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

Abstract

The present invention provides a liquid crystal composition, a liquid crystal display element, and a use of the liquid crystal composition, the liquid crystal composition having characteristics such as high upper limit temperature, low lower limit temperature, low viscosity, large optical anisotropy, large negative dielectric anisotropy, large elastic constant, large specific resistance, high stability with respect to light, and high stability with respect to heat. At least one characteristic is fully satisfied, or at least two characteristics are properly balanced. The liquid crystal composition contains, as component A, a specific compound having large optical anisotropy and large negative dielectric anisotropy. A specific compound having a high upper limit temperature or a low viscosity as component B, a specific compound having a large negative dielectric anisotropy as component C, or a specific compound having a polymerizable group as additive X may be contained.

Description

Technical Field

[0001] The present invention relates to a liquid crystal composition, a liquid crystal display element containing the composition, and the use of the liquid crystal composition. In particular, it relates to a liquid crystal composition having a negative dielectric anisotropy and a liquid crystal display element containing the composition and having modes such as IPS, VA, FFS, FPA, etc. It also relates to a polymer-stabilized alignment type liquid crystal display element. Background Art

[0002] In liquid crystal display elements, the classification based on the operation 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), etc. The classification based on the driving method of the element is passive matrix (PM) and active matrix (AM). PM is classified as static, multiplex, etc., and AM is classified as thin film transistor (TFT), metal insulator metal (MIM), etc. The classification of TFT is amorphous silicon and polycrystalline silicon. The latter is classified into a high-temperature type and a low-temperature type according to the manufacturing process. The classification based on the light source is a reflective type using natural light, a transmissive type using a backlight, and a transflective 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 associated with the temperature range in which the element can be used. The preferred upper limit temperature of the nematic phase is about 70 °C or higher, and the preferred lower limit temperature of the nematic phase is about -10 °C or lower. The viscosity of the composition is associated with the response time of the element. In order for the element to display a moving image, a short response time is preferred. An ideal response time is shorter than 1 millisecond. Therefore, a low viscosity of the composition is preferred. A lower viscosity at low temperatures is more preferred.

[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, a large optical anisotropy or a small optical anisotropy, i.e., an appropriate optical anisotropy, is required. The product (Δn × d) of the optical anisotropy (Δn) of the composition and the cell gap (d) of the element is designed to maximize the contrast. The appropriate value of the product depends on the type of operation mode. In the case of an element in the VA mode, the value is in the range of about 0.30 μm to about 0.40 μm, and in the case of an element in the IPS mode or FFS mode, the value is in the range of about 0.20 μm to about 0.35 μm. In these cases, a composition having a large optical anisotropy is preferred for an element with a small cell gap. A large dielectric anisotropy of the composition contributes to a low threshold voltage, low power consumption, and high contrast in the element. Therefore, a large dielectric anisotropy is preferred. A large specific resistance of the composition contributes to a high voltage holding ratio and high contrast of the element. Therefore, a composition having a large specific resistance at the initial stage is preferred. A composition having a large specific resistance after long-term use is preferred. The stability of the composition against light or heat is associated with the lifespan of the element. When the stability is high, the lifespan of the element is long. Such properties are preferred for AM elements used in liquid crystal monitors, liquid crystal televisions, etc.

[0007] In a general liquid crystal display element, the vertical alignment of liquid crystal molecules can be achieved by using a specific polyimide alignment film. In a polymer sustained alignment (PSA) type liquid crystal display element, a polymer is combined with the alignment film. First, a composition containing a small amount of a polymerizable compound is injected into the element. Then, while applying a voltage between the substrates of the element, ultraviolet rays are irradiated onto the composition. The polymerizable compound polymerizes to form a polymer network structure in the composition. In the composition, the alignment of liquid crystal molecules can be controlled by the polymer, so the response time of the element is shortened and image burn-in is improved. Such an effect of the polymer can be expected in elements having modes such as TN, ECB, OCB, IPS, VA, FFS, and FPA.

[0008] In an AM element having a TN mode, a composition having a positive dielectric anisotropy is used. In an AM element having a VA mode, a composition having a negative dielectric anisotropy is used. In an AM element having an IPS mode or an FFS mode, a composition having a positive or negative dielectric anisotropy is used. In a polymer sustained alignment (PSA) type AM element, a composition having a positive or negative dielectric anisotropy is used.

[0009] In order to meet the required characteristics of the liquid crystal display element as described above, various compounds have been studied. In recent years, a compound containing sulfur and having a heterocyclic ring has been developed (Patent Document 1, Patent Document 2, etc.).

[0010] [Prior Art Documents]

[0011] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Laid-Open No. 2017-145384

[0013] [Patent Document 2] Japanese Patent Laid-Open No. 2021-165367 Summary of the Invention

[0014] [Problems to be Solved by the Invention]

[0015] The problems of the present invention are to provide a liquid crystal composition that fully satisfies 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, a large optical anisotropy, a large negative dielectric anisotropy, a large elastic constant, a large specific resistance, a high light stability, and a high heat stability. Another problem is to provide a liquid crystal composition having an appropriate balance between at least two of these properties. Another problem is to provide a liquid crystal display element containing such a composition. Another problem is to provide an AM element having properties such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast, and a long lifespan.

[0016] [Technical means for solving the problems]

[0017] The present invention relates to a liquid crystal composition and a liquid crystal display element containing the composition. The liquid crystal composition contains at least one compound selected from the compounds represented by formula (1) as component A and has a negative dielectric anisotropy.

[0018]

[0019] In formula (1), R 1 and R 2 are hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; X 1 and X 2 are O or S; L 1 and L 2 are hydrogen, fluorine, or trifluoromethyl; ring A and ring B are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine, chromane-2,6-diyl, chromane-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine, fluorene-2,7-diyl, fluorene-2,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzofuran-3,7-diyl, dibenzofuran-3,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzothiophene-3,7-diyl, dibenzothiophene-3,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, indane-2,5-diyl, indane-2,5-diyl in which at least one hydrogen is substituted with fluorine or chlorine, thiophene-2,5-diyl, or furan-2,5-diyl; Z 1 and Z 2 are a single bond, ethylene, vinylene, ethynylene, methoxy, or carbonyloxy; a and b are 0 or 1.

[0020] The present invention relates to a liquid crystal display element containing the liquid crystal composition.

[0021] The present invention relates to a polymer-stabilized alignment type liquid crystal display element containing the liquid crystal composition, and the polymerizable compounds in the liquid crystal composition are polymerized.

[0022] The present invention relates to the use of a liquid crystal composition for use in a liquid crystal display element.

[0023] The present invention relates to the use of a liquid crystal composition for use in a polymer-stabilized alignment type liquid crystal display element.

[0024] [Effects of the Invention]

[0025] The advantages of the present invention are to provide a liquid crystal composition that fully satisfies 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, a large optical anisotropy, a large negative dielectric anisotropy, a large elastic constant, a large specific resistance, a high light stability, and a high heat stability. Another advantage is to provide a liquid crystal composition having an appropriate balance between at least two of these properties. Another advantage is to provide a liquid crystal display element containing such a composition. Another advantage is to provide an AM element having properties such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, and a long lifespan. Detailed Embodiments

[0026] The usage of the terms in this specification is as described below. Sometimes, the terms "liquid crystal composition" and "liquid crystal display element" are abbreviated as "composition" and "element" respectively. "Liquid crystal display element" is a general term for a liquid crystal display panel and a liquid crystal display module. "Liquid crystalline compound" is a general term for compounds having a liquid crystal phase such as a nematic phase or a smectic phase, and compounds that do not have a liquid crystal phase but are mixed in the composition for the purpose of adjusting properties such as the temperature range of the nematic phase, viscosity, and dielectric anisotropy. The compound has a six-membered ring such as 1,4-cyclohexylene or 1,4-phenylene, and its molecule (liquid crystal molecule) is rod-like. "Polymerizable compound" is a compound added for the purpose of generating a polymer in the composition. A liquid crystalline compound having an alkenyl group is not classified as a polymerizable compound in its meaning.

[0027] A liquid crystal composition is prepared by mixing a variety of liquid crystalline compounds. Additives such as an optically active compound or a polymerizable compound are added as needed to the liquid crystal composition. Even when additives are added, the proportion of the liquid crystalline compounds is expressed as a mass percentage (mass%) based on the mass of the liquid crystal composition excluding the additives. The proportion of the additives is expressed as a mass percentage (mass%) based on the mass of the liquid crystal composition excluding the additives. That is, the proportion of the liquid crystalline compounds or additives is calculated based on the total mass of the liquid crystalline compounds. Sometimes parts per million by mass (ppm) is used. The proportions of the polymerization initiator and the polymerization inhibitor are expressed, except in the case of a polymerizable compound, based on the mass of the polymerizable compound.

[0028] Sometimes the "upper limit temperature of the nematic phase" is simply referred to as the "upper limit temperature". Sometimes the "lower limit temperature of the nematic phase" is simply referred to as the "lower limit temperature". The expression "increasing the dielectric anisotropy" means, in the case of a composition having a positive dielectric anisotropy, that its value increases positively, and in the case of a composition having a negative dielectric anisotropy, that its value increases negatively. "A large voltage holding ratio" 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 also has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after long-term use. Sometimes the characteristics of the composition or the element are studied by a time-dependent change test.

