CN111826171A - Liquid crystal composition, use thereof, and liquid crystal display element - Google Patents

Abstract

The present invention provides a liquid crystal composition which satisfies at least one of the characteristics of high upper limit temperature, low lower limit temperature, low viscosity, appropriate optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to light and high stability to heat, or has an appropriate balance between at least two of the characteristics, and a use thereof, and a liquid crystal display element. The liquid crystal composition of the present invention contains at least one compound selected from the compounds represented by formula (1) as an additive X, and may contain a specific compound having a large negative dielectric anisotropy as a component a, a specific compound having a high upper limit temperature or a small viscosity as a component B, or a specific compound having a polymerizable group as an additive Y.

Description

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

technical field

The present invention relates to a liquid crystal composition, a liquid crystal display element containing the composition, and the like. In particular, it relates to a liquid crystal composition with negative dielectric anisotropy, and a liquid crystal composition containing the composition and having in-plane switching (IPS), vertical alignment (VA), fringe field switching (FFS), electric field-induced photoreactive alignment ( FPA) and other modes of liquid crystal display elements. It also relates to a polymer-stabilized alignment type liquid crystal display element.

Background technique

In the liquid crystal display element, the classification based on the operation mode of liquid crystal molecules is: phase change (PC), twisted nematic (TN), super twisted nematic (STN), electronically controlled birefringence. (electrically controlled birefringence, ECB), optically compensated bend (optically compensated bend, OCB), in-plane switching (in-plane switching, IPS), vertical alignment (vertical alignment, VA), fringe field switching (fringe field switching, FFS), electric field Modes such as field-induced photo-reactive alignment (FPA). Component-based driving methods are classified into passive matrix (PM) and active matrix (AM). PM is classified into static type (static), multiplex type (multiplex), etc., AM is classified into thin film transistor (TFT), metal insulator metal (MIM) and the like. TFTs are classified into amorphous silicon and polycrystal silicon. The latter are classified into high temperature type and low temperature type according to the manufacturing process. The light source is classified into a reflective type using natural light, a transmissive type using a backlight, and a transflective type using both natural light and backlight.

The liquid crystal display element contains a liquid crystal composition having a nematic phase. The composition has suitable properties. By improving the properties of the composition, an AM device having good properties can be obtained. The associations among these properties are summarized in Table 1 below. The properties of the composition will be further described based on a commercially available AM device. The temperature range of the nematic phase correlates to the temperature range over which the element can be used. The preferable upper limit temperature of the nematic phase is about 70°C or more, and the preferable lower limit temperature of the nematic phase is about -10°C or less. The viscosity of the composition correlates to the response time of the element. In order to display a moving image with an element, it is preferable that the response time is short. The ideal is a response time of less than 1 millisecond. Therefore, the viscosity of the composition is preferably small. More preferably, the viscosity at low temperature is small.

The optical anisotropy of the composition correlates to the contrast of the element. Depending on the mode of the element, either a large optical anisotropy or a small optical anisotropy, ie, 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 contrast. An appropriate value of the product depends on the type of operation mode. In the element of the VA mode, the value is in the range of about 0.30 μm to about 0.40 μm, and in the element of the IPS mode or the FFS mode, the value is in the range of about 0.20 μm to about 0.30 μm. In these cases, compositions with large optical anisotropy are preferred for elements with small cell gaps. The large dielectric anisotropy of the composition contributes to the low threshold voltage, low power consumption and large contrast ratio of the device. Therefore, a large dielectric anisotropy is preferred. The large specific resistance of the composition contributes to the large voltage holding ratio and the large contrast ratio of the element. Therefore, a composition having a large specific resistance in the initial stage is preferable. A composition having a large specific resistance even after prolonged use is preferred. The stability of the composition to UV light or heat correlates with the lifetime of the element. When the stability is high, the life of the element is long. Such characteristics are preferable for AM elements used in liquid crystal monitors, liquid crystal televisions, and the like.

In general liquid crystal display elements, the vertical alignment of liquid crystal molecules can be achieved by a specific polyimide alignment film. In a polymer sustained alignment (polymer sustained alignment, PSA) type liquid crystal display element, a polymer and an alignment film are combined. First, a composition to which a small amount of a polymerizable compound is added is injected into the element. Next, the composition is irradiated with ultraviolet rays while applying a voltage between the substrates of the element. The polymerizable compound is polymerized to form a network structure of the polymer in the composition. In the composition, the polymer can be used to control the orientation of liquid crystal molecules, so that the response time of the element is shortened, and the afterimage of the image is improved. Such effects of polymers can be expected in elements having modes such as TN, ECB, OCB, IPS, VA, FFS, and FPA.

A composition having a positive dielectric anisotropy is used in an AM element having a TN mode. A composition having a negative dielectric anisotropy is used in an AM element having a VA mode. A composition having a positive or negative dielectric anisotropy is used in an AM element having an IPS mode or an FFS mode. A composition having positive or negative dielectric anisotropy is used in a polymer sustained alignment (PSA) type AM device.

Furthermore, these liquid crystal display elements are required to have excellent display quality without display defects such as afterimage and display unevenness, or with suppressed display defects such as afterimage and display unevenness. In order to realize the above situation, an attempt was made to add various additives to the liquid crystal composition to improve the reliability of the entire liquid crystal display (Liquid Crystal Display, LCD) panel.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-94412

SUMMARY OF THE INVENTION

[Problems to be Solved by Invention]

An object of the present invention is to provide a liquid crystal composition that satisfies the requirements of a high upper limit temperature of the nematic phase, a low minimum temperature of the nematic phase, low viscosity, suitable optical anisotropy, high dielectric anisotropy, and high specific resistance , at least one of the characteristics of high stability to light, high stability to heat, and large elastic constant. Another subject is to provide a liquid crystal composition having an appropriate balance between at least two of these properties. Another subject is to provide a liquid crystal display element containing such a composition. Another subject is to provide an AM element having characteristics such as a short response time, a high voltage holding ratio, a low threshold voltage, a high contrast ratio, and a long lifetime.

[Technical means to solve the problem]

The present inventors have studied various liquid crystal compounds and various chemical substances, found that the above-mentioned problems can be solved by using a specific compound, and completed the present invention. That is, the present invention relates to a liquid crystal composition containing at least one compound selected from the compounds represented by the formula (1) as an additive X, and a liquid crystal display element containing the same, and having Nematic phase and negative dielectric anisotropy.

In formula (1), R ^a is hydrogen, a group represented by formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms, Among alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by - CH=CH- or -C≡C- substituted, in these groups, at least one hydrogen can be substituted by halogen; R ^b is an alkyl group with 1 to 30 carbon atoms, an alicyclic hydrocarbon group with 3 to 30 carbon atoms, or a carbon number of 6 Aromatic hydrocarbon groups of to 30, among these groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH= CH- or -C≡C-substituted, in these groups, at least one hydrogen may be substituted by halogen; Z ^a and Z ^c are single bonds or alkylene groups with 1 to 30 carbon atoms, in the alkylene groups, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen ; Z ^b is a single bond, an alkylene group with a carbon number of 1 to 30, an alicyclic hydrocarbon group with a carbon number of 3 to 30 or an aromatic hydrocarbon group with a carbon number of 6 to 30, among these groups, at least one -CH ₂ - may be -S-, -O-, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by Halogen or group represented by formula (F) is substituted; S is sulfur; n is 0, 1, 2, 3 or 4; p is 0 or 1;

In formula (F), R ^c is an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 30 carbon atoms, among these groups, at least one -CH ₂ -may be Substituted by -S-, -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be Substituted by halogen; Z ^d is a single bond or an alkylene group having 1 to 30 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen; S is sulfur; m is 0, 1, 2, 3 or 4; r is 0 or 1.

[Effect of invention]

The advantages of the present invention are to provide a liquid crystal composition which fully satisfies the requirements of high upper limit temperature of nematic phase, low minimum temperature of nematic phase, low viscosity, appropriate optical anisotropy, large dielectric anisotropy and high specific resistance , at least one of the characteristics of high stability to light, high stability to heat, and large elastic constant. Another advantage is to provide a liquid crystal composition with a suitable balance between at least two of these properties. Another advantage is to provide a liquid crystal display element containing such a composition. Still another advantage is to provide an AM element with characteristics such as short response time, high voltage holding ratio, low threshold voltage, high contrast ratio, and long life.

Detailed ways

How to use the terms in this specification is as follows. The terms of "liquid crystal composition" and "liquid crystal display element" may be abbreviated as "composition" and "element", respectively. A "liquid crystal display element" is a general term for a liquid crystal display panel and a liquid crystal display module. "Liquid crystal compound" refers to a compound having a liquid crystal phase such as a nematic phase and a smectic phase, and a compound having no liquid crystal phase but for adjusting the temperature range, viscosity, and dielectric anisotropy of the nematic phase Generic term for compounds mixed into compositions for the purpose of properties such as these. 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. The "polymerizable compound" is a compound added for the purpose of producing a polymer in the composition. The liquid crystal compound having an alkenyl group is not classified as a polymerizable compound in its meaning.

