CN111826171B

CN111826171B - Liquid crystal composition, use thereof, and liquid crystal display element

Info

Publication number: CN111826171B
Application number: CN201911364791.5A
Authority: CN
Inventors: 森崇徳; 朝仓利树; 斋藤将之
Original assignee: JNC Corp; JNC Petrochemical Corp
Current assignee: JNC Corp; JNC Petrochemical Corp
Priority date: 2019-04-18
Filing date: 2019-12-26
Publication date: 2023-09-19
Anticipated expiration: 2039-12-26
Also published as: CN111826171A; JP2020176255A

Abstract

The invention provides a liquid crystal composition and use thereof, and a liquid crystal display element, wherein the liquid crystal composition fully satisfies at least one characteristic or has proper balance of at least two characteristics among the characteristics of high upper limit temperature, low lower limit temperature, low viscosity, proper optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to light and high stability to heat. The liquid crystal composition of the present invention contains at least one compound selected from the compounds represented by formula (1) as additive X, and may contain a specific compound having a large negative dielectric anisotropy as component a, a specific compound having a high upper limit temperature or a small viscosity as component B, or a specific compound having a polymerizable group as 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, the present invention relates to a liquid crystal composition having negative dielectric anisotropy, and a liquid crystal display element containing the composition and having modes such as in-plane switching (IPS), vertical Alignment (VA), fringe Field Switching (FFS), and field-induced photo-reactive alignment (FPA). And a polymer stabilized alignment type liquid crystal display element.

Background

In a liquid crystal display element, the operation modes based on liquid crystal molecules are classified as: phase Change (PC), twisted Nematic (TN), super twisted nematic (super twisted nematic, STN), electrically controlled birefringence (electrically controlled birefringence, ECB), optically compensated bend (optically compensated bend, OCB), in-plane switching (IPS), vertical alignment (vertical alignment, VA), fringe field switching (fringe field switching, FFS), field-induced photo-alignment (FPA), etc. modes. The driving modes based on the elements are classified into Passive Matrix (PM) and Active Matrix (AM). PM is classified into static type (static), multiplex type (multiplex) and the like, and AM is classified into thin film transistor (thin film transistor, TFT), metal-insulator-metal (metal insulator metal, MIM) and the like. TFTs are classified as amorphous silicon (amorphous silicon) and polysilicon (polycrystal silicon). The latter is classified into a high temperature type and a low temperature type according to the manufacturing process. The classification based on the light source is a reflection type using natural light, a transmission type using backlight, and a semi-transmission 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 characteristics of the composition, an AM element having good characteristics can be obtained. The correlation among these characteristics is summarized in table 1 below. The properties of the composition are further described based on commercially available AM elements. The temperature range of the nematic phase is associated with the temperature range in which the element can be used. The preferable upper limit temperature of the nematic phase is about 70 ℃ or higher, and the preferable lower limit temperature of the nematic phase is about-10 ℃ or lower. The viscosity of the composition is related to the response time of the element. In order to display a moving image in an element, the response time is preferably short. Ideally less than 1 millisecond of response time. Therefore, the viscosity of the composition is preferably small. More preferably, the viscosity at low temperature is small.

The optical anisotropy of the composition is related to the contrast of the element. Depending on the mode of the element, a large optical anisotropy or a small optical anisotropy, i.e., an appropriate optical anisotropy, is required. The product (Δn×d) of the optical anisotropy (Δn) of the composition and the cell gap (d) of the element is designed to maximize the contrast. The value of the appropriate product depends on the type of operation mode. In VA mode elements, the values are in the range of about 0.30 μm to about 0.40 μm, in IPS mode or FFS mode elements, the values are in the range of about 0.20 μm to about 0.30 μm. In these cases, a composition having large optical anisotropy is preferable for an element having a small cell gap. The large dielectric anisotropy of the composition contributes to a low threshold voltage, small power consumption and large contrast of the element. Therefore, a large dielectric anisotropy is preferable. The large specific resistance of the composition contributes to a large voltage holding ratio and a large contrast ratio of the element. Therefore, a composition having a large specific resistance in the initial stage is preferable. Compositions which have a large specific resistance after prolonged use are preferred. The stability of the composition to ultraviolet light or heat is related to the lifetime of the element. When the stability is high, the lifetime 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-purpose liquid crystal display devices, vertical alignment of liquid crystal molecules can be achieved by a specific polyimide alignment film. In a liquid crystal display element of polymer stable alignment (polymer sustained alignment, PSA), a polymer is combined with an alignment film. First, a composition to which a small amount of a polymerizable compound is added is injected into an 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 of polymer in the composition. In the composition, the orientation of liquid crystal molecules can be controlled by using the polymer, so that the response time of the element is shortened, and the afterimage of an image is improved. Such effects of the polymer can be expected in elements having a pattern such as TN, ECB, OCB, IPS, VA, FFS, FPA.

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

Further, these liquid crystal display elements are required to have excellent display quality without or with suppressed display defects such as afterimages and display irregularities. To achieve this, the following attempts were made: various additives are added 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 publication 2016-94412

Disclosure of Invention

[ problem to be solved by the invention ]

The invention provides a liquid crystal composition which fully satisfies at least one of the characteristics of high upper limit temperature of nematic phase, low lower limit temperature of nematic phase, low viscosity, proper optical anisotropy, large dielectric anisotropy, large specific resistance, high stability to light, high stability to heat and large elastic constant. Another object is to provide a liquid crystal composition having an appropriate balance between at least two of these characteristics. Another object is to provide a liquid crystal display element containing such a composition. A further object 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.

[ means of solving the problems ]

The present inventors have studied various liquid crystalline compounds and various chemical substances, and have found that the above problems can be solved by using specific compounds, and have 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 formula (1) as an additive X and having a nematic phase and negative dielectric anisotropy, and a liquid crystal display element containing the composition.

In the formula (1), R ^a At least one of hydrogen, a group represented by the formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms, an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group, -CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; r is 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; z is Z ^a Z is as follows ^c Is a single bond or an alkylene group having 1 to 30 carbon atoms, at least one of which is-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may be substituted by halogen; z is 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen or a group represented by formula (F); s is sulfur; n is 0, 1, 2, 3 or 4; p is 0 or 1;

in the 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; z is Z ^d Is a single bond or an alkylene of 1 to 30 carbon atomsA group of at least one-CH in the alkylene group ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may be substituted by halogen; s is sulfur; m is 0, 1, 2, 3 or 4; r is 0 or 1.

[ Effect of the invention ]

The present invention has an advantage of providing a liquid crystal composition which sufficiently satisfies at least one of characteristics such as high upper limit temperature of a nematic phase, low lower limit temperature of a nematic phase, low viscosity, proper optical anisotropy, high dielectric anisotropy, high specific resistance, high stability to light, high stability to heat, and high elastic constant. Another advantage is to provide a liquid crystal composition having an appropriate balance between at least two of these properties. Another advantage is to provide a liquid crystal display element containing such a composition. It is still another advantage to provide an AM device 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.

