CN112708426A

CN112708426A - Liquid crystal composition, liquid crystal display element, and use of liquid crystal composition in liquid crystal display element

Info

Publication number: CN112708426A
Application number: CN202011116647.2A
Authority: CN
Inventors: 片野裕子; 川上日向子; 近藤史尚
Original assignee: JNC Corp; JNC Petrochemical Corp
Current assignee: JNC Corp; JNC Petrochemical Corp
Priority date: 2019-10-25
Filing date: 2020-10-19
Publication date: 2021-04-27
Also published as: TW202116987A; JP2021070814A

Abstract

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

Description

Liquid crystal composition, liquid crystal display element, and use of liquid crystal composition in 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 containing a polymerizable compound and a polar compound having a polymerizable group (or a polymer thereof), and having a negative dielectric anisotropy, which enables vertical alignment of liquid crystal molecules by the action of the compound, a liquid crystal display element, and use of the liquid crystal composition in a liquid crystal display element.

Background

In a liquid crystal display device, the operation modes of 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 (static), multiplex (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 manufacturing steps. The light sources are 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 compositions are further illustrated based on commercially available AM elements. The temperature range of the nematic phase is related to the usable temperature range of the element. 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 is related to the response time of the element. In order to display a moving image as an element, the response time is preferably short. It is desirable that the response time be shorter than 1 millisecond. Therefore, it is preferable that the viscosity of the composition is small. Further, it is preferable that the viscosity at low temperature is low.

TABLE 1 Properties of the compositions and AM elements

The optical anisotropy of the composition is related to the contrast ratio 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 so that the contrast ratio is maximized. The appropriate value of the product depends on the kind of action 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 constant anisotropy of the composition contributes to a low threshold voltage, a small power consumption, and a large contrast ratio of the device. Therefore, it is preferable that the dielectric anisotropy is large. 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. A composition having a large specific resistance after a long-term use is preferable. The stability of the composition to ultraviolet light or heat is related to the lifetime of the component. When the stability is high, the life of the element is long. Such characteristics are preferable for AM elements used in liquid crystal monitors, liquid crystal televisions, and the like.

In a general-purpose liquid crystal display element, 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 Stabilized 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. Next, 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 for devices having modes such as TN, ECB, OCB, IPS, VA, FFS, FPA, and the like.

On the other hand, in a liquid crystal display element having no alignment film, a liquid crystal composition containing a polymer and a polar compound is used. First, a composition containing a small amount of a polymerizable compound and a small amount of a polar compound 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. Next, 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. Elements having modes such as TN, ECB, OCB, IPS, VA, FFS, and FPA can be expected to utilize such effects obtained by a combination of a polymer and a polar compound.

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. A composition having positive or negative dielectric anisotropy is used for a device having no alignment film. Compositions having negative dielectric anisotropy are disclosed in the following patent documents 1 to 4 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 present invention addresses the problem of providing a liquid crystal composition containing, as a first additive, a polar compound (1) having a polymerizable group, wherein the liquid crystal composition has excellent low-temperature solubility, high reactivity, and a high pretilt angle formation rate. Another object is to provide a liquid crystal composition in which vertical alignment of liquid crystal molecules can be achieved by the action of a polymer produced from the polymerizable compound and a polar compound. Still another subject 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. Still another object is to provide a liquid crystal composition having an appropriate balance between at least two of these characteristics. A further subject is a liquid crystal display element comprising such a composition. Another subject 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, at least one compound selected from the polar compounds represented by formula (1) (or the polymer) as a first additive is combined with a liquid crystalline compound, and the composition is used in a liquid crystal display element having no alignment film. Specifically, the present invention relates to a liquid crystal composition containing at least one selected from polymerizable 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, A¹The definition of the same symbol is referred to item 1 described later.

[ Effect of the invention ]

One of the advantages of the present invention is to provide a liquid crystal composition containing a polymerizable compound and a polar compound having a polymerizable group (or a polymer thereof), which has excellent low-temperature solubility, high reactivity, and a high pretilt angle formation rate. Another advantage is to provide a liquid crystal composition capable of realizing vertical alignment of liquid crystal molecules by the action of a polymer generated from the polymerizable compound and the polar compound. Still another advantage is a liquid crystal composition that sufficiently 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. Yet another advantage resides in providing a liquid crystal composition having a proper balance between at least two of these characteristics. Still another advantage resides in providing a liquid crystal display element including such a composition. Still another advantage is to provide an AM device 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 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 are not in a liquid crystal phase and are mixed in a 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. In the meaning, the liquid crystalline compound has only an alkenyl group and is not classified as a polymerizable compound.