The liquid crystal composition is prepared by mixing a plurality of liquid crystal compounds. Additives, such as an optically active compound and a polymerizable compound, are added to the said liquid crystal composition as needed. Even when an additive is added, the ratio of the liquid crystal compound is represented by the mass percentage (mass %) based on the mass of the liquid crystal composition not containing the additive. The ratio of the additive is represented by the mass percentage (mass %) based on the mass of the liquid crystal composition not containing the additive. That is, the ratio of the liquid crystal compound or the additive is calculated based on the total mass of the liquid crystal compound.

The "upper limit temperature of the nematic phase" is sometimes abbreviated as "upper limit temperature". The "lower limit temperature of the nematic phase" is sometimes abbreviated as "lower limit temperature". The expression "improving the dielectric anisotropy" means that the value of the composition with a positive dielectric anisotropy increases positively, and when the composition has a negative dielectric anisotropy, it means that the value is negative. increase to the ground. "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 not only at room temperature but also at a temperature close to the upper limit temperature after long-term use It has a large voltage holding ratio even at the temperature of the upper limit temperature. The properties of a composition or element are sometimes studied by time-varying tests.

The compound (1z) is described as an example. In the formula (1z), the symbols α and β enclosed by a hexagon correspond to the ring α and the 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 rings α. The two groups represented by the two rings α may be the same or different. The rules apply to any two rings α where the subscript 'x' is greater than 2. The rules also apply to other notations such as the bonding group Z. A diagonal line crossing one side of ring β indicates that any hydrogen on ring β may be substituted with a substituent (-Sp-P). The subscript 'y' indicates the number of substituents substituted. When the subscript 'y' is 0, there is no such substitution. When the subscript 'y' is 2 or more, a plurality of substituents (-Sp-P) are present on the ring β. In that case, the rule "may be the same, or it may be different" also applies. Again, the rules also apply when the notation for Ra is used in a variety of compounds.

In formula (1z), for example, the expression "Ra and Rb are alkyl, alkoxy or alkenyl" means that Ra and Rb are independently selected from the group of alkyl, alkoxy and alkenyl. Here, the group represented by Ra and the group represented by Rb may be the same or different. The rules also apply when the notation for Ra is used in various compounds. The rules also apply when more than one Ra is used in one compound.

At least one compound selected from the compounds represented by formula (1z) may be abbreviated as "compound (1z)" in some cases. "Compound (1z)" means one compound represented by formula (1z), a mixture of two compounds, or a mixture of three or more compounds. The same applies to compounds represented by other formulae. The expression "at least one compound selected from the compounds represented by formula (1z) and formula (2z)" means at least one compound selected from the group of compound (1z) and compound (2z).

The expression "at least one 'A'" means that the number of 'A's 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 There are also unlimited options. The expression "at least one _-CH2- may be substituted with -O-" is sometimes used. In that case, _-CH2 - _CH2 -CH2- can be converted to -O- _CH2 - _O- by substitution of a non-contiguous _-CH2- with -O-. However, there is no case where the adjoining _-CH2- is substituted with -O-. The reason is that -OO-CH ₂ - (peroxide) is generated in the substitution.

The alkyl group of the liquid crystal compound is linear or branched, and does not contain a cyclic alkyl group. Straight chain alkyl groups are preferred over branched alkyl groups. The same applies to terminal groups such as an alkoxy group and an alkenyl group. Regarding the stereo configuration related to 1,4-cyclohexylene, in order to increase the upper temperature limit, the trans configuration is preferred to the cis configuration. Since 2-fluoro-1,4-phenylene is left-right asymmetric, there are leftward (L) and rightward (R) directions.

The same applies to divalent groups such as tetrahydropyran-2,5-diyl. Furthermore, in order to raise the upper limit temperature, the preferable tetrahydropyran-2,5-diyl is rightward (R). The same applies to a bonding group (-COO- or -OCO-) such as a carbonyloxy group.

The present invention is the following items and the like.

Item 1. A liquid crystal composition containing at least one compound selected from the compounds represented by the formula (1) as the additive X, and having a nematic phase and a negative dielectric anisotropy.

In formula (1), R ^a is hydrogen, a group represented by formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms, Among alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by - CH=CH- or -C≡C- substituted, in these groups, at least one hydrogen can be substituted by halogen; R ^b is an alkyl group with 1 to 30 carbon atoms, an alicyclic hydrocarbon group with 3 to 30 carbon atoms, or a carbon number of 6 Aromatic hydrocarbon groups of to 30, among these groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH= CH- or -C≡C-substituted, in these groups, at least one hydrogen may be substituted by halogen; Z ^a and Z ^c are single bonds or alkylene groups with 1 to 30 carbon atoms, in the alkylene groups, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen ; Z ^b is a single bond, an alkylene group with a carbon number of 1 to 30, an alicyclic hydrocarbon group with a carbon number of 3 to 30 or an aromatic hydrocarbon group with a carbon number of 6 to 30, among these groups, at least one -CH ₂ - may be -S-, -O-, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by Halogen or group represented by formula (F) is substituted; S is sulfur; n is 0, 1, 2, 3 or 4; p is 0 or 1;

In formula (F), R ^c is an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 30 carbon atoms, among these groups, at least one -CH ₂ -may be Substituted by -S-, -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be Substituted by halogen; Z ^d is a single bond or an alkylene group having 1 to 30 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen; S is sulfur; m is 0, 1, 2, 3 or 4; r is 0 or 1.

Item 2. The liquid crystal composition according to Item 1, which contains, as the additive X, at least one compound selected from the group consisting of compounds represented by formula (1-1) to formula (1-4).

In formulas (1-1) to (1-4), R ^f is hydrogen, an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, Among these groups, at least one -CH ₂ - can be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; R ^g , ^Rh , R ⁱ and R ^j are hydrogen, an alkyl group having 1 to 5 carbon atoms, among these groups, at least one -CH ₂ - can be substituted by -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH =CH-substituted, at least one hydrogen may be substituted by a group represented by formula (F-1); R ^d and R ^e are alkyl groups with 1 to 20 carbon atoms, alicyclic hydrocarbon groups with 3 to 20 carbon atoms, or alicyclic hydrocarbon groups with carbon number 3 to 20. Aromatic hydrocarbon groups of 6 to 20, among these groups, at least one -CH ₂ - can be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- ; Z ^e and Z ^f are a single bond or an alkylene group with 1 to 10 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; Z ^g is an alkylene group having 1 to 6 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -S-, -O -, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - may be substituted by -CH=CH-; S is sulfur; n ¹ and n ² are 0, 1, 2 or 3;

In formula (F-1), R ^j is an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, among these groups, at least one -CH ₂ -Can be substituted by -O- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; Z ^h is a single bond or an alkylene group with a carbon number of 1 to 10, the alkylene In the group, at least one -CH ₂ - may be substituted by -O- or -CO-; S is sulfur; m ¹ is 0, 1, 2 or 3; r ¹ is 0 or 1.

Item 3. The liquid crystal composition according to Item 1 or Item 2, wherein the ratio of the additive X is in the range of 0.0001% by mass to 2% by mass.

Item 4. The liquid crystal composition according to any one of Items 1 to 3, which contains, as component A, at least one compound selected from the group consisting of compounds represented by formula (2).

In formula (2), R ^2a and R ^2b are hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons group, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine or chlorine; Ring A and Ring C are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran- 2,5-diyl, 1,4-phenylene, 1,4-phenylene with at least one hydrogen substituted with fluorine or chlorine, naphthalene-2,6-diyl, at least one hydrogen with fluorine or chlorine substituted Naphthalene-2,6-diyl, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring B is 2,3-difluoro -1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5 -Trifluoronaphthalene-2,6-diyl, 7,8-difluorochroman-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, 4, 6-Difluorodibenzofuran-3,7-diyl, 4,6-difluorodibenzothiophene-3,7-diyl or 1,1,6,7-tetrafluoroindan-2,5 -diyl; Z ^2a and Z ^2b are single bond, ethylene, vinylene, methyleneoxy or carbonyloxy; a is 0, 1, 2 or 3, b is 0 or 1; and a and b The sum is 3 or less.

Item 5. The liquid crystal composition according to any one of Items 1 to 4, which contains, as component A, at least one compound selected from the group consisting of compounds represented by formula (2-1) to formula (2-35) .

In formula (2-1) to formula (2-35), R ^2a and R ^2b are hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons , an alkenyloxy group having 2 to 12 carbons, or an alkyl group having 1 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine.

Item 6. The liquid crystal composition according to Item 4 or Item 5, wherein the ratio of Component A is in the range of 10% by mass to 90% by mass.

Item 7. The liquid crystal composition according to any one of Items 1 to 6, which contains, as component B, at least one compound selected from the group consisting of compounds represented by formula (3).

In formula (3), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or at least one hydrogen is substituted by fluorine or chlorine Alkenyl having 2 to 12 carbon atoms; Ring D and Ring E are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro- 1,4-phenylene; Z ^3a is a single bond, ethylene, vinylene, methyleneoxy or carbonyloxy; c is 1, 2 or 3.

Item 8. The liquid crystal composition according to any one of Items 1 to 7, which contains, as component B, at least one compound selected from the group consisting of compounds represented by formula (3-1) to formula (3-13) .

In formula (3-1) to formula (3-13), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or Alkenyl having 2 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine.