Detailed Description

The usage of the terms in this specification is as follows. The terms "liquid crystal composition" and "liquid crystal display element" are sometimes abbreviated as "composition" and "element", respectively. The term "liquid crystal display element" refers to a liquid crystal display panel and a liquid crystal display module. The "liquid crystalline compound" is a generic term for a compound having a liquid crystal phase such as a nematic phase or a smectic phase (smetic phase), and a compound which does not have a liquid crystal phase but is mixed in a composition for the purpose of adjusting characteristics such as a temperature range, viscosity, and dielectric anisotropy of the nematic phase. 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 forming a polymer in the composition. Liquid crystalline compounds having alkenyl groups are not classified as polymerizable compounds in their meaning.

The liquid crystal composition is prepared by mixing a plurality of liquid crystalline compounds. An additive such as an optically active compound or a polymerizable compound is optionally added to the liquid crystal composition. Even when the additive is added, the proportion of the liquid crystalline compound is represented by a mass percentage (mass%) based on the mass of the liquid crystal composition containing no additive. The proportion of the additive is represented by mass percent (mass%) based on the mass of the liquid crystal composition containing no additive. That is, the ratio of the liquid crystalline compound or the additive is calculated based on the total mass of the liquid crystalline 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 dielectric anisotropy" means that the value thereof increases positively when the composition has positive dielectric anisotropy, and that the value thereof increases negatively when the composition has negative dielectric anisotropy. The "large voltage holding ratio" means that the element has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature in the initial stage, and also has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after long-term use. The properties of the compositions or elements are sometimes investigated by time-varying tests.

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

In formula (1 z), for example, the expression "Ra and Rb are alkyl, alkoxy or alkenyl" means 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 may be different. The rules also apply when the notation of Ra is used in a variety of compounds. The rules also apply in the case of using a plurality of Ra in one compound.

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

The expression "at least one 'a'" means that the number of 'a' is arbitrary. The expression "at least one of the" A's "may be substituted with" B "means that the positions of" A "are arbitrary when the number of" A "is one, and that their positions may be selected without limitation when the number of" A "is two or more. Sometimes use "at least one-CH ₂ -can be expressed by-O-substitution ". In that case, -CH ₂ -CH ₂ -CH ₂ By non-contiguous-CH ₂ -conversion to-O-CH by-O-substitution ₂ -O-. However, there is no contiguous-CH ₂ -O-substituted case. The reason is that: in said substitution-O-O-CH is generated ₂ - (peroxides).

The alkyl group of the liquid crystal compound is linear or branched and does not contain a cyclic alkyl group. Linear alkyl groups are preferred over branched alkyl groups. These are also the same for terminal groups such as alkoxy, alkenyl and the like. Regarding the configuration related to 1, 4-cyclohexylene, the trans (trans) configuration is superior to the cis (cis) configuration in order to raise the upper temperature. Since 2-fluoro-1, 4-phenylene is asymmetric left and right, there are left (L) and right (R) facing directions.

The same applies to divalent radicals such as tetrahydropyran-2, 5-diyl. In order to raise the upper limit temperature, the tetrahydropyran-2, 5-diyl group is preferably oriented to the right (R). The same applies to bond groups (-COO-or-OCO-) such as carbonyloxy.

The present invention is the following items.

The liquid crystal composition according to item 1 contains at least one compound selected from the compounds represented by formula (1) as additive X, and has a nematic phase and negative dielectric anisotropy.

In the formula (1), R ^a At least one of hydrogen, a group represented by the formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms, an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group, -CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; r is 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; z is Z ^a Z is as follows ^c Is a single bond or an alkylene group having 1 to 30 carbon atoms, at least one of which is-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may be substituted by halogen; z is 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 a hydrocarbon group having 6 to 3 carbon atoms0, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen or a group represented by formula (F); s is sulfur; n is 0, 1, 2, 3 or 4; p is 0 or 1;

in the 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen; z is Z ^d Is a single bond or an alkylene group having 1 to 30 carbon atoms, at least one of which is-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may 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 at least one compound selected from the compounds represented by formulas (1-1) to (1-4) as an additive X.

In the formulae (1-1) to (1-4), R ^f Is hydrogen, alkyl of 1 to 20 carbon atoms, alicyclic hydrocarbon of 3 to 20 carbon atoms or aromatic hydrocarbon of 6 to 20 carbon atoms, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; r is R ^g 、R ^h 、R ⁱ R is R ^j Is hydrogen, alkyl of 1 to 5 carbon atoms, at least one of these groups being-CH ₂ -can be substituted by-O-or-CO-, at least one-CH ₂ -CH ₂ -cocoa warp-ch=cH-substitution, at least one hydrogen being substituted by a group represented by the formula (F-1); r is R ^d R is R ^e 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; z is Z ^e Z is as follows ^f An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; z is Z ^g Is an alkylene group having 1 to 6 carbon atoms, at least one of the alkylene groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; s is sulfur; n is n ¹ N is as follows ² 0, 1, 2 or 3;

in the 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, at least one of these groups being-CH ₂ -can be substituted by-O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; z is Z ^h An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -may be substituted by-O-or-CO-; s is sulfur; m is m ¹ 0, 1, 2 or 3; r is (r) ¹ 0 or 1.

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

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

In the formula (2), the amino acid sequence of the compound,R ^2a r is R ^2b Is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkenyloxy of 2 to 12 carbon atoms, or alkyl of 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring A and ring C are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene substituted with at least one hydrogen by fluorine or chlorine, naphthalene-2, 6-diyl substituted with at least one hydrogen by fluorine or chlorine, chromane-2, 6-diyl, or chromane-2, 6-diyl substituted with at least one hydrogen 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-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl, 4, 6-difluorodibenzofuran-3, 7-diyl, 4, 6-difluorodibenzothiophene-3, 7-diyl or 1,6, 7-tetrafluoroindan-2, 5-diyl; z is Z ^2a Z is as follows ^2b Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; a is 0, 1, 2 or 3, b is 0 or 1; and the sum of a and b is 3 or less.

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

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In the formulae (2-1) to (2-35), R ^2a R is R ^2b Is hydrogen, C1 to C112, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkenyloxy group having 2 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

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

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

In the formula (3), R ^3a R is R ^3b Is an alkyl group of 1 to 12 carbon atoms, an alkoxy group of 1 to 12 carbon atoms, an alkenyl group of 2 to 12 carbon atoms, or an alkenyl group of 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; 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 is Z ^3a Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; c is 1,2 or 3.

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

In the formulae (3-1) to (3-13), R ^3a R is R ^3b Is an alkyl group of 1 to 12 carbon atoms, an alkoxy group of 1 to 12 carbon atoms, an alkenyl group of 2 to 12 carbon atoms, or an alkenyl group of 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

The liquid crystal composition according to item 7 or item 8, wherein the proportion of component B is in the range of 10 to 90 mass%.

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

In the formula (4), the ring F and the ring I are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1, 3-dioxan-2-yl, pyrimidin-2-yl or pyridin-2-yl, and at least one hydrogen in these rings may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms, at least one hydrogen being substituted with 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, and in these rings, at least one hydrogen may be substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or at least one hydrogen may be substituted by fluorine or chlorine; z is Z ^4a Z is as follows ^4b An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -CO-, -COO-or-OCO-, at least one-CH ₂ -CH ₂ Can be modified by-ch=ch-, -C (CH ₃ )＝CH-、-CH＝C(CH ₃ ) -or-C (CH) ₃ )＝C(CH ₃ ) -substitution, of which at least one hydrogen may be substituted by fluorine or chlorine; p (P) ^4a 、P ^4b P ^4c Is a polymerizable group; sp (Sp) ^4a 、Sp ^4b Sp and Sp ^4c An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -COO-, -OCO-or-OCOO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may 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 formula (4), P ^4a 、P ^4b P ^4c Is a group selected from the polymerizable groups represented by the formulae (P-1) to (P-5).

