Liquid crystal composition, liquid crystal display element, and use of liquid crystal composition

Abstract

Provided are a liquid crystal composition, a liquid crystal display element, and a use of the liquid crystal composition. The liquid crystal composition contains, as component A, a specific compound having a high upper limit temperature, as component B, a specific compound having a large dielectric anisotropy, and as component C, a specific compound having a large dielectric constant in the short axis direction, and can also contain, as component D, a specific compound having a small viscosity or a high upper limit temperature, or as component E, a specific compound having a large dielectric constant in the short axis direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a liquid crystal composition, a liquid crystal display element and the like containing the composition. In particular, it relates to a liquid crystal composition having a positive dielectric anisotropy, and an active matrix (AM) element having a twisted nematic (TN), electrically controlled birefringence (ECB), optically compensated bend (OCB), in-plane switching (IPS), fringe field switching (FFS), or field-induced photo-reactive alignment (FPA) mode, containing the composition. BACKGROUND

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

[0003] The liquid crystal display element contains a liquid crystal composition having a nematic phase. The composition has appropriate properties. By improving the properties of the composition, an AM element having good properties can be obtained. The correlations among these properties are summarized in Table 1 below. The properties of the composition are further described based on commercially available AM elements. The temperature range of the nematic phase is correlated with the temperature range in which the element can be used. The preferred upper limit of the temperature of the nematic phase is about 70°C or higher, and the preferred lower limit of the temperature of the nematic phase is about -10°C or lower. The viscosity of the composition is correlated with the response time of the element. In order to display a dynamic image with the element, it is preferable that the response time be short. It is ideal that the response time be shorter than 1 msec. Therefore, it is preferable that the viscosity of the composition be small. It is further preferable that the viscosity at low temperature be small. The elastic constant of the composition is correlated with the contrast of the element. In the element, in order to improve the contrast, it is preferable that the elastic constant of the composition be large.

[0004] Table 1. Properties of the composition and properties of the AM element

[0005]

[0006] The optical anisotropy of the composition is associated with the contrast of the element. Depending on the mode of the element, either a large optical anisotropy or a small optical anisotropy, that is, an appropriate optical anisotropy, is required. The product (An x d) of the optical anisotropy (An) of the composition and the cell gap (d) of the element is designed so as to maximize the contrast. The value of the appropriate product depends on the kind of the mode of operation. In the case of an element of the mode of TN or the like, the appropriate value is about 0.45 μm. In this case, a composition having a large optical anisotropy is preferred for an element having a small cell gap. A large dielectric anisotropy of the composition contributes to a low threshold voltage, a small power consumption, and a large contrast of the element. Therefore, a large dielectric anisotropy is preferred. The dielectric anisotropy generally has a frequency dependence at low temperatures, and becomes small as the frequency becomes high. Therefore, at low temperatures, as the driving frequency becomes high, the motion of the liquid crystal molecules cannot follow the frequency change of the voltage, and display malfunctions occur. Therefore, the frequency dependence of the dielectric anisotropy at low temperatures is preferably small. A large specific resistance of the composition contributes to a large voltage holding ratio and a large contrast of the element. Therefore, a composition having a large specific resistance in the initial stage is preferred. A composition having a large specific resistance after long-term use is preferred. The stability of the composition to ultraviolet rays and heat is associated with the life of the liquid crystal display element. When these stabilities are high, the life of the element is long. Such properties are preferred for an AM element used for a liquid crystal monitor, a liquid crystal television, or the like.

[0007] A composition having a positive dielectric anisotropy is used in an AM element having a TN mode. A composition having a negative dielectric anisotropy is used in an AM element having a VA mode. A composition having a positive or negative dielectric anisotropy is used in an AM element of a polymer sustained alignment (PSA) type.

[0008] A composition having a positive or negative dielectric anisotropy is used in an AM element of an IPS mode or an FFS mode. It is generally known that, in the case where a composition having a positive dielectric anisotropy is used, the transmittance becomes low as compared with the case where a composition having a negative dielectric anisotropy is used. In order to improve the situation, it is proposed that a composition having a positive dielectric anisotropy contain a compound having a negative dielectric anisotropy (for example, Patent Document 1).

[0009] By containing a compound having a negative dielectric anisotropy, the dielectric constant in the short axis direction (ε ) of the composition or the ratio of the dielectric constant in the short axis direction to the dielectric anisotropy (ε / Δε) increases, and it is considered that the transmittance is improved. On the other hand, there is a problem that the response decreases by containing a compound having a negative dielectric anisotropy.

[0010] In addition, liquid crystal display elements are currently used for various purposes, and are required to maintain good display even under severe temperature conditions depending on the purpose. For this reason, it is necessary to appropriately operate in a wide temperature range or to have excellent response under severe temperature conditions. It is known that the response of a liquid crystal display element, particularly at low temperatures, is reduced, and in order to improve the situation, studies have been conducted (for example, Patent Literature 2). In addition, it is disclosed in Patent Literature 3 that a liquid crystal composition containing a tertiary cyclohexyl compound has a nematic phase in a wide temperature range.

[0011] [Related Art Documents]

[0012] [Patent Literature]

[0013] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2013-166936

[0014] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2002-294238

[0015] [Patent Literature 3] German Patent Application Publication No. 4414647 SUMMARY

[0016] [Problems to be Solved by the Invention]

[0017] The present application is to provide a liquid crystal composition and a liquid crystal display element, the liquid crystal composition sufficiently satisfying at least one of characteristics such as a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, a small viscosity, particularly a small viscosity at low temperatures, an appropriate optical anisotropy, a large dielectric anisotropy, a large dielectric constant in the short axis direction, a large ratio of the dielectric constant in the short axis direction to the dielectric anisotropy (ε⊥ / Δε), a small frequency dependence of the dielectric anisotropy at low temperatures, a large specific resistance, a high stability to light, a high stability to heat, and a large elastic constant, and the liquid crystal display element sufficiently satisfying at least one of characteristics such as a short response time, particularly a short response time at low temperatures, a low threshold voltage, particularly a low threshold voltage at low temperatures. Another problem is to provide a liquid crystal composition having an appropriate balance between at least two of characteristics such as a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, a small viscosity, particularly a small viscosity at low temperatures, an appropriate optical anisotropy, a large dielectric anisotropy, a large dielectric constant in the short axis direction, a large ratio of the dielectric constant in the short axis direction to the dielectric anisotropy (ε⊥ / Δε), a small frequency dependence of the dielectric anisotropy at low temperatures, a large specific resistance, a high stability to light, a high stability to heat, and a large elastic constant. Another problem is to provide an AM element having characteristics such as a large voltage holding ratio, a large contrast, and a long life.

[0018] [Technical Means for Solving the Problems]

[0019] The present application relates to a liquid crystal composition, a liquid crystal display element containing the composition, and a use of the liquid crystal composition, the liquid crystal composition containing, as component A, at least one compound selected from compounds represented by formula (1), as component B, at least one compound selected from compounds represented by formula (2), and as component C, at least one compound selected from compounds represented by formula (3), and having a positive dielectric anisotropy.

[0020]

[0021] In formula (1), R 1 is an alkyl group having 1 to 12 carbons or an alkenyl group having 2 to 12 carbons; R 2 is an alkenyl group having 2 to 12 carbons; Z 1 is a single bond or a vinylidene group;

[0022] In formula (2), R 3 is an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, or an alkenyl group having 2 to 12 carbons; ring A 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, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; Z 2 is a single bond, an ethylene group, a vinylidene group, a carbonyloxy group, or a difluoromethylenoxy group; X 1 and X 2 are hydrogen or fluorine; Y 1 is fluorine, chlorine, an alkyl group having 1 to 12 carbons in which at least one hydrogen is replaced with fluorine or chlorine, an alkoxy group having 1 to 12 carbons in which at least one hydrogen is replaced with fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbons in which at least one hydrogen is replaced with fluorine or chlorine; a is 1, 2, 3, or 4;

[0023] In formula (3), R 4 and R 5hydrogen, alkyl group having 1 to 12 carbons, alkoxy group having 1 to 12 carbons, alkenyl group having 2 to 12 carbons, or alkenyloxy group having 2 to 12 carbons; ring B and ring D 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 with fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced with fluorine or chlorine, chrysen-2,6-diyl, or chrysen-2,6-diyl in which at least one hydrogen is replaced with fluorine or chlorine; ring C is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochrysen-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, or 1,1,6,7-tetrafluoroindane-2,5-diyl; Z 3 and Z 4 is a single bond, ethylene, ethenylene, methyleneoxy, or carbonyloxy; b is 1, 2, or 3, and c is 0 or 1; and the sum of b and c is 2 or 3.

