CN111560257A

CN111560257A - Liquid crystal composition and liquid crystal display element

Info

Publication number: CN111560257A
Application number: CN201911005790.1A
Authority: CN
Inventors: 片野裕子; 川上日向子; 近藤史尚; 斋藤将之
Original assignee: JNC Corp; JNC Petrochemical Corp
Current assignee: JNC Corp; JNC Petrochemical Corp
Priority date: 2019-02-13
Filing date: 2019-10-22
Publication date: 2020-08-21
Also published as: JP2020132852A

Abstract

The invention provides a liquid crystal composition and a liquid crystal display element, wherein the liquid crystal composition contains a polar compound (or a polymer thereof) having a polymerizable group, and the liquid crystal composition has negative dielectric anisotropy, and the liquid crystal composition can achieve vertical alignment of liquid crystal molecules through the action of the compound. The present invention is a nematic liquid crystal composition containing a polar compound having a polymerizable group as a first additive and having negative dielectric anisotropy, which may also contain a specific liquid crystal compound having negative large dielectric anisotropy as a first component, a specific liquid crystal compound having a high upper limit temperature or a small viscosity as a second component, a polymerizable compound as a second additive, and a polar compound as a third additive, and a liquid crystal display element containing the composition.

Description

Liquid crystal composition and liquid crystal display element

Technical Field

The present invention relates to a liquid crystal composition, a liquid crystal display element containing the same, and the like. In particular, the present invention relates to a liquid crystal composition and a liquid crystal display device having negative dielectric anisotropy, which contain a polar compound (or a polymer thereof) having a polymerizable group and are capable of achieving vertical alignment of liquid crystal molecules by the action of the compound.

Background

In the liquid crystal display device, the operation modes based on liquid crystal molecules are classified into Phase Change (PC), Twisted Nematic (TN), Super Twisted Nematic (STN), Electrically Controlled Birefringence (ECB), Optically Compensated Bend (OCB), in-plane switching (IPS), Vertical Alignment (VA), Fringe Field Switching (FFS), field-induced photo-reactive alignment (FPA), and the like. The driving methods of the elements are classified into Passive Matrix (PM) and Active Matrix (AM). The PM is classified into a static type (static) and a multiplexing type (multiplex), etc., and the AM is classified into a Thin Film Transistor (TFT), a Metal Insulator Metal (MIM), etc. TFTs are classified into amorphous silicon (amorphous silicon) and polycrystalline silicon (polysilicon). The latter is classified into a high temperature type and a low temperature type according to the manufacturing process. The light source is classified into a reflection type using natural light, a transmission type using a 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 associations between the two properties are summarized in table 1 below. The properties of the composition are further illustrated 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 upper limit temperature of the nematic phase is preferably about 70 ℃ or higher, and the lower limit temperature of the nematic phase is preferably about-10 ℃ or lower. The viscosity of the composition correlates to the response time of the element. In order to display a moving image as an element, the response time is preferably short. Ideally shorter than 1 millisecond of response time. Therefore, it is preferable that the viscosity of the composition is small. Particularly, it is preferable that the viscosity at low temperature is low.

The optical anisotropy of the composition correlates with the contrast of the element. Depending on the mode of the element, a large optical anisotropy or a small optical anisotropy, that is, an appropriate optical anisotropy is required. The product (Δ n × d) of the optical anisotropy (Δ n) 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. The value is in the range of about 0.30 μm to about 0.40 μm in a VA mode element, and in the range of about 0.20 μm to about 0.30 μm in an IPS mode or FFS mode element. In these cases, a composition having a 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 in 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. Preferred are compositions having a large specific resistance after a long period of use. The stability of the composition to ultraviolet light or heat is correlated to the lifetime of the element. When the stability is high, the life of the element is long. Such characteristics are preferable for AM elements used for liquid crystal monitors, liquid crystal televisions, and the like.

In a general-purpose liquid crystal display device, the vertical alignment of liquid crystal molecules can be achieved by using a specific polyimide alignment film. In a liquid crystal display element of a Polymer Sustained Alignment (PSA) type, 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. Then, the composition was irradiated with ultraviolet rays while applying a voltage between the substrates of the element. The polymerizable compound is polymerized to form a network structure of the polymer in the composition. In the composition, the orientation of the liquid crystal molecules can be controlled by the polymer, so that the response time of the element is shortened, and the afterimage of the image is improved. Such effects of the polymer can be expected in devices having modes such as TN, ECB, OCB, IPS, VA, FFS, and FPA.

On the other hand, a liquid crystal composition containing a polymer and a polar compound is used for a liquid crystal display element having no alignment film. First, a composition to which a small amount of a polymerizable compound and a small amount of a polar compound are added is injected into an element. Here, the polar compound is adsorbed to the substrate surface of the element and aligned. The liquid crystal molecules are aligned according to the alignment. Then, the composition was irradiated with ultraviolet rays while applying a voltage between the substrates of the element. Here, the polymerizable compound is polymerized to stabilize the alignment of the liquid crystal molecules. In the composition, the orientation of the liquid crystal molecules can be controlled by the polymer and the polar compound, so that the response time of the element is shortened, and the afterimage of the image is improved. Further, the element having no alignment film does not require a step of forming an alignment film. Since the alignment film is not present, the resistance of the element is not lowered by the interaction between the alignment film and the composition. Such an effect of using a combination of a polymer and a polar compound can be expected in an element having a mode such as TN, ECB, OCB, IPS, VA, FFS, and FPA.

A composition having positive dielectric anisotropy is used for an AM element having a TN mode. A composition having negative dielectric anisotropy is used for an AM element having a VA mode. A composition having positive or negative dielectric anisotropy is used for an AM element having an IPS mode or an FFS mode. A composition having positive or negative dielectric anisotropy is used for a polymer stable alignment type AM device. The composition having positive or negative dielectric anisotropy is used in the element having no alignment film. Compositions having negative dielectric anisotropy are disclosed in the following patent documents 1 to 5 and the like.

[ Prior art documents ]

[ patent document ]

[ patent document 1] International publication No. 2014-090362

[ patent document 2] International publication No. 2014-094959

[ patent document 3] International publication No. 2013-004372

[ patent document 4] Japanese patent laid-open No. 2015-168826

Disclosure of Invention

[ problems to be solved by the invention ]

The problem of the present invention is to provide a liquid crystal composition containing a polar compound (or a polymer thereof) having a polymerizable group, wherein the polar compound has high compatibility with the liquid crystal compound at low temperature. Another problem is to provide a liquid crystal composition capable of achieving vertical alignment of liquid crystal molecules by the action of a polymer generated from the polar compound. Another problem is a liquid crystal composition that satisfies at least one of the characteristics of a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, a low viscosity, an appropriate optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat, and a large elastic constant. Another problem is to provide a liquid crystal composition having an appropriate balance between at least two of these characteristics. Another problem is a liquid crystal display element containing such a composition. Another problem is 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.

[ means for solving problems ]

In the present invention, a polar compound having a polymerizable group (or a polymer thereof) is combined with a liquid crystalline compound, and the composition is used for a polymer-stabilized alignment type liquid crystal display element and a liquid crystal display element having no alignment film. Specifically, the present invention relates to a liquid crystal composition containing at least one compound selected from polymerizable polar compounds represented by formula (1) as a first additive and having a nematic phase and negative dielectric anisotropy, and a liquid crystal display element containing the composition.

Here, R¹The definition of the same symbol is referred to item 1 described later.

[ Effect of the invention ]

An advantage of the present invention is to provide a liquid crystal composition containing a polar compound (or a polymer thereof) having a polymerizable group, wherein the polar compound has high compatibility with a liquid crystal compound at low temperature. Another advantage is to provide a liquid crystal composition capable of achieving vertical alignment of liquid crystal molecules by the action of a polymer generated from the polar compound. Another advantage is a liquid crystal composition that satisfies at least one of the characteristics of a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, a small viscosity, an appropriate optical anisotropy, a large negative dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light, a high stability to heat, and a large elastic constant. Another advantage is to provide a liquid crystal composition having an appropriate balance between at least two of these characteristics. Another advantage is to provide a liquid crystal display element containing such a composition. Still another advantage is to provide an AM element having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, and a long lifetime.

Detailed Description

The usage of the terms in the present specification is as follows. The terms "liquid crystal composition" and "liquid crystal display element" may be simply referred to as "composition" and "element", respectively. The term "liquid crystal display element" is a generic term for liquid crystal display panels and liquid crystal display modules. The "liquid crystalline compound" is a general term for compounds having a liquid crystal phase such as a nematic phase or a smectic phase, and compounds which do not have a liquid crystal phase and are mixed in the composition for the purpose of adjusting characteristics such as a temperature range, viscosity, and dielectric anisotropy of a nematic phase. The compound has a six-membered ring such as 1, 4-cyclohexylene or 1, 4-phenylene, and the molecules (liquid crystal molecules) thereof are rod-like (rod like). The "polymerizable compound" is a compound added for the purpose of forming a polymer in the composition. The liquid crystalline compound having an alkenyl group is not classified into a polymerizable compound in terms of its 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 added to the liquid crystal composition as needed. Even in the case where an 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 percentage (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 proportions of the polymerization initiator and the polymerization inhibitor are exceptionally represented based on the mass of the polymerizable compound.

The "upper limit temperature of the nematic phase" may be simply referred to as "upper limit temperature". The "lower limit temperature of the nematic phase" may be simply referred to as "lower limit temperature". The expression "increase in dielectric anisotropy" means that the value increases positively in a composition having positive dielectric anisotropy, and increases negatively in a composition having negative dielectric anisotropy. The "large voltage holding ratio" means that the device 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 composition or the element are sometimes investigated by time-varying tests.

The compound (1z) is exemplified. In formula (1z), the symbols α and β surrounded by a hexagon correspond to ring α and ring β, respectively, and represent a six-membered ring, a condensed ring, and the like. Where the subscript 'x' is 2, there are two rings α. The two groups represented by the two rings a may be the same or may also be different. The rule applies to any two rings a where subscript 'x' is greater than 2. The rules also apply to other tokens such as the bonding base Z. The slash across one side of the loop β indicates that any hydrogen on the loop β may be substituted with a substituent (-Sp-P). The subscript 'y' indicates the number of substituents substituted. When subscript 'y' is 0, there is no such substitution. When the subscript 'y' is 2 or more, a plurality of substituents (-Sp-P) are present on the ring β. In that case, the rules "may be the same, or may also be different" also apply. Furthermore, the rules also apply to the use of the notation of Ra in a variety of compounds.