Item 9. The liquid crystal composition according to Item 7 or Item 8, wherein the ratio of Component B is in the range of 10% by mass to 90% by mass.

Item 10. The liquid crystal composition according to any one of Items 1 to 9, which contains, as the additive Y, at least one compound selected from the group consisting of polymerizable compounds represented by formula (4).

In formula (4), ring F and ring I 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 can be fluorine, chlorine, alkyl with 1 to 12 carbons, alkoxy with 1 to 12 carbons, or at least One hydrogen is substituted by an alkyl group having 1 to 12 carbon atoms substituted by fluorine or chlorine; ring G is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1 ,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl , naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1 ,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, in these rings, at least one hydrogen can be replaced by fluorine, chlorine, carbon number from 1 to 12 The alkyl group, the alkoxy group of carbon number 1 to 12, or the alkyl group of carbon number 1 to 12 in which at least one hydrogen is substituted by fluorine or chlorine is substituted; Z ^4a and Z ^4b are single bonds or carbon number 1 to 10 In the alkylene group, at least one -CH ₂ - can be substituted by -O-, -CO-, -COO- or -OCO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH -, -C(CH ₃ )=CH-, -CH=C(CH ₃ )- or -C(CH ₃ )=C(CH ₃ )- substituted, in these groups, at least one hydrogen may be substituted by fluorine or chlorine ; P ^4a , P ^4b and P ^4c are polymerizable groups; Sp ^4a , Sp ^4b and Sp ^4c are single bonds or alkylene groups with 1 to 10 carbon atoms, and in the alkylene groups, at least one -CH ₂ - can be Substituted by -O-, -COO-, -OCO- or -OCOO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by fluorine or chlorine; d is 0, 1 or 2; e, f and g are 0, 1, 2, 3 or 4; and the sum of e, f and g is 1 or more.

Item 11. The liquid crystal composition according to Item 10, wherein, in the formula (4), P ^4a , P ^4b and P ^4c are polymerizable compounds selected from the group consisting of formulas (P-1) to (P-5) base in base.

In formula (P-1) to formula (P-5), M ¹ , M ² and M ³ are hydrogen, fluorine, alkyl group with carbon number 1 to 5, or carbon number 1 in which at least one hydrogen is substituted by fluorine or chlorine to 5 alkyl groups.

Item 12. The liquid crystal composition according to any one of Items 1 to 11, which contains at least one compound selected from the group consisting of polymerizable compounds represented by Formula (4-1) to Formula (4-29) as Additive Y.

In formula (4-1) to formula (4-29), Sp ^4a , Sp ^4b and Sp ^4c are a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - Can be substituted by -O-, -COO-, -OCO- or -OCOO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, among these groups, at least one hydrogen may be substituted with fluorine or chlorine; P ^4d , P ^4e and P ^4f are polymerizable groups selected from groups represented by formula (P-1) to formula (P-3);

In formulas (P-1) to (P-3), M ¹ , M ² and M ³ are hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or a carbon number 1 wherein at least one hydrogen is substituted by fluorine or chlorine to 5 alkyl groups.

Item 13. The liquid crystal composition according to any one of Items 10 to 12, wherein the ratio of the additive Y is in the range of 0.03 mass % to 10 mass %.

Item 14. A liquid crystal display element comprising the liquid crystal composition according to any one of Items 1 to 13.

Item 15. The liquid crystal display element according to item 14, wherein the operation mode of the liquid crystal display element is IPS mode, VA mode, FFS mode or FPA mode, and the driving method of the liquid crystal display element is an active matrix method.

Item 16. A polymer-stabilized alignment type liquid crystal display element comprising the liquid crystal composition according to any one of Items 10 to 13, wherein the polymerizable compound in the liquid crystal composition is polymerized.

Item 17. Use of a liquid crystal composition, which is the liquid crystal composition according to any one of Items 1 to 13, in a liquid crystal display element.

Item 18. Use of a liquid crystal composition, which is the liquid crystal composition according to any one of Items 10 to 13, in a polymer-stabilized alignment type liquid crystal display element.

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

The composition of the present invention will be described in the following order. First, the constitution of the component compounds in the composition will be described. Second, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. Third, the combination of the component compounds in the composition, the preferred ratio of the component compounds, and the basis thereof will be described. Fourth, preferred forms of the component compounds will be described. Fifth, preferred constituent compounds are shown. Sixth, additives that can be added to the composition will be described. Seventh, the synthesis method of the component compounds will be described. Finally, the use of the composition will be explained.

First, the constitution of the component compounds in the composition will be described. The composition contains various liquid crystal compounds. The composition may also contain additives. The additives are optically active compounds, antioxidants, ultraviolet absorbers, matting agents, pigments, defoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. From the viewpoint of the liquid crystal compound, the compositions are classified into composition (a) and composition (b). The composition (a) may contain other liquid crystal compounds, additives, and the like in addition to the liquid crystal compound selected from the compound (2) and the compound (3). The "other liquid crystal compound" is a liquid crystal compound different from the compound (2) and the compound (3). Such a compound is mixed in the composition for the purpose of further adjusting the properties.

The composition (b) contains substantially only the liquid crystal compound selected from the compound (2) and the compound (3). "Substantially" means that the composition (b) may contain additives, but does not contain other liquid crystal compounds. Composition (b) has a small amount of ingredients compared to composition (a). From the viewpoint of cost reduction, the composition (b) is superior to the composition (a). The composition (a) is superior to the composition (b) in that the characteristics can be further adjusted by mixing other liquid crystal compounds.

Second, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. Based on the effects of the present invention, the main characteristics of the component compounds are summarized in Table 2. In the notation in Table 2, L means large or high, M means medium, and S means small or low. The notations L, M, S are classifications based on qualitative comparisons between the constituent compounds, and 0 (zero) means less than S.

Table 2. Characteristics of liquid crystal compounds

characteristic Compound (2) Compound (3) upper limit temperature S～L S～L Viscosity M～L S～M optical anisotropy M～L S～L Dielectric Anisotropy M～L¹⁾ 0 specific resistance L L

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

The main effects of the component compounds are as follows. Additive X acts as an antioxidant and contributes to high stability to heat or light. Since the compound (1) is added in a small amount, the properties such as the upper limit temperature, optical anisotropy, and dielectric anisotropy are not affected in many cases. Compound (2) increases the dielectric anisotropy and lowers the minimum temperature. Compound (3) lowers the viscosity or raises the upper limit temperature. Since compound (4) is polymerizable, it is polymerized to form a polymer. Since the polymer stabilizes the alignment of liquid crystal molecules, the response time of the device is shortened.

Organic compounds are degraded by light or thermal energy and generate free radicals. The free radicals act as linking carriers, and further react with other organic compounds and the like to generate new radicals, which are linked. In addition, when the reaction proceeds, peroxides are generated, and new radicals are also generated from the peroxides and loaded into the chain. A compound having the action of stopping such radical chaining is called a radical chaining inhibitor (primary antioxidant). Phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol are used as general primary antioxidants, supply hydrogen of phenol moiety to radicals, and have low activity due to steric hindrance and the like. phenoxy radicals. Then, it further captures and stabilizes radicals. The increase of free radicals is inhibited by this action. On the other hand, with respect to the peroxide generated during the deterioration process, the peroxide is decomposed to form an inert compound, thereby suppressing the loading of the chain by the generated radical. Those having such an action are called peroxide decomposers (secondary antioxidants), and sulfur-based antioxidants (thioether compounds), phosphorus-based antioxidants (phosphite compounds), and the like are generally used.

The additive X of the present invention is at least one compound selected from the compounds represented by the formula (1). The OH group of the compound becomes a phenoxy radical to capture the radical, thereby exhibiting a high antioxidant effect. Moreover, it also functions as a peroxide decomposer by the sulfur (S) contained in the structure of the said compound.

Third, the combination of the component compounds in the composition, the preferred ratio of the component compounds, and the basis thereof will be described. Preferred combinations of 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). A more preferable combination is compound (1)+compound (2)+compound (3) or compound (1)+compound (2)+compound (3)+compound (4).

The preferable ratio of the additive X is 0.0001 mass % or more, and the preferable ratio of the additive X is about 2.0000 mass % or less in order to lower the minimum temperature. A more preferable ratio is in the range of about 0.0050 mass % to about 1.0000 mass %. A particularly preferable ratio is in the range of about 0.0100 mass % to about 0.1000 mass %.

In order to increase the dielectric anisotropy, the preferable ratio of the compound (2) is about 10 mass % or more, and the preferable ratio of the compound (2) is about 90 mass % or less in order to lower the minimum temperature. A more preferable ratio is in the range of about 20% by mass to about 80% by mass. A particularly preferable ratio is in the range of about 30% by mass to about 70% by mass.

The preferred ratio of compound (3) is about 10 mass % or more in order to increase the upper limit temperature or to reduce viscosity, and the preferred ratio of compound (3) is about 90 mass % or less in order to increase the dielectric anisotropy. A more preferable ratio is in the range of about 20% by mass to about 80% by mass. A particularly preferable ratio is in the range of about 30% by mass to about 70% by mass.