[0024] [Effects of the Invention]

[0025] An advantage of the present application is to provide a liquid crystal composition and a liquid crystal display element that satisfy at least one of the properties such as a high upper limit temperature of the nematic phase, a low lower limit temperature of the nematic phase, a small viscosity, particularly a small viscosity at low temperature, an appropriate optical anisotropy, a large dielectric anisotropy, a large dielectric constant in the short axis direction (ε⊥), a large ratio of the dielectric constant in the short axis direction to the dielectric anisotropy (ε⊥ / Δε), a small frequency dependence of the dielectric anisotropy at low temperature, a large specific resistance, a high stability to light, a high stability to heat, a large elastic constant, and the like, and a liquid crystal display element that satisfies at least one of the properties such as a short response time, particularly a short response time at low temperature, a low threshold voltage, particularly a low threshold voltage at low temperature, and the like, in which the liquid crystal composition satisfies at least two of the properties such as a high upper limit temperature of the nematic phase, a low lower limit temperature of the nematic phase, a small viscosity, particularly a small viscosity at low temperature, an appropriate optical anisotropy, a large dielectric anisotropy, a large dielectric constant in the short axis direction, a large ratio of the dielectric constant in the short axis direction to the dielectric anisotropy (ε⊥ / Δε), a small frequency dependence of the dielectric anisotropy at low temperature, a large specific resistance, a high stability to light, a high stability to heat, a large elastic constant, and the like, in which the liquid crystal display element has an appropriate balance between the properties. Another advantage is to provide an AM element having properties such as a large voltage holding ratio, a large contrast, a long life, and the like. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a graph showing the frequency dependence of the dielectric anisotropy at -20°C of the liquid crystal compositions of Comparative Example 1, Example 1, and Example 2. DETAILED DESCRIPTION

[0027] The usage of terms in this specification is as described below. The terms "liquid crystal composition" and "liquid crystal display element" are sometimes simply referred to as "composition" and "element", respectively. The "liquid crystal display element" is a general term for a liquid crystal display panel and a liquid crystal display module. The "liquid crystal compound" is a general term for a compound having a liquid crystal phase such as a nematic phase, a smectic phase, and a compound mixed in the composition for the purpose of adjusting the temperature range of the nematic phase, the viscosity, the dielectric anisotropy, and the like. The compound has a six-membered ring such as 1,4-cyclohexylene or 1,4-phenylene, and the molecule (liquid crystal molecule) is rod like. The "polymerizable compound" is a compound added for the purpose of generating a polymer in the composition. The liquid crystal compound having an alkenyl group is not classified as a polymerizable compound in its meaning. The term "low temperature" means a temperature of about -20°C or lower.

[0028] The liquid crystal composition is prepared by mixing a plurality of liquid crystal compounds. An additive such as an optically active compound or a polymerizable compound is added as needed in the liquid crystal composition. Even in the case where an additive is added, the proportion of the liquid crystal compound is represented by a mass percentage (mass %) based on the mass of the liquid crystal composition not containing the additive. The proportion of the additive is represented by a mass percentage (mass %) based on the mass of the liquid crystal composition not containing the additive. That is, the proportion of the liquid crystal compound or the additive is calculated based on the total mass of the liquid crystal compound. The proportions of the polymerization initiator and the polymerization inhibitor are exceptions and are represented based on the mass of the polymerizable compound.

[0029] The "upper limit temperature of the nematic phase" is sometimes simply referred to as "upper limit temperature". The "lower limit temperature of the nematic phase" is sometimes simply referred to as "lower limit temperature". The expression "the dielectric anisotropy is increased" means that the value is increased positively in the case of a composition in which the dielectric anisotropy is positive, and the value is increased negatively in the case of a composition in which the dielectric anisotropy is negative. "The voltage holding ratio is large" means that the element has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature in the initial stage, and has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after a long time of use. Sometimes the properties of the composition or the element are investigated by a time-dependent change test.

[0030]

[0031] The following is described using compound (1z) as an example. In formula (1z), the symbols a and b in the hexagon indicate the a-ring and the b-ring, respectively, and indicate a ring such as a six-membered ring, a condensed ring, and the like. When subscript 'x' is 2, two a-rings are present. The two groups indicated by the two a-rings can be the same or can be different. The same rule applies to any two a-rings when subscript 'x' is greater than 2. The same rule also applies to other symbols such as the bonding group Z. The diagonal line that cuts one side of the b-ring indicates that any hydrogen on the b-ring can be substituted with a substituent (-Sp-P). Subscript 'y' indicates the number of substituents that are substituted. When subscript 'y' is 0, no such substitution is present. When subscript 'y' is 2 or more, multiple substituents (-Sp-P) are present on the b-ring. In this case, the rule that "can be the same or can be different" also applies. Furthermore, the same rule also applies to cases in which the symbol for Ra is used for multiple compounds.

[0032] In formula (1z), for example, the expression "Ra and Rb are an alkyl group, an alkoxy group, or an alkenyl group" means that Ra and Rb are independently selected from the group of an alkyl group, an alkoxy group, and an alkenyl group. Here, the group represented by Ra can be the same as or different from the group represented by Rb.

[0033] Sometimes, at least one compound selected from the compounds represented by formula (1z) is simply referred to as "compound (1z)". "Compound (1z)" means one compound represented by formula (1z), a mixture of two compounds, or a mixture of three or more compounds. The same applies to compounds represented by other formulas. The expression "at least one compound selected from the compounds represented by formula (1z) and formula (2z)" means at least one compound selected from the group of compound (1z) and compound (2z).

[0034] The expression "at least one 'A'" means that the number of 'A' is arbitrary. The expression "at least one 'A' can be substituted with 'B'" means that when the number of 'A' is one, the position of 'A' is arbitrary, and when the number of 'A' is two or more, their positions can also be selected without limitation. Sometimes the expression "at least one -CH2- can be substituted with -O-" is used. In this case, -CH2-CH2-CH2- can be converted to -O-CH2-O- by -O- substitution of non-adjacent -CH2-. However, there is no case in which adjacent -CH2- is substituted with -O-. The reason for this is that -O-O-CH2- (peroxide) is generated in the substitution.

[0035] The alkyl group of the liquid crystalline compound is linear or branched, and does not include a cyclic alkyl group. The linear alkyl group is preferable to the branched alkyl group. The same is true for the terminal group such as alkoxy group, alkenyl group, and the like. As for the configuration related to 1,4-cyclohexylene group, in order to increase the upper limit temperature, the trans configuration is preferable to the cis configuration. Since 2-fluoro-1,4-phenylene group is left-right asymmetric, there are left (L) and right (R).

[0036]

[0037] The same is true for the divalent group such as tetrahydropyran-2,5-diyl group. The same is true for the bonding group (-COO- or -OCO-) such as carbonyloxy group.

[0038] The present application is the following item or the like.

[0039] Item 1. A liquid crystal composition containing, 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 component C, at least one compound selected from the compounds represented by formula (3), and having a positive dielectric anisotropy.

[0040]

[0041] In formula (1), R 1 is an alkyl group having 1 to 12 carbons or an alkenyl group having 2 to 12 carbons; R 2 is an alkenyl group having 2 to 12 carbons; Z 1 is a single bond or a vinylidene group;

[0042] In formula (2), R 3 is an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, or an alkenyl group having 2 to 12 carbons; ring A is 1,4-cyclohexylene group, 1,4-phenylene group, 2-fluoro-1,4-phenylene group, 2,3-difluoro-1,4-phenylene group, 2,6-difluoro-1,4-phenylene group, pyrimidine-2,5-diyl group, 1,3-dioxane-2,5-diyl group, or tetrahydropyran-2,5-diyl group; Z 2 is a single bond, ethylene group, vinylidene group, carbonyloxy group, or difluoromethylenoxy group; X 1 and X 2 are hydrogen or fluorine; Y 1 is fluorine, chlorine, an alkyl group having 1 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine, an alkoxy group having 1 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyloxy group having 2 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine; a is 1, 2, 3, or 4;

[0043] In formula (3), R 4 and R5 hydrogen, an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, an alkenyl group having a carbon number of 2 to 12, or an alkenyloxy group having a carbon number of 2 to 12; ring B and ring D 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 with fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is replaced with fluorine or chlorine, chrysen-2,6-diyl, or chrysen-2,6-diyl in which at least one hydrogen is replaced with fluorine or chlorine; ring C is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochrysen-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, or 1,1,6,7-tetrafluoroindane-2,5-diyl; Z 3 and Z 4 is a single bond, ethylene, vinylene, methyleneoxy, or carbonyloxy; b is 1, 2, or 3, and c is 0 or 1; and the sum of b and c is 2 or 3.

[0044] Item 2. The liquid crystal composition according to item 1, containing at least one compound selected from the group consisting of compounds represented by formula (1-1) and formula (1-2) as component A.

[0045]

[0046] In formula (1-1) and formula (1-2), R 1 is an alkyl group having a carbon number of 1 to 12 or an alkenyl group having a carbon number of 2 to 12.

[0047] Item 3. The liquid crystal composition according to item 1 or item 2, wherein the proportion of component A is in the range of 1 to 20 mass%.

[0048] Item 4. The liquid crystal composition according to any one of items 1 to 3, containing at least one compound selected from the group consisting of compounds represented by formula (2-1) to formula (2-36) as component B.

[0049]

[0050]

[0051]

[0052]

[0053] In formula (2-1) to formula (2-36), R 3 is an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, or an alkenyl group having a carbon number of 2 to 12.

[0054] Item 5. The liquid crystal composition according to any one of items 1 to 4, wherein the proportion of component B is in the range of 10 to 85 mass%.

[0055] Item 6. The liquid crystal composition according to any one of items 1 to 5, containing at least one compound selected from the group consisting of compounds represented by formulae (3-1) to (3-20) as component C.

[0056]

[0057]

[0058] In formulae (3-1) to (3-20), R 4 and R 5 are hydrogen, an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, an alkenyl group having a carbon number of 2 to 12, or an alkenyloxy group having a carbon number of 2 to 12.

