optical anisotropy or dielectric anisotropy, Ring A is preferably 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,6-difluoro-1,4-phenylene.

[0122] Ring B is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl. To increase the upper limit temperature, Ring B is preferably 1,4-cyclohexylene. To increase optical anisotropy, Ring B is preferably 1,4-phenylene. To increase dielectric anisotropy, Ring B is preferably 2-fluoro-1,4-phenylene or 2,6-difluoro-1,4-phenylene.

[0123] In Ring A and Ring B, tetrahydropyran-2,5-diyl is,

[0124]

[0125] Preferably

[0126]

[0127] Ring C and Ring D are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene. In order to reduce viscosity or increase the upper limit temperature, Ring C or Ring D is preferably 1,4-cyclohexylene. In order to increase optical anisotropy or lower the lower limit temperature, Ring C or Ring D is preferably 1,4-phenylene or 2-fluoro-1,4-phenylene.

[0128] Ring E and Ring G are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chromane-2,6-diyl, or chromane-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine.

[0129] Preferred examples of 1,4-phenylene groups in which at least one hydrogen atom is replaced by fluorine or chlorine include 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, or 2-chloro-3-fluoro-1,4-phenylene. An example of a naphthalene-2,6-diyl group in which at least one hydrogen atom is replaced by fluorine or chlorine is 3,4,5-trifluoronaphthalene-2,6-diyl. An example of a chromane-2,6-diyl group in which at least one hydrogen atom is replaced by fluorine or chlorine is 7,8-difluorochromane-2,6-diyl. To reduce viscosity, a preferred ring E or ring G is a 1,4-cyclohexylene group. To increase optical anisotropy or lower the minimum temperature, a preferred ring E or ring G is a 1,4-phenylene group.

[0130] Ring F is 2,3-difluoro-1,4-phenylene, 1,8-difluorophenanthrene-2,7-diyl, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochromane-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl (FLF4), 4,6-difluorodibenzofuran-3,7-diyl (DBFF2), 4,6-difluorodibenzothiophene-3,7-diyl (DBTF2), or 1,1,6,7-tetrafluoroindene-2,5-diyl (InF4).

[0131]

[0132] In order to reduce the viscosity, the preferred ring F is 2,3-difluoro-1,4-phenylene.

[0133] Z 1 For single bond, carbonyl group, or difluoromethylene group. In order to reduce the viscosity, the preferred Z 1 For single bonds, in order to improve dielectric anisotropy, the preferred Z 1 is a carbonyloxy group or a difluoromethyleneoxy group. 2 In order to improve the dielectric anisotropy and lower the minimum temperature, the preferred Z 2 Z is difluoromethyleneoxy. 3 is, a single bond, ethylene, vinylidene, carbonyloxy, or difluoromethyleneoxy. In order to reduce the viscosity, the preferred Z 3 For single bonds, in order to improve dielectric anisotropy, the preferred Z 3 Z is difluoromethyleneoxy. 4 is, a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy. In order to reduce the viscosity, Z is preferably 4 is a single bond. 5 and Z 6 In order to improve the optical anisotropy or lower the minimum temperature, the preferred Z5 or Z 6 For a single bond.

[0134] Divalent groups such as methyleneoxy are bilaterally asymmetric. Among methyleneoxy groups, -CH2O- is preferred over -OCH2-. Among carbonyloxy groups, -COO- is preferred over -OCO-. Among difluoromethyleneoxy groups, -CF2O- is preferred over -OCF2-.

[0135] X 1 and X 2 For hydrogen or fluorine. In order to reduce the viscosity, the preferred X 1 or X 2 is hydrogen, and in order to improve the dielectric anisotropy, the preferred X 1 or X 2 is fluorine. 3 、X 4 、X 5 、X 6 、X 7 , and X 8 For hydrogen or fluorine. In order to reduce the viscosity, the preferred X 3 、X 4 、X 5 、X 6 、X 7 , or X 8 is hydrogen, and in order to improve the dielectric anisotropy, the preferred X 3 、X 4 、X 5 、X 6 、X 7 , or X 8 is fluorine. 9 and X 10 In order to improve the dielectric anisotropy, the preferred X 9 or X 10 For fluorine.

[0136] Y 1 is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine. 1 Y is fluorine. 2 is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine. 2It is fluorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

[0137] A preferred example of the alkyl group in which at least one hydrogen atom is replaced by fluorine or chlorine is trifluoromethyl. A preferred example of the alkoxy group in which at least one hydrogen atom is replaced by fluorine or chlorine is trifluoromethoxy.

[0138] a is 1 or 2. Preferably, a is 1 to reduce viscosity, and is 2 to increase the upper limit temperature or to increase optical anisotropy. b is 1, 2, 3, or 4. Preferably, b is 1 or 2 to reduce viscosity, and is 3 or 4 to increase dielectric anisotropy. c is 1, 2, or 3. Preferably, c is 1 to reduce viscosity, and is 2 or 3 to increase the upper limit temperature or to increase optical anisotropy. d is 0, 1, 2, or 3, and e is 0 or 1, with the sum of d and e being 3 or less. Preferably, d or e is 1 to increase optical anisotropy and reduce the lower limit temperature.

[0139] In formula (7), Ring I and Ring K are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxan-2-yl, pyrimidin-2-yl, or pyridin-2-yl. In these rings, at least one hydrogen atom may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is substituted with fluorine or chlorine. Preferably, Ring I or Ring K is phenyl. Ring J is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, or pyridine-2,5-diyl. In these rings, at least one hydrogen atom may be replaced by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. Preferred ring J is 1,4-phenylene or 2-fluoro-1,4-phenylene.