In the formulae (P-1) to (P-5), M ¹ 、M ² M and M ³ Is hydrogen, fluorine, alkyl of 1 to 5 carbon atoms, or alkyl of 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

The liquid crystal composition according to any one of items 1 to 11, which contains at least one compound selected from the polymerizable compounds represented by the formulas (4-1) to (4-29) as an additive Y.

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In the formulas (4-1) to (4-29), sp ^4a 、Sp ^4b Sp and Sp ^4c An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -COO-, -OCO-or-OCOO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by fluorine or chlorine; p (P) ^4d 、P ^4e P ^4f Is a polymerizable group selected from groups represented by the formulas (P-1) to (P-3);

in the formulae (P-1) to (P-3), M ¹ 、M ² M and M ³ Is hydrogen,Fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

The liquid crystal composition according to any one of items 10 to 12, wherein the proportion of the additive Y is in the range of 0.03 to 10 mass%.

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

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

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

The use of the liquid crystal composition according to any one of items 1 to 13 in a liquid crystal display element.

The use of the liquid crystal composition according to any one of items 10 to 13 in a liquid crystal display element of polymer-stabilized alignment.

The invention also includes the following. (a) The composition contains one compound, two compounds or more than three compounds selected from optically active compounds, antioxidants, ultraviolet absorbers, pigments, defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors and other additives. (b) an AM element comprising the composition. (c) The composition further comprising a polymerizable compound, and an AM element having a polymer-stabilized-orientation (PSA) system comprising the composition. (d) An AM element of polymer stabilized orientation (PSA) comprising the composition, the polymerizable compound in the composition being polymerized. (e) A component comprising the composition and having a pattern of PC, TN, STN, ECB, OCB, IPS, VA, FFS or FPA. (f) a permeable member comprising said 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 said composition.

The composition of the present invention is described in the following order. First, the constitution of the constituent compounds in the composition will be described. Second, the main characteristics of the constituent compounds and the main effects of the compounds on the composition will be described. Third, the combination of component compounds in the composition, preferred proportions of component compounds, and their correspondence will be described. Fourth, preferred forms of the component compounds will be described. Fifth, preferred component compounds are shown. Sixth, additives that can be added to the composition are described. Seventh, a method for synthesizing the component compounds will be described. Finally, the use of the composition will be described.

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

The composition (b) contains substantially only a liquid crystalline compound selected from the group consisting of the compounds (2) and (3). "substantially" means that the composition (b) may contain additives but does not contain other liquid crystalline compounds. The amount of the component (b) is small compared with the 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 crystalline compounds.

Second, the main characteristics of the constituent 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 constituent compounds are summarized in table 2. In the notation of table 2, L means large or high, M means medium, and S means small or low. The notation L, M, S is a classification based on qualitative comparisons between constituent compounds, with 0 (zero) referring to less than S.

TABLE 2 Properties of liquid Crystal Compounds

Characteristics of	Compound (2)	Compound (3)
			Upper limit temperature	S～L	S～L
Viscosity of the mixture	M～L	S～M
			Optical anisotropy	M～L	S～L
Dielectric anisotropy	M～L ¹⁾	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 constituent compounds are as follows. The additive X acts as an antioxidant contributing to a high stability to heat or light. Since the amount of the compound (1) to be added is small, in many cases, the compound (1) has no influence on properties such as an upper limit temperature, optical anisotropy, and dielectric anisotropy. The compound (2) increases dielectric anisotropy and decreases the lower limit temperature. The compound (3) decreases the viscosity or increases the upper limit temperature. Since the compound (4) is polymerizable, a polymer is formed by polymerization. The polymer stabilizes the alignment of the liquid crystal molecules, thus shortening the response time of the element.

The organic compound is degraded by light or thermal energy and generates radicals. The radicals act as a chain carrier and react with other organic compounds and the like to generate new radicals, which are linked. In addition, when the reaction is carried out, a peroxide is generated, and new radicals are also generated from the peroxide and are loaded in the chain. Compounds having the effect of stopping such radical chain linking are called radical chain linking inhibitors (primary antioxidants). Phenol antioxidants such as 2, 6-di-t-butyl-4-methylphenol are used as normal primary antioxidants, and hydrogen in the phenol part is supplied to the radical, and the radical itself becomes a phenoxy radical having low activity due to steric hindrance or the like. Then, radical trapping is further performed to stabilize the reaction product. The increase of radicals is suppressed by the action. On the other hand, with respect to the peroxide generated during the degradation, the peroxide is decomposed to form an inert compound, thereby suppressing loading of the generated radical on the chain. Such an agent is called a peroxide decomposer (secondary antioxidant), and a sulfur-based antioxidant (sulfide compound) or a phosphorus-based antioxidant (phosphite compound) is usually 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 perform radical trapping, thereby exerting a high antioxidant effect. In addition, sulfur (S) contained in the structure of the compound also acts as a peroxide decomposer.

Third, the combination of component compounds in the composition, preferred proportions of component compounds, and their correspondence 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 (4), compound (1) +compound (3) +compound (4) or compound (1) +compound (2) +compound (3) +compound (4). Further, a preferable combination is compound (1) +compound (2) +compound (3) or compound (1) +compound (2) +compound (3) +compound (4).

The preferable proportion of the additive X is 0.0001 mass% or more, and the preferable proportion of the additive X is about 2.0000 mass% or less in order to lower the lower limit temperature. Further, the preferable ratio is in the range of about 0.0050% by mass to about 1.0000% by mass. Particularly preferred proportions are in the range of about 0.0100% to about 0.1000% by mass.

The preferable proportion of the compound (2) is about 10 mass% or more for improving dielectric anisotropy, and about 90 mass% or less for lowering the lower limit temperature. Further, the preferable ratio is in the range of about 20 to about 80 mass%. Particularly preferred proportions are in the range of about 30 to about 70 mass%.

The preferable proportion of the compound (3) is about 10 mass% or more for increasing the upper limit temperature or for reducing the viscosity, and about 90 mass% or less for increasing the dielectric anisotropy. Further, the preferable ratio is in the range of about 20 to about 80 mass%. Particularly preferred proportions are in the range of about 30 to about 70 mass%.

The additive Y is added to the composition for the purpose of adapting the element for polymer stabilization orientation. The preferable proportion of the additive Y is about 0.03 mass% or more for aligning the liquid crystal molecules, and about 10 mass% or less for preventing defective display of the element. Further, the preferable ratio is in the range of about 0.1% by mass to about 2% by mass. Particularly preferred proportions are in the range of about 0.2% to about 1.0% by mass.