[0059] Item 7. The liquid crystal composition according to any one of items 1 to 6, wherein the proportion of component C is in the range of 10 to 50 mass%.

[0060] Item 8. The liquid crystal composition according to any one of items 1 to 7, containing at least one compound selected from the group consisting of compounds represented by formula (4) as component D.

[0061]

[0062] In formula (4), R 6 and R 7 are an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, an alkenyl group having a carbon number of 2 to 12, or an alkenyl group having a carbon number of 2 to 12 in which at least one hydrogen is substituted with fluorine or chlorine; ring E and ring F are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 5 is a single bond, ethylene, methyleneoxy, or carbonyloxy; d is 1, 2, or 3; wherein, when d is 2 and both Z 5 are single bonds, ring F is 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene.

[0063] Item 9. The liquid crystal composition according to any one of items 1 to 8, containing at least one compound selected from the group consisting of compounds represented by formulae (4-1) to (4-13) as component D.

[0064]

[0065]

[0066] In equations (4-1) to (4-13), 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 that has at least one hydrogen atom substituted with fluorine or chlorine.

[0067] Item 10. The liquid crystal composition according to Item 8 or Item 9, wherein the proportion of component D is in the range of 10% by mass to 75% by mass.

[0068] Item 11. The liquid crystal composition according to any one of items 1 to 10, comprising at least one compound selected from the compounds represented by formula (5) as component E.

[0069]

[0070] In equation (5), 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, or an alkenyloxy group having 2 to 12 carbon atoms; ring G is 1,4-cyclohexene, 1,4-cyclohexenyl, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene with at least one hydrogen substituted by fluorine or chlorine, naphth-2,6-diyl, naphth-2,6-diyl with at least one hydrogen substituted by fluorine or chlorine, chromoline-2,6-diyl, or chromoline-2,6-diyl with at least one hydrogen substituted by fluorine or chlorine. -Diyl; ring I is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthyl-2,6-diyl, 7,8-difluorochrome-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-tetrafluoroindane-2,5-diyl; Z 6 It is a single bond, ethylidene, vinylidene, methyleneoxy, or carbonyloxy; e is 0 or 1.

[0071] Item 12. The liquid crystal composition according to any one of items 1 to 11, comprising at least one compound selected from the compounds represented by formulas (5-1) to (5-15) as component E.

[0072]

[0073]

[0074] In equations (5-1) to (5-15), R 8 and R 9hydrogen, alkyl group having 1 to 12 carbons, alkoxy group having 1 to 12 carbons, alkenyl group having 2 to 12 carbons, or alkenyloxy group having 2 to 12 carbons.

[0075] Item 13. The liquid crystal composition according to Item 11 or Item 12, wherein the proportion of Component E is in the range of 1 to 30 mass%.

[0076] Item 14. The liquid crystal composition according to any one of Items 1 to 13, wherein the upper limit temperature of the nematic phase is 70°C or higher, and the optical anisotropy at a wavelength of 589 nm (measured at 25°C) is 0.07 or more, and the dielectric anisotropy at a frequency of 1 kHz (measured at 25°C) is 2.0 or more.

[0077] Item 15. The liquid crystal composition according to any one of Items 1 to 14, for use in a liquid crystal display element whose operation mode is IPS mode or FFS mode.

[0078] Item 16. A liquid crystal display element comprising the liquid crystal composition according to any one of Items 1 to 14.

[0079] Item 17. The liquid crystal display element according to Item 16, wherein the operation mode of the liquid crystal display element is TN mode, ECB mode, OCB mode, IPS mode, FFS mode, or FPA mode, and the driving method of the liquid crystal display element is active matrix method.

[0080] Item 18. Use of a liquid crystal composition, which is the liquid crystal composition according to any one of Items 1 to 14, for a liquid crystal display element.

[0081] The present application also includes the following items. (a) The composition containing one compound, two compounds, or three or more compounds selected from among additives such as optically active compounds, antioxidants, ultraviolet absorbers, extinction agents, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. (b) An AM element containing the composition. (c) The composition further containing a polymerizable compound, and an AM element of a polymer sustained alignment (PSA) type containing the composition. (d) An AM element of a polymer sustained alignment (PSA) type containing the composition, in which the polymerizable compound in the composition is polymerized. (e) An element containing the composition and having a mode of PC, TN, STN, ECB, OCB, IPS, VA, FFS, or FPA. (f) A transmissive element containing the composition. (g) Use of the composition as a composition having a nematic phase. (h) Use of an optically active composition obtained by adding an optically active compound to the composition.

[0082] The composition of the present application is explained in the following order. First, the composition is explained. Second, the main characteristics of the component compounds, and the main effects of the compounds on the composition or the element are explained. Third, the combination of the component compounds in the composition, the preferred ratio, and the basis thereof are explained. Fourth, the preferred form of the component compounds is explained. Fifth, the preferred component compounds are shown. Sixth, the additives that can be added to the composition are explained. Seventh, the synthesis method of the component compounds is explained. Finally, the use of the composition is explained.

[0083] First, the composition is explained. The composition contains a plurality of liquid crystalline compounds. The composition can also contain additives. The additives are optically active compounds, antioxidants, ultraviolet absorbers, flatting agents, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. From the viewpoint of the liquid crystalline compounds, the composition is classified into Composition A and Composition B. Composition A can contain, in addition to the liquid crystalline compound selected from the group consisting of Compound (1), Compound (2), Compound (3), Compound (4), and Compound (5), other liquid crystalline compounds, additives, and the like. The "other liquid crystalline compounds" are liquid crystalline compounds different from Compound (1), Compound (2), Compound (3), Compound (4), and Compound (5). Such compounds are mixed in the composition for the purpose of further adjusting the characteristics.

[0084] Composition B substantially contains only the liquid crystalline compound selected from the group consisting of Compound (1), Compound (2), Compound (3), Compound (4), and Compound (5). "Substantially" means that Composition B can contain additives, but does not contain other liquid crystalline compounds. Compared with Composition A, the number of components of Composition B is small. From the viewpoint of reducing the cost, Composition B is superior to Composition A. From the viewpoint that the characteristics can be further adjusted by mixing other liquid crystalline compounds, Composition A is superior to Composition B.

[0085] In order to prepare a liquid crystal composition having an appropriate balance between at least two of the characteristics of a high upper limit temperature of the nematic phase, a low lower limit temperature of the nematic phase, a small viscosity, an appropriate optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to light, a high stability to heat, a large elastic constant, and the like, it is preferred that the compound represented by Formula (S) and the compound represented by Formula (T) are not contained.

[0086]

[0087]

[0088] In Formula (S), R S1 and R S2fluorinated alkoxy, fluorine, chlorine or cyano; ring A S is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is substituted with fluorine, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; ring B S is 2,3-difluoro-1,4-phenylene, 4,6-difluorodibenzo-furan-3,7-diyl or 4,6-difluorodibenzo-thiophene-3,7-diyl; Z S is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy or difluoromethyleneoxy; s is 0, 1, 2 or 3;

[0089] In formula (T), R T1 and R T2 is alkyl, alkenyl, alkoxy, alkenyloxy, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy, fluorine, chlorine or cyano; ring A T is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is substituted with fluorine, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; t is 1 or 2.

[0090] Second, the main properties of the component compounds and the main effects of the compounds on the composition or the element are described. The main properties of the component compounds are summarized in Table 2. In the notation of Table 2, L means large or high, M means moderate, and S means small or low. The notation L, M, S is a classification based on a qualitative comparison between the component compounds, and the notation 0 (zero) means smaller than S.

[0091] Table 2. Properties of liquid crystalline compounds

[0092] Properties Compound (1) Compound (2) Compound (3) Compound (4) Compound (5) Upper limit temperature L S ~ L M ~ L S ~ L S ~ M Viscosity S ~ M M ~ L M ~ L S ~ M M ~ L Optical anisotropy S M ~ L M ~ L S ~ L M ~ L Dielectric anisotropy 0 M ~ L M ~ L 1) ]] 0 M ~ L 1) ]] Specific resistance L L L L L

[0093] 1) The value of dielectric anisotropy is negative, and the notation indicates the magnitude of the absolute value

[0094] The main effects of the component compounds are as follows. Compound (1) increases the upper limit temperature and the elastic constant. Compound (2) increases the dielectric anisotropy. Compound (3) increases the dielectric constant in the short axis direction. Compound (4) decreases the viscosity or increases the upper limit temperature. Compound (5) increases the dielectric constant in the short axis direction.

[0095] Third, the combination, preferable ratio and the like of the component compounds in the composition are described. The preferable combination of the component compounds in the composition is compound (1) + compound (2) + compound (3), compound (1) + compound (2) + compound (3) + compound (4), compound (1) + compound (2) + compound (3) + compound (5) or compound (1) + compound (2) + compound (4) + compound (5). Particularly preferable combination is compound (1) + compound (2) + compound (3) + compound (4).

[0096] In order to increase the upper limit temperature and the elastic constant, the preferable ratio of compound (1) is about 1 mass% or more, and in order to decrease the lower limit temperature, the preferable ratio of compound (1) is about 20 mass% or less. Further preferable ratio is in the range of about 5 mass% to about 20 mass%. Particularly preferable ratio is in the range of about 5 mass% to about 15 mass%.