[0140] Z 7 and Z 8is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one -CH2- group may be replaced by -O-, -CO-, -COO-, or -OCO-, and at least one -CH2CH2- group may be replaced by -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)-, or -C(CH3)=C(CH3)-. In these groups, at least one hydrogen group may be replaced by fluorine or chlorine. Preferred Z 7 or Z 8 is a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO- or -OCO-. 7 or Z 8 For a single bond.

[0141] Sp 1 To Sp 3 is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one -CH2- group may be replaced by -O-, -COO-, -OCO-, or -OCOO-, and at least one -CH2CH2- group may be replaced by -CH=CH- or -C≡C-. In these groups, at least one hydrogen group may be replaced by fluorine or chlorine. Preferred Sp 1 To Sp 3 is a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO-, -OCO-, -CO-CH=CH- or -CH=CH-CO-. Further preferred Sp 1 To Sp 3 For a single bond.

[0142] i is 0, 1, or 2. Preferably, i is 0 or 1. f, g, and h are 0, 1, 2, 3, or 4, and the sum of f, g, and h is 1 or more. Preferably, f, g, or h is 1 or 2.

[0143] P 1 To P 3 Is a polymerizable group. 1 To P 3 is a polymerizable group selected from the groups represented by formula (P-1) to formula (P-5). 1 To P 3 It is a group represented by formula (P-1), formula (P-2) or formula (P-3). Particularly preferred is P 1 To P 3 is a group represented by formula (P-1) or formula (P-2). 1 To P 3 is a group represented by formula (P-1). A preferred group represented by formula (P-1) is -OCO-CH=CH2 or -OCO-C(CH3)=CH2. The wavy lines in formulas (P-1) to (P-5) indicate bonding sites.

[0144]

[0145] In formula (P-1) to formula (P-5), M 1 To M 3 M is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. 1 To M 3 M is hydrogen or methyl. By setting it to hydrogen or methyl, the reactivity can be improved. 1 is hydrogen or methyl, and further preferably M 2 or M 3 For hydrogen.

[0146] In formula (7-1) to formula (7-29), P 4 To P 6 is a group represented by formula (P-1) to formula (P-3). 4 To P 6 It is the formula (P-1) or the formula (P-2). A more preferred formula (P-1) is -OCO-CH=CH2 or -OCO-C(CH3)=CH2.

[0147] The wavy lines in formula (P-1) to formula (P-3) indicate bonding sites.

[0148]

[0149] Fifth, preferred component compounds are shown. Preferred compound (1) is compound (1-1) to compound (1-9) described in item 2. Among these compounds, at least one component A is preferably compound (1-3), compound (1-7), or compound (1-8). Preferably, two or more compounds (1-3), compound (1-7), and compound (1-8) are combined.

[0150] Preferred compound (2) is compound (2-1) to compound (2-8) described in item 4. Among these compounds, it is preferred that at least one component B is compound (2-1), compound (2-2), compound (2-3), compound (2-4), compound (2-5), compound (2-6), or compound (2-8). It is particularly preferred that at least one component B is compound (2-1).

[0151] Combining compound (1) and compound (2) can produce a composition that is particularly excellent in dielectric anisotropy and lower limit temperature. From this viewpoint, combinations of compound (1-3) and compound (2-1), compound (1-7) and compound (2-1), or compound (1-8) and compound (2-1) are particularly preferred.

[0152] Additive X is an optically active compound and is not particularly limited as long as it can exhibit a cholesteric phase. From the perspective of not affecting the physical properties of the main liquid crystal composition, a content of approximately 10% by mass or less is preferred. To achieve this, optically active compounds with a high HTP (helical twist power) are preferred. Preferred additives X include compounds (3-1) to (3-7) described in Item 6. Among these compounds, compound (3-4) is particularly preferred.

[0153] Preferred compound (4) is compound (4-1) to compound (4-26) described in Item 9. Among these compounds, at least one of component C is preferably compound (4-20) or compound (4-21).

[0154] Preferred compound (5) is compound (5-1) to compound (5-20) described in item 12. Among these compounds, at least one of component D is preferably compound (5-1), compound (5-10), compound (5-15), compound (5-16), compound (5-17), compound (5-19), or compound (5-20). Preferably, the total proportion of compound (5-1), compound (5-10), compound (5-15), compound (5-16), compound (5-17), compound (5-18), compound (5-19), or compound (5-20) is 20% to 50% by mass.

[0155] Preferred compound (6) is compound (6-1) to compound (6-36) described in Item 15. Among these compounds, it is preferred that at least one of component E is compound (6-19).

[0156] Preferred compound (7) is compound (7-1) to compound (7-29) described in item 17. Among these compounds, at least one of the additives Y is preferably compound (7-1), compound (7-2), compound (7-24), compound (7-25), compound (7-26), or compound (7-27). At least two of the additives Y are preferably a combination of compound (7-1) and compound (7-2), compound (7-1 and compound (7-18), compound (7-2) and compound (7-24), compound (7-2) and compound (7-25), compound (7-2) and compound (7-26), compound (7-25) and compound (7-26), or compound (7-18) and compound (7-24).

[0157] Sixth, additives that can be added to the composition are described. These additives include antioxidants, ultraviolet absorbers, matting agents, pigments, defoaming agents, polar compounds, etc.

[0158] In order to prevent the decrease in resistivity when heated in the atmosphere, or to maintain a high voltage holding rate not only at room temperature but also at a temperature close to the upper limit temperature after the element has been used for a long time, antioxidants such as compounds (8-1) to (8-3) can be further added to the composition.

[0159]

[0160] Compound (8-2) has low volatility and therefore effectively maintains a high voltage holding ratio even at room temperature and at temperatures close to the upper temperature limit after prolonged use of the device. The preferred ratio of the antioxidant is about 50 ppm or more to achieve its effect, and about 600 ppm or less to avoid lowering the upper temperature limit or increasing the lower temperature limit. A more preferred ratio is in the range of about 100 ppm to about 300 ppm.