Fourth, preferred forms of the component compounds will be described. In the formula (1), R ^a At least one of hydrogen, a group represented by the formula (F), an alkyl group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and an aromatic hydrocarbon group having 6 to 30 carbon atoms, an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group, -CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen. Preferred R ^a Is hydrogen, a group represented by the formula (F), an alkyl group having 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 -may be substituted with-ch=ch-. R is 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen. Preferred R ^b Is an alkyl group of 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 -may be substituted with-ch=ch-. Z is Z ^a Z is as follows ^c Is a single bond or an alkylene group having 1 to 30 carbon atoms, at least one of which is-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may be substituted by halogen. Preferred Z ^a Or Z is ^c An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -may be substituted by-O-or-CO-. Z is 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, at least one of these groups being-CH ₂ -can be taken via-S-, -O-, -NH-or-CO-Instead, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, of which at least one hydrogen may be substituted by halogen or a group represented by formula (F). Preferred Z ^b An alkylene group having 1 to 30 carbon atoms and at least one of these groups-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-, at least one hydrogen may be substituted by a group represented by formula (F). S is sulfur. n is 0, 1, 2, 3 or 4. Preferably n is 2.p is 0 or 1.

In the 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by halogen. Preferred R ^c Alkyl of 1 to 15 carbon atoms, of which at least one-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Z is Z ^d Is a single bond or an alkylene group having 1 to 30 carbon atoms, at least one of which is-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, at least one hydrogen may be substituted by halogen. Preferred Z ^d An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -may be substituted by-O-or-CO-. S is sulfur. m is 0, 1, 2, 3 or 4. Preferably m is 2.r is 0 or 1.

In the formulae (1-1) to (1-4), R ^f Is hydrogen, alkyl of 1 to 20 carbon atoms, alicyclic hydrocarbon of 3 to 20 carbon atoms or aromatic hydrocarbon of 6 to 20 carbon atoms, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Preferred R ^f Is hydrogen, alkyl of 1 to 15 carbon atoms, at least one-CH ₂ -may be substituted by-O-or-CO-. R is R ^g 、R ^h 、R ⁱ R is R ^j Is hydrogen, alkyl of 1 to 5 carbon atoms, at least one of these groups being-CH ₂ -can be taken via-O-or-CO-Instead, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-, at least one hydrogen may be substituted with a group represented by formula (F-1). Preferred R ^g 、R ^h 、R ⁱ Or R is ^j Alkyl of 1 to 5 carbon atoms, of which at least one-CH ₂ -may be substituted by-O-or-CO-. R is R ^d R is R ^e 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Preferred R ^d Or R is ^e Alkyl of 1 to 15 carbon atoms, of which at least one-CH ₂ -may be substituted by-S-, -O-, or-CO-. Z is Z ^e Z is as follows ^f An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Preferred Z ^e Or Z is ^f An alkylene group having 1 to 5 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -may be substituted by-O-or-CO-. Z is Z ^g Is an alkylene group having 1 to 6 carbon atoms, at least one of the alkylene groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Preferred Z ^g An alkylene group having 1 to 5 carbon atoms, at least one of the alkylene groups being-CH ₂ -may be substituted by-O-or-CO-. S is sulfur. n is n ¹ N is as follows ² 0, 1, 2 or 3. Preferred n ¹ Or n ² 2.

In the 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, at least one of these groups being-CH ₂ -can be substituted by-O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-. Preferred R ^j Alkyl of 1 to 15 carbon atoms, of which at least one-CH ₂ -may be substituted by-O-or-CO-. Z is Z ^h An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -may be substituted by-O-or-CO-. Preferred Z ^h Is a single bond orAn alkylene group having 1 to 5 carbon atoms, at least one of the alkylene groups being-CH ₂ -may be substituted by-O-or-CO-. m is m ¹ 0, 1, 2 or 3. Preferred m ¹ 2.r is (r) ¹ 0 or 1.

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

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In the formula (2) and the formula (3), R ^2a R is R ^2b Is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkenyloxy of 2 to 12 carbon atoms, or alkyl of 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. For improved stability, R is preferably ^2a Or R is ^2b Is an alkyl group having 1 to 12 carbon atoms, R is preferably selected for improving dielectric anisotropy ^2a Or R is ^2b Alkoxy groups having 1 to 12 carbon atoms. R is R ^3a R is R ^3b Is an alkyl group of 1 to 12 carbon atoms, an alkoxy group of 1 to 12 carbon atoms, an alkenyl group of 2 to 12 carbon atoms, or an alkenyl group of 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. In order to reduce the viscosity, R is preferably ^3a Or R is ^3b Alkenyl of 2 to 12 carbon atoms, R is preferable for improving stability ^3a Or R is ^3b Is an alkyl group having 1 to 12 carbon atoms.

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

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy. Further preferred alkoxy groups are methoxy or ethoxy groups for reducing 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 the viscosity. The preferred stereochemistry of-ch=ch-in these alkenyl groups depends on the position of the double bond. Among alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and 3-hexenyl, the trans configuration is preferable for the purpose of lowering viscosity and the like. Among alkenyl groups such as 2-butenyl, 2-pentenyl and 2-hexenyl, the cis configuration is preferable.

Preferred alkenyloxy groups are ethyleneoxy, allyloxy, 3-butenyloxy, 3-pentenyloxy or 4-pentenyloxy. Further preferred alkenyloxy groups are allyloxy or 3-butenyloxy groups for reducing the viscosity.

Preferred examples of the at least one hydrogen fluorine-or chlorine-substituted alkyl group are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or 8-fluorooctyl. Further preferable examples of the compound are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl and 5-fluoropentyl for improving dielectric anisotropy.

Preferred examples of the at least one hydrogen fluorine or chlorine substituted alkenyl group are 2, 2-difluorovinyl, 3-difluoro-2-propenyl, 4-difluoro-3-butenyl, 5-difluoro-4-pentenyl or 6, 6-difluoro-5-hexenyl. Further preferable examples are 2, 2-difluorovinyl group or 4, 4-difluoro-3-butenyl group for reducing the viscosity.

Ring A and ring C are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene substituted with at least one hydrogen by fluorine or chlorine, naphthalene-2, 6-diyl substituted with at least one hydrogen by fluorine or chlorine, chromane-2, 6-diyl, or chromane-2, 6-diyl substituted with at least one hydrogen by fluorine or chlorine. Preferred examples of "1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine" are 2-fluoro-1, 4-phenylene, 2, 3-difluoro-1, 4-phenylene or 2-chloro-3-fluoro-1, 4-phenylene. In order to reduce the viscosity, the preferred ring A or ring C is a 1, 4-cyclohexylene group, in order to improve the dielectric anisotropy, the preferred ring A or ring C is a tetrahydropyran-2, 5-diyl group, and in order to improve the optical anisotropy, the preferred ring A or ring C is a 1, 4-phenylene group. The tetrahydropyran-2, 5-diyl group is:

Or (b)

Preferably, it is:

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-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl (FLF 4), 4, 6-difluorodibenzofuran-3, 7-diyl (DBFF 2), 4, 6-difluorodibenzothiophene-3, 7-diyl (DBTF 2) or 1,6, 7-tetrafluoroindan-2, 5-diyl (InF 4).