[0097] In order to increase the dielectric anisotropy, the preferable ratio of compound (2) is about 10 mass% or more, and in order to decrease the lower limit temperature, the preferable ratio of compound (2) is about 85 mass% or less. Further preferable ratio is in the range of about 10 mass% to about 70 mass%. Particularly preferable ratio is in the range of about 10 mass% to about 50 mass%.

[0098] In order to increase the dielectric constant in the short axis direction, the preferable ratio of compound (3) is about 10 mass% or more, and in order to decrease the lower limit temperature, the preferable ratio of compound (3) is about 50 mass% or less. Further preferable ratio is in the range of about 10 mass% to about 40 mass%. Particularly preferable ratio is in the range of about 15 mass% to about 40 mass%.

[0099] In order to decrease the viscosity or in order to increase the upper limit temperature, the preferable ratio of compound (4) is about 10 mass% or more, and in order to increase the dielectric anisotropy, the preferable ratio of compound (4) is about 75 mass% or less. Further preferable ratio is in the range of about 20 mass% to about 70 mass%. Particularly preferable ratio is in the range of about 30 mass% to about 65 mass%.

[0100] In order to increase the dielectric constant in the short axis direction, the preferable ratio of compound (5) is about 1 mass% or more, and in order to decrease the lower limit temperature, the preferable ratio of compound (5) is about 30 mass% or less. Further preferable ratio is in the range of about 1 mass% to about 25 mass%. Particularly preferable ratio is in the range of about 1 mass% to about 20 mass%.

[0101] Fourth, the preferable form of the component compounds is described. In formula (1), formula (2), formula (3), formula (4) and formula (5), R 1is an alkyl group having 1 to 12 carbons or an alkenyl group having 2 to 12 carbons. In order to improve stability, the preferred R 1 is an alkyl group having 1 to 12 carbons. The particularly preferred R 1 is a propyl group. R 2 is an alkenyl group having 2 to 12 carbons. The preferred R 2 is an ethenyl group. R 3 is an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, or an alkenyl group having 2 to 12 carbons. In order to improve stability, the preferred R 3 is an alkyl group having 1 to 12 carbons. R 4 and R 5 are hydrogen, an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, an alkenyl group having 2 to 12 carbons, or an alkenyloxy group having 2 to 12 carbons. In order to improve stability, the preferred R 4 or R 5 is an alkyl group having 1 to 12 carbons, and in order to reduce viscosity, the preferred R 4 or R 5 is an alkenyl group having 2 to 12 carbons, and in order to improve dielectric anisotropy, the preferred R 4 or R 5 is an alkoxy group having 1 to 12 carbons. R 6 and R 7 are hydrogen, an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, an alkenyl group having 2 to 12 carbons, or an alkenyloxy group having 2 to 12 carbons. In order to reduce viscosity or in order to reduce the lower limit temperature, the preferred R 6 or R 7 is an alkenyl group having 2 to 12 carbons, and in order to improve stability, the preferred R 6 or R 7 is an alkyl group having 1 to 12 carbons. R 8 and R 9 are hydrogen, an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, an alkenyl group having 2 to 12 carbons, or an alkenyloxy group having 2 to 12 carbons. In order to improve stability, the preferred R 8 or R 9 is an alkyl group having 1 to 12 carbons, and in order to reduce viscosity, the preferred R 8 or R 9 is an alkenyl group having 2 to 12 carbons, and in order to improve dielectric anisotropy, the preferred R 8 or R 9 is an alkoxy group having 1 to 12 carbons.

[0102] The preferred alkyl group is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or an octyl group. In order to reduce viscosity, the further preferred alkyl group is a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group.

[0103] Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or heptyloxy. In order to reduce the viscosity, further preferred alkoxy groups are methoxy or ethoxy.

[0104] Preferred alkenyl groups are ethenyl, 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. In order to reduce the viscosity, further preferred alkenyl groups are ethenyl, 1-propenyl, 3-butenyl or 3-pentenyl. The preferred stereoconfiguration of the -CH=CH- in these alkenyl groups depends on the position of the double bond. In order to reduce the viscosity and for other reasons, the trans configuration is preferred in alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl. The cis configuration is preferred in alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl.

[0105] Preferred alkenyloxy groups are ethenyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy or 4-pentenyloxy. In order to reduce the viscosity, further preferred alkenyloxy groups are allyloxy or 3-butenyloxy.

[0106] Preferred examples of alkyl groups in which at least one hydrogen is replaced by fluorine or chlorine are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or 8-fluorooctyl. In order to increase the dielectric anisotropy, further preferred examples are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl.

[0107] Preferred examples of alkenyl groups in which at least one hydrogen is replaced by fluorine or chlorine are 2,2-difluoroethenyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl or 6,6-difluoro-5-hexenyl. In order to reduce the viscosity, further preferred examples are 2,2-difluoroethenyl or 4,4-difluoro-3-butenyl.

[0108] Ring A 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, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl. In order to increase the upper temperature limit, preferred is 1,4-cyclohexylene, in order to increase the optical anisotropy, preferred is 1,4-phenylene, in order to increase the dielectric anisotropy, preferred is 2,6-difluoro-1,4-phenylene. Tetrahydropyran-2,5-diyl is

[0109]

[0110] or

[0111]

[0112] preferably

[0113]

[0114] Ring B, ring D and ring G are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene substituted by fluorine or chlorine at least once, naphthalene-2,6-diyl, naphthalene-2,6-diyl substituted by fluorine or chlorine at least once, chrysen-2,6-diyl, or chrysen-2,6-diyl substituted by fluorine or chlorine at least once. Preferred examples of "1,4-phenylene substituted by fluorine or chlorine at least once" are 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene or 2-chloro-3-fluoro-1,4-phenylene. In order to reduce the viscosity, preferred ring B, ring D or ring G is 1,4-cyclohexylene, in order to increase the dielectric anisotropy, preferred ring B, ring D or ring G is tetrahydropyran-2,5-diyl, in order to increase the optical anisotropy, preferred ring B, ring D or ring G is 1,4-phenylene. Tetrahydropyran-2,5-diyl in ring B, ring D and ring G is

[0115]

[0116] or

[0117]

[0118] preferably

[0119]

[0120] Ring C is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochrysen-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl (FLF4) or 1,1,6,7-tetrafluoroindane-2,5-diyl (InF4). In order to increase the dielectric constant in the short axis direction, preferred ring C is 2,3-difluoro-1,4-phenylene.

[0121] Ring E and ring F are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene. In order to reduce the viscosity or in order to increase the upper temperature limit, preferred ring E or ring F is 1,4-cyclohexylene, in order to increase the optical anisotropy or in order to reduce the lower temperature limit, preferred ring E or ring F is 1,4-phenylene or 2-fluoro-1,4-phenylene.

[0122] Ring I is 2,3-difluoro-l,4-phenylene, 2-chloro-3-fluoro-l,4-phenylene, 2,3-difluoro-5-methyl-l,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-difluorodibenzo furan-3,7-diyl (DBFF2), 4,6-difluorodibenzo thiophene-3,7-diyl (DBTF2), or 1,1,6,7-tetrafluoroindane-2,5-diyl (InF4).

[0123]

[0124] To reduce viscosity, the preferred ring I is 2,3-difluoro-l,4-phenylene, and to increase dielectric anisotropy, the preferred ring I is 4,6-difluorodibenzo thiophene-3,7-diyl.

[0125] Z 1 is a single bond or vinylene. Z 2 is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethylenoxy. To reduce viscosity, the preferred Z 2 is a single bond, and to increase dielectric anisotropy, the preferred Z 2 is difluoromethylenoxy. Z 3 , Z 4 , and Z 6 is a single bond, ethylene, vinylene, methylenoxy, or carbonyloxy. To reduce viscosity, the preferred Z 3 , Z 4 , or Z 6 is a single bond, and to reduce the lower limit temperature, the preferred Z 3 , Z 4 , or Z 6 is ethylene, and to increase dielectric anisotropy, the preferred Z 3 , Z 4 , or Z 6 is methylenoxy. Z 5 is a single bond, ethylene, methylenoxy, or carbonyloxy. To reduce viscosity, the preferred Z 5 is a single bond.

[0126] The divalent groups such as methylenoxy are left-right asymmetric. In methylenoxy, -CH2O- is preferred to -OCH2-. In carbonyloxy, -COO- is preferred to -OCO-. In difluoromethylenoxy, -CF2O- is preferred to -OCF2-.

[0127] X 1 , and X 2 is hydrogen or fluorine. To increase dielectric anisotropy, the preferred X 1 , or X 2 is fluorine.

[0128] Y 1 is fluorine, chlorine, an alkyl group having a carbon number of 1 to 12 in which at least one hydrogen is replaced by fluorine or chlorine, an alkoxy group having a carbon number of 1 to 12 in which at least one hydrogen is replaced by fluorine or chlorine, or an alkenyloxy group having a carbon number of 2 to 12 in which at least one hydrogen is replaced by fluorine or chlorine. In order to improve the dielectric anisotropy, the preferred Y 1 is fluorine, an alkyl group having a carbon number of 1 to 12 in which at least one hydrogen is replaced by fluorine or chlorine, or an alkoxy group having a carbon number of 1 to 12 in which at least one hydrogen is replaced by fluorine or chlorine. The preferred example of the alkyl group in which at least one hydrogen is replaced by fluorine or chlorine is a trifluoromethyl group. The preferred example of the alkoxy group in which at least one hydrogen is replaced by fluorine or chlorine is a trifluoromethoxy group.