Additive Y is added to the composition for the purpose of being suitable for a polymer-stabilized oriented element. In order to orientate liquid crystal molecules, the preferable ratio of the additive Y is about 0.03 mass % or more, and the preferable ratio of the additive Y is about 10 mass % or less in order to prevent the display failure of an element. A more preferable ratio is in the range of about 0.1% by mass to about 2% by mass. A particularly preferable ratio is in the range of about 0.2 mass % to about 1.0 mass %.

Fourth, preferred forms of the component compounds will be described. In formula (1), R ^a is hydrogen, a group represented by formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms, Among alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by - CH=CH- or -C≡C- substituted, in these groups, at least one hydrogen may be substituted by halogen. Preferred R ^a is hydrogen, a group represented by formula (F), an alkyl group having 1 to 15 carbon atoms, at least one -CH ₂ - may be substituted by -S-, -O- or -CO-, at least one -CH ₂ -CH2- may be substituted with -CH= _CH- . R ^b is an alkyl group having ₁ to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms. O-, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - may be substituted by -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be substituted by halogen. Preferred R ^b is an alkyl group with 1 to 15 carbon atoms, at least one -CH ₂ - can be substituted by -S-, -O- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH -replace. Z ^a and Z ^c are a single bond or an alkylene group having 1 to 30 carbon atoms, in the alkylene group, at least one -CH ₂ - may be substituted by -O-, -NH- or -CO-, and at least one - _CH2 -CH2- may be substituted with -CH= _CH- or -C≡C-, and at least one hydrogen may be substituted with halogen. Preferred Z ^a or Z ^c is a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted with -O- or -CO-. Z ^b is a single bond, an alkylene group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms, among these groups, at least one -CH ₂ - may be via - S-, -O-, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by halogen or a group represented by the formula (F). Preferred Z ^b is a single bond, an alkylene group having 1 to 30 carbon atoms, among these groups, at least one -CH ₂ - may be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - may be substituted with -CH=CH-, and at least one hydrogen may be substituted with a group represented by formula (F). S is sulfur. n is 0, 1, 2, 3 or 4. The preferred n is 2. p is 0 or 1.

In formula (F), R ^c is an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms or an aromatic hydrocarbon group having 6 to 30 carbon atoms, among these groups, at least one -CH ₂ -may be Substituted by -S-, -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be Substituted by halogen. Preferred R ^c is an alkyl group having 1 to 15 carbon atoms, among these groups, at least one -CH ₂ - may be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - may be substituted by -CH=CH- substituted. Z ^d is a single bond or an alkylene group having 1 to 30 carbon atoms, in the alkylene group, at least one -CH ₂ - may be substituted by -O-, -NH- or -CO-, and at least one -CH ₂ - CH ₂ - may be substituted with -CH=CH- or -C≡C-, and at least one hydrogen may be substituted with halogen. Preferred Z ^d is a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted with -O- or -CO-. S is sulfur. m is 0, 1, 2, 3 or 4. The preferred m is 2. r is 0 or 1.

In formulas (1-1) to (1-4), R ^f is hydrogen, an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, Among these groups, at least one -CH ₂ - may be substituted with -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - may be substituted with -CH=CH-. Preferred R ^f is hydrogen, alkyl having 1 to 15 carbons, and at least one -CH ₂ - may be substituted by -O- or -CO-. R ^g , ^Rh , R ⁱ and R ^j are hydrogen, an alkyl group having 1 to 5 carbon atoms, among these groups, at least one -CH ₂ - may be substituted by -O- or -CO-, and at least one -CH ₂ - CH ₂ - may be substituted with -CH=CH-, and at least one hydrogen may be substituted with a group represented by formula (F-1). Preferred R ^g , ^Rh , R ⁱ or R ^j are alkyl groups having 1 to 5 carbon atoms, and among these groups, at least one -CH ₂ - may be substituted with -O- or -CO-. R ^d and ^Re are alkyl groups with 1 to 20 carbons, alicyclic hydrocarbon groups with 3 to 20 carbons or aromatic hydrocarbon groups with 6 to 20 carbons, among these groups, at least one -CH ₂ - may be through -S -, -O- or -CO- substituted, at least one _{-CH2 -} CH2- may be substituted with -CH=CH-. Preferred R ^d or ^Re is an alkyl group having 1 to 15 carbon atoms, and among these groups, at least one -CH ₂ - may be substituted with -S-, -O- or -CO-. Z ^e and Z ^f are a single bond or an alkylene group having 1 to 10 carbon atoms, in the alkylene group, at least one -CH ₂ - may be substituted by -O-, -NH- or -CO-, and at least one - _CH2 -CH2- may be substituted with -CH= _CH- . Preferred Z ^e or Z ^f is a single bond or an alkylene group having 1 to 5 carbon atoms, in which at least one -CH ₂ - may be substituted by -O- or -CO-. Z ^g is an alkylene group having 1 to 6 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH _{2 -CH2-} may be substituted with -CH=CH-. Preferred Z ^g is an alkylene group having 1 to 5 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted by -O- or -CO-. S is sulfur. n ¹ and n ² are 0, 1, 2 or 3. Preferably n ¹ or n ² is 2.

In formula (F-1), R ^j is an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, among these groups, at least one -CH ₂ - may be substituted with -O- or -CO-, at least one _{-CH2 -} CH2- may be substituted with -CH=CH-. Preferred R ^j is an alkyl group having 1 to 15 carbon atoms, and among these groups, at least one -CH ₂ - may be substituted with -O- or -CO-. Z ^h is a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted with -O- or -CO-. Preferred Z ^h is a single bond or an alkylene group having 1 to 5 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted by -O- or -CO-. m ¹ is 0, 1, 2 or 3. The preferred m ¹ is 2. r ¹ is 0 or 1.

As representative specific examples of the additive X, the compounds represented by the formula (1-A) to the formula (1-J) are shown, but the present invention is not limited to these.

In formula (2) and formula (3), R ^2a and R ^2b are hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, and 2 carbons alkenyloxy group to 12, or an alkyl group of carbon number 1 to 12 in which at least one hydrogen is substituted with fluorine or chlorine. In order to improve stability, preferable R ^2a or R ^2b is an alkyl group having 1 to 12 carbon atoms, and in order to improve dielectric anisotropy, preferable R ^2a or R ^2b is an alkoxy group having 1 to 12 carbon atoms. R ^3a and R ^3b are an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, an alkenyl group having 2 to 12 carbons, or an alkyl group having 2 to 12 carbons in which at least one hydrogen is substituted by fluorine or chlorine alkenyl. In order to reduce viscosity, preferable R ^3a or R ^3b is an alkenyl group having 2 to 12 carbon atoms, and in order to improve stability, preferable R ^3a or R ^3b is an alkyl group having 1 to 12 carbon atoms.

Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. In order to reduce viscosity, further preferred alkyl groups are methyl, ethyl, propyl, butyl or pentyl.

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy or heptyloxy. Further preferred alkoxy groups are methoxy groups or ethoxy groups in order to lower the viscosity.

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. Further preferred alkenyl groups are vinyl, 1-propenyl, 3-butenyl or 3-pentenyl in order to reduce viscosity. The preferred stereoconfiguration of -CH=CH- in these alkenyl groups depends on the position of the double bond. In order to reduce viscosity, etc., alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, and 3-hexenyl are preferable for the trans configuration. Among alkenyl groups such as 2-butenyl, 2-pentenyl, and 2-hexenyl, the cis configuration is preferred.

Preferred alkenyloxy groups are vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy or 4-pentenyloxy. Further preferred alkenyloxy groups are allyloxy groups or 3-butenyloxy groups in order to lower the viscosity.

Preferred examples of the 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-fluorohexyl Fluoroheptyl or 8-fluorooctyl. In order to increase the dielectric anisotropy, more preferable examples are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, or 5-fluoropentyl.

Preferred examples of the 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. In order to reduce viscosity, a more preferable example is 2,2-difluorovinyl or 4,4-difluoro-3-butenyl.

Ring A and Ring C are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene, at least one hydrogen through fluorine or Chlorine-substituted 1,4-phenylene, naphthalene-2,6-diyl, naphthalene-2,6-diyl with at least one hydrogen substituted with fluorine or chlorine, chroman-2,6-diyl, or Chromane-2,6-diyl with at least one hydrogen replaced by 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-fluoro-1,4-phenylene -Chloro-3-fluoro-1,4-phenylene. In order to reduce viscosity, preferred ring A or ring C is 1,4-cyclohexylene, and in order to increase dielectric anisotropy, preferred ring A or ring C is tetrahydropyran-2,5-diyl, in order to increase dielectric anisotropy Optically anisotropic, preferred ring A or ring C is 1,4-phenylene. Tetrahydropyran-2,5-diyl is:

or

Preferably:

Ring B is 2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4- Phenylene, 3,4,5-trifluoronaphthalene-2,6-diyl, 7,8-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 ) or 1,1,6,7-tetrafluoroindan-2,5-diyl (InF4).

In order to reduce the viscosity, the preferred ring B is 2,3-difluoro-1,4-phenylene, and in order to reduce the optical anisotropy, the preferred ring B is 2-chloro-3-fluoro-1,4-phenylene In order to improve the dielectric anisotropy, the preferred ring B is 7,8-difluorochroman-2,6-diyl.