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

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

The expression "at least one 'a'" means that the number of 'a's is arbitrary. The expression "at least one 'a' may be substituted with 'B' means that the position of 'a' is arbitrary when the number of 'a' is one, and the position thereof may be selected without limitation when the number of 'a' is two or more. Sometimes using "at least one-CH₂-may be substituted by-O-. In said case, -CH₂-CH₂-CH₂Can pass through non-contiguous-CH₂-conversion to-O-CH by-O-substitution₂-O-. However, there is no adjacencyTo the-CH₂-substituted by-O-. The reason is that: in said substitution-O-CH is formed₂- (peroxides).

The alkyl group of the liquid crystalline compound is linear or branched and does not include a cyclic alkyl group. Straight chain alkyls are preferred over branched alkyls. The same applies to terminal groups such as alkoxy groups and alkenyl groups. For the configuration (configuration) related to 1, 4-cyclohexylene, the trans configuration is preferred over the cis configuration in order to increase the upper limit temperature. Since 2-fluoro-1, 4-phenylene is asymmetric in the left-right direction, it is present in the left (L) and right (R) directions.

The same applies to divalent radicals such as tetrahydropyran-2, 5-diyl. The same applies to a bonding group (-COO-or-OCO-) such as carbonyloxy.

The present invention is as follows.

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

In the formula (1), the reaction mixture is,

R¹is hydrogen or alkyl with 1 to 15 carbon atoms, in which at least one-CH₂-may be substituted by-O-or-S-, at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

ring A¹And ring A²Is 1, 4-cyclohexylene group, 1, 4-cyclohexenylene group, 1, 4-phenylene group, naphthalene-2, 6-diyl group, tetrahydropyran-2, 5-diyl group, 1, 3-dioxane-2, 5-diyl group, pyrimidine-2, 5-diyl group or pyridine-2, 5-diyl group, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having a carbon number of 1 to 10, an alkenyl group having a carbon number of 2 to 10, an alkoxy group having a carbon number of 1 to 10 or an alkenyloxy group having a carbon number of 2 to 10,of these groups, at least one hydrogen may be substituted by fluorine or chlorine;

a is 0, 1,2, 3 or 4;

Z¹is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

Sp¹、Sp²and Sp³Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

M¹、M²、M³and M⁴Hydrogen, fluorine, chlorine, 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;

R²is hydrogen, a group represented by the formula (1-a) or an alkyl group having 1 to 10 carbon atoms, wherein at least one-CH group is present in the alkyl group₂-may be substituted by-O-at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine, R³Is a group represented by the formula (1-a);

in the formula (1-a),

Sp⁴is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

R⁴is hydrogen or alkyl of 1 to 10 carbon atoms, R⁵Is an alkyl group having 1 to 10 carbon atoms.

Item 2. the liquid crystal composition according to item 1, which contains at least one compound selected from the polymerizable polar compounds represented by formulae (1-1) to (1-12) as a first additive.

In the formulae (1-1) to (1-12),

R¹an alkyl group having 1 to 10 carbon atoms;

Z¹¹and Z¹²Is a single bond or-CH₂CH₂-；

Y¹、Y²、Y³、Y⁴、Y⁵And Y⁶Is hydrogen, fluorine, methyl or ethyl;

Sp¹is a single bond or an alkylene group having 1 to 5 carbon atoms, in which at least one-CH group₂-may be substituted by-O-.

Item 3. the liquid crystal composition according to item 1 or item 2, wherein the proportion of the first additive is in a range of 0.1 to 10% by mass.

Item 4. the liquid crystal composition according to any one of item 1 to item 3, which contains at least one compound selected from the compounds represented by formula (2) as a first component.

In the formula (2), R⁷And R⁸Is hydrogen, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, alkenyloxy group having 2 to 12 carbon atoms, or alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring B and ring D are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2,6-diyl, or chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring C is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, 7, 8-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl, 4, 6-difluorodibenzofuran-3, 7-diyl, 4, 6-difluorodibenzothiophene-3, 7-diyl, or 1,1,6, 7-tetrafluoroindan-2, 5-diyl; z²And Z³Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; b is 0, 1,2 or 3, c is 0 or 1, and the sum of b and c is 3 or less.

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

In the formulae (2-1) to (2-35), R⁷And R⁸Is hydrogen, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, alkenyloxy group having 2 to 12 carbon atoms, or alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine.

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

Item 7. the liquid crystal composition according to any one of item 1 to item 6, which contains at least one compound selected from the compounds represented by formula (3) as a second component.

In the formula (3), R⁹And R¹⁰Is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine; ring E and ring F are 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene or 2, 5-difluoro-1, 4-phenylene; z⁴Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; d is 1,2 or 3.

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

In formulae (3-1) to (3-13), R⁹And R¹⁰Is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine.

Item 9. the liquid crystal composition of item 7 or 8, wherein the proportion of the second component is in a range of 10 to 90 mass%.

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

In the formula (4), ring G and ring J are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1, 3-dioxan-2-yl, pyrimidin-2-yl or pyridin-2-yl, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring I is 1, 4-cyclohexylene, 1, 4-cyclohexenylene1, 4-phenylene, naphthalene-1, 2-diyl, naphthalene-1, 3-diyl, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl, naphthalene-1, 7-diyl, naphthalene-1, 8-diyl, naphthalene-2, 3-diyl, naphthalene-2, 6-diyl, naphthalene-2, 7-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; z⁵And Z⁶Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂May be substituted by-O-, -CO-, -COO-or-OCO-, and at least one-CH₂CH₂-may be via-CH ═ CH-, -C (CH)₃)＝CH-、-CH＝C(CH₃) -or-C (CH)₃)＝C(CH₃) -substituted, at least one hydrogen being substituted by fluorine or chlorine; p¹、P²And P³Is a polymerizable group; sp⁷、Sp⁸And Sp⁹Is a single bond or alkylene with 1 to 10 carbon atoms, and Sp⁷、Sp⁸And Sp⁹In (1), at least one-CH₂May be substituted by-O-, -COO-, -OCO-or-OCOO-, and at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro; h 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 of item 10, wherein, in formula (4), P¹、P²And P³Is a group selected from the polymerizable groups represented by the formulae (P-1) to (P-5).

In the formulae (P-1) to (P-5), M⁷、M⁸And M⁹Is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine.

Item 12. the liquid crystal composition according to any one of items 1 to 11, which contains at least one compound selected from polymerizable compounds represented by formulae (4-1) to (4-29) as a second additive.

In formulae (4-1) to (4-29), Sp⁷、Sp⁸And Sp⁹Is a single bond or alkylene with 1 to 10 carbon atoms, and Sp⁷、Sp⁸And Sp⁹In (1), at least one-CH₂May be substituted by-O-, -COO-, -OCO-or-OCOO-, and at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro; p¹、P²And P³Is a group selected from the polymerizable groups represented by the formulae (P-1) to (P-3),

in the formulae (P-1) to (P-3), M⁷、M⁸And M⁹Is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine.

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

Item 14. the liquid crystal composition according to any one of item 1 to item 13, which contains at least one compound selected from polymerizable polar compounds represented by formulae (5-1) to (5-3) as a third additive.

In the formulae (5-1) to (5-3),

R⁵⁰is hydrogen, fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine;

R⁵¹is-OH, -NH₂、-OR⁵³、-N(R⁵³)₂or-Si (R)⁵³)₃The radicals represented, herein, R⁵³Is hydrogen or alkyl with 1 to 5 carbon atoms, in which at least one-CH₂-may be substituted by-O-at least one-CH₂CH₂-may be substituted by-CH ═ CH-, where at least one hydrogen may be substituted by fluorine;

R⁵²is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, at least one hydrogen may be substituted by fluorine or chlorine;

ring A⁵⁰And ring B⁵⁰Is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, in which at least one hydrogen may be substituted by fluorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted by fluorine;

Z⁵⁰is a single bond, -CH₂CH₂-、-CH＝CH-、-C≡C-、-COO-、-OCO-、-CF₂O-、-OCF₂-、-CH₂O-、-OCH₂-or-CF ═ CF —;

Sp⁵¹、Sp⁵²、Sp⁵³and Sp⁵⁴Is a single bond or a linear alkylene group having 1 to 7 carbon atoms, wherein at least one-CH group is present in the alkylene group₂-may be substituted by-O-, -COO-or-OCO-, at least one-CH₂CH₂-may be substituted by-CH ═ CH-, where at least one hydrogen may be substituted by fluorine;

a⁵⁰is 0, 1,2, 3 or 4;

a⁵¹is 1 or 2;

l is 0, 1,2, 3,4,5 or 6, at least one-CH of said alkylene group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine.

Item 15 the liquid crystal composition of item 14, wherein a proportion of the third additive is in a range of 0.05 to 10 mass%.

Item 16. a liquid crystal display element containing the liquid crystal composition according to any one of items 1 to 15.

The liquid crystal display device of item 17, wherein the liquid crystal display device operates in an IPS mode, a VA mode, an FFS mode, or an FPA mode, and the liquid crystal display device is driven in an active matrix mode.

Item 18. a polymer-stabilized alignment type liquid crystal display element, comprising the liquid crystal composition according to any one of items 1 to 15, and at least one compound selected from the group consisting of the first additive, the second additive, and the third additive in the liquid crystal composition is polymerized.

Item 19. A liquid crystal display element having no alignment film, which comprises the liquid crystal composition according to any one of items 1 to 15, and at least one compound selected from the group consisting of the first additive, the second additive, and the third additive in the liquid crystal composition is polymerized.

Item 20. use of a liquid crystal composition according to any one of items 1 to 15 in a liquid crystal display element.

Item 21. use of a liquid crystal composition according to any one of items 1 to 15 in a liquid crystal display element of a polymer stabilized alignment type.

Item 22. use of a liquid crystal composition according to any one of items 1 to 15 in a liquid crystal display element having no alignment film.

The present invention also includes the following items. (a) A method for manufacturing a liquid crystal display element, comprising disposing the liquid crystal composition between two substrates, and irradiating the composition with light in a state where a voltage is applied to the composition to polymerize a polar compound having a polymerizable group contained in the composition. (b) The liquid crystal composition has an upper limit temperature of a nematic phase of 70 ℃ or higher, an optical anisotropy at a wavelength of 589nm (measured at 25 ℃) of 0.08 or higher, and a dielectric anisotropy at a frequency of 1kHz (measured at 25 ℃) of-2 or lower.