For reducing the viscosity, the preferred ring B is 2, 3-difluoro-1, 4-phenylene, for reducing the optical anisotropy, the preferred ring B is 2-chloro-3-fluoro-1, 4-phenylene, and for improving 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 reduce the viscosity or to raise the upper temperature, the preferred ring D or ring E is 1, 4-cyclohexylene and in order to lower the lower temperature, the preferred ring D or ring E is 1, 4-phenylene.

Z ^2a Z is as follows ^2b Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy. To reduce the viscosity, Z is preferably ^2a Or Z is ^2b Is a single bond, Z is preferably selected in order to lower the lower limit temperature ^2a Or Z is ^2b Ethylene, Z is preferable for improving dielectric anisotropy ^2a Or Z is ^2b Is methyleneoxy. Z is Z ^3a Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy. To reduce the viscosity, Z is preferably ^3a Is a single bond.

In the methyleneoxy group, -CH ₂ O-is better than-OCH ₂ -. Of the 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 the viscosity, a is preferably 1, and in order to raise the upper limit temperature, a is preferably 2 or 3. In order to reduce the viscosity, b is preferably 0, and in order to reduce the lower limit temperature, b is preferably 1.c is 1, 2 or 3. In order to reduce the viscosity, c is preferably 1, and in order to raise the upper limit temperature, c is preferably 2 or 3.

In the formula (4), P ^4a 、P ^4b P ^4c Is a polymerizable group. Preferred P ^4a 、P ^4b Or P ^4c Is a polymerizable group selected from the groups represented by the formulas (P-1) to (P-5). Further preferably P ^4a 、P ^4b Or P ^4c Is of formula (P-1) or formula (P-2). Particularly preferred formula (P-1) is-OCO-ch=ch ₂ or-OCO-C (CH) ₃ )＝CH ₂ . The wavy lines of the formulae (P-1) to (P-5) represent the bonding sites.

In the formulae (P-1) to (P-5), M ¹ 、M ² M and M ³ Is hydrogen, fluorine, alkyl of 1 to 5 carbon atoms, or alkyl of 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. In order to increase the reactivity, M is preferably ¹ 、M ² Or M ³ Is hydrogen or methyl. Further preferably M ¹ Methyl group, and preferably M ² Or M ³ Is hydrogen.

In the formulae (4-1) to (4-29), P ^4d 、P ^4e P ^4f Represented by the formulae (P-1) to (P-3)A base. Preferred P ^4d 、P ^4e Or P ^4f Is of formula (P-1) or formula (P-2). Further preferred formula (P-1) is-OCO-CH=CH ₂ or-OCO-C (CH) ₃ )＝CH ₂ . The wavy lines of the formulae (P-1) to (P-3) represent the bonding sites.

In formula (4), sp ^4a 、Sp ^4b Sp and Sp ^4c An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -COO-, -OCO-or-OCOO-, at least one-CH ₂ -CH ₂ -may be substituted by-ch=ch-or-c≡c-, in which groups at least one hydrogen may be substituted by fluorine or chlorine. Preferred Sp ^4a 、Sp ^4b Or Sp ^4c Is a single bond, -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, pyrimidin-2-yl or pyridin-2-yl, at least one hydrogen of which may be substituted by fluorine, chlorine, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, or alkyl of 1 to 12 carbon atoms, at least one hydrogen of which is substituted by fluorine or chlorine. 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, and in these rings at least one hydrogen may be substituted by fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or at least one hydrogen substituted by fluorine or chlorine. Preferred ring G is 1, 4-phenylene or 2-fluoro-1, 4-phenylene.

Z ^4a Z is as follows ^4b An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -CO-, -COO-or-OCO-, at least one-CH ₂ -CH ₂ -cocoa warp-CH＝CH-、-C(CH ₃ )＝CH-、-CH＝C(CH ₃ ) -or-C (CH) ₃ )＝C(CH ₃ ) -substitution, in which at least one hydrogen may be substituted by fluorine or chlorine. Preferred Z ^4a Or Z is ^4b Is a single bond, -CH ₂ CH ₂ -、-CH ₂ O-、-OCH ₂ -, -COO-or-OCO-. Further preferably Z ^4a Or Z is ^4b Is a single bond.

d is 0, 1 or 2. Preferably 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. Preferably e, f or g is 1 or 2.

Fifth, preferred component compounds are shown. Preferred compounds (1) are the compounds (1-1) to (1-4) as defined in item 2. Of these compounds, the compound (1-2) or the compound (1-3) is preferable.

Preferred compounds (2) are the compounds (2-1) to (2-35) as described in item 5. Of these compounds, at least one of component A is preferably 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 compound (2-10), compound (2-6) and compound (2-16), and compound (2-10) and compound (2-16) in combination.

Preferred compounds (3) are the compounds (3-1) to (3-13) as described in item 8. Of 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 a combination of compound (3-1) and compound (3-6).

Preferred compounds (4) are the compounds (4-1) to (4-29) as described in item 12. Of these compounds, at least one of the additives Y is preferably 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 a combination of compound (4-18) and compound (4-24).

Sixth, additives that can be added to the composition are 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 inducing a helical structure of the liquid crystal molecules to impart a twist angle (twist angle). Examples of such compounds are compounds (5-1) to (5-5). The preferable proportion of the optically active compound is about 5 mass% or less. Further, the preferable ratio is in the range of about 0.01 to about 2 mass%.

In order to prevent the decrease in specific resistance due to 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 period of time, antioxidants such as the compounds (6-1) to (6-3) may be further added to the composition.

Since the compound (6-2) has low volatility, it is effective 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 period of time. In order to obtain the effect, the preferable proportion of the antioxidant is about 50ppm or more, and in order not to lower the upper limit temperature or in order not to raise the lower limit temperature, the preferable proportion of the antioxidant is about 600ppm or less. Further preferred ratios are in the range of about 100ppm to about 300 ppm.

Preferred 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 compounds (7-1) to (7-16) and the like. In order to obtain the effect, the preferable proportion of these absorbents or stabilizers is about 50ppm or more, and in order not to lower the upper limit temperature or in order not to raise the lower limit temperature, the preferable proportion of these absorbents or stabilizers is about 10000ppm or less. Further preferred ratios are in the range of about 100ppm to about 10000 ppm.

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The matting agent is a compound that receives light energy absorbed by the liquid crystalline compound and converts the light energy into heat energy to prevent the decomposition of the liquid crystalline compound. Preferred examples of the matting agent are compounds (8-1) to (8-7) and the like. In order to obtain the above-mentioned effect, the preferable proportion of these matting agents is about 50ppm or more, and in order not to raise the lower limit temperature, the preferable proportion of these matting agents is about 20000ppm or less. Further preferred ratios are in the range of about 100ppm to about 10000 ppm.

To adapt to a Guest Host (GH) mode element, a dichroic dye (dichromatic dye) such as an azo dye, an anthraquinone dye, or the like is added to the composition. The preferable proportion of the coloring matter is in the range of about 0.01% by mass to about 10% by mass. To prevent bubbling, defoamers such as dimethyl silicone oil, methyl phenyl silicone oil, and the like are added to the composition. In order to obtain the above effect, the preferable proportion of the antifoaming agent is about 1ppm or more, and in order to prevent the display failure, the preferable proportion of the antifoaming agent is about 1000ppm or less. Further preferred ratios are in the range of about 1ppm to about 500 ppm.