Ring D and ring E are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene. In order to lower the viscosity or to increase the upper limit temperature, the preferred ring D or ring E is 1,4-cyclohexylene, and in order to lower the lower limit temperature, the preferred ring D or ring E is 1,4-phenylene.

Z ^2a and Z ^2b are a single bond, ethylene group, vinylene group, methyleneoxy group or carbonyloxy group. In order to reduce the viscosity, the preferred Z ^2a or Z ^2b is a single bond, in order to reduce the minimum temperature, the preferred Z ^2a or Z ^2b is ethylene, in order to improve the dielectric anisotropy, the preferred Z ^2a or Z ^2b is methylene Oxygen. Z ^3a is a single bond, ethylene, vinylene, methyleneoxy or carbonyloxy. In order to reduce viscosity, the preferred Z ^3a is a single bond.

In the methyleneoxy group, -CH ₂ O- is better than -OCH ₂ -. Among carbonyloxy groups, -COO- is better than -OCO-.

a is 0, 1, 2 or 3, b is 0 or 1, and the sum of a and b is 3 or less. In order to reduce viscosity, preferable a is 1, and in order to raise the upper limit temperature, preferable a is 2 or 3. In order to lower the viscosity, b is preferably 0, and in order to lower the minimum temperature, b is preferably 1. c is 1, 2 or 3. In order to lower the viscosity, c is preferably 1, and in order to increase the upper limit temperature, c is preferably 2 or 3.

In formula (4), P ^4a , P ^4b and P ^4c are polymerizable groups. Preferable P ^4a , P ^4b or P ^4c is a polymerizable group selected from groups represented by formula (P-1) to formula (P-5). Further preferred P ^4a , P ^4b or P ^4c is the formula (P-1) or the formula (P-2). A particularly preferred formula (P-1) is -OCO-CH=CH ₂ or -OCO-C(CH ₃ )=CH ₂ . The wavy lines of the formula (P-1) to the formula (P-5) indicate the bonding site.

In formula (P-1) to formula (P-5), M ¹ , M ² and M ³ are hydrogen, fluorine, alkyl group with carbon number 1 to 5, or carbon number 1 in which at least one hydrogen is substituted by fluorine or chlorine to 5 alkyl groups. In order to increase reactivity, preferred M ¹ , M ² or M ³ is hydrogen or methyl. More preferably, M ¹ is methyl, and more preferably M ² or M ³ is hydrogen.

In formula (4-1) to formula (4-29), P ^4d , P ^4e and P ^4f are groups represented by formula (P-1) to formula (P-3). Preferred P ^4d , P ^4e or P ^4f are of formula (P-1) or formula (P-2). A more preferable formula (P-1) is -OCO-CH=CH ₂ or -OCO-C(CH ₃ )=CH ₂ . The wavy lines of the formula (P-1) to the formula (P-3) indicate the bonding site.

In formula (4), Sp ^4a , Sp ^4b and Sp ^4c are a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be via -O-, -COO- , -OCO- or -OCOO-, at least one -CH ₂ -CH ₂ - may be substituted with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be substituted with fluorine or chlorine. Preferred Sp ^4a , Sp ^4b or Sp ^4c are single bonds, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO-, -OCO-, -CO-CH=CH- or -CH =CH-CO-. Further preferred Sp ^4a , Sp ^4b or Sp ^4c is a single bond.

Ring F and Ring I are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxan-2-yl, pyrimidine- 2-yl or pyridin-2-yl, in these rings, at least one hydrogen can be through fluorine, chlorine, alkyl with 1 to 12 carbons, alkoxy with 1 to 12 carbons, or at least one hydrogen through fluorine or chlorine Substituted alkyl group having 1 to 12 carbon atoms. Preferred ring F or ring I is phenyl. Ring G is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1 ,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl , naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2, 5-diyl or pyridine-2,5-diyl, in these rings, at least one hydrogen can be replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or at least one hydrogen Substituted with alkyl having 1 to 12 carbons substituted with fluorine or chlorine. Preferred ring G is 1,4-phenylene or 2-fluoro-1,4-phenylene.

Z ^4a and Z ^4b are a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - may be substituted by -O-, -CO-, -COO- or -OCO- , at least one -CH ₂ -CH ₂ - can be via -CH=CH-, -C(CH ₃ )=CH-, -CH=C(CH ₃ )- or -C(CH ₃ )=C(CH ₃ ) -Substituted, in these groups, at least one hydrogen may be replaced by fluorine or chlorine. Preferred Z ^4a or Z ^4b is a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -OCH ₂ -, -COO- or -OCO-. Further preferred Z ^4a or Z ^4b is a single bond.

d is 0, 1 or 2. Preferred d is 0 or 1. e, f and g are 0, 1, 2, 3 or 4, and the sum of e, f and g is 1 or more. Preferred e, f or g are 1 or 2.

Fifth, preferred constituent compounds are shown. Preferred compounds (1) are the compounds (1-1) to (1-4) described in item 2. Among these compounds, compound (1-2) or compound (1-3) is preferable.

Preferred compounds (2) are the compounds (2-1) to (2-35) described in item 5. Among these compounds, it is preferable that at least one of the components A is compound (2-1), compound (2-3), compound (2-6), compound (2-8), compound (2-10), compound ( 2-14) or compound (2-16). Preferably, at least two of the components A are compound (2-1) and compound (2-8), compound (2-1) and compound (2-14), compound (2-3) and compound (2-8) , compound (2-3) and compound (2-14), compound (2-3) and compound (2-16), compound (2-6) and compound (2-8), compound (2-6) and A combination of compound (2-10), compound (2-6) and compound (2-16), and compound (2-10) and compound (2-16).

Preferred compounds (3) are the compounds (3-1) to (3-13) described in item 8. Among these compounds, at least one of the components B is preferably compound (3-1), compound (3-3), compound (3-5), compound (3-6), compound (3-8) or compound ( 3-9). Preferably, at least two of the components B are compound (3-1) and compound (3-3), compound (3-1) and compound (3-5), or compound (3-1) and compound (3-6) The combination.

Preferred compounds (4) are the compounds (4-1) to (4-29) described in Item 12. Among these compounds, it is preferable that at least one of the additives Y 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 the additives Y are 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 combinations of compounds (4-24).

Sixth, additives that can be added to the composition will be described. Such additives are optically active compounds, antioxidants, ultraviolet absorbers, matting agents, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. The optically active compound is added to the composition for the purpose of imparting a torsion angle by inducing a helical structure of liquid crystal molecules. Examples of such compounds are compound (5-1) to compound (5-5). A preferable ratio of the optically active compound is about 5% by mass or less. A more preferable ratio is in the range of about 0.01% by mass to about 2% by mass.

In order to prevent a decrease in specific resistance caused by heating in the atmosphere or to maintain a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after using the element for a long time, the compound (6 -1) Antioxidants such as compound (6-3) are added to the composition.

Since the compound (6-2) has low volatility, it is effective for maintaining a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after using the element for a long time. In order to obtain the effect, the preferable ratio of the antioxidant is about 50 ppm or more, and the preferable ratio of the antioxidant is about 600 ppm or less in order not to lower the upper limit temperature or not to raise the lower limit temperature. A further preferred ratio is in the range of about 100 ppm to about 300 ppm.

Preferable examples of the ultraviolet absorber are benzophenone derivatives, benzoate derivatives, triazole derivatives, and the like. 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) and the like. In order to obtain the effect, the preferable ratio of these absorbents or stabilizers is about 50 ppm or more, and in order not to lower the upper limit temperature or not to raise the lower limit temperature, the preferable ratio of these absorbents or stabilizers is about 10000 ppm or less. A further preferred ratio is in the range of about 100 ppm to about 10,000 ppm.

The matting agent is a compound that prevents decomposition of the liquid crystal compound by receiving light energy absorbed by the liquid crystal compound and converting it into thermal energy. Preferred examples of the matting agent are compound (8-1) to compound (8-7) and the like. In order to obtain the said effect, the preferable ratio of these matting agents is about 50 ppm or more, and in order not to raise the minimum temperature, the preferable ratio of these matting agents is about 20000 ppm or less. A further preferred ratio is in the range of about 100 ppm to about 10,000 ppm.

Dichroic dyes such as azo-based dyes, anthraquinone-based dyes, and the like are added to the composition in order to be suitable for a guest host (GH) mode device. A preferable ratio of the pigment 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 methyl phenyl silicone oil, are added to the composition. In order to obtain the above-mentioned effects, the preferable ratio of the antifoaming agent is about 1 ppm or more, and the preferable ratio of the antifoaming agent is about 1000 ppm or less in order to prevent poor display. A further preferred ratio is in the range of about 1 ppm to about 500 ppm.

A polymerizable compound is used in order to be suitable for a polymer-stabilized orientation (PSA) type element. Compound (4) is suitable for this purpose. A polymerizable compound different from the compound (4) may be added to the composition together with the compound (4). Preferred examples of such polymerizable compounds are acrylates, methacrylates, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (oxiranes, oxetanes), vinyl ketones, and the like compound. Further preferred examples are derivatives of acrylate or methacrylate. The preferable ratio of compound (4) is 10 mass % or more based on the total mass of a polymerizable compound. A more preferable ratio is 50 mass % or more. A particularly preferable ratio is 80% by mass or more. The most preferable ratio is 100 mass %.