The present invention also includes the following items. (c) The composition contains at least one compound selected from the group consisting of compounds (5) to (7) described in Japanese patent laid-open No. 2006-199941, which are liquid-crystalline compounds having positive dielectric anisotropy. (d) The composition contains at least two compounds selected from the polar compounds (1). (e) The composition further contains a polar compound different from the polar compound (1). (f) The composition contains additives such as one, two or at least three kinds of optically active compounds, an antioxidant, an ultraviolet absorber, a delustering agent, a coloring matter, an antifoaming agent, a polymerizable compound different from the polymerizable compound (4), a polymerization initiator, and a polymerization inhibitor. (g) An AM element comprising the composition. (h) An element comprising the composition and having a TN mode, an ECB mode, an OCB mode, an IPS mode, an FFS mode, a VA mode, or an FPA mode. (i) A permeable element comprising the composition. (j) The composition is used as a composition having a nematic phase. (k) A composition prepared by adding an optically active compound to the composition is used as an optically active composition.

The composition of the present invention is illustrated in the following order. First, the composition is explained. Secondly, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. Third, the combination of the components in the composition, the preferred proportions of the components, and their basis are described. Fourth, preferred embodiments of the component compounds will be described. Fifth, preferred component compounds are shown. Sixth, additives that can be added to the composition will be described. Seventh, a method for synthesizing the component compound will be explained. Finally, the use of the composition is illustrated.

First, the composition is explained. The composition contains a plurality of liquid crystalline compounds. The composition may also contain additives. The additive is an optically active compound, an antioxidant, an ultraviolet absorber, a matting agent, a coloring matter, an antifoaming agent, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, a polar compound, or the like. From the viewpoint of the liquid crystalline compound, the compositions are classified into composition a and 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 compounds (2) and (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 substantially contains only a liquid crystalline compound selected from the compound (2) and the compound (3). "substantially" means that the composition B may contain additives but does not contain other liquid crystalline compounds. The amount of component compounds of composition B is lower compared to composition a. From the viewpoint of cost reduction, composition B is superior to composition a. From the viewpoint that the characteristics can be further adjusted by mixing other liquid crystalline compounds, the composition a is superior to the composition B.

Secondly, the main characteristics of the component compounds and the main effects of the compounds on the characteristics of the composition will be described. The main properties of the component compounds are summarized in Table 2. In the notation of Table 2, L means large or high, M means medium, and S means small or low. The notation L, M, S is a classification based on qualitative comparisons between component compounds, with notation 0 (zero) meaning less than S (small).

TABLE 2 characterization of the Compounds

Compound (I)	(2)	(3)
			Upper limit temperature	S～L	S～L
Viscosity of the oil	M～L	S～M
			Optical anisotropy	M～L	S～L
Dielectric anisotropy	M～L¹⁾	0
			Specific resistance	L	L

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

When the component compounds are mixed in the composition, the main effects of the component compounds on the properties of the composition are as follows. The compound (1) is adsorbed on the substrate surface by the action of the polar group, and controls the orientation of the liquid crystal molecules. In order to obtain a desired effect, the compound (1) is required to have high compatibility with the liquid crystalline compound. It is considered that the compound (1) has a six-membered ring such as 1, 4-cyclohexylene or 1, 4-phenylene and has a rod-like molecular structure to improve compatibility, and therefore is most suitable for the purpose. The compound (1) forms a polymer by polymerization. The polymer stabilizes the orientation of liquid crystal molecules, thereby shortening the response time of the element and improving the afterimage of the image. The compound (2) increases the dielectric anisotropy and lowers the lower limit temperature. The compound (3) raises the upper limit temperature or lowers the viscosity. The compound (4) forms a polymer by polymerization. The polymer stabilizes the orientation of liquid crystal molecules, thereby shortening the response time of the element and improving the afterimage of the image. From the viewpoint of alignment of liquid crystal molecules, the polymer of the compound (1) is expected to be more effective than the polymer of the compound (4) because it has an interaction with the substrate surface. The compounds (5-1) to (5-3) are adsorbed on the substrate surface by the action of the polar group in the same manner as the compound (1), and control the alignment of the liquid crystal molecules. The compound (1) can be used together with the compound (1) to improve the orientation and solubility.

Third, the combination of the components in the composition, the preferred proportions of the components, and their basis are described. Preferred combinations of the components in the composition are compound (1) + compound (2), compound (1) + compound (2) + compound (3), compound (1) + compound (2) + compound (4), compound (1) + compound (2) + compound (3) + compound (5-1), compound (1) + compound (2) + compound (3) + compound (5-2), compound (1) + compound (2) + compound (3) + compound (5-3), compound (1) + compound (2) + compound (3) + compound (4) + compound (5-1), compound (1) + compound (2) + compound (3) + compound (4) + compound (5-2), or compound (1) + compound (2) + compound (4) + compound (5-2) & compound (1) + compound (2) + compound (3) + compound (4) + compound (5-2) 3) + Compound (4) + Compound (5-3)

The compound (1), the compound (5-2) or the compound (5-3) is added to the composition for the purpose of controlling the alignment of liquid crystal molecules. The preferable proportion of the compound (1) is about 0.05% by mass or more for aligning liquid crystal molecules, and about 10% by mass or less for preventing display defects of the device. A particularly preferred ratio is in the range of about 0.1% to about 7% by mass. A particularly preferred ratio is in the range of about 0.5% to about 5% by mass. The preferable proportion of the compound (5-1), the compound (5-2) or the compound (5-3) is about 0.03% by mass or more for aligning liquid crystal molecules, and the preferable proportion of the compound (5-1), the compound (5-2) or the compound (5-3) is about 10% by mass or less for preventing display defects of the element. A particularly preferred ratio is in the range of about 0.1% to about 7% by mass. A particularly preferred ratio is in the range of about 0.5% to about 5% by mass.

The preferable proportion of the compound (2) is about 10% by mass or more for improving the dielectric anisotropy, and the preferable proportion of the compound (2) is about 90% by mass or less for lowering the lower limit temperature. A particularly preferred ratio is in the range of about 20% to about 85% by mass. A particularly preferred ratio is in the range of about 30% by mass to about 85% by mass.

The preferable proportion of the compound (3) is about 10% by mass or more in order to increase the upper limit temperature or to decrease the viscosity, and the preferable proportion of the compound (3) is about 90% by mass or less in order to increase the dielectric anisotropy. A particularly preferred ratio is in the range of about 15% to about 75% by mass. A particularly preferred ratio is in the range of about 15% to about 60% by mass.

The preferable proportion of the compound (4) is about 0.03 mass% or more in order to improve the long-term reliability of the alignment, and the preferable proportion of the compound (4) is about 10 mass% or less in order to prevent the display failure of the element. A particularly preferred ratio is in the range of about 0.1% to about 2% by mass. A particularly preferred ratio is in the range of about 0.2% to about 1.0% by mass.

Fourth, preferred embodiments of the component compounds will be described. First, two liquid crystalline compounds are summarized and described. Next, the first additive, the third additive (polar compound having a polymerizable group), and the second additive (polymerizable compound) will be described in this order.

(a) Liquid crystalline compound

In the formulae (2) and (3), R⁷And R⁸Is hydrogen, alkyl of 1 to 12 carbon atoms, C1 to 12An alkoxy group, 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. For improved stability, R is preferred⁷Or R⁸Is an alkyl group having 1 to 12 carbon atoms, and R is preferably selected to improve dielectric anisotropy⁷Or R⁸R is an alkoxy group having 1 to 12 carbon atoms, and is preferable for reducing viscosity and lowering threshold voltage⁷Or R⁸Is an alkenyl group having 2 to 12 carbon atoms. R⁹And R¹⁰Is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine. Preferred R for reducing viscosity⁹Or R¹⁰An alkenyl group having 2 to 12 carbon atoms, and R is preferably selected for the purpose of improving stability⁹Or R¹⁰Is an alkyl group having 1 to 12 carbon atoms.

Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. Particularly preferred alkyl groups for reducing the viscosity are ethyl, propyl, butyl, pentyl or heptyl.

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy. Particularly preferred alkoxy groups for reducing viscosity are methoxy or ethoxy.

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. Particularly preferred alkenyl groups for reducing the viscosity are vinyl, 1-propenyl, 3-butenyl or 3-pentenyl. The preferred steric configuration of-CH ═ CH-in these alkenyl groups depends on the position of the double bond. For reasons of viscosity reduction and the like, the trans configuration is preferred among alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl. Among alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl, the cis configuration is preferred.

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

Preferred examples of alkyl groups in which at least one hydrogen is replaced by fluorine or chlorine are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or 8-fluorooctyl. For the purpose of improving the dielectric anisotropy, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl is particularly preferable.

Preferred examples of alkenyl groups in which at least one hydrogen is substituted by fluorine or chlorine are 2, 2-difluorovinyl, 3-difluoro-2-propenyl, 4-difluoro-3-butenyl, 5-difluoro-4-pentenyl or 6, 6-difluoro-5-hexenyl. For the purpose of reducing the viscosity, 2-difluorovinyl or 4, 4-difluoro-3-butenyl is particularly preferable.

Ring B and ring D are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, or chroman-2, 6-diyl in which at least one hydrogen is substituted 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. The ring B or D is preferably a1, 4-cyclohexylene group for lowering the viscosity, a tetrahydropyran-2, 5-diyl group for improving the dielectric anisotropy, and a1, 4-phenylene group for improving the optical anisotropy.

Ring C is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, 7, 8-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl (FLF4), 4, 6-difluorodibenzofuran-3, 7-diyl (DBTF2), 4, 6-difluorodibenzothiophene-3, 7-diyl (DBTF2), or 1,1,6, 7-tetrafluoroindan-2, 5-diyl (InF 4).

In order to improve the dielectric anisotropy, the preferable ring C is 2, 3-difluoro-1, 4-phenylene.

Ring E and ring F are 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene or 2, 5-difluoro-1, 4-phenylene. For lowering the viscosity or for increasing the upper temperature limit, the preferred ring E or ring F is 1, 4-cyclohexylene, and for lowering the lower temperature limit, the preferred ring E or ring F is 1, 4-phenylene.

Z²And Z³Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy. For reducing the viscosity, preferred is Z²Or Z³Is a single bond, and Z is preferably a bond for improving dielectric anisotropy²Or Z³Is methyleneoxy. Z⁴Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy. For reducing the viscosity, preferred is Z⁴Is a single bond.

b is 1,2 or 3, c is 0 or 1, and the sum of b and c is 3 or less. For lowering the viscosity, b is preferably 1, and for raising the upper limit temperature, b is preferably 2 or 3. For lowering the viscosity, c is preferably 0, and for lowering the lower limit temperature, c is preferably 1. d is 1,2 or 3. For lowering the viscosity, d is preferably 1, and for raising the upper limit temperature, d is preferably 2 or 3.