[0029]

[0030] The compound (1z) will be described as an example. In formula (1z), the notations α and β surrounded by a hexagon correspond to ring α and ring β, respectively, and represent rings such as a six-membered ring and a condensed ring. When the subscript 'x' is 2, there are two ring αs. The two groups represented by the two ring αs may be the same or different. The above rule applies to any two ring αs when the subscript 'x' is greater than 2. The above rule also applies to other notations such as the bonding group Z. The slant line cutting across one side of ring β indicates that any hydrogen on ring β may be substituted with a substituent (-Sp-P). The subscript 'y' represents the number of the substituents to be substituted. When the subscript 'y' is 0, such substitution does not exist. When the subscript 'y' is 2 or more, there are multiple substituents (-Sp-P) on ring β. In the above case, the rule of "may be the same or may be different" also applies. Furthermore, the above rule also applies to the case where the notation Ra is used for a variety of compounds.

[0031] 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 consisting of an alkyl group, an alkoxy group and an alkenyl group. That is, the group represented by Ra and the group represented by Rb may be the same or different.

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

[0033] The expression "at least one 'A'" means that the number of 'A' is arbitrary. The expression "at least one 'A' may be substituted by '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- may be substituted by -O-" is used. In this case, -CH2CH2-CH2- can be converted to -O-CH2-O- by substituting non-adjacent -CH2- with -O-. However, there is no case where adjacent -CH2- is substituted by -O-. The reason is that -O-O-CH2- (peroxide) is generated in the substitution.

[0034] When the alkyl group of a liquid crystal compound is simply described as "alkyl", it is linear or branched and does not include a cyclic alkyl group. "Alkyl" and "cyclic alkyl" can be clearly distinguished. A linear alkyl group is superior to a branched alkyl group. The same applies to end groups such as alkoxy groups and alkenyl groups. Regarding the stereoconfiguration related to 1,4-cyclohexylene, in order to increase the upper limit temperature, the trans configuration is superior to the cis configuration. Since 2-fluoro-1,4-phenylene is asymmetric left and right, there are left (L) and right (R).

[0035]

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

[0037] The present invention is as follows.

[0038] Item 1. A liquid crystal composition containing at least one compound selected from the compounds represented by formula (1) as component A and having a negative dielectric anisotropy.

[0039]

[0040] In formula (1), R 1 and R 2is hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; X 1 and X 2 is O or S; L 1 and L 2 is hydrogen, fluorine or trifluoromethyl; Ring A and Ring B are 1,4 - cyclohexylene, 1,4 - cyclohexenylene, tetrahydropyran - 2,5 - diyl, 1,4 - phenylene, 1,4 - phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene - 2,6 - diyl, naphthalene - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, chromane - 2,6 - diyl, chromane - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, fluorene - 2,7 - diyl, fluorene - 2,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzofuran - 3,7 - diyl, dibenzofuran - 3,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzothiophene - 3,7 - diyl, dibenzothiophene - 3,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, indane - 2,5 - diyl, indane - 2,5 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, thiophene - 2,5 - diyl or furan - 2,5 - diyl; Z 1 and Z 2 is a single bond, ethylene, vinylene, ethynylene, methoxy or carbonyloxy; a and b are 0 or 1.

[0041] Item 2. The liquid crystal composition according to Item 1, wherein, in formula (1), X 1 and X 2 At least one of them is S.

[0042] Item 3. The liquid crystal composition according to Item 1 or Item 2, which contains at least one compound selected from the compounds represented by formula (1 - 1) to formula (1 - 3) as component A.

[0043]

[0044] In formula (1 - 1) to formula (1 - 3), R 1 and R 2 are hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; L 1 and L 2 are hydrogen, fluorine or trifluoromethyl.

[0045] Item 4. The liquid crystal composition according to Item 1 or Item 2, wherein the proportion of component A is in the range of 3% by mass to 20% by mass.

[0046] Item 5. The liquid crystal composition according to any one of Items 1 to 4, which contains at least one compound selected from the compounds represented by the formula (2) as Component B.

[0047]

[0048] In the formula (2), R 3 and R 4 are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; Ring C and Ring D are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z 3 is a single bond, ethylene, vinylene, methoxy or carbonyloxy; c is 1, 2 or 3.

[0049] Item 6. The liquid crystal composition according to any one of Items 1 to 5, which contains at least one compound selected from the compounds represented by the formula (2-1) to the formula (2-15) as Component B.

[0050]

[0051]

[0052] In the formula (2-1) to the formula (2-15), R 3 and R 4 are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

[0053] Item 7. The liquid crystal composition according to Item 5 or Item 6, wherein the proportion of Component B is in the range of 10% by mass to 90% by mass.

[0054] Item 8. The liquid crystal composition according to any one of Items 1 to 7, which contains at least one compound selected from the compounds represented by the formula (3) as Component C.

[0055]

[0056] In the formula (3), R 5 and R 6is hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; Ring E and Ring G are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine, chromane-2,6-diyl, or chromane-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine; Ring F is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 1,8-difluorophenanthrene-2,7-diyl, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-difluorochromane-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, 4,6-difluorodibenzofuran-3,7-diyl, 4,6-difluorodibenzothiophene-3,7-diyl, 1,1,6,7-tetrafluoroindane-2,5-diyl, or 1,3,4-thiadiazole-2,5-diyl; Z 4 and Z 5 is a single bond, ethylene, vinylene, methoxy or carbonyloxy; d is 0, 1, 2 or 3, and e is 0 or 1; and the sum of d and e is 3 or less.

[0057] Item 9. The liquid crystal composition according to any one of Items 1 to 8, which contains at least one compound selected from the compounds represented by Formula (3-1) to Formula (3-37) as Component C.

[0058]

[0059]

[0060]

[0061]

[0062] In Formula (3-1) to Formula (3-37), R 5 and R 6 are hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

[0063] Item 10. The liquid crystal composition according to Item 8 or Item 9, wherein the proportion of Component C is in the range of 10% by mass to 85% by mass.

[0064] Item 11. The liquid crystal composition according to any one of Items 1 to 10, which contains at least one compound selected from the polymerizable compounds represented by the formula (4) as the additive X.

[0065]

[0066] In the formula (4), Ring I and Ring K are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidin-2-yl or pyridin-2-yl, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; Ring J is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidin-2,5-diyl or pyridin-2,5-diyl, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; Z 6 and Z 7 is a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH2- may be substituted with -O-, -CO-, -COO- or -OCO-, at least one -CH2CH2- may be substituted with -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)- or -C(CH3)=C(CH3)-, and at least one hydrogen in these groups may be substituted with fluorine or chlorine; P 1 to P 3 is a polymerizable group; Sp 1 to Sp 3 is a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH2- may be substituted with -O-, -COO-, -OCO- or -OCOO-, at least one -CH2CH2- may be substituted with -CH=CH- or -C≡C-, and at least one hydrogen in these groups may be substituted with fluorine or chlorine; f is 0, 1 or 2; g, h and i are 0, 1, 2, 3 or 4; and the sum of g, h and i is 1 or more.

[0067] Item 12. The liquid crystal composition according to Item 11, wherein, in the formula (4), P 1 to P 3 is a group selected from the polymerizable groups represented by the formula (P-1) to the formula (P-5).

[0068]

[0069] In Formulas (P-1) to (P-5), M 1 to M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

[0070] Item 13. The liquid crystal composition according to any one of Items 1 to 12, which contains at least one compound selected from the polymerizable compounds represented by Formulas (4-1) to (4-29) as Additive X.

[0071]

[0072]

[0073]

[0074] In Formulas (4-1) to (4-29), Sp 1 to Sp 3 is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one -CH2- may be substituted with -O-, -COO-, -OCO- or -OCOO-, at least one -CH2CH2- may be substituted with -CH=CH- or -C≡C-, and at least one hydrogen in these groups may be substituted with fluorine or chlorine; P 4 to P 6 is a polymerizable group selected from the groups represented by Formulas (P-1) to (P-3);

[0075]

[0076] In Formulas (P-1) to (P-3), M 1 to M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

[0077] Item 14. The liquid crystal composition according to any one of Items 11 to 13, wherein the proportion of Additive X is in the range of 0.03% by mass to 10% by mass.

[0078] Item 15. A liquid crystal display element containing the liquid crystal composition according to any one of Items 1 to 14.

[0079] Item 16. The liquid crystal display element according to Item 15, wherein the operation mode is an IPS mode, a VA mode, an FFS mode or an FPA mode, and the driving method is an active matrix method.

[0080] Item 17. A polymer-stabilized aligned liquid crystal display element, comprising the liquid crystal composition according to any one of Items 11 to 14, wherein the polymerizable compound in the liquid crystal composition has been polymerized.

[0081] Item 18. Use of a liquid crystal composition, the liquid crystal composition being the liquid crystal composition according to any one of Items 1 to 14, for use in a liquid crystal display element.

[0082] Item 19. Use of a liquid crystal composition, the liquid crystal composition being the liquid crystal composition according to any one of Items 11 to 14, for use in a polymer-stabilized aligned liquid crystal display element.