Polymerizable compounds such as compound (4) are polymerized by ultraviolet irradiation. The polymerization can also be carried out in the presence of an appropriate initiator such as a photopolymerization initiator. Appropriate conditions for carrying out the polymerization, appropriate types of initiators, and appropriate amounts are known to those skilled in the art and are described in the literature. For example, as a photopolymerization initiator, Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF), or Darocur 1173 (registered trademark) ; BASF (BASF)) is suitable for free radical polymerization. The preferable ratio of the photopolymerization initiator is in the range of about 0.1% by mass to about 5% by mass based on the total mass of the polymerizable compound. A more preferable ratio is in the range of about 1% by mass to about 3% by mass.

When storing a polymerizable compound such as compound (4), a polymerization inhibitor may be added to prevent polymerization. The polymerizable compound is usually added to the composition without removing the polymerization inhibitor. Examples of polymerization inhibitors are hydroquinone, hydroquinone derivatives such as methyl hydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, phenothiazine, and the like.

Seventh, the synthesis method of the component compounds will be described. These compounds can be synthesized by known methods. Synthetic methods are exemplified. Compound (1-A) is Irganox 1520L (registered trademark; BASF), and compound (1-B) is Irganox 1726 (registered trademark; BASF) ), available from BASF. Compound (1-C) and compound (1-D) can be obtained from Tokyo Chemical Industry (TCI). Compound (1-E) is generally known as a medicinal product called Probucol, and is available from Tokyo Chemical Industry (TCI). Compound (1-F) can be obtained from Tokyo Chemical Industry (TCI). Compound (2-1) was synthesized by the method described in Japanese Patent Laid-Open No. 2000-053602. Compound (3-1) was synthesized by the method described in Japanese Patent Laid-Open No. Sho 59-176221. Compound (4-18) was 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) and the like were synthesized by the method described in the specification of US Pat. No. 3,660,505.

Compounds for which synthetic methods are not described can be obtained through Organic Syntheses (Organic Syntheses, John Wiley & Sons, Inc), Organic Reactions (John Wiley & Sons, Inc) ), "Comprehensive Organic Synthesis" (Comprehensive Organic Synthesis, Pergamon Press), New Experimental Chemistry Lecture (Maruzen) and other books to synthesize. Compositions are prepared by known methods from the compounds obtained in the manner described. For example, the component compounds are mixed and then heated to dissolve each other.

Finally, the use of the composition will be explained. The composition mainly has a lower limit temperature of about -10°C or lower, an upper limit temperature of about 70°C or higher, and an optical anisotropy in the range of about 0.07 to about 0.20. A composition having an optical anisotropy in the range of about 0.08 to about 0.25 can also be prepared by controlling the ratio of the component compounds, or by mixing other liquid crystal compounds. Compositions having 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 devices. The composition is particularly suitable for transmissive AM devices. 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.

The composition can be used in AM devices. Furthermore, it can also be used for PM elements. The composition can be used for AM elements and PM elements having modes such as PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA, and the like. It is particularly preferred for AM elements having TN, OCB, IPS mode or FFS mode. In the AM element having the IPS mode or the FFS mode, when no voltage is applied, the alignment of the liquid crystal molecules may be parallel or vertical with respect to the glass substrate. These elements can be reflective, transmissive or transflective. It is preferably used for the element of the transmission type. It can also be used for amorphous silicon-TFT elements or polysilicon-TFT elements. The composition can also be used for a nematic curvilinear aligned phase (NCAP) type element produced by microencapsulation or a polymer in which a three-dimensional network polymer is formed in the composition. A polymer dispersed (PD) type element.

[Example]

The present invention will be described in more detail by way of examples. The present invention is not limited by these examples. The present invention comprises a mixture of the composition of Example 1 and the composition of Example 2. The present invention also includes mixtures obtained by mixing at least two of the compositions of the examples. The synthesized compounds were identified by methods such as nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) analysis. The properties of the compound, composition, and device were measured by the methods described below.

NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for the measurement. In the measurement of ¹ H-NMR, the sample is dissolved in a deuterated solvent such as CDCl ₃ , and the measurement is performed at room temperature under the conditions of 500 MHz and 16 accumulation times. Tetramethylsilane was used as an internal standard. In the measurement of ¹⁹ F-NMR, CFCl ₃ was used as an internal standard, and the cumulative number of times was 24. In the description of NMR spectra, s means singlet, d means doublet, t means triplet, q means quartet, and quin means quintet. (quintet), sex means sextet, m means multiplet, br means broad.

Gas chromatographic analysis: A GC-14B gas chromatograph manufactured by Shimadzu Corporation was used for the measurement. The carrier gas was helium (2 mL/min). The sample vaporization chamber was set to 280°C, and the detector (flameionization detector (FID)) was set to 300°C. For the separation of component compounds, a capillary column DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by Agilent Technologies Inc. was used; the stationary liquid phase was dimethylpolysiloxane; sex). After the column was held at 200°C for 2 minutes, the temperature was raised to 280°C at a rate of 5°C/min. After the sample was prepared as an acetone solution (0.1 mass %), 1 μL of the solution was injected into the sample vaporization chamber. The recorder is a C-R5A type chromatograph package (Chromatopac) manufactured by Shimadzu Corporation or its equivalent. The obtained gas chromatogram showed the retention time of the peak and the area of the peak corresponding to the component compounds.

As a solvent for diluting the sample, chloroform, hexane, or the like can be used. In order to separate the component compounds, the following capillary columns can be used. HP-1 manufactured by Agilent Technologies Inc. (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm), Rtx-1 manufactured by Restek Corporation (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm), BP-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by SGE International Pty. Ltd, Australia. For the purpose of preventing overlapping 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 was used.

The ratio of the liquid crystal compound contained in the composition can be calculated by the method described below. The mixture of liquid crystal compounds was analyzed by gas chromatography (FID). The area ratio of the peaks in the gas chromatogram corresponds to the ratio of the liquid crystal compound. When the capillary column described above is used, the correction factor of each liquid crystal compound can be regarded as 1. Therefore, the ratio (mass %) of the liquid crystal compound can be calculated from the area ratio of the peaks.

Test sample: When measuring the properties of the composition or element, the composition is directly used as a sample. When the properties of the compound were measured, a sample for measurement was prepared by mixing the compound (15% by mass) with the mother liquid crystal (85% by mass). From the value obtained by the measurement, the characteristic value of the compound was calculated by an extrapolation method. (Extrapolated value)={(Measured value of sample)−0.85×(Measured value of mother liquid crystal)}/0.15. When the smectic phase (or crystal) is precipitated at 25°C at the stated ratio, the ratio of the compound to the mother liquid crystal is 10 mass %: 90 mass %, 5 mass %: 95 mass %, 1 mass %: 99 mass % The order of mass % was changed. The values of the upper limit temperature, optical anisotropy, viscosity, and dielectric anisotropy related to the compound were obtained by the extrapolation method.

The following mother liquid crystals were used. The ratio of the component compounds is represented by mass %.

Measurement method: The measurement of the characteristic was carried out by the following method. Many of these methods are methods described in or modified from the JEITA standards (JEITA·ED-2521B) reviewed and formulated by the Japan Electronics and Information Technology Industries Association (JEITA). A thin film transistor (TFT) was not mounted on the TN element used for the measurement.

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

(2) Lower limit temperature of nematic phase (TC; ° _C ): The sample with nematic phase is put into a glass bottle, and the temperature is set at 0 °C, -10 °C, -20 °C, -30 °C and -40 °C After storing in a refrigerator for 10 days, the liquid crystal phase was observed. For example, when the sample maintains the state of the nematic phase at -20°C and changes to the crystalline or smectic phase at -30°C, it is recorded as T _C <-20°C. The lower limit temperature of the nematic phase is sometimes abbreviated as "lower limit temperature".

(3) Viscosity (bulk viscosity; η; measured at 20° C.; mPa·s): For the measurement, an E-type rotational viscometer manufactured by Tokyo Keiki Co., Ltd. was used.

(4) Viscosity (rotational viscosity; γ1; measured at 25° C.; mPa·s): The rotational viscosity measurement system LCM-2 type of TOYO Technica Co., Ltd. was used for the measurement. A sample was injected into a VA element in which the distance (cell gap) between two glass substrates was 10 μm. A rectangular wave (55V, 1 ms) was applied to the element. The peak current and peak time of the transient current generated by the application were measured. Using these measured values and dielectric anisotropy, the value of rotational viscosity was obtained. The dielectric anisotropy was measured by the method described in Measurement (6).

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

(6) Dielectric anisotropy (Δε; measured at 25° C.): The value of the dielectric anisotropy was calculated according to the formula of Δε=ε∥−ε⊥. The dielectric constants (ε∥ and ε⊥) were measured as follows.

1) Measurement of dielectric constant (ε∥): A solution of octadecyltriethoxysilane (0.16 mL) in ethanol (20 mL) was applied on a sufficiently cleaned glass substrate. After the glass substrate was rotated with a spinner, it was heated at 150° C. for 1 hour. A sample was placed in a VA element having a distance (cell gap) between two glass substrates of 4 μm, and the element was sealed with an adhesive cured by ultraviolet rays. A sine wave (0.5 V, 1 kHz) was applied to the element, and the dielectric constant (ε∥) in the long axis direction of the liquid crystal molecules was measured after 2 seconds.