(b) A first additive and a third additive

The compound (1) is preferably stable to ultraviolet light or heat. When the compound (1) is added to the composition, the compound preferably does not lower the voltage holding ratio of the device. The compound (1) preferably has low volatility. The preferred molar mass is 130g/mol or more. Particularly preferred molar masses are in the range from 150g/mol to 700 g/mol. Preferred compound (1) has an acryloyloxy group (-OCO-CH ═ CH)₂) Methacryloxy (-OCO- (CH))₃)C＝CH₂) Such as a polymerizable group.

R¹Is hydrogen or alkyl with 1 to 10 carbon atoms, in which at least one-CH₂-may be substituted by-O-or-S-, at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred R¹Is hydrogen, alkyl with 1 to 5 carbon atoms, alkoxy with 1 to 5 carbon atoms or alkyl with 1 to 5 carbon atomsAn oxyalkyl group. Especially preferred R¹Is an alkyl group having 1 to 5 carbon atoms. R²Is hydrogen, a group represented by the formula (1-a) or an alkyl group having 1 to 10 carbon atoms, wherein at least one-CH group is present in the alkyl group₂-may be substituted by-O-at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred R²Hydrogen or an alkyl group having 1 to 5 carbon atoms. Especially preferred R²Is an alkyl group having 1 to 5 carbon atoms. R³Is a group represented by the formula (1-a).

In the formula (1-a), Sp⁴Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. R⁴Is hydrogen or alkyl of 1 to 10 carbon atoms, R⁵Is an alkyl group having 1 to 10 carbon atoms. Preferred R⁴Is hydrogen or alkyl of 1 to 5 carbon atoms, preferably R⁵Is an alkyl group having 1 to 5 carbon atoms. Sp⁴Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred is Sp⁴Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-.

Ring A¹And ring A²Is 1, 4-cyclohexylene group, 1, 4-cyclohexenylene group, 1, 4-phenylene group, naphthalene-2, 6-diyl group, tetrahydropyran-2, 5-diyl group, 1, 3-dioxane-2, 5-diyl group, pyrimidine-2, 5-diyl group or pyridine-2, 5-diyl group, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having a carbon number of 1 to 10, an alkenyl group having a carbon number of 2 to 10, an alkoxy group having a carbon number of 1 to 10 or an alkenyloxy group having a carbon number of 2 to 10, and in these groups, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having a carbon number of 1 to 10, an alkenyl group havingFluorine or chlorine. Preferred ring A¹Or ring A²Is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl or 3-ethyl-1, 4-phenylene, and in these rings, at least one hydrogen may be substituted with fluorine, an alkyl group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms or an alkoxy group having 1 to 7 carbon atoms. Particularly preferred ring A¹Or ring A²Is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, naphthalene-2, 6-diyl or 3-ethyl-1, 4-phenylene.

Z¹Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred Z¹Is a single bond, -CH₂CH₂-、-(CH₂)₄-、-CH＝CH-、-C≡C-、-COO-、-OCO-、-CF₂O-、-OCF₂-、-CH₂O-、-OCH₂-or-CF ═ CF-. Particularly preferred Z¹Is a single bond or-CH₂CH₂-。

Sp¹、Sp²And Sp³Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂At least one-CH which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-)₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred is Sp¹、Sp²And Sp³Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂-may be substituted by-O-at least one-CH₂CH₂-may be substituted by-CH ═ CH-. Particularly preferred is Sp¹、Sp²And Sp³Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which at least one-CH group₂-may be substituted by-O-.

M¹、M²、M³And M⁴Hydrogen, fluorine, chlorine, 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. Preferred M¹、M²、M³And M⁴Hydrogen or an alkyl group having 1 to 3 carbon atoms.

a is 0, 1,2, 3 or 4. Preferably a is 1,2 or 3.

In formulae (1-1) to (1-12), Y¹、Y²、Y³、Y⁴、Y⁵And Y⁶Is hydrogen, fluorine, methyl or ethyl.

In the formulae (5-1), (5-2) and (5-3), R⁵⁰Is hydrogen, fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms wherein at least one hydrogen is substituted with fluorine. Preferred R⁵⁰Is an alkyl group having 1 to 10 carbon atoms. R⁵¹is-OH, -NH₂、-OR⁵³、-N(R⁵³)₂or-Si (R)⁵³)₃The radicals represented, herein, R⁵³Is hydrogen or alkyl with 1 to 5 carbon atoms, in which at least one-CH₂-may be substituted by-O-at least one-CH₂CH₂-may be substituted by-CH ═ CH-, where at least one hydrogen may be substituted by fluorine. From the viewpoint of high solubility in the liquid crystal composition, R⁵¹preferably-OH or-NH₂。R⁵²Is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine.

Ring A⁵⁰And ring B⁵⁰Is 1, 4-cyclohexylene group, 1, 4-cyclohexenylene group, 1, 4-phenylene group, naphthalene-2, 6-diyl group, tetrahydropyran-2, 5-diyl group, 1, 3-dioxane-2, 5-diyl group, pyrimidine-2, 5-diyl group or pyridine-2, 5-diyl group, and in these rings, at least one hydrogen may be substituted with fluorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine.

Z⁵⁰Is a single bond, -CH₂CH₂-、-CH＝CH-、-C≡C-、-COO-、-OCO-、-CF₂O-、-OCF₂-、-CH₂O-、-OCH₂-or-CF ═ CF-. Particularly preferred Z⁵⁰Is a single bond.

Sp⁵¹、Sp⁵²、Sp⁵³And Sp⁵⁴Is a single bond or an alkylene group having 1 to 7 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -COO-or-OCO-, at least one-CH₂CH₂-may be substituted by-CH ═ CH-, where at least one hydrogen may be substituted by fluorine. Preferred is Sp⁵¹、Sp⁵²、Sp⁵³And Sp⁵⁴Is a single bond or alkylene having 1 to 7 carbon atoms.

a⁵⁰Is 0, 1,2, 3 or 4, preferably 1 or 2.

(c) Second additive

In the formula (4), the ring G and the ring J are a cyclohexyl group, a cyclohexenyl group, a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a tetrahydropyran-2-yl group, a1, 3-dioxan-2-yl group, a pyrimidin-2-yl group or a pyridin-2-yl group, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. Preferred ring G or ring J is phenyl. Ring I is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-1, 2-diyl, naphthalene-1, 3-diyl, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl, naphthalene-1, 7-diyl, naphthalene-1, 8-diyl, naphthalene-2, 3-diyl, naphthalene-2, 6-diyl, naphthalene-2, 7-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, in which at least one hydrogen atom may be replaced by fluorine, chlorine, an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, Or at least one hydrogen is substituted with a fluorine or chlorine substituted alkyl group having 1 to 12 carbon atoms. Preferred ring I is 1, 4-phenylene or 2-fluoro-1, 4-phenylene.

Z⁵And Z⁶Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂May be substituted by-O-, -CO-, -COO-or-OCO-, and at least one-CH₂CH₂-may be via-CH ═ CH-, -C (CH)₃)＝CH-、-CH＝C(CH₃) -or-C (CH)₃)＝C(CH₃) -substitution, of which at least one hydrogen may be substituted by fluorine or chlorine. Preferred Z⁵Or Z⁶Is a single bond, -CH₂CH₂-、-CH₂O-、-OCH₂-, -COO-or-OCO-. Particularly preferred Z⁵Or Z⁶Is a single bond.

P¹、P²And P³Is a polymerizable group. Preferred P¹、P²Or P³Is a polymerizable group selected from the group of groups represented by the formulae (P-1) to (P-5). Especially preferred P¹、P²Or P³Is a group represented by the formula (P-1), the formula (P-2) or the formula (P-3). Particularly preferred P¹、P²Or P³Is a group represented by the formula (P-1) or (P-2). Most preferred P¹、P²Or P³Is a group represented by the formula (P-1). A preferred group represented by formula (P-1) is-OCO-CH ═ CH₂or-OCO-C (CH)₃)＝CH₂. The wavy lines of the formulae (P-1) to (P-5) represent the sites of bonding.

In the formulae (P-1) to (P-5), M⁷、M⁸And M⁹Is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine. For the purpose of enhancing reactivity, M is preferred⁷、M⁸Or M⁹Is hydrogen or methyl. Particularly preferred M⁷Is hydrogen or methyl, and particularly preferred M⁸Or M⁹Is hydrogen.

Sp⁷、Sp⁸And Sp⁹Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂May be substituted by-O-, -COO-, -OCO-or-OCOO-, and at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine. Preferred is Sp⁷、Sp⁸Or Sp⁹Is a single bond, -CH₂CH₂-、-CH₂O-、-OCH₂-, -COO-, -OCO-, -CO-CH-or-CH-CO-. Particularly preferred is Sp⁷、Sp⁸Or Sp⁹Is a single bond.

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

Fifth, preferred component compounds are shown. Preferred compound (1) is the compound (1-1) to the compound (1-12) described in the item 2. Of these compounds, it is preferable that at least one of the first additives is the compound (1-1), the compound (1-2), the compound (1-4), the compound (1-5), the compound (1-7), the compound (1-8), the compound (1-10), or the compound (1-11). Preferably, at least two of the first additives are a combination selected from the group consisting of the compound (1-2), the compound (1-3), the compound (1-5), the compound (1-6), the compound (1-8), the compound (1-9), the compound (1-11), and the compound (1-12).

Preferred compound (2) is the compound (2-1) to the compound (2-35) described in the item 5. Of these compounds, it is preferable that at least one of the first components is compound (2-1), compound (2-2), compound (2-3), compound (2-6), compound (2-7), compound (2-8), compound (2-9), compound (2-10), compound (2-13), compound (2-14) or compound (2-18). Preferably, the first component contains at least two of the compounds (2-1 and 2-8), the compounds (2-1 and 2-14), the compounds (2-3 and 2-8), the compounds (2-3 and 2-10), the compounds (2-3 and 2-14), the compounds (2-6 and 2-8), the compounds (2-6 and 2-10), the compounds (2-6 and 2-18), the compounds (2-7 and 2-8), the compounds (2-7 and 2-9), the compounds (2-7 and 2-10), the compounds (2-7 and 2-14) or the compounds (2-10) and their derivatives Combinations of compounds (2-14).