[0083] The present invention also includes the following items. (a) The composition, which contains one compound, two compounds, or three or more compounds selected from additives such as optically active compounds, antioxidants, ultraviolet absorbers, light extinction agents, dyes, defoaming agents, polymerizable compounds, polymerization initiators, and polymerization inhibitors. (b) An AM element, which contains the composition. (c) The composition further containing a polymerizable compound, and a polymer-stabilized aligned (PSA) type AM element containing the composition. (d) A polymer-stabilized aligned (PSA) type AM element, which contains the composition, and the polymerizable compound in the composition has been polymerized. (e) An element, which contains the composition and has a mode of PC, TN, STN, ECB, OCB, IPS, VA, FFS, or FPA. (f) A transmissive element, which contains 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.

[0084] The composition of the present invention will be described in the following order. First, the structure of the composition will be described. Second, the main characteristics of the component compounds and the main effects brought by the compounds to the composition or the element will be described. Third, the combination, preferred ratio, and basis thereof of the component compounds in the composition will be described. Fourth, the preferred forms of the component compounds will be described. Fifth, the preferred component compounds will be shown. Sixth, the additives that can be added to the composition will be described. Seventh, the synthesis method of the component compounds will be described. Finally, the use of the composition will be described.

[0085] First, the structure of the composition is described. The composition contains a variety of liquid crystalline compounds. The composition may also contain additives. The additives are optical active compounds, antioxidants, ultraviolet absorbers, light extinction agents, pigments, defoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, etc. From the perspective of the liquid crystalline compounds, the composition is classified into composition (a) and composition (b). Composition (a) may further contain other liquid crystalline compounds, additives, etc. in addition to the liquid crystalline compounds selected from compound (1), compound (2), and compound (3). "Other liquid crystalline compounds" are liquid crystalline compounds different from compound (1), compound (2), and compound (3). Such compounds are mixed into the composition for the purpose of further adjusting the properties.

[0086] Composition (b) substantially contains only the liquid crystalline compounds selected from compound (1), compound (2), and compound (3). "Substantially" means that although composition (b) may contain additives, it does not contain other liquid crystalline compounds. Compared with composition (a), the number of components in composition (b) is small. From the perspective of cost reduction, composition (b) is superior to composition (a). From the perspective of being able to further adjust the properties by mixing other liquid crystalline compounds, composition (a) is superior to composition (b).

[0087] Second, the main properties of the component compounds and the main effects brought by the compounds to the composition or the element are described. Based on the effects of the present invention, the main properties of the component compounds are summarized in Table 2. In the notations of Table 2, L means large or high, M means medium, and S means small or low. The notations L, M, and S are classifications based on the qualitative comparison between the component compounds, and 0 (zero) means less than S.

[0088] Table 2. Properties of Liquid Crystalline Compounds

[0089] Compound Compound (1) Compound (2) Compound (3) Upper limit temperature L S~L S~L Viscosity M S~M M~L Optical anisotropy L S~L M~L Dielectric anisotropy <![CDATA[M~L 1) > 0 <![CDATA[M~L 1) > Specific resistance L L L

[0090] 1) The dielectric anisotropy is negative, and the notation represents the magnitude of the absolute value.

[0091] The main effects of the component compounds are as follows. Compound (1) increases the upper limit temperature, optical anisotropy, and dielectric anisotropy. Compound (2) increases the upper limit temperature or decreases the viscosity. Compound (3) increases the dielectric anisotropy or decreases the lower limit temperature. Compound (4) provides a polymer through polymerization. Since the polymer stabilizes the orientation of liquid crystal molecules, it shortens the response time of the element and improves the image burn-in.

[0092] Third, the combinations, preferred ratios, and bases thereof of the component compounds in the composition are described. The preferred combinations of the component compounds in the composition are Compound (1) + Compound (2), Compound (1) + Compound (3), Compound (1) + Compound (2) + Compound (3), Compound (1) + Compound (2) + Compound (4), Compound (1) + Compound (3) + Compound (4), or Compound (1) + Compound (2) + Compound (3) + Compound (4). Further preferred combinations are Compound (1) + Compound (2) or Compound (1) + Compound (2) + Compound (3).

[0093] To increase the upper limit temperature, optical anisotropy, and dielectric anisotropy, the preferred ratio of Compound (1) is about 3% by mass or more. To lower the lower limit temperature, the preferred ratio of Compound (1) is about 20% by mass or less. Further preferred ratios are in the range of about 3% by mass to about 15% by mass. Particularly preferred ratios are in the range of about 3% by mass to about 12% by mass.

[0094] To increase the upper limit temperature or to lower the viscosity, the preferred ratio of Compound (2) is about 10% by mass or more. To increase the dielectric anisotropy, the preferred ratio of Compound (2) is about 90% by mass or less. Further preferred ratios are in the range of about 20% by mass to about 80% by mass. Particularly preferred ratios are in the range of about 30% by mass to about 70% by mass.

[0095] To increase the dielectric anisotropy or to lower the lower limit temperature, the preferred ratio of Compound (3) is about 10% by mass or more. To lower the viscosity, the preferred ratio of Compound (3) is about 85% by mass or less. Further preferred ratios are in the range of about 20% by mass to about 75% by mass. Particularly preferred ratios are in the range of about 30% by mass to about 60% by mass.

[0096] Compound (4) is added to the composition for the purpose of being suitable for polymer-stabilized alignment type elements. To align the liquid crystal molecules, the preferred ratio of Compound (4) is about 0.03% by mass or more. To prevent display defects in the elements, the preferred ratio of Compound (4) is about 10% by mass or less. Further preferred ratios are in the range of about 0.1% by mass to about 2% by mass. Particularly preferred ratios are in the range of about 0.2% by mass to about 1.0% by mass.

[0097] Fourth, the preferred forms of the component compounds are described. In Formulas (1), (2), and (3), R 1 and R 2is hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. To increase the dielectric anisotropy, preferred R 1 or R 2 is an alkoxy group having 1 to 12 carbon atoms. To increase the stability, preferred R 1 or R 2 is an alkyl group having 1 to 12 carbon atoms. R 3 and R 4 are an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. To increase the stability, preferred R 3 or R 4 is an alkyl group having 1 to 12 carbon atoms. To reduce the viscosity, preferred R 3 or R 4 is an alkenyl group having 2 to 12 carbon atoms. R 5 and R 6 are hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. To increase the stability, preferred R 5 or R 6 is an alkyl group having 1 to 12 carbon atoms. To reduce the viscosity, preferred R 5 or R 6 is an alkenyl group having 2 to 12 carbon atoms. To increase the dielectric anisotropy, preferred R 5 or R 6 is an alkoxy group having 1 to 12 carbon atoms.

[0098] Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. To reduce the viscosity, more preferred alkyl groups are methyl, ethyl, propyl, butyl or pentyl.

[0099] Preferred cycloalkyl groups are cyclopropyl, cyclobutyl or cyclopentyl.

[0100] Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy. To reduce the viscosity, more preferred alkoxy groups are methoxy or ethoxy.

[0101] Preferred alkenyl groups are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. For reducing viscosity, more preferred alkenyl groups are vinyl, 1-propenyl, 3-butenyl or 3-pentenyl. The preferred stereoconfiguration of -CH=CH- in these alkenyl groups depends on the position of the double bond. For reasons such as reducing viscosity, in alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl, the trans configuration is preferred. In alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl, the cis configuration is preferred.

[0102] Preferred alkenyloxy groups are vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy or 4-pentenyloxy. For reducing viscosity, more preferred alkenyloxy groups are allyloxy or 3-butenyloxy.

[0103] Preferred examples of an alkyl group in which at least one hydrogen is substituted with fluorine or chlorine are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or 8-fluorooctyl. For increasing dielectric anisotropy, more preferred examples are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl.

[0104] Preferred examples of an alkenyl group in which at least one hydrogen is substituted with fluorine or chlorine are 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl or 6,6-difluoro-5-hexenyl. For reducing viscosity, more preferred examples are 2,2-difluorovinyl or 4,4-difluoro-3-butenyl.

[0105] Ring A and Ring B are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine, chromane-2,6-diyl, chromane-2,6-diyl in which at least one hydrogen is substituted with fluorine or chlorine, fluorene-2,7-diyl, fluorene-2,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzofuran-3,7-diyl, dibenzofuran-3,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzothiophene-3,7-diyl, dibenzothiophene-3,7-diyl in which at least one hydrogen is substituted with fluorine or chlorine, indane-2,5-diyl, indane-2,5-diyl in which at least one hydrogen is substituted with fluorine or chlorine, thiophene-2,5-diyl or furan-2,5-diyl. For reducing viscosity, preferred Ring A or Ring B is 1,4-cyclohexylene, and for increasing optical anisotropy, preferred Ring A or Ring B is 1,4-phenylene or 2-fluoro-1,4-phenylene.

[0106] Rings C and D are 1,4 - cyclohexylene, 1,4 - phenylene, 2 - fluoro - 1,4 - phenylene, or 2,5 - difluoro - 1,4 - phenylene. For reducing viscosity, the preferred ring C or D is 1,4 - cyclohexylene, and for increasing optical anisotropy, the preferred ring C or D is 1,4 - phenylene or 2 - fluoro - 1,4 - phenylene.