[0129] a is 1, 2, 3 or 4. In order to reduce the viscosity, the preferred a is 2, and in order to improve the dielectric anisotropy, the preferred a is 3. b is 1, 2 or 3, c is 0 or 1, and the sum of b and c is 2 or 3. The preferred combination of b and c is b is 1 and c is 1, or b is 2 and c is 0. d is 1, 2 or 3. In order to reduce the viscosity, the preferred d is 1, and in order to improve the upper limit temperature, the preferred d is 2 or 3. e is 0 or 1.

[0130] In formula (4), when d is 2 and both Z 5 is a single bond, ring F is a 1,4-phenylene group, a 2-fluoro-1,4-phenylene group or a 2,5-difluoro-1,4-phenylene group.

[0131] Fifth, preferred component compounds are shown. The preferred compound (1) is compound (1-1) and compound (1-2) described in item 2. The particularly preferred is compound (1-1) in which R 1 is a propyl group, and compound (1-2) in which R 1 is a propyl group. It is preferred that at least two of the components A are a combination of compound (1-1) and compound (1-2).

[0132] Preferred compounds (2) are compounds (2-1) to (2-36) described in item 4. Among these compounds, it is preferred that at least one of the component B is compound (2-2), compound (2-8), compound (2-13), compound (2-15), compound (2-16), compound (2-17), compound (2-19), compound (2-23), compound (2-24), compound (2-25), compound (2-27), compound (2-28), compound (2-30), or compound (2-31). Further preferred is that at least one of the component B is compound (2-19) or compound (2-30). Preferred is that at least two of the component B is a combination of compound (2-2) and compound (2-19), compound (2-2) and compound (2-24), compound (2-2) and compound (2-25), compound (2-2) and compound (2-30), compound (2-19) and compound (2-24), compound (2-19) and compound (2-25), or compound (2-19) and compound (2-30). Particularly preferred is that at least two of the component B is a combination of compound (2-19) and compound (2-30).

[0133] Preferred compounds (3) are compounds (3-1) to (3-20) described in item 6. Among these compounds, it is preferred that at least one of the component C is compound (3-1), compound (3-2), compound (3-3), compound (3-7), compound (3-12), compound (3-13), or compound (3-14). Particularly preferred is that at least one of the component C is compound (3-1) or compound (3-7). Particularly preferred is that at least one of the component C is R 4 compound (3-1) which is an alkenyl group having 2 to 4 carbons, or R 4 compound (3-7) which is an alkenyl group having 2 to 4 carbons. Preferred is that at least two of the component C is a combination of compound (3-1) and compound (3-7).

[0134] Preferred compounds (4) are compounds (4-1) to (4-13) described in item 9. Among these compounds, it is preferred that at least one of the component D is compound (4-1), compound (4-3), compound (4-5), compound (4-6), compound (4-7), compound (4-8), or compound (4-10). Particularly preferred is that at least one of the component D is compound (4-1), compound (4-5), compound (4-8), or compound (4-10). Preferred is that at least one of R 6 and R 7 compound (4) which is an alkenyl group having 2 to 4 carbons. Preferred is that at least one of R 6 and R 7Compounds (4-1) in which R is a propyl group, a vinyl group or a 1-propenyl group. Particularly preferred are compounds (4-1) in which R 6 Compounds (4-1) in which R is a propyl group or a 1-propenyl group and R 7 Compounds (4-1) in which R is a vinyl group. The proportion of compounds (4-1) in which R is a vinyl group is preferably 30% by mass or more, particularly preferably 40% by mass or more. 7 The proportion of compounds (4-1) in which R is a vinyl group is preferably 30% by mass or more, particularly preferably 40% by mass or more.

[0135] Preferred compounds (5) are compounds (5-1) to (5-15) described in item 12. Of these compounds, it is preferred that at least one of the components E is a compound (5-1), a compound (5-2), a compound (5-3), a compound (5-6) or a compound (5-7).

[0136] Preferred are compounds (2) in which ring A is a 1,4-phenylene group, a 2-fluoro-1,4-phenylene group, a 2,6-difluoro-1,4-phenylene group or a 1,3-dioxane-2,5-diyl group, and the total proportion of these compounds and the compound (3) is preferably 20% by mass or more, particularly preferably 25% by mass or more.

[0137] Sixth, additives which can be added to the composition are described. Such additives are optically active compounds, antioxidants, ultraviolet absorbers, flatting agents, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds and the like. An optically active compound is added to the composition for the purpose of inducing a helical structure of liquid crystal molecules to impart a torsion angle. Examples of such compounds are compounds (6-1) to (6-5). The preferred proportion of the optically active compound is about 5% by mass or less. Further, the preferred proportion is in the range of about 0.01% by mass to about 2% by mass.

[0138]

[0139] In order to prevent a decrease in specific resistance caused by heating in the atmosphere or in order to maintain a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after the element is used for a long time, an antioxidant such as a compound (7-1) to (7-3) can further be added to the composition.

[0140]

[0141] The compound (7-2) is effective in maintaining a large voltage retention rate not only at room temperature but also at a temperature close to the upper limit temperature after the element is used for a long time because of small volatility. In order to obtain the effect, the preferable proportion of the antioxidant is about 50 ppm or more, and in order not to lower the upper limit temperature or not to raise the lower limit temperature, the preferable proportion of the antioxidant is about 600 ppm or less. Further, the preferable proportion is in the range of about 100 ppm to about 300 ppm.

[0142] The preferable examples of the ultraviolet absorber are benzophenone derivatives, benzoate derivatives, triazole derivatives, and the like. In addition, a light stabilizer such as an amine having steric hindrance is also preferable. The preferable examples of the light stabilizer are compounds (8-1) to (8-16), and the like. In order to obtain the effect, the preferable proportion of these absorbers or stabilizers is about 50 ppm or more, and in order not to lower the upper limit temperature or not to raise the lower limit temperature, the preferable proportion of these absorbers or stabilizers is about 10,000 ppm or less. Further, the preferable proportion is in the range of about 100 ppm to about 10,000 ppm.

[0143]

[0144]

[0145] The light extinction agent is a compound that prevents the decomposition of the liquid crystalline compound by accepting the light energy absorbed by the liquid crystalline compound and converting it into heat energy. The preferable examples of the light extinction agent are compounds (9-1) to (9-7), and the like. In order to obtain the effect, the preferable proportion of these light extinction agents is about 50 ppm or more, and in order not to raise the lower limit temperature, the preferable proportion of these light extinction agents is about 20,000 ppm or less. Further, the preferable proportion is in the range of about 100 ppm to about 10,000 ppm.

[0146]

[0147] In order to be suitable for a guest host (GH) mode element, a dichroic dye such as an azo-based dye, an anthraquinone-based dye, and the like is added to the composition. The preferable proportion of the dye is in the range of about 0.01 mass% to about 10 mass%. In order to prevent bubbling, an antifoaming agent such as a dimethyl silicone oil, a methylphenyl silicone oil, and the like is added to the composition. In order to obtain the effect, the preferable proportion of the antifoaming agent is about 1 ppm or more, and in order to prevent display malfunctions, the preferable proportion of the antifoaming agent is about 1,000 ppm or less. Further, the preferable proportion is in the range of about 1 ppm to about 500 ppm.

[0148] In order to be suitable for a polymer sustained alignment (PSA) type of element, a polymerizable compound is used. Preferred examples of such a polymerizable compound are acrylate, methacrylate, vinyl compound, vinyloxy compound, propenyl ether, epoxy compound (oxirane, oxetane), vinyl ketone, and the like. Further preferred examples are derivatives of acrylate or methacrylate. The preferable proportion is about 10% by mass or more, based on the total mass of the polymerizable compound. Further preferable proportion is about 50% by mass or more. Particularly preferable proportion is about 80% by mass or more. The most preferable proportion is 100% by mass.

[0149] In the case of storing the polymerizable compound, a polymerization inhibitor can also be added in order to prevent polymerization. The polymerizable compound is usually added to the composition in a state in which the polymerization inhibitor has not been removed. Examples of the polymerization inhibitor are hydroquinone, hydroquinone derivatives such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, phenothiazine, and the like.

[0150] The polar compound is an organic compound having polarity. Here, a compound having an ionic bond is not included. An atom such as oxygen, sulfur, and nitrogen is electronegative and has a tendency to have a partial negative charge. Carbon and hydrogen are neutral or have a tendency to have a partial positive charge. Polarity is generated due to the uneven distribution of partial charges between different kinds of atoms in a compound. For example, the polar compound has at least one of partial structures such as -OH, -COOH, -SH, -NH2, >NH, >N-.

[0151] Seventh, the synthesis method of the component compounds is described. These compounds can be synthesized using known methods. An example of the synthesis method is described. Compound (1-1) is synthesized using the method described in the specification of German Patent Application Publication No. 4414647. Compound (2-19) is synthesized using the method described in Japanese Patent Kokai No. 10-251186. Compound (3-1) and compound (5-1) are synthesized using the method described in Japanese Patent Tokkai No. 2-503441. Compound (4-1) is synthesized using the method described in Japanese Patent Kokai No. 59-176221. An antioxidant is commercially available. Compound (7-1) is available from Sigma-Aldrich Corporation. Compound (7-2) and the like are synthesized by the method described in the specification of U.S. Patent No. 3660505.