In order to be suitable for a polymer stabilized oriented (PSA) type element, a polymerizable compound is used. Compound (4) is suitable for the purpose. A polymerizable compound different from the compound (4) and the compound (4) may be added together to the composition. Preferable examples of such polymerizable compounds are compounds such as acrylic acid esters, methacrylic acid esters, vinyl compounds, ethyleneoxy compounds, propenyl ethers, epoxy compounds (oxetanes ), vinyl ketones, and the like. Further preferred examples are derivatives of acrylic acid esters or methacrylic acid esters. The preferable proportion of the compound (4) is 10 mass% or more based on the total mass of the polymerizable compounds. Further, the ratio is preferably 50% by mass or more. The ratio is particularly preferably 80% by mass or more. The most preferred ratio is 100 mass%.

The polymerizable compound such as the compound (4) is polymerized by ultraviolet irradiation. The polymerization may be carried out in the presence of a suitable initiator such as a photopolymerization initiator. Suitable conditions for carrying out the polymerization, suitable types of initiators, and suitable amounts are known to the person skilled in the art and are described in the literature. For example, brilliant best (Irgacure) 651 (registered trademark; BASF), brilliant best (Irgacure) 184 (registered trademark; BASF), or Darocur 1173 (registered trademark; BASF) as a photopolymerization initiator is suitable for radical polymerization. The preferable proportion 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. Further, the preferable ratio is in the range of about 1 to about 3 mass%.

In the case of preserving a polymerizable compound such as the compound (4), a polymerization inhibitor may be added for the purpose of preventing polymerization. The polymerizable compound is usually added to the composition in a state where the polymerization inhibitor is not removed. Examples of the polymerization inhibitor are hydroquinone, hydroquinone derivatives such as methyl hydroquinone, 4-tert-butyl catechol, 4-methoxyphenol, phenothiazine (phenothiazine), and the like.

Seventh, a method for synthesizing the component compounds will be described. These compounds can be synthesized by known methods. The synthesis method is exemplified. Compound (1-A) is cellobious (Irganox) 1520L (registered trademark; basf (BASF)), and compound (1-B) is cellobious (Irganox) 1726 (registered trademark; basf) obtainable from Basf (BASF). Compounds (1-C) and (1-D) are available from Tokyo Chemical Industry (TCI). The compound (1-E) is generally known as a pharmaceutical called Probucol (Probucol), and is available from Tokyo Chemical Industry (TCI). Compound (1-F) is available from Tokyo Chemical Industry (TCI). The compound (2-1) was synthesized by the method described in Japanese patent application laid-open No. 2000-053602. The compound (3-1) was synthesized by the method described in Japanese patent application laid-open No. 59-176221. The compound (4-18) was synthesized by the method described in Japanese patent application laid-open No. 7-101900. Antioxidants are commercially available. Compound (6-1) was obtained from Sigma Aldrich (Sigma-Aldrich Corporation). The compound (6-2) and the like are synthesized by the method described in the specification of U.S. Pat. No. 3660505.

Compounds not described in the synthesis method can be synthesized by the methods described in the books of organic Synthesis (Organic Syntheses, john Weili father-son publishing Co., john Wiley & Sons, inc.), (organic reactions) (Organic Reactions, john Weili father-son publishing Co., john Wiley & Sons, inc.), (comprehensive organic Synthesis) (Comprehensive Organic Synthesis, pegman publishing Co., pergamon Press)), new laboratory chemistry lectures (Wash), and the like. The compositions are prepared by known methods from the compounds obtained in the manner described. For example, the constituent compounds are mixed and then dissolved in each other by heating.

Finally, the use of the composition will be described. The composition has primarily a lower temperature of about-10 ℃ or less, an upper temperature of about 70 ℃ or more, and an optical anisotropy in the range of about 0.07 to about 0.20. Compositions having optical anisotropies in the range of about 0.08 to about 0.25 may also be prepared by controlling the proportions of the constituent compounds, or by mixing other liquid crystalline compounds. Compositions having optical anisotropies ranging from about 0.10 to about 0.30 can also be prepared by trial and error. The components containing the composition have a large voltage holding ratio. The composition is suitable for AM elements. 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 elements. And can also be used for PM elements. The composition can be used for AM elements and PM elements having a mode of PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA or the like. Particularly preferred is for an AM element having TN, OCB, IPS mode or FFS mode. In an AM element having an IPS mode or FFS mode, when no voltage is applied, the liquid crystal molecules may be aligned parallel to the glass substrate or perpendicular to the glass substrate. These elements may be reflective, transmissive or semi-transmissive. Preferably for a permeation type element. Can also be used for amorphous silicon-TFT elements or polysilicon-TFT elements. The composition may be used for a nematic curve alignment phase (nematic curvilinear aligned phase, NCAP) element produced by microencapsulation (microencapsulation) or a polymer dispersed (polymer dispersed, PD) element formed by forming a three-dimensional network polymer in the composition.

Examples (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 a mixture of at least two of the compositions of the examples. The synthesized compound is identified by nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) analysis or the like. The characteristics of the compounds, compositions and devices were measured by the methods described below.

NMR analysis: DRX-500 manufactured by Bruker Biospin was used for the measurement. ¹ In the measurement of H-NMR, a sample was dissolved in CDCl ₃ The measurement was performed at room temperature under conditions of 500MHz and 16 times of total times in an isodeuterated solvent. Using tetramethylsilane asIs an internal standard. ¹⁹ In the determination by F-NMR, CFCl was used ₃ As an internal standard, this was performed 24 times in total. In the description of nuclear magnetic resonance spectroscopy, s refers to a single peak (single), d refers to a double peak (doublet), t refers to a triple peak (triplet), q refers to a quadruple peak (quateset), quinte refers to a quintet, sex refers to a hexa peak (setet), m refers to a multiple peak (multiplet), and br refers to a broad peak (broad).

Gas chromatography analysis: for measurement, a GC-14B type gas chromatograph manufactured by Shimadzu corporation was used. The carrier gas was helium (2 mL/min). The sample vaporization chamber was set at 280℃and the detector (flame ionization detector (flame ionization detector, FID)) was set at 300 ℃. The separation of the component compounds was carried out using a capillary column DB-1 (30 m in length, 0.32mm in inside diameter, 0.25 μm in thickness; dimethylpolysiloxane as the stationary liquid phase; nonpolar) manufactured by Agilent technologies Co., ltd. (Agilent Technologies Inc.). After the column was held at 200℃for 2 minutes, the temperature was raised to 280℃at a rate of 5℃per minute. After preparing a sample into an acetone solution (0.1 mass%), 1. Mu.L of the acetone solution was injected into the sample vaporization chamber. The record was a C-R5A chromatograph component (Chromatopac) manufactured by Shimadzu corporation or an equivalent thereof. The obtained gas chromatogram shows the retention time of the peak corresponding to the component compound and the area of the peak.