[0107] Rings E and G are 1,4 - cyclohexylene, 1,4 - cyclohexenylene, tetrahydropyran - 2,5 - diyl, 1,4 - phenylene, 1,4 - phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene - 2,6 - diyl, naphthalene - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, chroman - 2,6 - diyl, or chroman - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine. Preferred examples of "1,4 - phenylene in which at least one hydrogen is substituted with fluorine or chlorine" are 2 - fluoro - 1,4 - phenylene, 2,3 - difluoro - 1,4 - phenylene, or 2 - chloro - 3 - fluoro - 1,4 - phenylene. For reducing viscosity, the preferred ring E or G is 1,4 - cyclohexylene, for increasing dielectric anisotropy, the preferred ring E or G is tetrahydropyran - 2,5 - diyl, and for increasing optical anisotropy, the preferred ring E or G is 1,4 - phenylene.

[0108] The tetrahydropyran - 2,5 - diyl in rings A, B, E, and G is

[0109]

[0110] preferably

[0111]

[0112] Ring F is 2,3 - difluoro - 1,4 - phenylene, 2 - chloro - 3 - fluoro - 1,4 - phenylene, 2,3 - difluoro - 5 - methyl - 1,4 - phenylene, 1,8 - difluorophenanthrene - 2,7 - diyl, 3,4,5 - trifluoronaphthalene - 2,6 - diyl, 7,8 - difluorochroman - 2,6 - diyl, 3,4,5,6 - tetrafluorofluorene - 2,7 - diyl (FLF4), 4,6 - difluorodibenzofuran - 3,7 - diyl (DBFF2), 4,6 - difluorodibenzothiophene - 3,7 - diyl (DBTF2), 1,1,6,7 - tetrafluoroindane - 2,5 - diyl (InF4), or 1,3,4 - thiadiazole - 2,5 - diyl.

[0113]

[0114] For reducing the viscosity, the preferred ring F is 2,3-difluoro-1,4-phenylene, and for increasing the dielectric anisotropy, the preferred ring F is 1,8-difluorophenanthrene-2,7-diyl or 4,6-difluorodibenzothiophene-3,7-diyl.

[0115] Z 1 and Z 2 is a single bond, ethylene, vinylene, ethynylene, methoxy or carbonyloxy. For reducing the viscosity, the preferred Z 1 or Z 2 is a single bond, and for increasing the dielectric anisotropy, the preferred Z 1 or Z 2 is methoxy. Z 3 is a single bond, ethylene, vinylene, methoxy or carbonyloxy. For reducing the viscosity, the preferred Z 3 is a single bond. Z 4 and Z 5 is a single bond, ethylene, vinylene, methoxy or carbonyloxy. For reducing the viscosity, the preferred Z 4 or Z 5 is a single bond, and for increasing the elastic constant, the preferred Z 4 or Z 5 is ethylene, and for increasing the dielectric anisotropy, the preferred Z 4 or Z 5 is methoxy.

[0116] Divalent groups such as methoxy are asymmetric left and right. In methoxy, -CH2O- is superior to -OCH2-. In carbonyloxy, -COO- is superior to -OCO-.

[0117] L 1 and L 2 are hydrogen, fluorine or trifluoromethyl. For reducing the viscosity and increasing the dielectric anisotropy, the preferred L 1 or L 2 is fluorine.

[0118] X 1 and X 2 are O or S. For expanding the temperature range of the nematic phase, it is preferred that X 1 and X 2 at least one of them is S. Particularly preferably, X 1 and X 2 one of them is S and the other is O.

[0119] a and b are 0 or 1. To reduce the viscosity and the lower limit temperature, preferably a or b is 0. Particularly preferably, both a and b are 0. To reduce the viscosity, preferably c is 1, and to increase the upper limit temperature, preferably c is 2 or 3. d is 0, 1, 2 or 3, e is 0 or 1, and the sum of d and e is 3 or less. To reduce the viscosity, preferably d is 0 or 1, and to increase the upper limit temperature, preferably d is 2. To reduce the viscosity, preferably e is 0, and to increase the upper limit temperature, preferably e is 1.

[0120] In formula (4), ring I and ring K are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl, pyrimidin-2-yl or pyridin-2-yl. In these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. Preferably, ring I or ring K is phenyl. Ring J is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidin-2,5-diyl or pyridin-2,5-diyl. In these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. Preferably, ring J is 1,4-phenylene or 2-fluoro-1,4-phenylene.

[0121] Z 6 and Z 7 is a single bond or an alkylene group having 1 to 10 carbon atoms. In the alkylene group, at least one -CH2- may be substituted with -O-, -CO-, -COO- or -OCO-, and at least one -CH2CH2- may be substituted with -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)- or -C(CH3)=C(CH3)-. In these groups, at least one hydrogen may be substituted with fluorine or chlorine. Preferably, Z 6 or Z 7 is a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO- or -OCO-. More preferably, Z 6 or Z 7 is a single bond.

[0122] Sp 1 to Sp 3is a single bond or an alkylene group having 1 to 10 carbon atoms. In the alkylene group, at least one -CH2- may be substituted by -O-, -COO-, -OCO- or -OCOO-, and at least one -CH2CH2- may be substituted by -CH=CH- or -C≡C-. In these groups, at least one hydrogen may be substituted by fluorine or chlorine. Preferred Sp 1 to Sp 3 is a single bond, -CH2CH2-, -CH2O-, -OCH2-, -COO-, -OCO-, -CO-CH=CH- or -CH=CH-CO-. Further preferred Sp 1 to Sp 3 is a single bond.

[0123] f is 0, 1 or 2. Preferred f is 0 or 1. g, h and i are 0, 1, 2, 3 or 4, and the sum of g, h and i is 1 or more. Preferred g, h or i is 1 or 2.

[0124] P 1 to P 3 is a polymerizable group. Preferred P 1 to P 3 is a polymerizable group selected from the groups represented by formula (P-1) to formula (P-5). Further preferred P 1 to P 3 is a group represented by formula (P-1), formula (P-2) or formula (P-3). Particularly preferred P 1 to P 3 is a group represented by formula (P-1) or formula (P-2). Most preferred P 1 to P 3 is a group represented by formula (P-1). The preferred group represented by formula (P-1) is -OCO-CH=CH2 or -OCO-C(CH3)=CH2. The wavy lines in formula (P-1) to formula (P-5) indicate the bonding sites.

[0125]

[0126] In formula (P-1) to formula (P-5), M 1 to M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted by fluorine or chlorine. To improve the reactivity, preferred M 1 to M 3 is hydrogen or methyl. Further preferred M 1 is hydrogen or methyl, and further preferred M 2 or M 3 is hydrogen.

[0127] In formula (4-1) to formula (4-29), P 4 to P 6is a group represented by formula (P-1) to formula (P-3). Preferred P 4 to P 6 is formula (P-1) or formula (P-2). Further preferred formula (P-1) is -OCO-CH=CH2 or -OCO-C(CH3)=CH2. The wavy lines in formula (P-1) to formula (P-3) represent the bonding sites.

[0128]

[0129] Fifth, preferred component compounds are shown. Preferred compound (1) is compound (1-1) to compound (1-3) described in item 3. Among these compounds, at least one of the preferred component A is compound (1-1) or compound (1-2). From the viewpoint of lowering the lower limit temperature, a plurality of compound (1-1), a plurality of compound (1-2) or a combination of compound (1-1) and compound (1-2) is preferred.

[0130] Preferred compound (2) is compound (2-1) to compound (2-15) described in item 6. Among these compounds, at least one of the preferred component B is compound (2-1), compound (2-2), compound (2-3), compound (2-4), compound (2-5), compound (2-7), compound (2-8) or compound (2-12). Further preferred is that at least one of component B is compound (2-1), compound (2-4) or compound (2-7), and the total of these is preferably 35% by mass or more. Preferred is R 3 and R 4 in which at least one of them is an alkenyl group having 2 to 4 carbon atoms in compound (2), and the total of these is preferably 35% by mass or more. Preferred is that at least two of component B are compound (2-1) and compound (2-4), compound (2-1) and compound (2-7) or compound (2-1) and compound (2-12).

[0131] The preferred compound (3) is compound (3-1) to compound (3-36) described in item 9. Among these compounds, preferably at least one of component C is compound (3-1), compound (3-6), compound (3-8), compound (3-9), compound (3-10), compound (3-14), compound (3-19) or compound (3-36). The total proportion of compound (3-1), compound (3-6), compound (3-8), compound (3-14) and compound (3-36) is preferably in the range of 40% to 60% by mass. In addition, it is also preferred that the total proportion of compound (3-9), compound (3-10) and compound (3-36) is 30% by mass or more. Particularly preferably, at least one of component C is compound (3-36), and the proportion of compound (3-36) is preferably in the range of 5% to 10% by mass. Preferably, at least two of component C are a combination of compound (3-1) and compound (3-36), compound (3-6) and compound (3-36), compound (3-8) and compound (3-36), compound (3-9) and compound (3-36), compound (3-10) and compound (3-36) or compound (3-14) and compound (3-36).

[0132] The preferred compound (4) is compound (4-1) to compound (4-29) described in item 13. Among these compounds, preferably at least one of additive X is compound (4-1), compound (4-2), compound (4-24), compound (4-25), compound (4-26) or compound (4-27). Preferably, at least two of additive X are a combination of compound (4-1) and compound (4-2), compound (4-1) and compound (4-18), compound (4-2) and compound (4-24), compound (4-2) and compound (4-25), compound (4-2) and compound (4-26), compound (4-25) and compound (4-26) or compound (4-18) and compound (4-24).