[0152] Compounds for which no synthesis method is described can be synthesized using the methods described in the following books: Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), New Experimental Chemistry Course (Maruzen), and the like. The composition is prepared from the compounds obtained in the described manner using known methods. For example, the component compounds are mixed, and then dissolved in each other by heating.

[0153] Finally, the use of the composition is described. The composition has a lower limit temperature of about -10°C or lower, an upper limit temperature of about 70°C or higher, and an optical anisotropy in the range of about 0.07 to about 0.20. A composition having an optical anisotropy in the range of about 0.08 to about 0.25 can also be prepared by controlling the ratio of the component compounds, or by mixing other liquid crystalline compounds. A composition having an optical anisotropy in the range of about 0.10 to about 0.30 can also be prepared by trial and error. An element containing the composition has a large voltage holding ratio. The composition is suitable for an AM element. The composition is particularly suitable for a transmissive AM element. The composition can be used as a composition having a nematic phase, and can be used as an optically active composition by adding an optically active compound.

[0154] The composition can be used for an AM element. Further, it can also be used for a PM element. The composition can be used for an AM element and a PM element having a PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA, or the like mode. It is particularly preferable to be used for an AM element having a TN, OCB, IPS mode, or FFS mode. In an AM element having an IPS mode or FFS mode, the alignment of the liquid crystal molecules can be parallel to the glass substrate, or can also be vertical, when no voltage is applied. These elements can be reflective, transmissive, or semi-transmissive. It is preferable to be used for a transmissive element. It can also be used for an amorphous silicon-TFT element or a polycrystalline silicon-TFT element. The composition can also be used for an element of a nematic curvilinear aligned phase (NCAP) type prepared by microencapsulation, or an element of a polymer dispersed (PD) type formed by forming a three-dimensional network polymer in the composition.

[0155] [Examples]

[0156] The present application is further explained by way of examples. The present application is not limited by these examples. The present application includes a mixture of the composition of Example 1 and the composition of Example 2. The present application also includes a mixture of at least two of the compositions of the examples. The synthesized compounds are identified by methods such as Nuclear Magnetic Resonance (NMR) analysis. The properties of the compounds, compositions, and elements are measured by the methods described below.

[0157] NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for measurement. 1 In the measurement of H-NMR, the sample was dissolved in deuterated solvent such as CDCl3, and measurement was performed at room temperature at 500 MHz with a cumulative number of 16 times. Tetramethylsilane was used as an internal standard. 19 In the measurement of F-NMR, CFCI3 was used as an internal standard, and measurement was performed with a cumulative number of 24 times. In the description of nuclear magnetic resonance spectra, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, m means multiplet, and br means broad.

[0158] Gas chromatography analysis: GC-14B manufactured by Shimadzu Corporation was used for measurement. The carrier gas was helium (2 mL / min). The sample vaporization chamber was set to 280°C, and the detector (flame ionization detector (FID)) was set to 300°C. A capillary column DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm; stationary liquid phase: dimethylpolysiloxane; non-polar) manufactured by Agilent Technologies Inc. was used for separation of the component compounds. The column was kept at 200°C for 2 minutes, and then raised to 280°C at a rate of 5°C / min. The sample was prepared as an acetone solution (0.1 mass%), and 1 μL thereof was injected into the sample vaporization chamber. The recording was performed using a Chromatopac C-R5A manufactured by Shimadzu Corporation or an equivalent product. The obtained gas chromatogram showed the retention time of the peak corresponding to the component compound and the area of the peak.

[0159] As a solvent for diluting the sample, chloroform, hexane, or the like can be used. In order to separate the component compounds, a capillary column such as HP-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by Agilent Technologies Inc., Rtx-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by Restek Corporation, or BP-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by SGE International Pty. Ltd. in Australia can be used. In order to prevent overlapping of the peaks of the compounds, a capillary column CBP1-M50-025 (length 50 m, inner diameter 0.25 mm, film thickness 0.25 μm) manufactured by Shimadzu Seisakusho can be used.

[0160] The proportion of the liquid crystalline compound contained in the composition can be calculated by the following method. The mixture of the liquid crystalline compounds is analyzed by gas chromatography (FID). The area ratio of the peaks in the gas chromatogram corresponds to the proportion of the liquid crystalline compounds. When the above-mentioned capillary column is used, the correction factor of each liquid crystalline compound can be regarded as 1. Therefore, the proportion (mass %) of the liquid crystalline compounds can be calculated from the area ratio of the peaks.

[0161] Measurement of sample: In the measurement of the properties of the composition or the element, the composition is directly used as the sample. In the measurement of the properties of the compound, a sample for measurement is prepared by mixing the compound (15 mass %) in a mother liquid crystal (85 mass %). From the values obtained by the measurement, the property values of the compound are calculated by an extrapolation method. (Extrapolated value) = {(measured value of the sample) - 0.85 x (measured value of the mother liquid crystal)} / 0.15. When the smectic phase (or crystal) is precipitated at 25°C at the above-mentioned proportion, the proportion of the compound to the mother liquid crystal is changed in the order of 10 mass %:90 mass %, 5 mass %:95 mass %, 1 mass %:99 mass %. The values of the upper limit temperature, the optical anisotropy, the viscosity, and the dielectric anisotropy related to the compound are calculated by the extrapolation method.

[0162] The following mother liquid crystal was used. The proportion of the component compound is represented by mass %.

[0163]

[0164] Measurement Methods: The characteristics are measured using the methods described below. These methods are mostly those described in the JEITA standard (JEITA·ED-2521B) reviewed and formulated by the Japan Electronics and Information Technology Industries Association (JEITA), or modified versions thereof. No thin-film transistors (TFTs) are mounted on the TN element used for measurement.

[0165] (1) Upper limit temperature of nematic phase (NI; °C): The sample is placed on a hot plate of a melting point measuring apparatus equipped with a polarizing microscope and heated at a rate of 1 °C / min. The temperature at which a portion of the sample changes from a nematic phase to an isotropic liquid is measured. Sometimes the upper limit temperature of the nematic phase is simply referred to as the "upper limit temperature".

[0166] (2) Lower limit temperature of nematic phase (T) C (℃): Place the sample containing the nematic phase in a glass bottle and store it in a freezer at 0℃, -10℃, -20℃, -30℃, and -40℃ for 10 days, then observe the liquid crystal phase. For example, if the sample remains in the nematic phase at -20℃ but changes to a crystalline or lamellar phase at -30℃, then T C It is recorded as <-20℃. Sometimes the lower limit temperature of the nematic phase is simply referred to as the "lower limit temperature".

[0167] (3) Viscosity (volume viscosity; η; measured at 20°C; mPa·s): The E-type rotational viscometer manufactured by Tokyo Keiki Co., Ltd. was used for the measurement.

[0168] (4-1) Viscosity (Rotational viscosity; γ1(25); measured at 25°C; mPa-s): Measured according to the method described in M. Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37 (1995). The sample was put in a TN cell with a twist angle of 0° and a cell gap of 5 μm between two glass substrates. Voltage was applied to the cell stepwise in the range of 16 to 19.5 V with a unit of 0.5 V. After 0.2 seconds from the application of voltage, the voltage was applied repeatedly with the condition of applying only one rectangular wave (rectangular pulse; 0.2 seconds) and not applying (2 seconds). The peak current and the peak time of the transient current generated by the application were measured. The value of the rotational viscosity was obtained according to these measured values and the calculation formula (10) described on page 40 of the paper by M. Imai et al. The value of the dielectric anisotropy required in the calculation was obtained using the cell for measuring the rotational viscosity and by the method described below.

[0169] (4-2) Viscosity (Rotational viscosity; γ1(-30); measured at -30°C; mPa-s): Same as (4-1) except that the measurement was performed at -30°C.

[0170] (5) Optical anisotropy (Refractive index anisotropy; Δn; measured at 25°C): Measured using an Abbe refractometer with a polarizing plate mounted on an ocular lens using light of wavelength 589 nm. After rubbing the surface of a main prism in one direction, the sample was dropped onto the main prism. The refractive index n∥ was measured when the direction of polarization was parallel to the direction of rubbing. The refractive index n⊥ was measured when the direction of polarization was perpendicular to the direction of rubbing. The value of the optical anisotropy was calculated according to the formula Δn = n∥ - n⊥.

[0171] (6) Dielectric anisotropy (Δε; measured at 25°C): The sample was put in a TN cell with a cell gap of 9 μm between two glass substrates and a twist angle of 80 degrees. The dielectric constant in the long axis direction of the liquid crystal molecule (ε∥) was measured after applying a sine wave (10 V, 1 kHz) to the cell for 2 seconds. The dielectric constant in the short axis direction of the liquid crystal molecule (ε⊥) was measured after applying a sine wave (0.5 V, 1 kHz) to the cell for 2 seconds. The value of the dielectric anisotropy was calculated according to the formula Δε = ε∥ - ε⊥.