Preferred compound (3) is the compound (3-1) to the compound (3-13) described in the item 8. Of these compounds, it is preferable that at least one of the second components is compound (3-1), compound (3-2), compound (3-3), compound (3-5), compound (3-6), compound (3-8) or compound (3-9). Preferably, at least two of the second components 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 compound (4) is the compound (4-1) to the compound (4-29) described in the item 12. Of these compounds, it is preferable that at least one of the second additives is the compound (4-1), the compound (4-2), the compound (4-24), the compound (4-25), the compound (4-26), the compound (4-27), or the compound (4-29). Preferably, at least two of the second additives are a combination of the compound (4-1) and the compound (4-2), the compound (4-1) and the compound (4-18), the compound (4-2) and the compound (4-24), the compound (4-2) and the compound (4-25), the compound (4-2) and the compound (4-26), the compound (4-25) and the compound (4-26), or the compound (4-18) and the compound (4-24).

Sixth, an additive other than the first additive that can be added to the composition will be described. Such additives include optically active compounds, antioxidants, ultraviolet absorbers, delustering agents, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, and the like. An optically active compound is added to the composition for the purpose of inducing a helical structure of liquid crystal molecules to impart a twist angle (torsionangle). Examples of such compounds are compound (6-1) to compound (6-5). The preferable proportion of the optically active compound is about 5% by mass or less. A particularly preferred ratio is in the range of about 0.01% to about 2% by mass.

An antioxidant is added to the composition in order to prevent a decrease in specific resistance caused by heating in the atmosphere or to maintain a large voltage holding ratio at room temperature and at a temperature close to the upper limit temperature even after the device is used for a long time. Preferable examples of the antioxidant are compound (7-1) to compound (7-3) and the like.

Since the compound (7-2) has low volatility, it is effective for maintaining a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after the device is used for a long time. In order to obtain the above effect, the preferable ratio of the antioxidant is about 50ppm or more, and in order not to lower the upper limit temperature or to raise the lower limit temperature, the preferable ratio of the antioxidant is about 600ppm or less. Particularly preferred ratios are in the range of about 100ppm to about 300 ppm.

Preferable examples of the ultraviolet absorber include benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Light stabilizers such as sterically hindered amines are also preferred. Preferable examples of the light stabilizer are compound (8-1) to compound (8-16) and the like. The preferable proportion of these absorbents or stabilizers is about 50ppm or more in order to obtain the above effects, and about 10000ppm or less in order not to lower the upper limit temperature or not to raise the lower limit temperature. Particularly preferred ratios range from about 100ppm to about 10000 ppm.

The matting agent is a compound that receives light energy absorbed by the liquid crystalline compound and converts the light energy into thermal energy to prevent decomposition of the liquid crystalline compound. Preferable examples of the matting agent are a compound (9-1) to a compound (9-7) and the like. The preferable proportion of these matting agents is about 50ppm or more in order to obtain the above effects, and about 20000ppm or less in order not to raise the lower limit temperature. Particularly preferred ratios range from about 100ppm to about 10000 ppm.

In order to be suitable for a guest-host (GH) mode element, a dichroic dye (dichromatic dye) such as an azo dye or an anthraquinone dye is added to the composition. The preferable ratio of the pigment ranges from about 0.01% by mass to about 10% by mass.

In order to prevent bubbling, an antifoaming agent such as dimethylsilicone oil or methylphenylsilicone oil is added to the composition. The preferable ratio of the defoaming agent is about 1ppm or more in order to obtain the above effects, and about 1000ppm or less in order to prevent display failure. Particularly preferred ratios are in the range of about 1ppm to about 500 ppm.

Polymerizable compounds are used to adapt to polymer-stabilized alignment (PSA) type devices. The compound (1), the compound (4), the compound (5-1), the compound (5-2) and the compound (5-3) are suitable for the purpose. The compound (1), the compound (4), the compound (5-1), the compound (5-2), the compound (5-3), and another polymerizable compound other than the compound (1), the compound (4), the compound (5-1), the compound (5-2), and the compound (5-3) may be added to the composition. Preferable examples of such polymerizable compounds are compounds such as acrylic acid esters, methacrylic acid esters, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (oxetane ) and vinyl ketones. Particularly preferred examples are acrylates or methacrylates. The reactivity of the polymerizable compound and the pretilt angle of the liquid crystal molecules can be adjusted by changing the types of the compound (1), the compound (4), the compound (5-1), the compound (5-2), and the compound (5-3) or by combining other polymerizable compounds with the compound (1), the compound (4), the compound (5-1), the compound (5-2), and the compound (5-3) at an appropriate ratio. By optimizing the pretilt angle, a short response time of the element can be achieved. Since the alignment of the liquid crystal molecules is stabilized, a large contrast ratio or a long lifetime can be achieved.

The polymerizable compound is polymerized by ultraviolet irradiation. The polymerization may be carried out in the presence of an appropriate initiator such as a photopolymerization initiator. Suitable conditions for carrying out the polymerization, suitable types of initiators, and suitable amounts are known to those skilled in the art and are described in the literature. For example, brilliant good solid (Irgacure)651 (registered trademark; Basf), brilliant good solid (Irgacure)184 (registered trademark; Basf), or Delocur (Darocur)1173 (registered trademark; Basf) as a photopolymerization initiator is suitable for radical polymerization. The preferable proportion of the photopolymerization initiator ranges from about 0.1% by mass to about 5% by mass based on the mass of the polymerizable compound. A particularly preferred ratio is in the range of about 1% to about 3% by mass.

In order to prevent polymerization, a polymerization inhibitor may be added during storage of the polymerizable compound. 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-t-butyl catechol, 4-methoxyphenol, phenothiazine and the like.

The polar compound is an organic compound having polarity. Here, a compound having an ionic bond is not included. Atoms such as oxygen, sulfur and nitrogen are negatively charged and tend to have a partial negative charge. Carbon and hydrogen are neutral or tend to have a partial positive charge. Polarity arises because part of the charge is distributed unequally among the atoms of different species in the compound. For example, the polar compound has-OH, -COOH, -SH, -NH₂、>NH、>N-, or the like.

Seventh, a method for synthesizing the component compound will be explained. These compounds can be synthesized using known methods. A synthesis method is exemplified. The synthesis method of the compound (1) is described in the section of examples. The compound (2-1) is synthesized by the method described in Japanese patent laid-open No. Hei 2-503441. The compound (3-5) is synthesized by the method described in Japanese patent laid-open No. 57-165328. The compound (4-18) is synthesized by the method described in Japanese patent laid-open No. Hei 7-101900. Compound (7-1) is available from Sigma Aldrich (Sigma-Aldrich corporation). The compound (7-2) and the like were 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 method described in the following protocol: organic Synthesis (Organic Syntheses, John Wiley parent publishing company (Sons, Inc.), "Organic Reactions (Organic Reactions, John Wiley parent publishing company (John Wiley & Sons, Inc.)," Comprehensive Organic Synthesis (pegman publishing company (Pergamon Press)), new experimental chemistry lecture (pill-good)), and the like. The compositions are prepared from the compounds obtained in the manner described, using known methods. For example, the component compounds are mixed and then dissolved in each other by heating.

Finally, the use of the composition is illustrated. Most compositions have 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. A composition having an optical anisotropy in the range of about 0.08 to about 0.25 may be prepared by controlling the ratio of the component compounds, or by mixing other liquid crystalline compounds. Further, a composition having an optical anisotropy in the range of about 0.10 to about 0.30 may also be prepared by trial and error. The device containing the composition has a large voltage holding ratio. The composition is suitable for AM elements. The composition is particularly suitable for transmissive AM elements. The composition can be used as a composition having a nematic phase, and can be used as an optically active composition by adding an optically active compound.

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 modes such as PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA and the like. Particularly preferably for AM elements having TN, OCB, IPS mode or FFS mode. In an AM element having an IPS mode or an FFS mode, the alignment of liquid crystal molecules may be parallel to a glass substrate or may be perpendicular to the glass substrate when no voltage is applied. These elements may be reflective, transmissive or transflective. Preferably for use in transmissive devices. It can also be used for an amorphous silicon-TFT element or a polysilicon-TFT element. The composition may be used for a Nematic Curvilinear Aligned Phase (NCAP) type element prepared by microencapsulation (microencapsulation) or a Polymer Dispersed (PD) type element in which a three-dimensional network polymer is formed in the composition.

An example of a method for producing a polymer-stabilized alignment type device is as follows. An element including two substrates, which are referred to as an array substrate and a color filter substrate, is prepared. The substrate has an alignment film. At least one of the substrates has an electrode layer. The liquid crystal composition is prepared by mixing liquid crystalline compounds. A polymerizable compound is added to the composition. Further additives may be added as required. Injecting the composition into an element. Light irradiation is performed in a state where a voltage is applied to the element. Ultraviolet rays are preferred. The polymerizable compound is polymerized by light irradiation. A composition containing a polymer is produced by the polymerization. The polymer stable alignment type element is manufactured in the order as described above.

In the above procedure, when a voltage is applied, the liquid crystal molecules are aligned by the action of the alignment film and the electric field. Depending on the orientation, the molecules of the polymerizable compound are also oriented. Since the polymerizable compound is polymerized by ultraviolet rays in the above state, a polymer maintaining the above orientation is produced. By the effect of the polymer, the response time of the element is shortened. Since the afterimage of the image is a poor operation of the liquid crystal molecules, the afterimage is also improved by the effect of the polymer. Further, the polymerizable compound in the composition may be polymerized in advance, and the composition may be disposed between substrates of the liquid crystal display element.

When a polar compound having a polymerizable group (i.e., a polymerizable compound) such as the compound (1), the compound (5-2), or the compound (5-3) is used, an alignment film is not required on the substrate of the element. The element without the alignment film is manufactured from the substrate without the alignment film according to the order described in the first two paragraphs.

In the order, the compound (1), the compound (5-2) and the compound (5-3) are arranged on the substrate due to the interaction of the polar group with the substrate surface. The liquid crystal molecules are aligned according to the alignment. When a voltage is applied, the alignment of the liquid crystal molecules is further promoted. Since the polymerizable group is polymerized by ultraviolet rays in the above state, a polymer in which the above orientation is maintained is produced. The polymer has an effect of additionally stabilizing the orientation of liquid crystal molecules, thereby shortening the response time of the device. Since the afterimage of the image is a poor operation of the liquid crystal molecules, the afterimage is also improved by the effect of the polymer.