[0161] Preferred examples of ultraviolet absorbers include benzophenone derivatives, benzoate derivatives, and triazole derivatives. Light stabilizers such as amines with steric hindrance are also preferred. Preferred examples of light stabilizers include compounds (9-1) to (9-16). The preferred ratio of these absorbers or stabilizers is about 50 ppm or more to achieve their effects, and about 10,000 ppm or less to avoid lowering the upper limit temperature or raising the lower limit temperature. A more preferred ratio is in the range of about 100 ppm to about 10,000 ppm.

[0162]

[0163]

[0164] A matting agent is a compound that receives light energy absorbed by a liquid crystal compound and converts it into heat energy, thereby preventing the decomposition of the liquid crystal compound. Preferred examples of matting agents include compounds (10-1) to (10-7). The preferred ratio of these matting agents is about 50 ppm or more to achieve their effect, and about 20,000 ppm or less to avoid raising the minimum temperature.

[0165] A further preferred ratio is in the range of about 100 ppm to about 10,000 ppm.

[0166]

[0167] To make it suitable for guest-host mode elements, dichroic dyes such as azo dyes and anthraquinone dyes are added to the composition. The preferred ratio of the dye is in the range of about 0.01 mass % to about 10 mass %. To prevent foaming, a defoaming agent such as dimethyl silicone oil and methylphenyl silicone oil is added to the composition. The preferred ratio of the defoaming agent is about 1 ppm or more to achieve its effect and about 1000 ppm or less to prevent display defects. A more preferred ratio is in the range of about 1 ppm to about 500 ppm.

[0168] In order to make it suitable for polymer supported alignment (PSA) type elements, a polymerizable compound is used. Preferred examples of such polymerizable compounds are compounds such as acrylates, methacrylates, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (ethylene oxide, butylene oxide), and vinyl ketones. Further preferred examples are derivatives of acrylates or methacrylates. The preferred ratio is about 10% by mass or more based on the total mass of the polymerizable compound. A further preferred ratio is about 50% by mass or more. A particularly preferred ratio is about 80% by mass or more. The most preferred ratio is 100% by mass.

[0169] During storage of polymerizable compounds, a polymerization inhibitor may be added to prevent polymerization. Polymerizable compounds are typically added directly to the composition without removing the polymerization inhibitor. Examples of polymerization inhibitors include hydroquinone, hydroquinone derivatives such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, and phenothiazine.

[0170] Polar compounds are organic compounds with polarity. This excludes compounds with ionic bonds. Atoms such as oxygen, sulfur, and nitrogen are more electronegative and tend to carry a partial negative charge. Carbon and hydrogen are neutral or tend to carry a partial positive charge. Polarity arises from the uneven distribution of partial charges between different types of atoms in a compound. For example, polar compounds have at least one moiety such as -OH, -COOH, -SH, -NH2, >NH, or >N-.

[0171] Seventh, the synthesis method of the component compounds is described. These compounds can be synthesized by known methods. Example synthesis methods. Compound (1-7) is synthesized by the method described in Japanese Patent Application Laid-Open No. 10-114733. Compound (2-1) is synthesized by the method described in Japanese Patent Application Laid-Open No. 10-81679. Compound (3-4) is synthesized by the method described in International Publication No. 2014-97952. Compound (4-13) is synthesized by the method described in Japanese Patent Application Laid-Open No. 10-251186. Compound (5-1) is synthesized by the method described in Japanese Patent Application Laid-Open No. 9-77692. Compound (6-1) is synthesized by the method described in Japanese Patent Application Laid-Open No. 2-503441. Compound (8-1) can be obtained from Sigma-Aldrich Corporation. Compound (8-2) and the like are synthesized by the method described in the specification of U.S. Patent No. 3,660,505.

[0172] Compounds for which no synthesis methods are described can be synthesized using methods described in monographs such as Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Lectures (Maruzen). Compositions are compounds obtained in this manner and are prepared using known methods. For example, the component compounds are mixed and then dissolved in each other by heating.

[0173] Finally, the application of the composition will be described. This composition is a liquid crystal composition having a cholesteric phase, obtained by adding an optically active compound to a host liquid crystal composition having a nematic phase. This differs from liquid crystal compositions having an optically isotropic liquid crystal phase. This composition primarily has a lower temperature limit of approximately -10°C or less, an upper temperature limit of approximately 60°C or greater, and an optical anisotropy ranging from approximately 0.15 to approximately 0.35. Devices containing this composition exhibit high voltage holding ratios.

[0174] [Example]

[0175] The present invention is further described in detail by way of examples. The present invention is not limited by these examples. The present invention encompasses mixtures of the composition of Example 1 and the composition of Example 2. The present invention also encompasses mixtures of at least two of the compositions of the examples. The synthesized compounds were identified by methods such as NMR analysis. The properties of the compounds, compositions, and devices were measured by the methods described below.

[0176] NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for measurement. 1 H-NMR measurements were performed by dissolving the sample in a deuterated solvent such as CDCl 3 at room temperature, at 500 MHz, and with an integration frequency of 16. Tetramethylsilane was used as an internal standard. 19 F-NMR measurements were performed using CFCl3 as an internal standard with an integration frequency of 24. In the description of nuclear magnetic resonance spectra, s represents a singlet, d represents a doublet, t represents a triplet, q represents a quartet, quin represents a quintet, sex represents a sextet, m represents a multiplet, and br represents a broad peak.