As the solvent for diluting the sample, chloroform, hexane or the like can be used. For separation of the constituent compounds, the following capillary column may be used. HP-1 (30 m in length, 0.32mm in inside diameter, 0.25 μm in film thickness) manufactured by Agilent technologies Inc. (Agilent Technologies Inc.), rtx-1 (30 m in length, 0.32mm in inside diameter, 0.25 μm in film thickness) manufactured by Ruis Tex Co., ltd., and BP-1 (30 m in length, 0.32mm in inside diameter, 0.25 μm in film thickness) manufactured by Australian SGE International Inc. (SGE International Pty.Ltd.). For the purpose of preventing the overlapping of the peaks of the compounds, capillary columns CBP1-M50-025 (length 50M, inner diameter 0.25mm, film thickness 0.25 μm) manufactured by Shimadzu corporation can be used.

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

Measuring a sample: the composition is used directly as a sample in determining the characteristics of the composition or element. In measuring the characteristics of the compound, a measurement sample was prepared by mixing the compound (15 mass%) with a mother liquor crystal (85 mass%). From the values obtained by the measurement, the characteristic values of the compounds were calculated by extrapolation (extrapolation method). (extrapolated value) = { (measurement of sample) -0.85× (measurement of mother liquor crystal) }/0.15. When a smectic phase (or crystal) is precipitated at 25 ℃ at the ratio, the ratio of the compound to the mother liquid crystal is 10 mass%: 90 mass%, 5 mass%: 95 mass%, 1 mass%: 99 mass% sequence was changed. The upper limit temperature, optical anisotropy, viscosity and dielectric anisotropy values related to the compound were obtained by the extrapolation method.

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

The measuring method comprises the following steps: the characteristics were measured by the following method. Most of these methods are those described in JEITA standards (JEITA. ED-2521B) established by the Japanese society for electronic information technology and technology (Japan Electronics and Information Technology Industries Association; referred to as JEITA) and modified. A Thin Film Transistor (TFT) was not mounted on the TN element for measurement.

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

(2) Lower limit temperature of nematic phase (T _C The method comprises the steps of carrying out a first treatment on the surface of the DEG C): after placing a sample having a nematic phase in a glass bottle and keeping the temperature in a freezer at 0 ℃, -10 ℃, -20 ℃, -30 ℃ and-40 ℃ for 10 days, a liquid crystal phase was observed. For example, when the sample maintains a nematic phase at-20℃and changes to a crystalline or smectic phase at-30℃it is referred to as T _C <-20 ℃. The lower limit temperature of the nematic phase is sometimes abbreviated as "lower limit temperature".

(3) Viscosity (bulk viscosity; eta; measured at 20 ℃ C.; mPa.s): for measurement, an E-type rotary viscometer manufactured by Tokyo counter Co., ltd was used.

(4) Viscosity (rotational viscosity; gamma.1; measured at 25 ℃ C.; mPa.s): for the measurement, the rotary tack rate measurement system LCM-2 type was used by TOYO technology Co., ltd. Samples were injected into VA elements having a gap (cell gap) of 10 μm between two glass substrates. Rectangular waves (55V, 1 ms) were applied to the element. The peak current (peak current) and the peak time (peak time) of the transient current (transient current) generated by the application are determined. Using these measured values, a 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 ℃): the measurement was performed by an abbe refractometer having a polarizing plate attached to an eyepiece using light having a wavelength of 589 nm. After rubbing the surface of the primary prism in one direction, a sample is dropped onto the primary prism. The refractive index n/is measured when the direction of polarization is parallel to the direction of rubbing. The refractive index n+.t is measured when the direction of polarization is perpendicular to the direction of rubbing. The value of the optical anisotropy is calculated from the equation of Δn=n-n ∈.

(6) Dielectric anisotropy (. DELTA.. Epsilon.; measured at 25 ℃ C.): the value of dielectric anisotropy is calculated from the equation of Δε=ε - ε. The dielectric constant (. Epsilon. T) was measured as follows.

1) Determination of dielectric constant (ε): a well-cleaned glass substrate was coated with a solution of octadecyltriethoxysilane (0.16 mL) in ethanol (20 mL). After the glass substrate was rotated by a rotator, the glass substrate was heated at 150℃for 1 hour. Samples were placed in VA elements having a gap (cell gap) of 4 μm between two glass substrates, and the elements were sealed with an adhesive cured by ultraviolet rays. A sine wave (0.5V, 1 kHz) was applied to the element, and the dielectric constant (. Epsilon./V) of the liquid crystal molecules was measured in the long axis direction after 2 seconds.

2) Determination of dielectric constant (ε+.T): a polyimide solution was coated on the sufficiently cleaned glass substrate. The obtained alignment film was subjected to rubbing treatment after firing the glass substrate. Samples were placed in a TN cell having a gap (cell gap) between two glass substrates of 9 μm and a twist angle of 80 degrees. A sine wave (0.5V, 1 kHz) was applied to the element, and the dielectric constant (. Epsilon. DELTA.T.) of the liquid crystal molecules was measured in the short axis direction after 2 seconds.

(7) Threshold voltage (Vth; measured at 25 ℃ C.; V): for the measurement, an LCD5100 type luminance meter manufactured by tsukamu electronics corporation was used. The light source is a halogen lamp. A sample was placed in a VA element having a gap (cell gap) between two glass substrates of 4 μm and a normally black mode (normally black mode) having an anti-parallel rubbing direction, and the element was sealed with an adhesive cured by ultraviolet rays. The voltage (60 Hz, rectangular wave) applied to the element was increased stepwise from 0V to 20V in units of 0.02V. At this time, light is irradiated from the vertical direction to the element, and the amount of light transmitted through the element is measured. A voltage-transmittance curve was prepared in which the transmittance at the maximum light amount was 100% and the transmittance at the minimum light amount was 0%. The threshold voltage is represented by a voltage at which the transmittance becomes 10%.

(8) Voltage holding ratio (VHR-9; measured at 25 ℃;%) was: the TN element for measurement had a polyimide alignment film, and the interval (cell gap) between two glass substrates was 5. Mu.m. The element is sealed with an adhesive that is hardened by ultraviolet rays after the sample is placed. The TN-cell was charged by applying a pulse voltage (1V, 60 μs). The decaying voltage was measured by a high-speed voltmeter over a period of 166.7 milliseconds to determine the area a between the voltage curve and the horizontal axis of the unit cycle. Area B is the area when unattenuated. The voltage holding ratio is expressed by the percentage of the area a to the area B.

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

(10) Voltage holding ratio (VHR-11; measured at 60 ℃ C.;%) was: after irradiation with ultraviolet light, the voltage holding ratio was measured to evaluate the stability to ultraviolet light. The TN element for measurement had a polyimide alignment film, and the cell gap was 5. Mu.m. Injecting a sample into the cell, irradiating with 5mW/cm ² Ultraviolet rays for 167 minutes. The light source was black light (F40T 10/BL (peak wavelength 369 nm) manufactured by Kawasaki (EYEGRAPHICS) Co., ltd.) and the element was spaced 5mm from the light source. In the measurement of VHR-11, the decaying voltage was measured during 166.7 milliseconds. Compositions with large VHR-11 have large stability to UV light.