[ examples ]

The present invention will be further described in detail by way of examples. The present invention is not limited by these examples. The present invention comprises mixtures of composition M1 with composition M2. The invention also includes mixtures of at least two of the compositions of the examples. The synthesized compound is identified by Nuclear Magnetic Resonance (NMR) analysis or the like. The properties of the compounds, compositions and devices were measured by the following methods.

NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for the measurement.¹In the measurement of H-NMR, a sample was dissolved in CDCl₃The measurement was performed in the deuterated solvent at room temperature under conditions of 500MHz and 16 cumulative times. Tetramethylsilane was used as an internal standard.¹⁹In the measurement of F-NMR, CFCl was used₃As an internal standard, the number of times is accumulated to 24 times. In the description of the nmr spectra, s is a singlet (singlet), d is a doublet (doublt), t is a triplet (triplet), q is a quartet (quatet), quin is a quintet (quintet), sex is a sextant (sextet), m is a multiplet (multiplet), and br is a broad (broad).

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

As a solvent for diluting the sample, chloroform, hexane, etc. can be used. To separate the constituent compounds, the following capillary column may be used. HP-1 (length 30m, inner diameter 0.32mm, film thickness 0.25 μm) manufactured by Agilent Technologies Inc., Rtx-1 (length 30m, inner diameter 0.32mm, film thickness 0.25 μm) manufactured by Rasteck Corporation, BP-1 (length 30m, inner diameter 0.32mm, film thickness 0.25 μm) manufactured by Australian SGE International Pty.Ltd. For the purpose of preventing overlapping of compound peaks, capillary columns manufactured by Shimadzu corporation CBP1-M50-025 (length 50M, inner diameter 0.25mm, film thickness 0.25 μ M) were used.

The ratio 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 (% by mass) of the liquid crystalline compound can be calculated from the area ratio of the peak.

Measurement of the sample: when the characteristics of the composition and the element were measured, the composition was used as a sample as it is. In order to measure the characteristics of the compound, a sample for measurement was prepared by mixing the compound (15 mass%) in a mother liquid crystal (85 mass%). From the values obtained by the measurement, the characteristic values of the compounds were calculated by an extrapolation method (extrapolation method). (extrapolated value) { (measured value of sample) — 0.85 × (measured value of mother liquid crystal) }/0.15. When the smectic phase (or crystals) precipitates at 25 ℃ at the ratio, the ratio of the compound to the mother liquid crystal is set at 10 mass%: 90% by mass and 5% by mass: 95% by mass and 1% by mass: the order of 99 mass% was changed. The values of the upper limit temperature, optical anisotropy, viscosity and dielectric anisotropy relating to the compound were determined by the extrapolation method.

The following mother liquid crystal was used. The proportion of the component compounds is represented by mass%.

The determination method comprises the following steps: the characteristics were measured by the following methods. These methods are mostly described in JEITA standard (JEITA. ED-2521B) examined and established by the Japan electronic Information Technology Industries Association (JEITA), or modified. The TN element used for the measurement was not provided with a Thin Film Transistor (TFT).

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

(2) Lower limit temperature (T) of nematic phase_C(ii) a C): the nematic phase was observed after the sample was placed in a glass bottle and kept in a freezer at 0 ℃, -10 ℃, -20 ℃, -30 ℃ and-40 ℃ for 10 days. For example, when the sample is kept in a nematic phase at-20 ℃ and changed to a crystalline or smectic phase at-30 ℃, T is set_CIs described as<-20 ℃. The lower limit temperature of the nematic phase may be simply referred to as "lower limit temperature".

(3) Viscosity (. eta.; measured at 20 ℃ C.; mPas): for the measurement, an E-type rotational viscometer manufactured by tokyo counter gmbh was used.

(4) Viscosity (rotational viscosity; γ 1; measured at 25 ℃; mPas): for the measurement, a rotational viscosity ratio measuring system LCM-2 of Toyo technologies (TOYOCORATION) Co. A VA device having a gap (cell gap) of 10 μm between two glass substrates was used as a sample. A rectangular wave (55V, 1ms) was applied to the element. The peak current (peak current) and peak time (peak time) of the transient current (transient current) generated by the application are measured. These measured values and the dielectric anisotropy are used to obtain values of rotational viscosity. The dielectric anisotropy was measured by the method described in measurement (6).

(5) Optical anisotropy (refractive index anisotropy; Δ n; measured at 25 ℃): the measurement was performed using light having a wavelength of 589nm by an Abbe refractometer having a polarizing plate attached to an eyepiece lens. After rubbing the surface of the main prism in one direction, the sample was dropped onto the main prism. The refractive index n/is measured when the direction of polarization is parallel to the direction of rubbing. The refractive index n ″) is measured when the direction of the polarized light is perpendicular to the direction of the friction. The value of the optical anisotropy is calculated from the formula Δ n ═ n/n ″.

(6) Dielectric anisotropy (. DELTA.; measured at 25 ℃): the value of the dielectric anisotropy is calculated according to the formula Δ ═/. The dielectric constant (//and ≠ was determined as follows.

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

2) Determination of dielectric constant (. DELTA.): the polyimide solution was coated on the well-cleaned glass substrate. After the glass substrate is fired, the obtained alignment film is subjected to rubbing treatment. The sample was injected into a TN cell having a cell gap of 9 μm between two glass substrates and a twist angle of 80 degrees. Sine wave (0.5V, 1kHz) was applied to the element, and the dielectric constant (#) in the short axis direction of the liquid crystal molecules was measured after 2 seconds.

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

(8) Voltage holding ratio (initial VHR; measured at 60;%): the sample was sealed in a VA cell having a glass substrate without an alignment film. The gap between the two glass substrates (cell gap) was 3.5 μm. After the sample is injected, the element is sealed with an adhesive cured with ultraviolet rays. The VA element was charged by applying a pulse voltage (1V, 60 μ sec). The decayed voltage was measured by a high-speed voltmeter over a period of 1667 ms, and the area a between the voltage curve per unit cycle and the horizontal axis was determined. The area B is the area where the voltage is not attenuated. The voltage holding ratio is expressed by a percentage of the area a to the area B.

(9) Voltage holding ratio (UV-VHR; measured at 60;%): after the VA device into which the sample was injected was irradiated with ultraviolet light, the voltage holding ratio was measured to evaluate the stability to ultraviolet light. For measurement, the VA cell using a glass substrate having no alignment film had a gap (cell gap) of 3.5 μm between the two glass substrates. The sample was injected into the cell and 15J of 5 mw light was irradiated using UV2 as the light source. Thereafter, the UV-VHR was assayed under the same assay conditions as the initial VHR. Compositions with large UV-VHRs have a large stability to UV light. The UV-VHR is preferably 90% or more, particularly preferably 95% or more.

(10) Voltage holding ratio (heated VHR; measured at 60;%): after the VA device into which the sample was injected was heated, the voltage holding ratio was measured to evaluate the stability to heat. For measurement, the VA cell using a glass substrate having no alignment film had a gap (cell gap) of 3.5 μm between the two glass substrates. The elements were filled with the sample and heated in a thermostat at 140 ℃ for 1 hour. Thereafter, the heated VHR is measured under the same measurement conditions as the initial VHR. Compositions with large heated VHRs have a large stability to heat. The heating VHR is preferably 90% or more, and particularly preferably 95% or more.

(11) Response time (. tau.; measured at 25 ℃ C.; ms): for measurement, a luminance meter model LCD5100 manufactured by tsukamur electronics gmbh was used. The light source is a halogen lamp. The Low-pass filter (Low-pass filter) is set to 5 kHz. The sample was placed in a VA device having a spacing (cell gap) of 3.5 μm between two glass substrates and no alignment film. The element is sealed with an adhesive hardened with ultraviolet rays. The element was irradiated with 78mW/cm while applying a voltage of 30V²UV 449 seconds (35J) (405 nm). For the irradiation of ultraviolet rays, a multi-metal lamp for ultraviolet curing M04-L41 manufactured by Kawasaki (EYE GRAPHICS) Co., Ltd was used. A rectangular wave (120Hz) is applied to the element. At this time, the element was irradiated with light from the vertical direction, and the amount of light transmitted through the element was measured. The transmittance was regarded as 100% when the light amount reached the maximum, and as 0% when the light amount was the minimum. The maximum voltage of the rectangular wave is set so that the transmittance becomes 90%. The lowest voltage of the rectangular wave is 2.5V set to have a transmittance of 0%. The response time is represented by the time (rise time; millisecond) required for the transmittance to change from 10% to 90%.

(12) Elastic constant (K11: splay (splay) elastic constant, K33: bend (bend) elastic constant; measured at 25 ℃; pN): for the measurement, an elastic constant measuring instrument model EC-1 manufactured by Toyang technology (TOYO Corporation) Ltd was used. A sample was placed in a vertical alignment cell having a gap (cell gap) of 20 μm between two glass substrates. A charge of 20 to 0 volts was applied to the cell, and the electrostatic capacitance and applied voltage were measured. The values of the measured electrostatic capacitance (C) and applied voltage (V) were fitted (fitting) using the equations (2.98) and (2.101) on page 75 of the handbook of liquid crystal devices (journal of the industry), and the value of the elastic constant was obtained from the equation (2.100).

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

(14) Pretilt angle stability (Δ Pt angle; degree): the change in the pretilt angle of the liquid crystal display element was evaluated. The pretilt angle Pt before the stress was applied was measured (before), and after applying a rectangular wave of 7V and 60Hz to the element for 24 hours, the pretilt angle Pt after the stress was measured again (after). From these values, the change Δ Pt angle (deg.) of the pretilt angle is calculated using the following equation.

Δ Pt Angle (after) -Pt Angle (before)

For measurement of pretilt angle, opati-Pro (manufactured by shintech corporation) was used. It can be said that the smaller the Δ Pt angle, the smaller the change in pretilt angle, and the better the pretilt angle stability. The Δ Pt angle is particularly preferably 0.1 ° or less.

(15) Alignment stability (liquid crystal alignment axis stability): the change in the liquid crystal alignment axis on the electrode side of the liquid crystal display element was evaluated. The liquid crystal alignment angle phi (before) on the electrode side before the stress was applied was measured, after which a square wave of 4.5V and 60Hz was applied to the element for 20 minutes, and then short-circuited for 1 second, and after 1 second and 5 minutes, the liquid crystal alignment angle phi (after) on the electrode side was measured again. From these values, the change Δ Φ (deg.) of the liquid crystal alignment angle after 1 second and 5 minutes was calculated using the following formula.