2) Measurement of dielectric constant (ε⊥): A polyimide solution was applied on a sufficiently cleaned glass substrate. After calcining the glass substrate, a rubbing process is performed on the obtained alignment film. A sample was placed in a TN element with a gap (cell gap) of two glass substrates of 9 μm and a twist angle of 80 degrees. A sine wave (0.5 V, 1 kHz) was applied to the element, and the dielectric constant (ε⊥) in the short axis direction of the liquid crystal molecules was measured after 2 seconds.

(7) Threshold voltage (Vth; measured at 25° C.; V): An LCD5100 luminance meter manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The light source is a halogen lamp. A sample was placed in a normally black mode VA element in which the distance between two glass substrates (cell gap) was 4 μm and the rubbing direction was anti-parallel, and the adhesive was hardened by ultraviolet rays. The components are sealed. The voltage (60 Hz, rectangular wave) applied to the element was increased in steps from 0V to 20V in units of 0.02V. At this time, the element was irradiated with light from a vertical direction, and the amount of light transmitted through the element was measured. A voltage-transmittance curve was prepared in which the transmittance was 100% when the light amount reached the maximum, and the transmittance was 0% when the light amount was the smallest. The threshold voltage is represented by the voltage at which the transmittance becomes 10%.

(8) Voltage holding ratio (VHR-9; measured at 25° C.; %): The TN element used for the measurement had a polyimide alignment film, and the distance (cell gap) between two glass substrates was 5 μm. The element is sealed with an adhesive cured by ultraviolet rays after placing the sample. The TN element was charged by applying a pulse voltage (1 V, 60 microseconds). The decayed voltage was measured with a high-speed voltmeter for a period of 166.7 milliseconds, and the area A between the voltage curve per unit cycle and the horizontal axis was obtained. Area B is the area without attenuation. Voltage retention is expressed as the percentage of area A relative to area B.

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

(10) Voltage holding ratio (VHR-11; measured at 60° C.; %): After irradiation with ultraviolet rays, the voltage holding ratio was measured to evaluate the stability to ultraviolet rays. The TN element used for the measurement has a polyimide alignment film, and the cell gap is 5 μm. A sample was injected into the element and irradiated with ultraviolet rays of 5 mW/cm ² for 167 minutes. The light source was black light, F40T10/BL (peak wavelength 369 nm) manufactured by EYEGRAPHICS Co., Ltd., and the distance between the element and the light source was 5 mm. In the measurement of VHR-11, the decaying voltage was measured in a period of 166.7 milliseconds. Compositions with large VHR-11 have large UV stability.

(11) Voltage holding ratio (VHR-12; measured at 60° C.; %): After heating the TN element injected with the sample in a constant temperature bath at 120° C. for 20 hours, the voltage holding ratio was measured to evaluate the resistance to heat. stability. In the measurement of VHR-12, the decaying voltage was measured in a period of 166.7 milliseconds. Compositions with large VHR-12 have large thermal stability.

(12) Response time (τ; measured at 25° C.; ms): LCD5100 luminance meter manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The light source is a halogen lamp. Set the Low-pass filter to 5kHz. A sample was placed in a normally black mode VA element in which the distance between two glass substrates (cell gap) was 4 μm and the rubbing direction was antiparallel. The elements are sealed with an adhesive that hardens by UV light. A rectangular wave (60 Hz, 10 V, 0.5 seconds) was applied to the element. At this time, the element was irradiated with light from a vertical direction, and the amount of light transmitted through the element was measured. When the light amount reaches the maximum, the transmittance is regarded as 100%, and when the light amount is the minimum, the transmittance is regarded as 0%. The response time is represented by the time (fall time; fall time; milliseconds) required for the transmittance to change from 90% to 10%.

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

Examples of compositions are shown below. The component compounds are represented by symbols based on the definitions in Table 3 below. In Table 3, the steric configuration related to 1,4-cyclohexylene is trans configuration. The number in parentheses following the notated compound indicates the formula to which the compound belongs. The symbol (-) refers to other liquid crystal compounds. The ratio (percentage) of the liquid crystal compound is the mass percentage (mass %) based on the mass of the liquid crystal composition not containing the additive. Finally, the characteristic values of the composition are summarized.

Table 3. Representation of compounds using symbols

R-(A ₁ )-Z ₁ -...- _{Zn -(A n )} -R'

[Comparative Example 1]

NI=68.0°C; T _C <-20°C;Δn=0.103;Δε=-2.8; VHR-11=75.5%

The composition obtained by adding the compound (1-E) to the composition of Comparative Example 1 was referred to as Example 1.

[Example 1]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=68.0°C; T _C <-20°C;Δn=0.103;Δε=-2.8; VHR-11=81.9%

[Example 2]

Compound (1-E) was added to the composition in a proportion of 0.0500% by mass.

NI=77.8°C; T _C <-20°C;Δn=0.105;Δε=-3.5; VHR-11=95.3%

[Example 3]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=76.1℃; T _C <-20℃;η=15.2mPa·s;Δn=0.107;Δε=-2.1; VHR-11=95.6%.

[Example 4]

Compound (1-D) was added to the composition in a proportion of 0.0500% by mass.

NI=77.3℃; T _C <-20℃;η=16.1mPa·s;Δn=0.102;Δε=-2.8; VHR-11=97.6%

[Example 5]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=75.9℃; η=18.4mPa·s; Δn=0.105; Δε=-3.4; VHR-11=95.0%

[Example 6]

Compound (1-E) was added to the composition in a ratio of 0.0100% by mass.

NI=74.0°C; T _C <-20°C;Δn=0.098;Δε=-3.0; VHR-11=92.2%

[Example 7]

Compound (1-E) was added to the composition in a proportion of 0.0750 mass %.

NI=74.2°C; Δn=0.0991; Δε=-2.6; VHR-11=94.6%

[Example 8]

Compound (1-E) was added to the composition in a proportion of 0.0750 mass %.

NI=73.8°C; T _C <-20°C;Δn=0.105;Δε=-2.3; VHR-11=90.1%

[Example 9]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=79.8°C; T _C <-20°C;Δn=0.100;Δε=-3.3; VHR-11=92.2%

[Example 10]

Compound (1-D) was added to the composition in a proportion of 0.0750 mass %.

NI=75.9℃; T _C <-20℃;η=17.8mPa·s;Δn=0.083;Δε=-2.8; VHR-11=97.6%

[Example 11]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=72.4°C; T _C <-20°C;η=11.4mPa·s;Δn=0.094;Δε=-1.9; VHR-11=95.5%

[Example 12]

Compound (1-E) was added to the composition in a proportion of 0.0750 mass %.

NI=69.9°C; T _C <-20°C;Δn=0.105;Δε=-2.2; VHR-11=94.2%

[Example 13]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=70.2°C; T _C <-20°C;Δn=0.107;Δε=-2.6; VHR-11=85.9%

[Example 14]

Compound (1-E) was added to the composition in a proportion of 0.0750 mass %.

NI=73.9°C; T _C <-20°C;Δn=0.117;Δε=-2.1; VHR-11=89.9%

[Example 15]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=75.0°C; T _C <-20°C;Δn=0.106;Δε=-3.3; VHR-11=88.3%

[Example 16]

Compound (1-E) was added to the composition in a ratio of 0.1000% by mass.

NI=82.4°C; T _C <-20°C;Δn=0.094;Δε=-3.0; VHR-11=94.3%

The voltage holding ratio (VHR-11) after ultraviolet irradiation of the composition of Comparative Example 1 was 75.5%. On the other hand, the VHR-11 of the compositions of Examples 1 to 14 was in the range of 81.9% to 97.6%. Therefore, it can be concluded that the liquid crystal composition of the present invention has more excellent characteristics.