[0172] (7-1) Threshold voltage (Vth(25); measured at 25°C; V): A brightness meter (Liquid Crystal Display (LCD) 5100 type) manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The light source was a halogen lamp. The sample was placed in an FFS element having a cell gap of 3.2 (μm) between two glass substrates. A voltage (32 Hz, rectangular wave) was applied to the element, which was increased from 0 V to 10 V in stages of 0.01 V. At this time, light was irradiated to the element from the vertical direction, and the amount of light transmitted through the element was measured. A voltage-transmittance curve was prepared in which the transmittance was 100% at the time when the amount of light was the maximum and the transmittance was 0% at the time when the amount of light was the minimum. The threshold voltage was represented by the voltage at which the transmittance was 90%.

[0173] (7-2) Threshold voltage (Vth(-30); measured at -30°C; V): The same as (7-1) except that the measurement was performed at -30°C.

[0174] (8) Voltage holding ratio (VHR-9; measured at 25°C; %): A TN element used for the measurement had a polyimide alignment film, and the cell gap between two glass substrates was 5 μm. The element was sealed with an adhesive that was hardened with ultraviolet light after the sample was placed therein. The element was charged by applying a pulse voltage (1 V, 60 μsec) thereto. The voltage that attenuated during 1000 msec was measured with a high-speed voltmeter, and the area A between the voltage curve per cycle and the horizontal axis was calculated. The area B was the area when there was no attenuation. The voltage holding ratio was represented by the percentage of the area A with respect to the area B.

[0175] (9) Voltage holding ratio (VHR-10; measured at 60°C; %): The voltage holding ratio was measured in the same procedure as described above except that the measurement was performed at 60°C instead of 25°C. The obtained value is represented by VHR-10.

[0176] (10) Voltage holding ratio (VHR-11; measured at 60°C; %): The voltage holding ratio was measured after irradiation of ultraviolet light, and the stability to ultraviolet light was evaluated. A TN element used for the measurement had a polyimide alignment film, and the cell gap was 5 μm. The sample was injected into the element, and ultraviolet light (5 mW / cm2) was irradiated for 167 minutes. The light source was a black light (peak wavelength 369 nm) manufactured by EYE GRAPHICS Co., Ltd., and the distance between the element and the light source was 5 mm. In the measurement of VHR-11, the voltage that attenuated during 1000 msec was measured. A composition having a large VHR-11 had a large stability to ultraviolet light. 2

[0177] ​(11) Voltage holding ratio (VHR-12; measured at 60°C; %): The voltage holding ratio was measured after a TN element into which a sample was injected was heated in a constant temperature bath at 120°C for 20 hours, to evaluate stability against heat. In the measurement of VHR-12, the voltage that attenuated in a period of 1000 milliseconds was measured. A composition having a large VHR-12 has a large stability against heat.

[0178] (12) Voltage holding ratio (VHR-13; measured at 60°C; %): The voltage holding ratio was measured after a TN element into which a sample was injected was heated in a constant temperature bath at 100°C for three weeks, to evaluate stability against heat. In the measurement of VHR-13, the voltage that attenuated in a period of 1000 milliseconds was measured. A composition having a large VHR-13 has a large stability against heat.

[0179] (13) Voltage holding ratio (VHR-14; measured at 60°C; %): The voltage holding ratio was measured after a TN element into which a sample was injected was left on a backlight for two weeks, to evaluate stability against a backlight. In the measurement of VHR-14, the voltage that attenuated in a period of 1000 milliseconds was measured. A composition having a large VHR-14 has a large stability against a backlight.

[0180] (14-1) Response time (τ(25); measured at 25°C; ms): An LCD brightness meter Model LCD5100 manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The light source was a halogen lamp. A low-pass filter was set to 5 kHz. A sample was put in an FFS element in which the interval between two glass substrates (cell gap) was 3.2 μm. A rectangular wave (60 Hz, 5 V, 0.5 seconds) was applied to the element. At this time, light was irradiated to the element from the vertical direction, and the amount of light that passed through the element was measured. The transmittance was regarded as 100% when the amount of light became the maximum, and as 0% when the amount of light was the minimum. The rise time (τr: risetime; milliseconds) was the time required for the transmittance to change from 90% to 10%. The fall time (τf: fall time; milliseconds) was the time required for the transmittance to change from 10% to 90%. The response time was represented by the sum of the rise time and the fall time that were calculated in this manner.

[0181] (14-2) Response time (τ(-30); measured at -30°C; ms): The same as (14-1), except that the measurement was performed at -30°C and the application conditions of the rectangular wave were changed (60 Hz, 5 V, 15 seconds).

[0182] (15) Elastic constant (K; measured at 25°C; pN): The measurement was performed using an HP4284A-type LCR meter manufactured by Yokogawa Hewlett Packard, Inc. A sample was placed in a horizontal alignment element having a cell gap of 20 μm between two glass substrates. An electric charge of 0 volt to 20 volts was applied to the element, and the static capacitance and the applied voltage were measured. The measured values of the static capacitance (C) and the applied voltage (V) were fitted using the formula (2.98), formula (2.101) in "Liquid Crystal Device Handbook" (Nikkan Kogyo Shimbun), page 75, and the values of K11 and K33 were obtained according to formula (2.99). Next, the values of K11 and K33 just obtained were used in formula (3.18) in "Liquid Crystal Device Handbook", page 171, to calculate K22. The elastic constant was represented by the average of K11, K22 and K33 obtained in this manner.

[0183] (16) Specific resistance (p; measured at 25°C; Ωcm): A sample 1.0 mL was injected into a container provided with an electrode. A direct current voltage (10 V) was applied to the container, and the direct current after 10 seconds was measured. The specific resistance was calculated according to the following formula. (Specific resistance) = {(Voltage) x (Capacitance of the container)} / {(Direct current) x (Dielectric constant of vacuum)}.

[0184] (17) Pitch (P; measured at room temperature; μm): The pitch was measured by the wedge method. Refer to "Liquid Crystal Concise", page 196 (issued in 2000, Maruzen). A sample was injected into a wedge cell, and the interval (d2-dl) of disclination lines was observed by a polarizing microscope (Nikon (K.K.), trade name MM40 / 60 series) after standing at room temperature for 2 hours. The pitch (P) was calculated according to the following formula in which the angle of the wedge cell is represented by θ. P = 2 x (d2-dl) x tan θ.

[0185] (18) Dielectric constant in short axis direction (ε⊥; measured at 25°C): A sample was placed in a TN element having a cell gap of 9 μm between two glass substrates, and a twist angle of 80 degrees. A sinusoidal wave (0.5 V, 1 kHz) was applied to the element, and the dielectric constant in the short axis direction of the liquid crystal molecules (ε⊥) was measured after 2 seconds.

[0186] (19) Frequency dependence of dielectric anisotropy (F10; measured at -20°C): A sample was placed in a TN element with a 9 μm gap (cell gap) between two glass substrates and a twist angle of 80 degrees. A sine wave (0.5V, 100Hz, 200Hz, 500Hz, 800Hz, 1kHz, 2kHz, 5kHz, 8kHz, 10kHz, 20kHz, 50kHz, 80kHz, 100kHz) was applied to the element, and the dielectric constant (ε⊥) of the liquid crystal molecules in the short axis direction was measured after 2 seconds. The frequency at which the dielectric anisotropy decreased by 10% relative to the dielectric anisotropy at 100Hz was defined as F10. The larger the F10, the smaller the frequency dependence.

[0187] Examples of the compositions are shown below. The constituent compounds are represented by symbols based on the definitions in Table 3 below. In Table 3, the stereoconfiguration associated with 1,4-cyclohexylene is the trans configuration. The number in parentheses following the symbolized compound indicates the chemical formula to which the compound belongs. The symbol (-) indicates other liquid crystal compounds. The proportion (percentage) of the liquid crystal compounds is a mass percentage (mass %) based on the mass of the liquid crystal composition excluding additives. Finally, the characteristic values ​​of the compositions are summarized.

[0188] Table 3. Representation of compounds using notations

[0189] R-(A1)-Z1-·····-Z n -(A n )-R'

[0190]

[0191] [Comparative Example 1]

[0192] Prepare a composition that does not contain compound (1).

[0193]

[0194]

[0195] NI=105.2℃; Tc<-20℃; Δn=0.111; Δε=2.7; ε⊥ / Δε=1.3; Vth(25)=2.81V; Vth(-30)=3.52V; γ 1(25)=73.7mPa·s; γ1(-30)=2835.5mPa·s; τ(25)=25.2ms; τ(-30)=669.5ms; F10=260Hz.

[0196] [Example 1]

[0197]

[0198] NI=105.3℃; Tc<-40℃; Δn=0.111; Δε=2.7; ε⊥ / Δε=1.3; Vth(25)=2.85V; Vth(-30)=3.32V; γ1(25)=67.2mPa ·s; γ1(-30)=2311.5mPa·s; τ(25)=23.2ms; τ(-30)=539.5ms; F10=330Hz; VHR-10=95.1%; VHR-14=79.7%.

[0199] [Example 2]

[0200]

[0201]

[0202] NI=104.3℃; Tc<-40℃; Δn=0.111; Δε=2.6; ε⊥ / Δε=1.4; Vth(25)=2.83V; Vth(-30)=3.02V; γ1(25)=71.0mPa ·s; γ1(-30)=2154.1mPa·s; τ(25)=23.6ms; τ(-30)=494.3ms; F10=570Hz; VHR-10=94.8%; VHR-14=79.3%.