Δφ(deg.)＝φ(after)-φ(before)

These measurements were carried out with reference to J.Hilbert, B.Jansen, C.Hexingg, J.F.Elman, E.Montbahh, D.Blainet and P.J.Bos (J.Hilfiker, B.Johs, C.Herzinger, J.F.Elman, E.Montbach, D.Bryant, and P.J.Bos), Solid Films (Thin Solid Films), 455-plus 456, (2004) 596-plus 600. It can be said that the smaller the Δ Φ, the smaller the rate of change of the liquid crystal alignment axis, the better the stability of the liquid crystal alignment axis.

(16) Low temperature solubility of polar compounds: the polar compound as the first additive was added to the composition (M1) having a nematic phase at an arbitrary ratio. Then, the sample was placed in a glass bottle, and after keeping the vial in a freezer at-20 ℃ for 10 days, the liquid crystal phase was observed. From the viewpoint of transportation or storage of the liquid crystal material, it is preferable that the nematic phase is maintained without precipitation of the added polar compound at-10 ℃ for 10 days. It is particularly preferred that the nematic phase is maintained at-20 ℃ for 10 days.

[ Synthesis example 1]

Synthesis of Compound (PC-1)

Step 1 of

4-Methylmorpholine N-oxide (NMO) (37.4g) and Tetrahydrofuran (THF) (500ml) were placed in a reactor and cooled to 0 ℃. Diisobutylaluminum Hydride (DIBAL) (1.00M; n-hexane solution; 285ml) was slowly added dropwise thereto, and stirred at 0 ℃ for 30 minutes. Compound (T-1) (25.0ml) was slowly added dropwise thereto, and stirred at 0 ℃ for 1 hour. Then, acetaldehyde (27.5ml) and boron trifluoride diethyl ether complex (61.9ml) were added dropwise in this order, and the mixture was allowed to return to room temperature and stirred for 10 hours. The reaction mixture was poured into 1N hydrochloric acid (500ml), and the aqueous layer was extracted with diethyl ether. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (volume ratio, heptane: ethyl acetate ═ 3: 1) to obtain compound (T-2) (23.7 g; 67%).

Step 2

Compound (T-2) (23.6g), 1, 4-dioxane (200ml) and water (200ml) were placed in a reactor and cooled to 0 ℃. Lithium hydroxide monohydrate (10.3g) was added thereto, returned to room temperature and stirred for 8 hours. The reaction mixture was poured into water, and 1N hydrochloric acid (41.0ml) was slowly added thereto to make the mixture acidic, and then the aqueous layer was extracted with ethyl acetate. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure to obtain compound (T-3) (19.0 g; 99%).

Step 3 of

Compound (T-3) (19.0g) and methylene chloride (200ml) were placed in a reactor and cooled to 0 ℃. After triethylamine (22.8ml) was added thereto, compound (T-4) (32.6g) was slowly added dropwise, returned to room temperature and stirred for 8 hours. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (volume ratio, heptane: ethyl acetate ═ 3: 1) to obtain compound (T-5) (19.7 g; 51%).

Step 4

Compound (T-5) (19.7g) and methylene chloride (400ml) were placed in a reactor and cooled to 0 ℃. Triisopropylsilyltriflate (TIPSOTf) and compound (T-6) (9.77ml) were slowly added dropwise thereto, returned to room temperature and stirred for 8 hours. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The obtained organic layer was washed with water and brine in this order, and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (volume ratio, heptane: ethyl acetate 4: 1) to obtain compound (T-7) (32.1 g; 98%).

Step 5

Compound (T-7) (15.0g), 1, 4-dioxane (220ml) and water (58.0ml) were placed in a reactor and cooled to 0 ℃. Lithium hydroxide monohydrate (2.42g) was added thereto, returned to room temperature and stirred for 8 hours. The reaction mixture was poured into water, and 1N hydrochloric acid (20.0ml) was slowly added thereto to make the mixture acidic, and then the aqueous layer was extracted with ethyl acetate. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure to obtain compound (T-8) (10.0 g; 96%).

Step 6

Compound (T-9) (6.85g), compound (T-8) (5.92g), Dimethylaminopyridine (DMAP) (1.11g) and dichloromethane (170ml) synthesized according to the method described in WO2017209161A1 were put into a reactor and cooled to 0 ℃. A solution of Dicyclohexylcarbodiimide (DCC) (5.60g) in dichloromethane (30.0ml) was slowly added dropwise thereto, returned to room temperature and stirred for 12 hours. After insoluble matter was separated by filtration, the reaction mixture was poured into water, and the aqueous layer was extracted with dichloromethane. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (volume ratio, heptane: ethyl acetate ═ 5: 1) to obtain compound (T-10) (6.62 g; 58%).

Step 7

Compound (T-10) (6.62g) and THF (100ml) were placed in a reactor and cooled to 0 ℃. Tetrabutylammonium Fluoride (TBAF) (1.00M; THF solution; 12.6ml) was slowly added dropwise thereto and stirred at 0 ℃ for 1 hour. The reaction mixture was poured into water, and the aqueous layer was extracted with ethyl acetate. The obtained organic layer was washed with brine and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (volume ratio, heptane: ethyl acetate ═ 3: 1). Further, purification was performed by recrystallization from heptane to obtain compound (PC-1) (2.38 g; 48%).

The NMR analysis value of the obtained compound (PC-1) was as follows.

¹H-NMR: chemical shifts (ppm; CDCl)₃)：6.20(s,1H),6.09(s,1H),5.83(s,1H),5.57(t,J＝1.6Hz,1H),4.66-4.58(m,1H),4.36-4.26(m,2H),4.23-4.13(m,2H),2.65(d,J＝5.6Hz,1H),1.97-1.90(m,4H),1.85-1.75(m,8H),1.47-1.36(m,4H),1.34-0.78(m,22H).

The compounds (1-1) to (1-12) can be synthesized by the methods described in the synthesis examples.

The compounds in the examples are represented by symbols based on the definitions of table 3 below. In Table 3, the configuration of the 1, 4-cyclohexylene group-related solid is trans configuration. The numbers in parentheses after the symbols correspond to the numbers of the compounds. The symbol (-) indicates other liquid crystalline compounds. The ratio (percentage) of the liquid crystalline compound is a mass percentage (mass%) based on the mass of the liquid crystal composition. Finally, the values of the properties of the composition are summarized.

TABLE 3 formulation of Compounds Using symbols

R-(A₁)-Z₁-·····-Z_n-(A_n)-R′

Embodiments of the elements

1. Raw materials

A liquid crystal composition to which a polar compound is added is injected into an element having no alignment film. After irradiation with ultraviolet rays, the vertical alignment of the liquid crystal molecules in the cell was examined. First, the raw materials will be described. The starting materials are compositions M1 to M28, polar compounds (PC-1) to polar compounds (PC-10), and polymerizable compounds (RM-1) to polymerizable compounds (RM-9), which are listed in order.

[ composition M1]

NI＝73.2℃；Tc<-20℃；Δn＝0.113；Δ＝-4.0；Vth＝2.18V；η＝22.6mPa·s.

[ composition M2]

NI＝82.8℃；Tc<-30℃；Δn＝0.118；Δ＝-4.4；Vth＝2.13V；η＝22.5mPa·s.

[ composition M3]

NI＝78.1℃；Tc<-30℃；Δn＝0.107；Δ＝-3.2；Vth＝2.02V；η＝15.9mPa·s.

[ composition M4]

NI＝88.5℃；Tc<-30℃；Δn＝0.108；Δ＝-3.8；Vth＝2.25V；η＝24.6mPa·s；VHR-1＝99.1％；VHR-2＝98.2％；VHR-3＝97.8％.

[ composition M5]

NI＝81.1℃；Tc<-30℃；Δn＝0.119；Δ＝-4.5；Vth＝1.69V；η＝31.4mPa·s.

[ composition M6]

NI＝98.8℃；Tc<-30℃；Δn＝0.111；Δ＝-3.2；Vth＝2.47V；η＝23.9mPa·s.

[ composition M7]

NI＝77.5℃；Tc<-30℃；Δn＝0.084；Δ＝-2.6；Vth＝2.43V；η＝22.8mPa·s.

[ composition M8]

NI＝70.6℃；Tc<-20℃；Δn＝0.129；Δ＝-4.3；Vth＝1.69V；η＝27.0mPa·s.

[ composition M9]

NI＝93.0℃；Tc<-30℃；Δn＝0.123；Δ＝-4.0；Vth＝2.27V；η＝29.6mPa·s.

[ composition M10]

NI＝87.6℃；Tc<-30℃；Δn＝0.126；Δ＝-4.5；Vth＝2.21V；η＝25.3mPa·s.

[ composition M11]

NI＝93.0℃；Tc<-20℃；Δn＝0.124；Δ＝-4.5；Vth＝2.22V；η＝25.0mPa·s.

[ composition M12]

NI＝76.4℃；Tc<-30℃；Δn＝0.104；Δ＝-3.2；Vth＝2.06V；η＝15.6mPa·s.

[ composition M13]

NI＝78.3℃；Tc<-20℃；Δn＝0.103；Δ＝-3.2；Vth＝2.17V；η＝17.7mPa·s.

[ composition M14]

NI＝81.2℃；Tc<-20℃；Δn＝0.107；Δ＝-3.2；Vth＝2.11V；η＝15.5mPa·s.

[ composition M15]

NI＝88.7℃；Tc<-30℃；Δn＝0.115；Δ＝-1.9；Vth＝2.82V；η＝17.3mPa·s.

[ composition M16]

NI＝89.9℃；Tc<-20℃；Δn＝0.122；Δ＝-4.2；Vth＝2.16V；η＝23.4mPa·s.

[ composition M17]

NI＝77.1℃；Tc<-20℃；Δn＝0.101；Δ＝-3.0；Vth＝2.04V；η＝13.9mPa·s.

[ composition M18]

NI＝75.9℃；Tc<-20℃；Δn＝0.114；Δ＝-3.9；Vth＝2.20V；η＝24.7mPa·s.

[ composition M19]

NI＝75.9℃；Δn＝0.101；Δ＝-2.7.

[ composition M20]

NI＝78.4℃；Tc<-30℃；Δn＝0.105；Δ＝-2.7；Vth＝2.43V；η＝16.2mPa·s.

[ composition M21]

NI＝76.0℃；Tc<-20℃；Δn＝0.097；Δ＝-3.0；Vth＝2.20V.