[0177] Gas chromatography analysis: The measurement was performed using a GC-14B gas chromatograph manufactured by Shimadzu Corporation. The carrier gas was helium (2 mL / min). The sample vaporization chamber was set to 280°C, and the detector (FID) was set to 300°C. The component compounds were separated using a capillary column DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm; stationary liquid phase was dimethylpolysiloxane; non-polar) manufactured by Agilent Technologies Inc. This column was kept at 200°C for 2 minutes and then heated to 280°C at a rate of 5°C / min. After the sample was prepared into an acetone solution (0.1% by mass), 1 μL of it was injected into the sample vaporization chamber. The recorder was a C-R5A Chromatopac manufactured by Shimadzu Corporation, or its equivalent. The resulting gas chromatogram shows the retention time and peak area of the peaks corresponding to the component compounds.

[0178] As the solvent for diluting the sample, chloroform, hexane, etc. can be used. To separate the component compounds, the following capillary columns can be used. HP-1 manufactured by Agilent Technologies Inc. (length 30m, inner diameter 0.32mm, film thickness 0.25μm), Rtx-1 manufactured by Restek Corporation (length 30m, inner diameter 0.32mm, film thickness 0.25μm), BP-1 manufactured by SGE International Pty. Ltd (length 30m, inner diameter 0.32mm, film thickness 0.25μm). To prevent compound peaks from overlapping, a capillary column CBP1-M50-025 manufactured by Shimadzu Corporation (length 50m, inner diameter 0.25mm, film thickness 0.25μm) can be used.

[0179] The proportion of the liquid crystal compound contained in the composition can be calculated using the following method. The mixture of liquid crystal compounds is analyzed by gas chromatography (FID). The peak area ratio in the gas chromatogram is equivalent to the proportion of the liquid crystal compound. When using the capillary column described above, the correction factor of each liquid crystal compound can be regarded as 1. Therefore, the proportion (mass %) of the liquid crystal compound can be calculated from the peak area ratio.

[0180] Measuring sample: When measuring the properties of a composition or element, the composition is used directly as a sample. When measuring the properties of a compound, a sample for measurement is prepared by mixing the compound (15% by mass) into a main liquid crystal (85% by mass). The characteristic value of the compound is calculated by extrapolation from the value obtained by measurement. (Extrapolation value) = {(measurement value of the sample) - 0.85 × (measurement value of the main liquid crystal)} / 0.15. When the Smectic phase (or crystallization) precipitates at 25°C at this ratio, the ratio of the compound to the main liquid crystal is changed to 10% by mass: 90% by mass, 5% by mass: 95% by mass, and 1% by mass: 99% by mass, in sequence. The upper limit temperature, optical anisotropy, viscosity, and dielectric anisotropy of the compound are obtained by this extrapolation method.

[0181] The following host liquid crystal was used: The host liquid crystal was a composition consisting of mixture A, mixture B, and mixture C.

[0182] Mixture A 50%

[0183] Mixture B 25%

[0184] Mixture C 25%

[0185] Mixture A, mixture B, and mixture C are shown below.

[0186]

[0187] Mixture A is a mixture of compound (a), compound (b), and compound (c) at a mass ratio of 1:1:1. Mixture B is a mixture of compound (d), compound (e), and compound (f) at a mass ratio of 2:1:2. Mixture C is a mixture of compound (g), compound (h), and compound (i) at a mass ratio of 1:1:2.

[0188] Measurement Method: Characteristics were measured using the following methods. Most of these methods are described in the Japan Electronics and Information Technology Industries Association (JEITA) standard (JEITA ED-2521B), which was reviewed and established by the JEITA, or are modifications thereof. The TN devices used for the measurements did not have thin-film transistors (TFTs) installed.

[0189] (1) The upper limit temperature of the nematic phase (NI; ℃), the upper limit temperature of the cholesteric phase (N * I): Place the sample on a hot plate in a melting point measurement apparatus equipped with a polarizing microscope and heat at a rate of 1°C / min. Measure the temperature at which a portion of the sample transitions from a nematic or cholesteric phase to an isotropic liquid. The upper temperature limit of the nematic or cholesteric phase is simply referred to as the "upper temperature."

[0190] (2) The lower limit temperature of the nematic or cholesteric phase (T C ; ℃): Place a sample with a nematic or cholesteric phase in a glass bottle and store it in a freezer at 0℃, -10℃, -20℃, -30℃ and -40℃ for 10 days, and then observe the liquid crystal phase. For example, if the sample remains in the nematic or cholesteric phase at -20℃ and changes to a crystalline or Schmidt phase at -30℃, then the T C Recorded as <-20℃. When it changes to crystal or Schmidt phase at 0℃ or 25℃ (room temperature), T C They are expressed as >0° C. and >25° C., respectively. The lower limit temperature of the nematic phase or the cholesteric phase may be simply referred to as the “lower limit temperature”.

[0191] (3) Viscosity (bulk viscosity; η; measured at 20°C; mPa·s): Measurement was performed using an E-type rotational viscometer manufactured by Tokyo Keiki Co., Ltd.

[0192] (4) Viscosity (rotational viscosity; γ1; measured at 25°C; mPa·s): The measurement follows the method described by M. Imai et al. in Molecular Crystals and Liquid Crystals, Vol. 259, p. 37 (1995). The sample is placed in a TN element with a twist angle of 0° and a spacing (cell gap) of 5 μm between two glass substrates. Voltage is applied to the element in steps of 0.5 V in the range of 16 V to 19.5 V. After 0.2 seconds without voltage application, the conditions of applying only one rectangular wave (rectangular pulse; 0.2 seconds) and no voltage application (2 seconds) are repeated. The peak current and peak time of the transient current generated by the voltage application are measured. The rotational viscosity value is obtained from these measured values and the calculation formula (10) described on page 40 of the paper by M. Imai et al. The value of dielectric anisotropy required for this calculation is obtained by the method described below using the element for measuring this rotational viscosity.