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

(12) Response time (τ; measured at 25 ℃ C.; ms): for the measurement, an LCD5100 type luminance meter manufactured by tsukamu electronics corporation was used. The light source is a halogen lamp. The Low pass filter (Low pass filter) was set to 5kHz. Samples were placed in VA elements having a gap (cell gap) of 4 μm between two glass substrates and a normally black mode (normally black mode) in which the rubbing direction was antiparallel. The element is sealed using an adhesive that is hardened by ultraviolet light. Rectangular waves (60 Hz, 10V, 0.5 seconds) were applied to the element. At this time, light is irradiated from the vertical direction to the element, and the amount of light transmitted through the element is measured. The transmittance was regarded as 100% when the light amount reached the maximum, and as 0% when the light amount was minimum. The response time is expressed by the time required for the transmittance to change from 90% to 10% (fall time; millisecond).

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

Examples of the composition are shown below. The constituent compounds are represented by symbols based on the definition of table 3 below. In Table 3, the steric configuration associated with 1, 4-cyclohexylene was the trans configuration. The numbers located in brackets after the labeled compounds represent the chemical formulas to which the compounds belong. The symbol of (-) refers to other liquid crystalline compounds. The proportion (percentage) of the liquid crystalline compound is a mass percentage (mass%) based on the mass of the liquid crystal composition containing no additive. Finally, the characteristic values of the composition are summarized.

TABLE 3 expression of compounds using markers

R-(A ₁ )-Z ₁ -……-Z _n -(A _n )-R′

Comparative example 1

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NI＝68.0℃；T _C <-20℃；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 set as example 1.

Example 1

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

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

Example 2

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

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

Example 3

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

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

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Example 4

Compound (1-D) was added to the composition in a proportion of 0.0500 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 proportion of 0.1000 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 proportion of 0.0100 mass%.

NI＝74.0℃；T _C <-20℃；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℃；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℃；T _C <-20℃；Δn＝0.105；Δε＝-2.3；VHR-11＝90.1％

Example 9

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

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

Example 10

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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 proportion of 0.1000 mass%.

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

Example 12

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

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

Example 13

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

NI＝70.2℃；T _C <-20℃；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℃；T _C <-20℃；Δn＝0.117；Δε＝-2.1；VHR-11＝89.9％

Example 15

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

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

Example 16

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

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

The voltage holding ratio (VHR-11) of the composition of comparative example 1 after ultraviolet irradiation was 75.5%. On the other hand, the compositions of examples 1 to 14 have VHR-11 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 applicability ]

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

Claims

1. A liquid crystal composition containing at least one compound selected from the compounds represented by the formulas (1-2) to (1-4) as an additive X and having a nematic phase and negative dielectric anisotropy:

in the formulae (1-2) to (1-4), R ^g 、R ^h 、R ⁱ R is R ^j Is hydrogen, alkyl of 1 to 5 carbon atoms, at least one of these groups being-CH ₂ -can be substituted by-O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-, at least one hydrogen may be substituted with a group represented by formula (F-1); r is R ^d R is R ^e 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, at least one of these groups being-CH ₂ -can be substituted by-S-, -O-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; z is Z ^e Z is as follows ^f An alkylene group having 1 to 10 carbon atoms or a single bond, at least one of the alkylene groups-CH ₂ -can be substituted by-O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; z is Z ^g Is an alkylene group having 1 to 6 carbon atoms, at least one of the alkylene groups being-CH ₂ -can be substituted by-S-, -O-, -NH-or-CO-, at least one-CH ₂ -CH ₂ -may be substituted with-ch=ch-; s is sulfur; n is n ¹ N is as follows ² 0, 1, 2 or 3;

2. The liquid crystal composition according to claim 1, wherein the proportion of the additive X is in the range of 0.0001 to 2 mass%.

3. 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 the formula (2), R ^2a R is R ^2b Is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkenyloxy of 2 to 12 carbon atoms, or alkyl of 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring A and ring C are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene substituted with at least one hydrogen by fluorine or chlorine, naphthalene-2, 6-diyl substituted with at least one hydrogen by fluorine or chlorine, chromane-2, 6-diyl, or chromane-2, 6-diyl substituted with at least one hydrogen 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-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl, 4, 6-difluorodibenzofuran-3, 7-diyl, 4, 6-difluorodibenzothiophene-3, 7-diyl or 1,6, 7-tetrafluoroindan-2, 5-diyl; z is Z ^2a Z is as follows ^2b Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; a is 0, 1, 2 or 3, b is 0 or 1; and the sum of a and b is 3 or less.

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

in the formulae (2-1) to (2-35), R ^2a R is R ^2b Is hydrogen, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, alkenyl of 2 to 12 carbon atoms, alkenyloxy of 2 to 12 carbon atoms, or alkyl of 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

5. The liquid crystal composition according to claim 3, wherein the proportion of the component a is in the range of 10 to 90 mass%.

6. 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:

in the formula (3), R ^3a R is R ^3b Is an alkyl group of 1 to 12 carbon atoms, an alkoxy group of 1 to 12 carbon atoms, an alkenyl group of 2 to 12 carbon atoms, or an alkenyl group of 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; 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 is Z ^3a Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; c is 1, 2 or 3.

7. The liquid crystal composition according to claim 3, which contains at least one compound selected from the compounds represented by formula (3) as component B:

in (3)，R ^3a R is R ^3b Is an alkyl group of 1 to 12 carbon atoms, an alkoxy group of 1 to 12 carbon atoms, an alkenyl group of 2 to 12 carbon atoms, or an alkenyl group of 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; 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 is Z ^3a Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; c is 1, 2 or 3.

8. The liquid crystal composition according to claim 1, which contains at least one compound selected from the compounds represented by the formulas (3-1) to (3-13) as component B:

9. The liquid crystal composition according to claim 4, which contains at least one compound selected from the group consisting of compounds represented by the formulas (3-1) to (3-13) as component B:

10. The liquid crystal composition according to claim 6, wherein the proportion of the component B is in the range of 10 to 90 mass%.

11. The liquid crystal composition according to claim 1, which contains at least one compound selected from the polymerizable compounds represented by formula (4) as additive Y:

12. The liquid crystal composition according to claim 11, wherein in the formula (4), P ^4a 、P ^4b P ^4c Is a group selected from the polymerizable groups represented by the formulas (P-1) to (P-5):

13. The liquid crystal composition according to claim 1, which contains at least one compound selected from the polymerizable compounds represented by the formulas (4-1) to (4-29) as an additive Y:

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in the formulae (P-1) to (P-3), M ¹ 、M ² M and M ³ Is hydrogen, fluorine, alkyl of 1 to 5 carbon atoms, or alkyl of 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

14. The liquid crystal composition according to claim 11, wherein the proportion of the additive Y is in the range of 0.03 to 10 mass%.

15. A liquid crystal display element comprising the liquid crystal composition according to claim 1.

16. The liquid crystal display device according to claim 15, wherein the operation mode of the liquid crystal display device is in-plane switching mode, vertical alignment mode, fringe field switching mode or electric field induced photoreaction alignment mode, and the driving mode of the liquid crystal display device is active matrix mode.

17. A liquid crystal display element having a stable polymer alignment, comprising the liquid crystal composition according to claim 11, wherein the polymerizable compound in the liquid crystal composition is polymerized.

18. Use of the liquid crystal composition according to claim 1 in a liquid crystal display element.

19. Use of the liquid crystal composition according to claim 11 in a liquid crystal display element of polymer-stabilized alignment type.