[0203] The physical property values ​​of Comparative Example 1, Example 1, and Example 2 are summarized in Table 4.

[0204] Table 4. Summary of physical property values

[0205] Comparative Example 1 Example 1 Example 2 Vth(25) (V) 2.81 2.85 2.83 Vth(-30) (V) 3.52 3.32 3.02 γ1(25) (mPa-s) 73.7 67.2 71.0 γ1(-30) (mPa-s) 2835.5 2311.5 2154.1 τ(25) (ms) 25.2 23.2 23.6 τ(-30) (ms) 669.5 539.5 494.3 F10 (Hz) 260 330 570 ε⊥ / Δε 1.3 1.3 1.4

[0206] Regarding the threshold voltage (Vth), it was confirmed in Comparative Example 1 that the value at -30°C shifted towards a higher voltage side of 0.71V compared to the value at 25°C. On the other hand, it was confirmed in Examples 1 and 2 that the shifts stopped at 0.47V and 0.19V, respectively, and that Examples 1 and 2 were lower voltages at -30°C compared to Comparative Example 1.

[0207] Regarding rotational viscosity (γ1), Comparative Example 1 was compared with Examples 1 and 2, and it was confirmed that Examples 1 and 2 had low rotational viscosity, especially at -30°C, where they had significantly low rotational viscosity.

[0208] Regarding the response time (τ), Comparative Example 1 was compared with Examples 1 and 2, and it was confirmed that Examples 1 and 2 have short response times, especially at -30°C, where they have significantly shorter response times.

[0209] Figure 1This is a graph showing the frequency dependence of dielectric anisotropy at -20°C. It can be seen that Comparative Example 1 is located on the lower frequency side, where the dielectric anisotropy begins to decrease. Comparing F10, Comparative Example 1 is 260Hz, while Examples 1 and 2 are 330Hz and 570Hz, respectively. This indicates that Examples 1 and 2 have lower frequency dependence of dielectric anisotropy at -20°C.

[0210] As described above, the composition of the present invention has excellent response characteristics, and on the other hand, ε⊥ / Δε is equal to or better than that of Comparative Example 1. That is, in the present invention, transmittance can be maintained at or better than that of Comparative Example 1, and response characteristics are significantly improved.

[0211] [Example 3]

[0212]

[0213] NI=105.7℃; Tc<-30℃; Δn=0.102; Δε=3.0; ε⊥ / Δε=1.3; γ1(25)=83.7mPa·s; γ1(-30)=2600.0mPa·s; τ(25)=23.5ms; τ(-30)=614.0ms.

[0214] [Example 4]

[0215]

[0216] NI=105.8℃; Tc<-40℃; Δn=0.102; Δε=2.7; ε⊥ / Δε=1.3; γ1(25)=64.0mPa·s; γ1(-30)=2127.0mPa·s; τ(25)=23.6ms; τ(-30)=502.2ms.

[0217] [Example 5]

[0218]

[0219] NI=105.3℃; Tc<-40℃; Δn=0.101; Δε=2.6; ε⊥ / Δε=1.4; γ1(25)=69.0mPa·s; γ1(-30)=2326.0mPa·s; τ(25)=24.5ms; τ(-30)=533.0ms.

[0220] [Example 6]

[0221]

[0222] NI=105.4℃; Tc<-30℃; Δn=0.110; Δε=3.8; ε⊥ / Δε=1.4; γ1(25)=69.0mPa·s; γ1(-30)=2512.0mPa·s; τ(25)=25.5ms; τ(-30)=573.6ms.

[0223] [Example 7]

[0224]

[0225] NI=106.0℃; Tc<-30℃; Δn=0.127; Δε=2.6; ε⊥ / Δε=1.5; γ1(25)=81.6mPa·s

[0226] The following conclusions were drawn: the composition of the present invention and the liquid crystal display element using the same have excellent properties such as large ε⊥ / Δε, low rotational viscosity, low threshold voltage, short response time, and low frequency dependence of dielectric anisotropy, and have particularly excellent properties at low temperatures.

[0227] [Industry availability]

[0228] The liquid crystal composition of the present invention can be used in liquid crystal monitors, liquid crystal televisions, etc.

Claims

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 at least one compound selected from the compounds represented by formula (3) as component C, and having positive dielectric anisotropy. In equation (1), R 1 It is an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms; R 2 Alkenes with 2 to 12 carbon atoms; Z 1 It is a single bond or a vinylidene bond; In equation (2), R 3 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; ring A is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidin-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; Z 2 It is a single bond, ethylidene, vinylidene, carbonyloxy, or difluoromethoxy; X 1 and X 2 It is hydrogen or fluorine; Y 1 It is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms that has at least one hydrogen atom substituted with fluorine or chlorine, an alkoxy group having 1 to 12 carbon atoms that has at least one hydrogen atom substituted with fluorine or chlorine, or an alkenoxy group having 2 to 12 carbon atoms that has at least one hydrogen atom substituted with fluorine or chlorine; a is 1, 2, 3 or 4; In equation (3), R 4 and R 5 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, or an alkenyloxy group having 2 to 12 carbon atoms; ring B and ring D are 1,4-cyclohexene, 1,4-cyclohexenyl, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene with at least one hydrogen atom substituted with fluorine or chlorine, naphth-2,6-diyl, naphth-2,6-diyl with at least one hydrogen atom substituted with fluorine or chlorine, chromoline-2,6-diyl, or At least one hydrogen atom is fluorinated or chlorinated and is a chromoline-2,6-diyl; the ring C is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthyl-2,6-diyl, 7,8-difluorochromoline-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, or 1,1,6,7-tetrafluoroindane-2,5-diyl; Z 3 and Z 4 It is a single bond, ethylidene, vinylidene, methoxy, or carbonyl; b is 1, 2, or 3, c is 0 or 1; and the sum of b and c is 2 or 3.

2. The liquid crystal composition according to claim 1, comprising at least one compound selected from the compounds represented by formulas (1-1) and (1-2) as component A; In equations (1-1) and (1-2), R 1 It is an alkyl group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms.

3. The liquid crystal composition according to claim 1 or 2, wherein, The proportion of component A ranges from 1% to 20% by mass.

4. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formulas (2-1) to (2-36) as component B; In equations (2-1) to (2-36), R 3 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.

5. The liquid crystal composition according to claim 1 or 2, wherein, The proportion of component B ranges from 10% to 85% by mass.

6. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formulas (3-1) to (3-20) as component C; In equations (3-1) to (3-20), R 4 and R 5 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, or an alkenyloxy group having 2 to 12 carbon atoms.

7. The liquid crystal composition according to claim 1 or 2, wherein, The proportion of component C ranges from 10% to 50% by mass.

8. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formula (4) as component D; In equation (4), 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 substituted with at least one hydrogen atom by fluorine or chlorine; ring E and ring F are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 5 It is a single bond, ethylene, methyleneoxy, or carbonyloxy; d is 1, 2, or 3; wherein, In d=2 and two Z 5 When it is a single bond, the ring F is 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene.

9. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formulas (4-1) to (4-13) as component D; In equations (4-1) to (4-13), 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 that has at least one hydrogen atom substituted with fluorine or chlorine.

10. The liquid crystal composition according to claim 8, wherein, The proportion of component D ranges from 10% to 75% by mass.

11. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formula (5) as component E; In equation (5), 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, or an alkenyloxy group having 2 to 12 carbon atoms; ring G is 1,4-cyclohexene, 1,4-cyclohexenyl, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene with at least one hydrogen substituted by fluorine or chlorine, naphth-2,6-diyl, naphth-2,6-diyl with at least one hydrogen substituted by fluorine or chlorine, chromoline-2,6-diyl, or chromoline-2,6-diyl with at least one hydrogen substituted by fluorine or chlorine. -Diyl; ring I is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthyl-2,6-diyl, 7,8-difluorochrome-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-tetrafluoroindane-2,5-diyl; Z 6 It is a single bond, ethylidene, vinylidene, methyleneoxy, or carbonyloxy; e is 0 or 1.

12. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the compounds represented by formulas (5-1) to (5-15) as component E; In equations (5-1) to (5-15), 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, or an alkenyloxy group having 2 to 12 carbon atoms.

13. The liquid crystal composition according to claim 11, wherein, The proportion of component E ranges from 1% to 30% by mass.

14. The liquid crystal composition according to claim 1 or 2, wherein, The upper limit temperature of the nematic phase is 70°C or higher, and the optical anisotropy at a wavelength of 589 nm measured at 25°C is 0.07 or higher, and the dielectric anisotropy at a frequency of 1 kHz measured at 25°C is 2.0 or higher.

15. The liquid crystal composition according to claim 1 or 2, for use in a liquid crystal display element operating in an in-plane switching mode or an edge field switching mode.

16. A liquid crystal display element comprising the liquid crystal composition as described in any one of claims 1 to 14.

17. The liquid crystal display element according to claim 16, wherein, The liquid crystal display element operates in the following modes: twisted nematic mode, electrically controlled birefringence mode, optically compensated bending mode, in-plane switching mode, edge field switching mode, or electric field-induced light response orientation mode, and the liquid crystal display element is driven by an active matrix.

18. Use of a liquid crystal composition, said liquid crystal composition being the liquid crystal composition as described in any one of claims 1 to 14, for use in a liquid crystal display element.

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