[0193] (5) Optical anisotropy (refractive index anisotropy; Δn; measured at 25°C): Measured using light of 589 nm wavelength using an Abbe refractometer with a polarizing plate mounted on the eyepiece. After the surface of the main prism is rubbed in one direction, the sample is dropped onto the main prism. The refractive index n∥ is measured when the polarization direction is parallel to the rubbing direction. The refractive index n⊥ is measured when the polarization direction is perpendicular to the rubbing direction. The optical anisotropy value is calculated using the formula Δn = n∥ - n⊥.

[0194] (6) Dielectric anisotropy (Δε; measured at 25°C): A sample was placed in a TN device with a 9 μm gap (cell gap) between two glass substrates and a twist angle of 80 degrees. A sine wave (10 V, 1 kHz) was applied to the device, and after 2 seconds, the dielectric constant (ε∥) along the long axis of the liquid crystal molecules was measured. A sine wave (0.5 V, 1 kHz) was applied to the device, and after 2 seconds, the dielectric constant (ε⊥) along the short axis of the liquid crystal molecules was measured. The dielectric anisotropy value was calculated using the formula Δε = ε∥ - ε⊥.

[0195] (7-1) Threshold voltage (Vth(25); measured at 25°C; V): Measured using an LCD5200 luminance meter manufactured by Otsuka Electronics Co., Ltd. The light source is a halogen lamp. The sample is placed in an FFS element with a spacing (cell gap) of 3.2 (μm) between two glass substrates. The voltage applied to the element (32 Hz, rectangular wave) is increased stepwise by 0.01 V from 0 V to 10 V. During this process, light is irradiated from a direction perpendicular to the element, and the amount of light passing through the element is measured. When this light amount is maximum, the transmittance is 100%, and when this light amount is minimum, the transmittance is 0%, and a voltage-transmittance curve is prepared. The threshold voltage is expressed as the voltage when the transmittance reaches 95%.

[0196] (7-2) Threshold voltage (Vth(-30); measured at -30°C; V): Same as (7-1) except that it was measured at -30°C.

[0197] (8) Voltage holding ratio (VHR-1; measured at 25°C; %): The TN element used for measurement has a polyimide alignment film and the spacing between the two glass substrates (cell gap) is 5 μm. After the sample is injected into the element by vacuum injection, the injection port is sealed with a UV-curable adhesive. A pulse voltage (1 V, 60 microseconds) is applied to the TN element for charging. The voltage decayed during 166.7 milliseconds is measured with a high-speed voltmeter, and the area A between the voltage curve per unit period and the horizontal axis is calculated. Area B is the area when there is no decay. The voltage holding ratio is expressed as a percentage of area A to area B.

[0198] (9) Voltage holding ratio (VHR-2; measured at 60° C.; %): The voltage holding ratio was measured according to the same procedure as above, except that the measurement was performed at 60° C. instead of 25° C. The obtained value was expressed as VHR-2.

[0199] (10) Voltage holding ratio (VHR-3; measured at 60°C; %): After irradiation with ultraviolet light, the voltage holding ratio was measured to evaluate the stability against ultraviolet light. The TN element used for the measurement had a polyimide alignment film and a cell gap of 5 μm. The sample was injected into the element and irradiated with 5 mW / cm 2 The UV exposure time was 167 minutes. The light source was an Ai Graphics Co., Ltd. black light, F40T10 / BL (peak wavelength 369 nm), with a 5 mm gap between the element and the light source. The VHR-3 measurement measures the voltage decay over a period of 166.7 milliseconds. Compositions with a greater VHR-3 exhibit greater stability to UV rays.

[0200] (11) Voltage Holding Ratio (VHR-4; measured at 60°C; %): After heating a TN device filled with the sample in a thermostat at 120°C for 20 hours, the voltage holding ratio was measured to evaluate thermal stability. In the VHR-4 measurement, the voltage decayed over a period of 166.7 milliseconds. Compositions with larger VHR-4 values exhibited greater thermal stability.

[0201] (12) Voltage Holding Ratio (VHR-5; measured at 60°C; %): After the TN device containing the sample was placed on a backlight for 2 weeks, the voltage holding ratio was measured to evaluate the stability against the backlight. In the VHR-5 measurement, the voltage decayed over a period of 166.7 milliseconds. Compositions with a larger VHR-5 exhibited greater stability against the backlight.

[0202] (13) Response time (τ; measured at 25°C; ms): Measured using an LCD5200 luminance meter manufactured by Otsuka Electronics Co., Ltd. The light source is a halogen lamp. The low-pass filter is set to 5 kHz. The sample is placed in a TN element with a spacing (cell gap) of 5 μm between two glass substrates. A rectangular wave (60 Hz, Vth (25), 0.5 seconds) is applied to the element. At this time, light is irradiated to the element from a vertical direction, and the amount of light reflected by the element is measured. When this light amount is maximum, the reflectivity is 100%, and when this light amount is minimum, it is considered to be 0% reflectivity. The rise time (τr: rise time; milliseconds) is the time required for the reflectivity to change from 90% to 10%. The fall time (τf: fall time; milliseconds) is the time required for the reflectivity to change from 10% to 90%. The response time represents the sum of the rise time and fall time obtained in this way. To the device into which the sample was injected, voltage was applied from 0 V to 40 V in 1 V increments, and the voltage at which the device switched from the initial reflection state to the transmission state was defined as Vreset (V).