[0133] Sixth, additives that can be added to the composition will be described. Such additives are optically active compounds, antioxidants, ultraviolet absorbers, matting agents, pigments, defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, etc. For the purpose of inducing a helical structure of liquid crystal molecules to impart a torsion angle, an optically active compound is added to the composition. Examples of such compounds are compound (5-1) to compound (5-5). The preferred proportion of the optically active compound is about 5% by mass or less. A more preferred proportion is in the range of about 0.01% to about 2% by mass.

[0134]

[0135] To prevent a decrease in specific resistance caused by heating in the atmosphere, or to maintain a large voltage retention rate not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of the device, antioxidants such as compound (6-1) to compound (6-3) may be further added to the composition.

[0136]

[0137] Since compound (6-2) has low volatility, it is effective for maintaining a large voltage retention rate not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of the device. To obtain the above effect, the preferred proportion of the antioxidant is about 50 ppm or more, and to prevent a decrease in the upper limit temperature or an increase in the lower limit temperature, the preferred proportion of the antioxidant is about 600 ppm or less. A further preferred proportion is in the range of about 100 ppm to about 300 ppm.

[0138] Preferred examples of the ultraviolet absorber are benzophenone derivatives, benzoate derivatives, triazole derivatives, etc. In addition, light stabilizers such as sterically hindered amines are also preferred. Preferred examples of the light stabilizer are compound (7-1) to compound (7-16), etc. To obtain the above effect, the preferred proportion of these absorbers or stabilizers is about 50 ppm or more, and to prevent a decrease in the upper limit temperature or an increase in the lower limit temperature, the preferred proportion of these absorbers or stabilizers is about 10,000 ppm or less. A further preferred proportion is in the range of about 100 ppm to about 10,000 ppm.

[0139]

[0140]

[0141] The quencher is a compound that prevents the decomposition of the liquid crystalline compound by receiving the light energy absorbed by the liquid crystalline compound and converting it into heat energy. Preferred examples of the quencher are compound (8-1) to compound (8-7), etc. To obtain the above effect, the preferred proportion of these quenchers is about 50 ppm or more, and to prevent an increase in the lower limit temperature, the preferred proportion of these quenchers is about 20,000 ppm or less. A further preferred proportion is in the range of about 100 ppm to about 10,000 ppm.

[0142]

[0143] In order to be suitable for elements in the guest host (GH) mode, dichroic dyes such as azo dyes and anthraquinone dyes are added to the composition. The preferred proportion of the dye is in the range of about 0.01% by mass to about 10% by mass. In order to prevent bubbling, antifoaming agents such as dimethyl silicone oil and methylphenyl silicone oil are added to the composition. In order to obtain the above effects, the preferred proportion of the antifoaming agent is about 1 ppm or more, and in order to prevent poor display, the preferred proportion of the antifoaming agent is about 1000 ppm or less. A more preferred proportion is in the range of about 1 ppm to about 500 ppm.

[0144] In order to be suitable for elements of the polymer stabilized alignment (PSA) type, polymerizable compounds are used. Compound (4) is suitable for this purpose. Polymerizable compounds different from Compound (4) may also be added to the composition together with Compound (4). Preferred examples of such polymerizable compounds are compounds such as acrylates, methacrylates, vinyl compounds, vinyloxy compounds, allyl ethers, epoxy compounds (oxirane, oxetane), and vinyl ketones. More preferred examples are derivatives of acrylates or methacrylates. Based on the total mass of the polymerizable compounds, the preferred proportion of Compound (4) is 10% by mass or more. A more preferred proportion is 50% by mass or more. A particularly preferred proportion is 80% by mass or more. The most preferred proportion is 100% by mass.

[0145] Polymerizable compounds such as Compound (4) are polymerized by ultraviolet irradiation. Polymerization can also be carried out in the presence of a suitable initiator such as a photoinitiator. The suitable conditions for polymerization, the suitable type of initiator, and the suitable amount are known to those skilled in the art and are described in the literature. For example, Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF), or Darocur 1173 (registered trademark; BASF) as photoinitiators are suitable for free radical polymerization. Based on the total mass of the polymerizable compounds, the preferred proportion of the photoinitiator is in the range of about 0.1% by mass to about 5% by mass. A more preferred proportion is in the range of about 1% by mass to about 3% by mass.

[0146] When storing polymerizable compounds such as Compound (4), a polymerization inhibitor may be added to prevent polymerization. The polymerizable compounds are usually added to the composition in a state where the polymerization inhibitor has not been removed. Examples of the polymerization inhibitor are hydroquinone derivatives such as hydroquinone and methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, and phenothiazine.

[0147] Seventh, the synthesis methods of the component compounds are described. These compounds can be synthesized by known methods. Exemplary synthesis methods are shown. The synthesis example of compound (1) is described in Example 1. Compound (2-1) is synthesized by the method described in Japanese Patent Laid-Open No. 9-77692. Compound (3-1) is synthesized by the method described in Japanese Patent Publication No. 2-503441. Compound (4-18) is synthesized by the method described in Japanese Patent Laid-Open No. 7-101900. Antioxidants are commercially available. Compound (6-1) can be obtained from Sigma-Aldrich Corporation. Compound (6-2), etc. are synthesized by the method described in the specification of U.S. Patent No. 3660505.

[0148] Compounds for which the synthesis method is not described can be synthesized by 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), etc. The composition is prepared from the compounds obtained in the above manner by known methods. For example, the component compounds are mixed and then dissolved in each other by heating.

[0149] Finally, the uses of the composition are described. The composition mainly has a lower limit temperature of about -10°C or less, an upper limit temperature of about 70°C or more, 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 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. The element containing the composition has a large voltage holding ratio. The composition is suitable for AM elements. The composition is particularly suitable for transmissive AM elements. 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.

[0150] The composition can be used in AM elements. Furthermore, it can also be used in PM elements. The composition can be used in AM elements and PM elements having modes such as PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA, etc. Particularly preferably, it is used in AM elements having TN, OCB, IPS mode or FFS mode. In AM elements having IPS mode or FFS mode, when no voltage is applied, the alignment of liquid crystal molecules can be parallel to the glass substrate or can also be perpendicular. These elements can be reflective, transmissive or transflective. Preferably, it is used in transmissive elements. It can also be used in amorphous silicon-TFT elements or polycrystalline silicon-TFT elements. The composition can also be used in nematic curvilinear aligned phase (NCAP) type elements prepared by microencapsulation, or in polymer dispersed (PD) type elements formed with a three-dimensional network polymer in the composition.

[0151] [Examples]

[0152] The present invention will be further described in detail by way of examples. The present invention is not limited by these examples. The present invention includes a mixture of the composition of Example 1 and the composition of Example 2. The present invention also includes mixtures formed by mixing 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.

[0153] NMR analysis: DRX-500 manufactured by Bruker BioSpin was used during the measurement. 1 In the measurement of 1H-NMR, the sample was dissolved in a deuterated solvent such as CDCl3 and measured at room temperature under the conditions of 500 MHz and a cumulative number of 16 times. Tetramethylsilane was used as an internal standard. 19 In the measurement of 19F-NMR, CFCl3 was used as an internal standard and measured with a cumulative number of 24 times. In the description of nuclear magnetic resonance spectra, s refers to singlet, d refers to doublet, t refers to triplet, q refers to quartet, quin refers to quintet, sex refers to sextet, m refers to multiplet, and br refers to broad.

[0154] Gas chromatography analysis: When measuring, a GC-14B type gas chromatograph manufactured by Shimadzu Corporation was used. The carrier gas was helium (2 mL / min). The sample vaporization chamber was set at 280 °C, and the detector (flame ionization detector (FID)) was set at 300 °C. When separating the component compounds, a capillary column DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm; stationary liquid phase was dimethylpolysiloxane; non-polar) manufactured by Agilent Technologies Inc. was used. After maintaining the column at 200 °C for 2 minutes, it was heated to 280 °C at a rate of 5 °C / min. After preparing the sample into an acetone solution (0.1 mass%), 1 μL of it was injected into the sample vaporization chamber. The recorder was a C-R5A type chromatograph assembly (Chromatopac) manufactured by Shimadzu Corporation or its equivalent. The obtained gas chromatogram showed the retention time of the peaks corresponding to the component compounds and the area of the peaks.

[0155] Solvents for diluting the sample can be chloroform, hexane, etc. In order to separate the component compounds, the following capillary columns can be used. 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, BP-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by SGE International Pty. Ltd. of Australia. For the purpose of preventing the overlap of compound peaks, a capillary column CBP1-M50-025 (length 50 m, inner diameter 0.25 mm, film thickness 0.25 μm) manufactured by Shimadzu Corporation can be used.

[0156] The proportion of the liquid crystalline compound contained in the composition can be calculated by the method described below. Analyze the mixture of liquid crystalline compounds by gas chromatography (FID). The area ratio of the peaks in the gas chromatogram corresponds to the proportion of the liquid crystalline compound. When using the capillary columns described above, the correction factors of various liquid crystalline compounds can be regarded as 1. Therefore, the proportion (mass%) of the liquid crystalline compound can be calculated based on the area ratio of the peaks.