[ composition M22]

NI＝75.3℃；Δn＝0.109；Δ＝-3.1；Vth＝2.29V.

[ composition M23]

NI＝73.5℃；Tc<-20℃；Δn＝0.100；Δ＝-2.6.

[ composition M24]

NI＝74.8℃；Tc<-20℃；Δn＝0.099；Δ＝-3.2.

[ composition M25]

NI＝71.1℃；Tc<-20℃；Δn＝0.105；Δ＝-2.7.

[ composition M26]

NI＝75.6℃；Δn＝0.104；Δ＝-2.4.

[ composition M27]

NI＝76.5℃；Tc<-20℃；Δn＝0.098；Δ＝-3.0；Vth＝2.15V；η＝16.2mPa·s.

[ composition M28]

NI＝75.3℃；Tc<-20℃；Δn＝0.102；Δ＝-2.6；Vth＝2.41V；η＝17.5mPa·s.

The following polar compounds (PC-1) to (PC-7) were used as the first additives. The numbers in parentheses located at the rear correspond to the numbers of the compounds.

The following polar compounds (PC-8) to (PC-10) were used as the third additive. The numbers in parentheses located at the rear correspond to the numbers of the compounds.

The following polymerizable compounds (RM-1) to (RM-9) were used as the second additive. The numbers in parentheses located at the rear correspond to the numbers of the compounds.

2. Low temperature solubility of polar compounds

[ example 1]

The polar compound (PC-1) as the first additive was added to the composition (M1) at a ratio of 0.8 mass%. The composition showed a nematic phase at room temperature, and the result of NI (. degree. C.) was 71.8 ℃.

Then, the composition showing a nematic phase was placed in a glass bottle, and after keeping the bottle in a freezer at-20 ℃ for 10 days, the liquid crystal composition was observed, and as a result, the nematic phase was maintained.

Comparative example 1

For comparison, the polar compound (PC-8) as the third additive was added to the composition (M1) in a proportion of 1.5 mass% instead of the first additive. NI (. degree. C.) was confirmed in the same manner as in example 1, and the result was 71.2 ℃.

Then, the composition showing the nematic phase was put in a glass bottle, and after keeping the bottle in a freezer at-20 ℃ for 10 days, the liquid crystal composition was observed, and as a result, crystals of the polar compound (PC-8) were precipitated.

[ example 2 to example 40]

A liquid crystal composition to which a polar compound was added was prepared by changing the kind of the composition and the concentration of the polar compound, and low-temperature solubility was observed in the same manner as in example 1. The results are summarized in Table 4, in which the nematic phase was maintained in a freezer at-20 ℃ for 10 days as "O" and the precipitated crystals as "X".

TABLE 4 Low temperature solubility of polar Compounds

From the results in table 4, the liquid crystal composition to which the first additive was added had a low-temperature solubility of ∘. In addition, in examples 25 to 31, 33 and 35, the polar compound (PC-8) to the polar compound (PC-10) were further added as the third additive, and in the liquid crystal compositions of examples 32 to 40, the polymerizable compound (RM-1) to the polymerizable compound (RM-9) were further added, but the same results were obtained. On the other hand, in the liquid crystal composition to which the first additive was not added, the low-temperature solubility was x. The results show that the first additive of the present invention has excellent low-temperature solubility.

[ industrial applicability ]

The liquid crystal composition of the present invention can impart excellent low-temperature solubility. The liquid crystal display element containing the composition has the characteristics of short response time, high voltage holding ratio, low threshold voltage, high contrast, long service life and the like, and therefore, the liquid crystal display element can be used for liquid crystal projectors, liquid crystal televisions and the like.

Claims

1. A liquid crystal composition containing at least one compound selected from polymerizable polar compounds represented by formula (1) as a first additive and having a nematic phase and negative dielectric anisotropy;

in the formula (1), the reaction mixture is,

R¹is hydrogen or an alkyl group having 1 to 15 carbon atoms,in the alkyl group, at least one-CH₂-may be substituted by-O-or-S-, at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

ring A¹And ring A²Is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, in which at least one hydrogen may be substituted by fluorine, chlorine, an alkyl group having a carbon number of 1 to 10, an alkenyl group having a carbon number of 2 to 10, an alkoxy group having a carbon number of 1 to 10 or an alkenyloxy group having a carbon number of 2 to 10, and in which at least one hydrogen may be substituted by fluorine or chlorine;

a is 0, 1,2, 3 or 4;

in the formula (1-a),

2. The liquid crystal composition according to claim 1, wherein at least one compound selected from polymerizable polar compounds represented by formulae (1-1) to (1-12) is contained as the first additive;

in the formulae (1-1) to (1-12),

R¹an alkyl group having 1 to 10 carbon atoms;

Z¹¹and Z¹²Is a single bond or-CH₂CH₂-；

Y¹、Y²、Y³、Y⁴、Y⁵And Y⁶Is hydrogen, fluorine, methyl or ethyl;

3. The liquid crystal composition according to claim 1, wherein the proportion of the first additive is in the range of 0.1 to 10% by mass.

4. The liquid crystal composition according to claim 1, wherein at least one compound selected from the compounds represented by formula (2) is contained as a first component;

in the formula (2), R⁷And R⁸Is hydrogen, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, alkenyloxy group having 2 to 12 carbon atoms, or alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring B and ring D are 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, or chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring C is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, 7, 8-difluorochromane-2, 6-diyl, 3,4,5, 6-tetrafluorofluorene-2, 7-diyl, 4, 6-difluorodibenzofuran-3, 7-diyl, 4, 6-difluorodibenzothiophene-3, 7-diyl, or 1,1,6, 7-tetrafluoroindan-2, 5-diyl; z²And Z³Is a single bond, ethylene, vinylidene, methyleneoxy or carbonyloxy; b is 0, 1,2 or 3, c is 0 or 1, and the sum of b and c is 3 or less.

5. The liquid crystal composition according to claim 1, wherein at least one compound selected from the group consisting of compounds represented by formulae (2-1) to (2-35) is contained as a first component;

6. The liquid crystal composition according to claim 4, wherein the proportion of the first component is in the range of 10 to 90 mass%.

7. The liquid crystal composition according to claim 1, wherein at least one compound selected from the compounds represented by formula (3) is contained as a second component;

8. The liquid crystal composition according to claim 1, wherein at least one compound selected from the group consisting of compounds represented by formulae (3-1) to (3-13) is contained as a second component;

in formulae (3-1) to (3-13), R⁹And R¹⁰Is C1-12 alkyl, C1-12 alkoxy, C2-12 alkenyl, C1-12 alkyl with at least one hydrogen substituted by fluorine or chlorine, orAn alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

9. The liquid crystal composition according to claim 7, wherein the proportion of the second component is in the range of 10 to 90 mass%.

10. The liquid crystal composition according to claim 1, wherein at least one compound selected from the polymerizable compounds represented by formula (4) is contained as a second additive;

in the formula (4), ring G and ring J are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1, 3-dioxan-2-yl, pyrimidin-2-yl or pyridin-2-yl, and in these rings, at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine; ring I is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-1, 2-diyl, naphthalene-1, 3-diyl, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl, naphthalene-1, 7-diyl, naphthalene-1, 8-diyl, naphthalene-2, 3-diyl, naphthalene-2, 6-diyl, naphthalene-2, 7-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, in which at least one hydrogen atom may be replaced by fluorine, chlorine, an alkyl group having a carbon number of 1 to 12, an alkoxy group having a carbon number of 1 to 12, Or at least one hydrogen is substituted by a fluorine or chlorine substituted alkyl group of carbon number 1 to 12; z⁵And Z⁶Is a single bond or an alkylene group having 1 to 10 carbon atoms, in which at least one-CH group₂May be substituted by-O-, -CO-, -COO-or-OCO-, and at least one-CH₂CH₂-may be via-CH ═ CH-, -C (CH)₃)＝CH-、-CH＝C(CH₃) -or-C (CH)₃)＝C(CH₃) -substituted, at least one hydrogen being substituted by fluorine or chlorine; p¹、P²And P³Is a polymerizable group; sp⁷、Sp⁸And Sp⁹Is a single bond or a carbon number of 1 to 10 alkylene group, said Sp⁷、Sp⁸And Sp⁹In (1), at least one-CH₂May be substituted by-O-, -COO-, -OCO-or-OCOO-, and at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro; h 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.

11. The liquid crystal composition according to claim 10, wherein in formula (4), P¹、P²And P³Is a group selected from the polymerizable groups represented by the formulae (P-1) to (P-5);

12. The liquid crystal composition according to claim 1, wherein at least one compound selected from polymerizable compounds represented by formulae (4-1) to (4-29) is contained as a second additive;

in formulae (4-1) to (4-29), P¹、P²And P³Is a group selected from the polymerizable groups represented by the formulae (P-1) to (P-3),

in the formulae (P-1) to (P-3), M⁷、M⁸And M⁹Is hydrogen, fluorine or C1-5 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, at least one hydrogen may be substituted by fluorine or chlorine; sp⁷、Sp⁸And Sp⁹Is a single bond or alkylene with 1 to 10 carbon atoms, and Sp⁷、Sp⁸And Sp⁹In (1), at least one-CH₂May be substituted by-O-, -COO-, -OCO-or-OCOO-, and at least one-CH₂CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro.

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

14. The liquid crystal composition according to claim 1, wherein at least one compound selected from polymerizable polar compounds represented by formulae (5-1) to (5-3) is contained as a third additive;

in the formulae (5-1) to (5-3),

R⁵¹is-OH, -NH₂、-OR⁵³、-N(R⁵³)₂or-Si (R)⁵³)₃The radicals represented, herein, R⁵³Is hydrogen or alkyl with 1 to 5 carbon atoms, in which at least one-CH₂-may be substituted by-O-at least one-CH₂CH₂-may be via-CH ═CH-substituted, in which at least one hydrogen may be substituted by fluorine;

a⁵⁰is 0, 1,2, 3 or 4;

a⁵¹is 1 or 2;

15. The liquid crystal composition according to claim 14, wherein the proportion of the third additive is in the range of 0.05 to 10 mass%.

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

17. A polymer-stabilized alignment type liquid crystal display element comprising the liquid crystal composition according to claim 1, wherein at least one compound selected from the group consisting of the first additive, the second additive and the third additive in the liquid crystal composition is polymerized.

18. A liquid crystal display element having no alignment film, comprising the liquid crystal composition according to claim 1, and at least one compound selected from the group consisting of the first additive, the second additive and the third additive in the liquid crystal composition is polymerized.