[0203] (14) Elastic constant (K; measured at 25°C; pN): Measured using an HP4284A LCR meter manufactured by Yokogawa Hewlett-Packard Co., Ltd. The sample is placed in a horizontally aligned element with a spacing (cell gap) of 20 μm between two glass substrates. A charge of 0 volts to 20 volts is applied to the element, and the electrostatic capacitance and applied voltage are measured. The values of the measured electrostatic capacitance (C) and applied voltage (V) are fitted using equations (2.98) and (2.101) on page 75 of the "Liquid Crystal Device Handbook" (Nikkan Kogyo Shimbun), and the values of K11 and K33 are obtained from equation (2.99). Then, using equation (3.18) on page 171 of the same book, K22 is calculated using the values of K11 and K33 just obtained. The elastic constant represents the average value of K11, K22, and K33 obtained in this way.

[0204] (15) Specific resistance (ρ; measured at 25°C; Ωcm): 1.0 mL of the sample was injected into a container equipped with electrodes. A DC voltage (10 V) was applied to the container, and the DC current was measured after 10 seconds. Specific resistance was calculated using the following formula: (Specific resistance) = {(Voltage) × (Electrical capacitance of the container)} / {(DC current) × (Dielectric constant of vacuum)}.

[0205] (16) Helical pitch (P; measured at room temperature; μm): The helical pitch is measured by the wedge method. See "Liquid Crystal Handbook," page 196 (published in 2000, Maruzen). The sample is injected into a wedge cell and allowed to stand at room temperature for 2 hours. The spacing (d2-d1) between the disclination lines is then observed using a polarizing microscope (Nikon Corporation, trade name MM40 / 60 series). The helical pitch (P) is calculated using the following formula, where the angle of the wedge cell is represented by θ. P = 2 × (d2-d1) × tanθ.

[0206] (17) Dielectric constant in the short-axis direction (ε⊥; measured at 25°C): A sample was placed in a TN device with a 9 μm gap between two glass substrates (cell gap) and a twist angle of 80 degrees. A sine wave (0.5 V, 1 kHz) was applied to the device. After 2 seconds, the dielectric constant (ε⊥) in the short-axis direction of the liquid crystal molecules was measured.

[0207] (18) Frequency dependence of dielectric anisotropy (F10; measured at -20°C): A sample was placed in a TN device with a distance (cell gap) of 9 μm between two glass substrates and a twist angle of 80 degrees. A sine wave (0.5 V, 20 Hz, 50 Hz, 100 Hz, 1 kHz, 5 kHz, 10 kHz, 50 kHz, 100 kHz, 500 kHz, 1000 kHz) was applied to the device, and after 2 seconds, the dielectric constant (ε⊥) in the short axis direction of the liquid crystal molecules was measured. The frequency at which the dielectric anisotropy decreases by 10% relative to the dielectric anisotropy at 20 Hz is defined as F10. A larger F10 indicates a smaller frequency dependence.

[0208] (19) Reflected wavelength (λ, nm): Measurements were performed using a JASCO V-700 equipped with an ISV-922 integrating sphere unit for UV / VIS / NIR spectroscopy. The sample was placed in a device with a 5 μm gap (cell gap) between two glass substrates, and the reflected wavelength was measured at an incident angle of 5 degrees.

[0209] The following are examples of compositions. The component compounds are represented by symbols based on the definitions in Table 3 below. In Table 3, the stereo configuration of 1,4-cyclohexene is trans. The numbers in parentheses after the symbolized compound represent the chemical formula to which the compound belongs. The (-) symbol means other liquid crystal compounds. The ratio (percentage) of the liquid crystal compound is the mass percentage (mass %) based on the mass of the liquid crystal composition without additives. Finally, the characteristic values of the composition are summarized.

[0210] Table 3. Description of compounds using symbols R-(A1)-Z...-Zn-(An)-R'

[0211]

[0212] [Comparative Example 1]

[0213]

[0214] NI=112.9℃; Δn=0.208; Δε=31.3; Tc<-20℃.

[0215] To this composition was added 3.5% by mass of compound (3-4).

[0216] N * I=108.9℃; Δε=31.3; Tc<-20℃; Δλ=414nm; V reset =26V.

[0217]

[0218] [Comparative Example 2]

[0219]

[0220] NI=124.7℃; Δn=0.234; Δε=88.6; Tc>25℃.

[0221] To this composition was added 3.5% by mass of compound (3-4).

[0222] N * I=120.8℃; Δε=88.6; Tc>0℃; Δλ=430nm; V reset =16V.

[0223]

[0224] [Comparative Example 3]

[0225]

[0226] NI=110.9℃; Δn=0.236; Δε=66.7; Tc>0℃.

[0227] To this composition was added 3.2% by mass of compound (3-4).

[0228] N * I=107.0℃; Δε=66.7; Tc>0℃; Δλ=455nm; V reset =16V.

[0229]

[0230] [Example 1]

[0231]

[0232] NI=103.0℃; Δn=0.205; Δε=93.5; Tc<-20℃.

[0233] To this composition was added 3.5% by mass of compound (3-4).

[0234] N * I=99.1℃; Δε=93.5; Tc<-20℃; Δλ=425nm; V reset =15V.

[0235]

[0236] [Example 2]

[0237]

[0238] NI=122.5℃; Δn=0.222; Δε=83.4; Tc<-30℃.

[0239] To this composition was added 3.2% by mass of compound (3-4).

[0240] N * I=108.6℃; Δε=83.4; Tc<-30℃; Δλ=450nm; V reset =16V.

[0241]

[0242] [Example 3]

[0243]

[0244]

[0245] NI=107.3℃; Δn=0.224; Δε=75.0; Tc<-30℃.

[0246] To this composition was added 3.2% by mass of compound (3-4).

[0247] N * I=103.3℃; Δε=75.0; Tc<-30℃; Δλ=455nm; V reset =17V.