[0157] Test sample: When measuring the properties of a composition or component, the composition is directly used as the test sample. When measuring the properties of a compound, a test sample for measurement is prepared by mixing the compound (15% by mass) with a host liquid crystal (85% by mass). Based on the values obtained from the measurement, the property values of the compound are calculated using the extrapolation method. (Extrapolated value) = {(Measured value of the sample) - 0.85 × (Measured value of the host liquid crystal)} / 0.15. When a smectic phase (or crystal) precipitates at 25°C at the said ratio, the ratio of the compound to the host liquid crystal is changed in the order of 10%:90%, 5%:95%, 1%:99%. The upper limit temperature, optical anisotropy, viscosity, and dielectric anisotropy values related to the compound are obtained using the said interpolation method.

[0158] The following host liquid crystal is used. The ratio of the component compounds is expressed in mass%.

[0159]

[0160] Measurement method: The properties are measured using the following methods. Most of these methods are the methods described in the JEITA standard (JEITA·ED-2521B) deliberated and established by the Japan Electronics and Information Technology Industries Association (referred to as JEITA) or the methods modified therefrom. No thin film transistor (TFT) is installed on the TN element used for measurement.

[0161] (1) Upper limit temperature of nematic phase (NI; °C): The sample is placed on a hot plate of a melting point measuring device equipped with a polarizing microscope and heated at a rate of 1°C / min. The temperature at which a part of the sample changes from the 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".

[0162] (2) Lower limit temperature of nematic phase (T C ; °C): The sample having a nematic phase is placed in a glass bottle and stored in a freezer at 0°C, -10°C, -20°C, -30°C, and -40°C for 10 days, and the liquid crystal phase is observed. For example, when the sample remains in the nematic phase at -20°C and changes to a crystal or smectic phase at -30°C, T C is recorded as < -20°C. Sometimes the lower limit temperature of the nematic phase is simply referred to as the "lower limit temperature".

[0163] (3) Viscosity (kinematic viscosity; η; measured at 20°C; mPa·s): An E-type rotational viscometer manufactured by Tokyo Keiki Inc. is used for measurement.

[0164] (4) Viscosity (rotational viscosity; γ1; measured at 25 °C; mPa·s): When measuring, use the rotational viscosity measurement system LCM-2 type of Dongyang Technology Co., Ltd. Inject the sample into a VA element with a gap (cell gap) of 10 μm between two glass substrates. Apply a rectangular wave (55 V, 1 ms) to the element. Measure the peak current and peak time of the transient current generated by the application. Obtain the value of the rotational viscosity using these measured values and the dielectric anisotropy. The dielectric anisotropy is measured using the method described in measurement (6).

[0165] (5) Optical anisotropy (refractive index anisotropy; Δn; measured at 25 °C): Use light with a wavelength of 589 nm and measure it using an Abbe refractometer with a polarizing plate installed on the eyepiece. After rubbing the surface of the main prism in one direction, drop the sample onto the main prism. The refractive index n∥ is measured when the direction of polarization is parallel to the direction of rubbing. The refractive index n⊥ is measured when the direction of polarization is perpendicular to the direction of rubbing. The value of the optical anisotropy is calculated according to the formula Δn = n∥ - n⊥.

[0166] (6) Dielectric anisotropy (Δε; measured at 25 °C): The value of the dielectric anisotropy is calculated according to the formula Δε = ε∥ - ε⊥. The dielectric constants (ε∥ and ε⊥) are measured as follows.

[0167] 1) Measurement of dielectric constant (ε∥): Coat a solution of octadecyltriethoxysilane (0.16 mL) in ethanol (20 mL) on a thoroughly cleaned glass substrate. After rotating the glass substrate using a spinner, heat it at 150 °C for 1 hour. Place the sample in a VA element with a gap (cell gap) of 4 μm between two glass substrates and seal the element using an adhesive cured with ultraviolet light. Apply a sine wave (0.5 V, 1 kHz) to the element and measure the dielectric constant (ε∥) in the long axis direction of the liquid crystal molecules 2 seconds later.

[0168] 2) Measurement of dielectric constant (ε⊥): Coat a polyimide solution on a thoroughly cleaned glass substrate. After calcining the glass substrate, perform a rubbing treatment on the obtained alignment film. Place the sample in a TN element with a gap (cell gap) of 9 μm and a twist angle of 80 degrees between two glass substrates. Apply a sine wave (0.5 V, 1 kHz) to the element and measure the dielectric constant (ε⊥) in the short axis direction of the liquid crystal molecules 2 seconds later.

[0169] (7) Threshold voltage (Vth; measured at 25°C; V): When measuring, use a luminance meter model 5200 of Liquid Crystal Display (LCD) manufactured by Otsuka Electronics Co., Ltd. The light source is a halogen lamp. A sample is placed in a VA element in a normally black mode with a cell gap of 4 μm between two glass substrates and the rubbing directions being anti-parallel, and the element is sealed using an adhesive cured by ultraviolet light. The voltage (60 Hz, rectangular wave) applied to the element is increased stepwise from 0 V to 20 V in units of 0.02 V. At this time, light is irradiated on the element from the vertical direction, and the amount of light transmitted through the element is measured. A voltage-transmittance curve is made such that the transmittance is 100% when the light amount reaches the maximum and the transmittance is 0% when the light amount is the minimum. The threshold voltage is represented by the voltage when the transmittance reaches 10%.

[0170] (8) Voltage holding ratio (VHR-1; measured at 25°C; %): The TN element used for measurement has a polyimide alignment film, and the cell gap between two glass substrates is 5 μm. The element is sealed using an adhesive cured by ultraviolet light after placing the sample. A pulse voltage (5 V, 60 μs) is applied to the TN element for charging. The decaying voltage is measured using a high-speed voltmeter within a period of 16.7 ms, and the area A between the voltage curve per unit period and the horizontal axis is obtained. Area B is the area when there is no decay. The voltage holding ratio is represented by the percentage of area A with respect to area B.

[0171] (9) Voltage holding ratio (VHR-2; measured at 80°C; %): The voltage holding ratio is measured in the same procedure as above, except that the measurement is performed at 80°C instead of 25°C. The value obtained is represented by VHR-2.

[0172] (10) Voltage holding ratio (VHR-3; measured at 25°C; %): After irradiating ultraviolet light, the voltage holding ratio is measured to evaluate the stability against ultraviolet light. The TN element used for measurement has a polyimide alignment film, and the cell gap is 5 μm. A sample is injected into the element, and light is irradiated for 20 minutes. The light source is an ultra-high pressure mercury lamp USH-500D (manufactured by Ushio Electric), and the distance between the element and the light source is 20 cm. In the measurement of VHR-3, the decaying voltage is measured within a period of 16.7 ms. A composition with a large VHR-3 has a large stability against ultraviolet light. VHR-3 is preferably 90% or more, and more preferably 95% or more.

[0173] (11) Voltage holding ratio (VHR-4; measured at 25°C; %): After heating the TN element injected with the sample in a thermostat at 80°C for 500 hours, the voltage holding ratio is measured to evaluate the thermal stability. In the measurement of VHR-4, the decaying voltage is measured during 16.7 milliseconds. A composition with a large VHR-4 has high thermal stability.

[0174] (12) Response time (τ; measured at 25°C; ms): When measuring, a luminance meter model LCD5200 manufactured by Otsuka Electronics Co., Ltd. is used. The light source is a halogen lamp. The low-pass filter is set to 5 kHz. The sample is placed in a VA element in the normally black mode with a cell gap of 4 μm between two glass substrates and the rubbing directions being anti-parallel. The element is sealed using an adhesive cured by ultraviolet light. A rectangular wave (60 Hz, 10 V, 0.5 s) is applied to the element. At this time, light is irradiated onto the element from the vertical direction, and the amount of light transmitted through the element is measured. When the amount of light reaches the maximum, the transmittance is regarded as 100%, and when the amount of light is the minimum, the transmittance is regarded as 0%. The response time is represented by the time (fall time; milliseconds) required for the transmittance to change from 90% to 10%.

[0175] (13) Specific resistance (ρ; measured at 25°C; Ωcm): 1.0 mL of the sample is injected into a container equipped with electrodes. A DC voltage (10 V) is applied to the container, and the DC current after 10 seconds is measured. The specific resistance is calculated according to the following formula. (Specific resistance) = {(voltage) × (capacitance of the container)} / {(DC current) × (permittivity of vacuum)}.

[0176] (14) Line image sticking parameter (LISP; %): Line image sticking is generated by applying electrical stress to the liquid crystal display element. The luminance of the area with line image sticking and the luminance of the remaining area are measured. The ratio of the luminance decrease due to line image sticking is calculated, and the size of the line image sticking is represented by this ratio.

[0177] 14a) Measurement of luminance: An imaging color luminance meter (PM-1433F-0, manufactured by Radiant Zemax) is used to take an image of the element. The luminance of each area of the element is calculated by analyzing the image using software (Prometric 9.1, manufactured by Radiant Imaging). The light source uses a light-emitting diode (LED) backlight with an average luminance of 3500 cd / m 2 of.