[Industrial Availability]

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

Claims (20)

1. A liquid crystal composition comprising at least one compound selected from the compounds represented by the formula (1) as an additive X, and having a nematic phase and a negative dielectric anisotropy:

In formula (1), R ^a is hydrogen, a group represented by formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms, Among alkyl groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by - CH=CH- or -C≡C- substituted, in these groups, at least one hydrogen may be substituted by halogen; R ^b is an alkyl group with 1 to 30 carbon atoms, an alicyclic hydrocarbon group with 3 to 30 carbon atoms, or a carbon number of 6 Aromatic hydrocarbon groups of to 30, among these groups, at least one -CH ₂ - can be substituted by -S-, -O-, -NH- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH= CH- or -C≡C-substituted, in these groups, at least one hydrogen can be substituted by halogen; Z ^a and Z ^c are single bonds or alkylene groups with 1 to 30 carbons, in the alkylene groups, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen ; Z ^b is a single bond, an alkylene group with a carbon number of 1 to 30, an alicyclic hydrocarbon group with a carbon number of 3 to 30 or an aromatic hydrocarbon group with a carbon number of 6 to 30, among these groups, at least one -CH ₂ - may be -S-, -O-, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by Halogen or group represented by formula (F) is substituted; S is sulfur; n is 0, 1, 2, 3 or 4; p is 0 or 1;

In formula (F), R ^c is an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms. Among these groups, at least one -CH ₂ -may be Substituted by -S-, -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be Substituted by halogen; Z ^d is a single bond or an alkylene group having 1 to 30 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, at least one hydrogen can be substituted by halogen; S is sulfur; m is 0, 1, 2, 3 or 4; r is 0 or 1. 2. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by formula (1-1) to formula (1-4) as the additive X:

In formulas (1-1) to (1-4), R ^f is hydrogen, an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms, Among these groups, at least one -CH ₂ - can be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; R ^g , ^Rh , R ⁱ and R ^j are hydrogen, an alkyl group having 1 to 5 carbon atoms, among these groups, at least one -CH ₂ - can be substituted by -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH =CH-substituted, at least one hydrogen may be substituted by a group represented by formula (F-1); R ^d and R ^e are alkyl groups with 1 to 20 carbon atoms, alicyclic hydrocarbon groups with 3 to 20 carbon atoms, or alicyclic hydrocarbon groups with carbon number 3 to 20. Aromatic hydrocarbon groups of 6 to 20, among these groups, at least one -CH ₂ - can be substituted by -S-, -O- or -CO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- ; Z ^e and Z ^f are a single bond or an alkylene group with 1 to 10 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -O-, -NH- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; Z ^g is an alkylene group having 1 to 6 carbon atoms, in the alkylene group, at least one -CH ₂ - can be substituted by -S-, -O -, -NH- or -CO- substituted, at least one -CH ₂ -CH ₂ - may be substituted by -CH=CH-; S is sulfur; n ¹ and n ² are 0, 1, 2 or 3;

In formula (F-1), R ^j is an alkyl group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, among these groups, at least one -CH ₂ -Can be substituted by -O- or -CO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH-; Z ^h is a single bond or an alkylene group with a carbon number of 1 to 10, the alkylene In the group, at least one -CH ₂ - may be substituted by -O- or -CO-; S is sulfur; m ¹ is 0, 1, 2 or 3; r ¹ is 0 or 1. 3. The liquid crystal composition according to claim 1, wherein the ratio of the additive X is in the range of 0.0001% by mass to 2% by mass. 4. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by formula (2) as component A:

In formula (2), R ^2a and R ^2b are hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons group, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine or chlorine; Ring A and Ring C are 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran- 2,5-diyl, 1,4-phenylene, 1,4-phenylene with at least one hydrogen substituted with fluorine or chlorine, naphthalene-2,6-diyl, at least one hydrogen with fluorine or chlorine substituted Naphthalene-2,6-diyl, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring B is 2,3-difluoro -1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5 -Trifluoronaphthalene-2,6-diyl, 7,8-difluorochroman-2,6-diyl, 3,4,5,6-tetrafluorofluorene-2,7-diyl, 4, 6-Difluorodibenzofuran-3,7-diyl, 4,6-difluorodibenzothiophene-3,7-diyl or 1,1,6,7-tetrafluoroindan-2,5 -diyl; Z ^2a and Z ^2b are single bond, ethylene, vinylene, methyleneoxy or carbonyloxy; a is 0, 1, 2 or 3, b is 0 or 1; and a and b The sum is 3 or less. 5. The liquid crystal composition according to claim 1, which contains, as component A, at least one compound selected from compounds represented by formula (2-1) to formula (2-35),

In formula (2-1) to formula (2-35), R ^2a and R ^2b are hydrogen, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons , an alkenyloxy group having 2 to 12 carbons, or an alkyl group having 1 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine. 6. The liquid crystal composition according to claim 4, wherein the proportion of the component A is in the range of 10% by mass to 90% by mass. 7 . The liquid crystal composition according to claim 1 , which contains at least one compound selected from the compounds represented by formula (3) as component B: 8 .

In formula (3), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or at least one hydrogen is substituted by fluorine or chlorine Alkenyl having 2 to 12 carbon atoms; Ring D and Ring E are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro- 1,4-phenylene; Z ^3a is a single bond, ethylene, vinylene, methyleneoxy or carbonyloxy; c is 1, 2 or 3. 8. The liquid crystal composition according to claim 4, comprising at least one compound selected from the compounds represented by formula (3) as component B:

In formula (3), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or at least one hydrogen is substituted by fluorine or chlorine Alkenyl having 2 to 12 carbon atoms; Ring D and Ring E are 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro- 1,4-phenylene; Z ^3a is a single bond, ethylene, vinylene, methyleneoxy or carbonyloxy; c is 1, 2 or 3. 9 . The liquid crystal composition according to claim 1 , which contains, as component B, at least one compound selected from the group consisting of compounds represented by formula (3-1) to formula (3-13): 10 .

In formula (3-1) to formula (3-13), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or Alkenyl having 2 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine. 10 . The liquid crystal composition according to claim 5 , which contains, as component B, at least one compound selected from the group consisting of compounds represented by formula (3-1) to formula (3-13): 11 .

In formula (3-1) to formula (3-13), R ^3a and R ^3b are alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or Alkenyl having 2 to 12 carbons in which at least one hydrogen is substituted with fluorine or chlorine. 11. The liquid crystal composition according to claim 7, wherein the proportion of the component B is in the range of 10% by mass to 90% by mass. 12 . The liquid crystal composition according to claim 1 , which contains at least one compound selected from the polymerizable compounds represented by formula (4) as the additive Y: 12 .

In formula (4), ring F and ring I 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 can be fluorine, chlorine, alkyl with 1 to 12 carbons, alkoxy with 1 to 12 carbons, or at least One hydrogen is substituted by an alkyl group having 1 to 12 carbon atoms substituted by fluorine or chlorine; ring G is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1 ,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl , naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl, 1 ,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, in these rings, at least one hydrogen can be replaced by fluorine, chlorine, carbon number from 1 to 12 The alkyl group, the alkoxy group of carbon number 1 to 12, or the alkyl group of carbon number 1 to 12 substituted by at least one hydrogen is substituted by fluorine or chlorine; Z ^4a and Z ^4b are single bond or carbon number 1 to 10 subgroup In the alkylene group, at least one -CH ₂ - can be substituted by -O-, -CO-, -COO- or -OCO-, and at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH -, -C(CH ₃ )=CH-, -CH=C(CH ₃ )- or -C(CH ₃ )=C(CH ₃ )- substituted, in these groups, at least one hydrogen may be substituted by fluorine or chlorine ; P ^4a , P ^4b and P ^4c are polymerizable groups; Sp ^4a , Sp ^4b and Sp ^4c are single bonds or alkylene groups with 1 to 10 carbon atoms, and in the alkylene groups, at least one -CH ₂ - can be Substituted by -O-, -COO-, -OCO- or -OCOO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, in these groups, at least one hydrogen can be substituted by fluorine or chlorine; d is 0, 1 or 2; e, f and g are 0, 1, 2, 3 or 4; and the sum of e, f and g is 1 or more. 13. The liquid crystal composition according to claim 12, wherein in the formula (4), P ^4a , P ^4b and P ^4c are polymers selected from the group consisting of polymers represented by formula (P-1) to formula (P-5). The base in the sex base:

In formula (P-1) to formula (P-5), M ¹ , M ² and M ³ are hydrogen, fluorine, alkyl group with carbon number 1 to 5, or carbon number 1 in which at least one hydrogen is substituted by fluorine or chlorine to 5 alkyl groups. 14. The liquid crystal composition according to claim 1, comprising at least one compound selected from the group consisting of polymerizable compounds represented by formula (4-1) to formula (4-29) as additive Y:

In formula (4-1) to formula (4-29), Sp ^4a , Sp ^4b and Sp ^4c are a single bond or an alkylene group having 1 to 10 carbon atoms, and in the alkylene group, at least one -CH ₂ - Can be substituted by -O-, -COO-, -OCO- or -OCOO-, at least one -CH ₂ -CH ₂ - can be substituted by -CH=CH- or -C≡C-, among these groups, at least one hydrogen may be substituted with fluorine or chlorine; P ^4d , P ^4e and P ^4f are polymerizable groups selected from groups represented by formula (P-1) to formula (P-3);

In formulas (P-1) to (P-3), M ¹ , M ² and M ³ are hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or a carbon number 1 wherein at least one hydrogen is substituted by fluorine or chlorine to 5 alkyl groups. 15. The liquid crystal composition according to claim 12, wherein the ratio of the additive Y is in the range of 0.03% by mass to 10% by mass. 16. A liquid crystal display element comprising the liquid crystal composition according to claim 1. 17. The liquid crystal display element according to claim 16, wherein the operation mode of the liquid crystal display element is an in-plane switching mode, a vertical alignment mode, a fringe field switching mode or an electric field induced photoreactive alignment mode, and the driving mode of the liquid crystal display element is Active matrix method. 18 . A polymer-stabilized alignment type liquid crystal display element comprising the liquid crystal composition according to claim 12 , wherein the polymerizable compound in the liquid crystal composition is polymerized. 19 . 19. Use of a liquid crystal composition, which is the liquid crystal composition according to claim 1, in a liquid crystal display element. 20. Use of a liquid crystal composition, which is the liquid crystal composition according to claim 12, which is used in a polymer-stabilized alignment type liquid crystal display element.