[0248]

[0249] [Example 4]

[0250]

[0251] NI=109.1℃; Δn=0.224; Δε=74.2; Tc<-30℃.

[0252] To this composition was added 3.3% by mass of compound (3-4).

[0253] N * I=105.4℃; Δε=75.0; Tc<-30℃; Δλ=455nm; V reset =18V.

[0254]

[0255] [Example 5]

[0256]

[0257]

[0258] NI=110.2℃; Δn=0.224; Δε=74.4; Tc<-30℃.

[0259] To this composition was added 3.3% by mass of compound (3-4).

[0260] N * I=106.2℃; Δε=74.4; Tc<-30℃; Δλ=455nm; V reset =18V.

[0261]

[0262] [Example 6]

[0263]

[0264] NI=106.4℃; Δn=0.223; Δε=74.2; Tc<-30℃.

[0265] To this composition was added 3.3% by mass of compound (3-4).

[0266] N * I=102.5℃; Δε=74.2; Tc<-30℃; Δλ=455nm; V reset =18V.

[0267]

[0268] [Example 7]

[0269]

[0270]

[0271] NI=112.2℃; Δn=0.227; Δε=77.0; Tc<-30℃.

[0272] To this composition was added 3.3% by mass of compound (3-4).

[0273] N * I=108.3℃; Δε=77.0; Tc<-30℃; Δλ=455nm; V reset =17V.

[0274]

[0275] [Example 8]

[0276]

[0277] NI=114.4℃; Δn=0.228; Δε=76.1; Tc<-20℃.

[0278] To this composition was added 3.3% by mass of compound (3-4).

[0279] N * I=110.5℃; Δε=76.1; Tc<-20℃; Δλ=455nm; V reset =17V.

[0280]

[0281] [Example 9]

[0282]

[0283] NI=111.2℃; Δn=0.225; Δε=74.9; Tc<-20℃.

[0284] To this composition was added 3.3% by mass of compound (3-4).

[0285] N * I=107.2℃; Δε=74.9; Tc<-20℃; Δλ=455nm; V reset =18V.

[0286]

[0287] [Example 10]

[0288]

[0289]

[0290] NI=107.4℃; Δn=0.225; Δε=75.1; Tc<-30℃.

[0291] To this composition was added 3.3% by mass of compound (3-4).

[0292] N * I=103.5℃; Δε=75.1; Tc<-30℃; Δλ=455nm; V reset =17V.

[0293]

[0294] [Example 11]

[0295]

[0296] NI=106.0℃; Δn=0.233; Δε=51.7; Tc<-30℃.

[0297] To this composition was added 3.3% by mass of compound (3-4).

[0298] N * I=102.1℃; Δε=51.7; Tc<-30℃; Δλ=455nm; V reset =20V.

[0299]

[0300] [Example 12]

[0301]

[0302]

[0303] NI=104.8℃; Δn=0.237; Δε=53.3; Tc<-30℃.

[0304] To this composition was added 3.2% by mass of compound (3-4).

[0305] N * I=100.8℃; Δε=53.3; Tc<-30℃; Δλ=460nm; V reset =19V.

[0306]

[0307] [Example 13]

[0308]

[0309] NI=104.8℃; Δn=0.237; Δε=53.3; Tc<-30℃.

[0310] To this composition was added 2.1% by mass of compound (3-4).

[0311] N * I=102.3℃; Δε=53.3; Tc<-30℃; Δλ=660nm; V reset =19V.

[0312]

[0313] [Example 14]

[0314]

[0315] NI=100.9℃; Δn=0.211; Δε=55.5; Tc<-30℃.

[0316] To this composition was added 3.3% by mass of compound (3-4).

[0317] N * I=97.3℃; Δε=55.5; Tc<-30℃; Δλ=455nm; V reset =20V.

[0318]

[0319] Comparative Example 1 is a composition that does not contain formula (1), and its dielectric anisotropy is 31.3. Comparative Example 2 is a composition that does not contain formula (2), and its dielectric anisotropy is 88.6, and it crystallizes at 25°C. On the other hand, the composition of Example 1 has a dielectric anisotropy of 93.5 and does not crystallize even at -20°C. Similarly, the composition of Comparative Example 3 has a dielectric anisotropy of 66.7 and crystallizes at 0°C. In contrast, the composition of Example 2 has a dielectric anisotropy of 83.4 and does not crystallize even at -30°C. Thus, the composition of the present invention has a large dielectric anisotropy and a low minimum temperature.

[0320] Therefore, it can be concluded that the composition of the present invention has excellent properties.

[0321] [Industrial Applicability]

[0322] The liquid crystal composition of the present invention can be used in liquid crystal monitors, liquid crystal televisions, and the like.

Claims

1. A liquid crystal composition comprising, as component A, at least one compound selected from the compounds represented by formula (1), as component B, at least one compound selected from the compounds represented by formula (2), and as an additive X, an optically active compound, wherein the liquid crystal composition has a cholesteric phase. In formula (1), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; 1 is a single bond, a carbonyloxy group, or a difluoromethyleneoxy group; X 1 and X 2 is hydrogen or fluorine; a is 1 or 2; In formula (2), R 2 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Z 2 is a carbonyloxy group or a difluoromethyleneoxy group; X 3 、X 4 、X 5 、X 6 、X 7 and X 8 is hydrogen or fluorine; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

2. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (1-1) to formula (1-9) as component A, In formula (1-1) to formula (1-9), R 1 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; X 1 and X 2 is hydrogen or fluorine. 3 . The liquid crystal composition according to claim 1 , wherein the proportion of component A is in the range of 5% by mass to 50% by mass.

4. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (2-1) to formula (2-8) as component B, In formula (2-1) to formula (2-8), R 2 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine. The liquid crystal composition according to claim 1 , wherein the proportion of component B is in the range of 5% by mass to 50% by mass.

6. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (3-1) to formula (3-7) as the additive X, In formula (3-1) to formula (3-7), R 3 and R 4 It is hydrogen, halogen, -C≡N, -N=C=O, -N=C=S, -SF5, or an alkyl group having 1 to 10 carbon atoms, wherein at least one -CH2- in the alkyl group may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and at least one hydrogen in the multiple groups may be replaced by fluorine or chlorine. 7 . The liquid crystal composition according to claim 1 , wherein the proportion of the additive X is in the range of 0.1% by mass to 10% by mass.

8. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (4) as component C, In formula (4), R 5 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms; Ring B is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; 3 is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethyleneoxy; X 9 and X 10 is hydrogen or fluorine; Y 2 is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; b is 1, 2, 3, or 4.

9. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (4-1) to formula (4-26) as component C, In formula (4-1) to formula (4-26), R 5 It is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. 10 . The liquid crystal composition according to claim 8 , wherein the ratio of component C is in the range of 1% by mass to 50% by mass.

11. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (5) as component D, In formula (5), R 6 and R 7 is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine; Ring C and Ring D are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 4 is a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy; c is 1, 2, or 3.

12. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (5-1) to formula (5-20) as component D, In formula (5-1) to formula (5-20), R 6 and R 7 It is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. The liquid crystal composition according to claim 11 , wherein the ratio of component D is in the range of 10% by mass to 90% by mass.

14. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (6) as component E, In formula (6), R 8 and R 9 is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, alkenyloxy having 2 to 12 carbon atoms, or alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; Ring E and Ring G are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced by fluorine or chlorine, chromane-2,6-diyl, or at least one hydrogen is replaced by fluorine or chlorine. Chromane-2,6-diyl; Ring F is 2,3-difluoro-1,4-phenylene, 1,8-difluorophenanthrene-2,7-diyl, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochromane-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, 4,6-difluorodibenzofuran-3,7-diyl, 4,6-difluorodibenzothiophene-3,7-diyl, or 1,1,6,7-tetrafluoroindene-2,5-diyl; Z 5 and Z 6 is a single bond, ethylene, vinylene, methyleneoxy, or carbonyloxy; d is 0, 1, 2, or 3; e is 0 or 1; and the sum of d and e is 3 or less.

15. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by formula (6-1) to formula (6-36) as component E, In formula (6-1) to formula (6-36), R 8 and R 9 It is hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is replaced by fluorine or chlorine. The liquid crystal composition according to claim 14 , wherein the ratio of component E is in the range of 1% by mass to 10% by mass.

17. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of polymerizable compounds represented by formula (7) as the additive Y, In formula (7), ring I and ring K are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidin-2-yl, or pyridin-2-yl, and in the multiple rings, at least one hydrogen may be substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine; ring J is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene Z is selected from the group consisting of 1,4-diyl, 1,5-diyl, 1,6-diyl, 1,7-diyl, 1,8-diyl, 2,3-diyl, 2,6-diyl, 2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, 2,5-pyrimidine-2,5-diyl and 2,5-pyridine-2,5-diyl, wherein at least one hydrogen in the rings is substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine; 7 and Z 8 is a single bond or an alkylene group having 1 to 10 carbon atoms, wherein at least one -CH2- in the alkylene group may be substituted by -O-, -CO-, -COO-, or -OCO-, and at least one -CH2CH2- may be substituted by -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)-, or -C(CH3)=C(CH3)-, and at least one hydrogen in the multiple groups may be substituted by fluorine; 1 To P 3 is a polymerizing group; Sp 1 To Sp 3 is a single bond or an alkylene group with 1 to 10 carbon atoms, wherein Sp 1 To Sp 3 In the formula (a), at least one -CH2- may be replaced by -O-, -COO-, -OCO-, or -OCOO-, at least one -CH2CH2- may be replaced by -CH=CH- or -C≡C-, and at least one hydrogen may be replaced by fluorine; i is 0, 1, or 2; f, g, and h are 0, 1, 2, 3, or 4; and the sum of f, g, and h is 1 or greater.

18. The liquid crystal composition according to claim 17, wherein in formula (7), P 1 To P 3 is a group selected from the polymerizable groups represented by formula (P-1) to formula (P-5), In formula (P-1) to formula (P-5), M 1 To M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is replaced by fluorine. 1 To M 3 In the alkyl group, at least one -CH2- group may be substituted by -O-.

19. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of polymerizable compounds represented by formula (7-1) to formula (7-29) as the additive Y, In formula (7-1) to formula (7-29), Sp 1 To Sp 3 is a single bond or an alkylene group with 1 to 10 carbon atoms, wherein Sp 1 To Sp 3 wherein at least one -CH2- may be replaced by -O-, -COO-, -OCO-, or -OCOO-, at least one -CH2CH2- may be replaced by -CH=CH- or -C≡C-, and at least one hydrogen may be replaced by fluorine; 4 To P 6 is a polymerizable group selected from the groups represented by formula (P-1) to formula (P-3); In formula (P-1) to formula (P-3), M 1 To M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is replaced by fluorine, wherein M 1 To M 3 In the alkyl group, at least one -CH2- group may be substituted by -O-.

20. The liquid crystal composition according to claim 17, wherein the ratio of the additive Y is in the range of 0.1% by mass to 5% by mass. 21 . The liquid crystal composition according to claim 1 , wherein the optical anisotropy at a wavelength of 589 nm (measured at 25° C.) is 0.16 or more.

22. A liquid crystal element comprising the liquid crystal composition according to claim 1. 23 . The liquid crystal element according to claim 22 , which is a liquid crystal display element or a liquid crystal reflective element.

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