[0178] 14b) Setting of stress voltage: A specimen is placed in an FFS element (16 elements with 4 elements in the vertical direction and 4 elements in the horizontal direction) having a matrix structure with a cell gap of 3.5 μm, and the element is sealed using an adhesive cured by ultraviolet light. Polarizing plates are respectively arranged on the upper surface and the lower surface of the element in a manner that the polarization axes are orthogonal. Light is irradiated to the element and a voltage (rectangular wave, 60 Hz) is applied. The voltage is increased stepwise in units of 0.1 V within the range of 0 V to 7.5 V, and the luminance of the transmitted light at each voltage is measured. The voltage when the luminance reaches the maximum is simply referred to as V255. The voltage when the luminance reaches 21.6% of V255 (i.e., 127 gray levels) is simply referred to as V127.

[0179] 14c) Stress conditions: V255 (rectangular wave, 30 Hz) and 0.5 V (rectangular wave, 30 Hz) are applied to the element under the conditions of 60 °C for 23 hours, and a checkerboard pattern is displayed. Next, V127 (rectangular wave, 0.25 Hz) is applied, and the luminance is measured under the condition of an exposure time of 4000 milliseconds.

[0180] 14d) Calculation of line afterimage: The central 4 elements (2 elements in the vertical direction and 2 elements in the horizontal direction) among the 16 elements are used for the calculation. The 4 elements are divided into 25 regions (5 elements in the vertical direction and 5 elements in the horizontal direction). The average luminance of the 4 regions (2 elements in the vertical direction and 2 elements in the horizontal direction) located at the four corners is simply referred to as luminance A. The region formed by removing the regions at the four corners from the 25 regions is in a cross shape. Among the 4 regions formed by removing the central cross region from the cross-shaped region, the minimum value of the luminance is simply referred to as luminance B. The line afterimage is calculated according to the following formula. (Line afterimage) = (luminance A - luminance B) / luminance A × 100.

[0181] (15) Expandability: The expandability of the additive is qualitatively evaluated by applying a voltage to the element and measuring the luminance. The measurement of the luminance is performed in the same manner as in item 14a. The setting of the voltage (V127) is performed in the same manner as in item 14b. Herein, a VA element is used instead of the FFS element. The luminance is measured in the following manner. First, a DC voltage (2 V) is applied to the element for 2 minutes. Next, V127 (rectangular wave, 0.05 Hz) is applied, and the luminance is measured under the condition of an exposure time of 4000 milliseconds. The expandability is evaluated based on the results.

[0182] (16) Response time (τ-2; measured at -20°C; ms): When measuring, an LCD5200 type luminance meter manufactured by Otsuka Electronics Co., Ltd. was used. The light source was a halogen lamp. The low-pass filter was set to 5 kHz. The sample was placed in a VA element in the normally black mode with a cell gap of 4 μm between two glass substrates and the rubbing directions being anti-parallel. The element was sealed using an adhesive cured by ultraviolet light. A rectangular wave (60 Hz, 10 V, 0.5 s) was applied to the element. At this time, light was irradiated on the element from the vertical direction, and the amount of light transmitted through the element was measured. When the amount of light reached the maximum, the transmittance was regarded as 100%, and when the amount of light was the minimum, the transmittance was regarded as 0%. The response time was represented by the time required for the transmittance to change from 90% to 10% (fall time; milliseconds).

[0183] (17) Response time (τ-3; measured at -30°C; ms): When measuring, an LCD5200 type luminance meter manufactured by Otsuka Electronics Co., Ltd. was used. The light source was a halogen lamp. The low-pass filter was set to 5 kHz. The sample was placed in a VA element in the normally black mode with a cell gap of 4 μm between two glass substrates and the rubbing directions being anti-parallel. The element was sealed using an adhesive cured by ultraviolet light. A rectangular wave (60 Hz, 10 V, 0.5 s) was applied to the element. At this time, light was irradiated on the element from the vertical direction, and the amount of light transmitted through the element was measured. When the amount of light reached the maximum, the transmittance was regarded as 100%, and when the amount of light was the minimum, the transmittance was regarded as 0%. The response time was represented by the time required for the transmittance to change from 90% to 10% (fall time; milliseconds).

[0184] (18) Elastic constants (K11: splay elastic constant, K33: bend elastic constant; measured at 25°C; pN): When measuring, an EC-1 type elastic constant measuring instrument manufactured by Toyo Technica Co., Ltd. was used. The sample was placed in a vertically aligned cell with a cell gap of 20 μm between two glass substrates. A charge from 20 volts to 0 volts was applied to the cell, and the electrostatic capacitance and the applied voltage were measured. The measured values of the electrostatic capacitance (C) and the applied voltage (V) were fitted using the formulas (2.98) and (2.101) on page 75 of the "Liquid Crystal Device Handbook" (Nikkankogyo Shimbunsha), and the value of the elastic constant was obtained according to formula (2.100).

[0185] Compound (1-2-1) was synthesized through the following route.

[0186]

[0187] First step: Synthesis of compound (b)

[0188] Compound (a) (3 g, 12.1 mmol) and tetrahydrofuran (THF) (50 ml) were placed in a reaction vessel and cooled to -60 °C or lower. n-Butyllithium (1.6 M solution; 8 ml, 12.7 mmol) was added dropwise thereto, and the mixture was stirred for 1 hour. Subsequently, sulfur powder (0.47 g, 14.5 mmol) was added, and the mixture was stirred for 2 hours while warming up to 25 °C. Bromoacetaldehyde diethyl acetal (3.57 g, 18.13 mmol) and dimethylformamide (DMF) (50 ml) were added thereto, and the mixture was refluxed for 2 hours. The reaction solution was poured into water (100 ml), extracted with toluene (100 ml × 2), washed with water (100 ml), dehydrated with magnesium sulfate, and concentrated. The crude product was purified by column chromatography (silica gel, toluene) to obtain compound (b) as a white solid (4.3 g, yield 90%). In addition, compound (a) is a known substance and can be easily obtained, for example, according to the method described in Japanese Patent Application Laid-Open No. 2019-112607.

[0189] Second step: Synthesis of compound (c)

[0190] Compound (b) (4.3 g), polyphosphoric acid (8 g), and toluene (250 ml) were placed in a reaction vessel and heated under reflux for 5 hours. The reaction solution was poured into water (100 ml), extracted with toluene (100 ml × 2), washed with water (100 ml), dehydrated with magnesium sulfate, and concentrated. The crude product was purified by column chromatography (silica gel, toluene / heptane = 1 / 1) to obtain compound (c) as a white solid (2.1 g, yield 64%).

[0191] Third step: Synthesis of compound (1-2-1)

[0192] Compound (d) (2.1 g) and THF (100 ml) were placed in a reaction vessel and cooled to below -60°C. Lithium diisopropylamide (LDA, 1.1 M; n-hexane solution; 7.53 ml, 8.28 mmol) was added dropwise thereto, and the mixture was further stirred for 2 hours. Subsequently, a solution of iodopropane (1.76 g) in THF (10 ml) was added dropwise, and the mixture was stirred for 8 hours while warming back to 25°C. The reaction solution was poured into water (100 ml), extracted with toluene (100 ml × 2), washed with water (100 ml), dehydrated with magnesium sulfate, and concentrated. The crude product was purified by column chromatography (silica gel, toluene / heptane = 1 / 1) and recrystallization (ethanol) to obtain compound (1-2-1) as a white solid (1.77 g, yield 74%).

[0193] 1 H-NMR (CDCl3) δ 7.86 (s, 1H), 7.59 (d, 1H), 7.09 (d, 1H), 7.11 (dd, 1H), 4.23 (q, 2H), 2.90 (t, 3H), 1.82 (sex, 2H), 1.50 (t, 3H), 1.05 (t, 3H).

[0194] Upper limit temperature (NI) = 98.3°C; dielectric anisotropy (Δε) = -10.8; optical anisotropy (Δn) = 0.237; viscosity (η) = 70.4 mPa·s

[0195] Examples of the composition are shown below. The component compounds are represented by symbols based on the definitions in Table 3 below. In Table 3, the stereoconfiguration related to 1,4-cyclohexylene is the trans configuration. The numbers in parentheses after the symbols correspond to the compound numbers. The (-) symbol indicates other liquid crystalline compounds. The ratio (percentage) of the liquid crystalline compound is the mass percentage (mass%) based on the mass of the liquid crystal composition. Finally, the characteristic values of the composition are summarized.

[0196]

[0197] [Comparative Example 1]

[0198]

[0199] NI = 76.8°C; Δn = 0.132; Δε = -3.8; γ1 = 95.7 mPa·s.

[0200] [Example 1]

[0201] The composition obtained by replacing the thiophene derivative in Comparative Example 1 with compound (1-1) was designated as Example 1.

[0202]

[0203] NI = 76.2 °C; Tc < -20 °C; Δn = 0.131; Δε = -4.2; γ1 = 93.4 mPa·s.

[0204] [Example 2]

[0205]

[0206]

[0207] NI = 80.0 °C; Tc < -20 °C; Δn = 0.114; Δε = -3.6; γ1 = 77.3 mPa·s. [Example 3]

[0208]

[0209] NI = 80.5 °C; Tc < -30 °C; Δn = 0.110; Δε = -3.8; γ1 = 86.2 mPa·s. [Example 4]

[0210]

[0211]

[0212] NI = 80.8 °C; Tc < -30 °C; Δn = 0.114; Δε = -3.8; γ1 = 86.0 mPa·s. [Example 5]

[0213]

[0214] NI = 116.4 °C; Tc < -20 °C; Δn = 0.100; Δε = -2.5; γ1 = 150.0 mPa·s. [Example 6]

[0215]

[0216] NI = 120.0 °C; Tc < -20 °C; Δn = 0.096; Δε = -2.7; γ1 = 162.7 mPa·s. [Example 7]

[0217]

[0218]

[0219] NI = 71.0 °C; Δn = 0.130; Δε = -4.2; γ1 = 90.0 mPa·s. [Example 8]

[0220]

[0221] NI = 79.5 °C; Δn = 0.111; Δε = -3.8; γ1 = 86.0 mPa·s. [Example 9]

[0222]

[0223]

[0224] NI = 115.4 °C; Δn = 0.101; Δε = -2.5; γ1 = 149.8 mPa·s.

[0225] [Example 10]

[0226]

[0227] NI = 82.9 °C; Tc < -20 °C; Δn = 0.110; Δε = -4.0; γ1 = 86.8 mPa·s. [Example 11]

[0228]

[0229] NI = 116.3 °C; Tc < -20 °C; Δn = 0.097; Δε = -2.5; γ1 = 148.5 mPa·s. [Example 12]

[0230]

[0231]

[0232] NI = 105.9 °C; Tc < -20 °C; Δn = 0.100; Δε = -3.5; γ1 = 161.4 mPa·s. [Example 13]

[0233]

[0234] NI = 108.7 °C; Δn = 0.950; Δε = -3.4; γ1 = 147.6 mPa·s.

[0235] [Example 14]

[0236]

[0237]

[0238] NI = 74.6 °C; Tc < -20 °C; Δn = 0.100; Δε = -4.0; γ1 = 82.0 mPa·s. [Example 15]

[0239]

[0240] NI = 81.3 °C; Δn = 0.115; Δε = -3.5; γ1 = 79.7 mPa·s.

[0241] [Example 16]

[0242]

[0243] NI = 80.3 °C; Δn = 0.120; Δε = -3.4; γ1 = 80.3 mPa·s.

[0244] [Example 17]

[0245]

[0246]

[0247] NI = 80.3 °C; Tc < -20 °C; Δn = 0.114; Δε = -3.3; γ1 = 74.6 mPa·s. [Example 18]

[0248]

[0249] NI = 80.0 °C; Tc < -20 °C; Δn = 0.120; Δε = -3.5; γ1 = 79.2 mPa·s. [Example 19]

[0250]

[0251] NI = 78.8 °C; Tc < -20 °C; Δn = 0.110; Δε = -3.8; γ1 = 81.9 mPa·s. [Example 20]

[0252]

[0253]

[0254] NI = 79.5 °C; Tc < -20 °C; Δn = 0.109; Δε = -3.8; γ1 = 83.2 mPa·s. [Example 21]

[0255]

[0256] NI = 79.7 °C; Tc < -20 °C; Δn = 0.109; Δε = -3.8; γ1 = 83.4 mPa·s. [Example 22]

[0257]

[0258] NI = 80.0 °C; Tc < -20 °C; Δn = 0.114; Δε = -3.6; γ1 = 77.3 mPa·s. [Example 23]

[0259]

[0260] NI = 80.3 °C; Δn = 0.111; Δε = -3.6; γ1 = 82.5 mPa·s.

[0261] [Example 24]

[0262]

[0263] NI = 94.8 °C; Tc < -20 °C; Δn = 0.096; Δε = -2.6; γ1 = 72.6 mPa·s. [Example 25]

[0264]

[0265] NI = 94.4 °C; Tc < -30 °C; Δn = 0.101; Δε = -4.0; γ1 = 119.3 mPa·s.

[0266] [Example 26]

[0267]

[0268] NI = 90.5 °C; Δn = 0.100; Δε = -3.9; γ1 = 116.5 mPa·s.

[0269] [Example 27]

[0270]

[0271] Add 0.34% by mass of the polymerizable compound represented by (4-1) as additive X.

[0272]

[0273] NI = 74.2 °C; Δn = 0.129; Δε = -2.8; γ1 = 88.0 mPa·s.

[0274] [Example 28]

[0275]

[0276]

[0277] Add 0.30% by mass of the polymerizable compound represented by (4-25) as additive X.

[0278]

[0279] NI = 74.2 °C; Δn = 0.129; Δε = -2.8; γ1 = 88.0 mPa·s.

[0280] [Example 29]

[0281]

[0282] Add 0.29% by mass of the polymerizable compound represented by (4-1) and 0.05% by mass of the polymerizable compound represented by (4-25) as Additive X.

[0283]

[0284]

[0285] NI = 74.2 °C; Δn = 0.129; Δε = -2.8; γ1 = 88.0 mPa·s.

[0286] The rotational viscosity and dielectric anisotropy of the composition of Comparative Example 1 are 95.7 mPa·s and -3.8, respectively. On the other hand, the rotational viscosity and dielectric anisotropy of the composition of Example 1 are 93.4 mPa·s and -4.2, respectively. Therefore, it is concluded that the liquid crystal composition of the present invention has excellent properties.

[0287] [Industrial Applicability]

[0288] 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 contains at least one compound selected from the compounds represented by formula (1) as component A and has negative dielectric anisotropy; In formula (1), R 1 and R 2 are hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; X 1 and X 2 are O or S; L 1 and L 2 are hydrogen, fluorine or trifluoromethyl; ring A and ring B are 1,4 - cyclohexylene, 1,4 - cyclohexenylene, tetrahydropyran - 2,5 - diyl, 1,4 - phenylene, 1,4 - phenylene in which at least one hydrogen is substituted with fluorine or chlorine, naphthalene - 2,6 - diyl, naphthalene - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, chroman - 2,6 - diyl, chroman - 2,6 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, fluorene - 2,7 - diyl, fluorene - 2,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzofuran - 3,7 - diyl, dibenzofuran - 3,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, dibenzothiophene - 3,7 - diyl, dibenzothiophene - 3,7 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, indane - 2,5 - diyl, indane - 2,5 - diyl in which at least one hydrogen is substituted with fluorine or chlorine, thiophene - 2,5 - diyl or furan - 2,5 - diyl; Z 1 and Z 2 are a single bond, ethylene, vinylene, ethynylene, methoxy or carbonyloxy; a and b are 0 or 1.

2. The liquid crystal composition according to claim 1, wherein In formula (1), X 1 and X 2 at least one of which is S.

3. The liquid crystal composition according to claim 1 or 2, which contains at least one compound selected from the compounds represented by formulae (1-1) to (1-3) as component A; In Formulae (1-1) to (1-3), R 1 and R 2 are hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; L 1 and L 2 are hydrogen, fluorine, or trifluoromethyl.

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

5. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by formula (2) as component B; In formula (2), R 3 and R 4 are each independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen atom is substituted with fluorine or chlorine; ring C and ring D are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z 3 is a single bond, ethylene, vinylene, methoxylene or carbonyloxy; and c is 1, 2 or 3.

6. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by formulae (2-1) to (2-15) as component B; In formulas (2-1) to (2-15), R 3 and R 4 are each an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

7. The liquid crystal composition according to claim 5 or 6, wherein The proportion of component B ranges from 10% by mass to 90% by mass.

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

9. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by formulae (3-1) to (3-37) as component C; In formulas (3-1) to (3-37), R 5 and R 6 are hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

10. The liquid crystal composition according to claim 8, wherein The proportion of component C ranges from 10% by mass to 85% by mass.

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

12. The liquid crystal composition according to claim 11, wherein, In formula (4), P 1 to P 3 is a group selected from the polymerizable groups represented by formula (P-1) to formula (P-5); In formulas (P-1) to (P-5), M 1 to M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

13. The liquid crystal composition according to claim 1, which contains at least one compound selected from the polymerizable compounds represented by formulae (4-1) to (4-29) as additive X; In Formulae (4-1) to (4-29), Sp 1 to Sp 3 is a single bond or an alkylene group having 1 to 10 carbon atoms. In the alkylene group, at least one -CH2- may be substituted with -O-, -COO-, -OCO- or -OCOO-, at least one -CH2CH2- may be substituted with -CH=CH- or -C≡C-, and at least one hydrogen in these groups may be substituted with fluorine or chlorine; P 4 to P 6 is a polymerizable group selected from the groups represented by Formulae (P-1) to (P-3); In formulas (P-1) to (P-3), M 1 to M 3 is hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

14. The liquid crystal composition according to any one of claims 11 to 13, wherein The proportion of additive X ranges from 0.03% by mass to 10% by mass.

15. A liquid crystal display element contains the liquid crystal composition according to any one of claims 1 to 14.

16. The liquid crystal display element according to claim 15, wherein, The operation mode is in-plane switching mode, vertical alignment mode, fringe field switching mode or electrically induced photo-reactive alignment mode, and the driving method is active matrix method.

17. A polymer-stabilized alignment type liquid crystal display element contains the liquid crystal composition according to claim 11, and the polymerizable compound in the liquid crystal composition is polymerized.

18. A use of a liquid crystal composition, the liquid crystal composition is the liquid crystal composition according to any one of claims 1 to 14, and it is used in a liquid crystal display element.

19. A use of a liquid crystal composition, the liquid crystal composition is the liquid crystal composition according to claim 11, and it is used in a polymer-stabilized alignment type liquid crystal display element.

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