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 (parts by 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 "improving the dielectric anisotropy" means that the value increases positively in a composition having a positive dielectric anisotropy and negatively in a composition having a negative dielectric anisotropy. The term "high 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 or a condensed ring. 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 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 this case, rules that may be the same or different may also apply. Furthermore, the rules also apply to the use of the notation of Ra in a variety of compounds.

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

'at least one'The expression of a ' "means that the number of ' a ' is arbitrary. With respect to the expression "at least one 'a' may be substituted with 'B', when the number of 'a' is one, the position of 'a' is arbitrary, and when the number of 'a' is two or more, the positions of 'a' may be selected without limitation. 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, adjacent-CH₂-is not substituted by-O-. The reason for this is that: in the substitution, the formation of-O-CH₂- (peroxides).

The alkyl group of the liquid crystalline compound is linear or branched and does not contain 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. In order to increase the upper limit temperature, the steric configuration associated with the 1, 4-cyclohexylene group is a trans configuration rather than a cis configuration. Since 2-fluoro-1, 4-phenylene is asymmetric to the left and right, 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 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 10 carbon atoms, the R¹In (1), at least one-CH₂-may be substituted by-O-or-S-,at least one- (CH)₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro;

ring A¹And ring A²Independently 1, 2-cyclopropylene, 1, 3-cyclobutylene, 1, 3-cyclopentylene, 1, 4-cyclohexylene, 1, 4-cycloheptylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, decahydronaphthalene-2, 6-diyl, 1,2,3, 4-tetrahydronaphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, said ring A being¹And ring A²Wherein at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 9 carbon atoms or an alkenyloxy group having 2 to 9 carbon atoms, and at least one hydrogen may be substituted with fluorine or chlorine among the alkyl group, alkenyl group, alkoxy group and alkenyloxy group of the substituent;

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

b and c are independently 0, 1 or 2;

Z¹independently a single bond or alkylene having 1 to 6 carbon atoms, Z¹In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro;

X¹is a polar group having a heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, and silicon;

P¹and P²Independently a group selected from the group consisting of groups represented by formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) and formula (1-p 5);

in the formula (1-p1), the formula (1-p2), the formula (1-p3), the formula (1-p4) and the formula (1-p5),

Sp¹is a single bond or alkylene with 1 to 15 carbon atoms, and Sp¹In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro;

R²an alkyl group having 1 to 5 carbon atoms;

R³is a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 8 carbon atoms;

Y¹is chlorine, fluorine or bromine;

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

at P¹And P²In the case where at least one of the groups represented by the formulae (1-p1), (1-p2) and (1-p3),

Sp²is a single bond or alkylene with 1 to 10 carbon atoms, and Sp²In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-, -OCOO-or a group represented by the formula (1-a)₂)₂-may be substituted with-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4), or formula (1-p 5);

wherein, in the case where b and c are both 0,

Sp²is alkylene with 1 to 10 carbon atoms, and Sp²In (1), at least one-CH₂At least one-CH which may be substituted by a group represented by the formula (1-a)₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted with-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted with a group represented by formula (1-p1), formula (1-p2) or formula (1-p3), and at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5);

the liquid crystal composition according to item 1, wherein the polar group is represented by any one of formula (X-1) to formula (X-27);

in the formulae (X-1) to (X-27),

J¹and J²Independently hydrogen, or a linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms, and J¹And J²In (1), at least one-CH₂-may be substituted by-O-;

J³is hydrogen, or a linear alkyl group having 1 to 20 carbon atoms or a branched alkyl group having 3 to 20 carbon atoms, and J³In (1), at least one-CH₂-may be substituted by-O-, -COO-or-OCO-;

J⁴and J⁵Independently hydrogen or alkyl of carbon number 1 to 8;

Q¹is methine or nitrogen, where the hydrogen of the methine group may be substituted with an alkyl group having 1 to 6 carbon atoms;

U¹and U²Independently is-CH₂-, -O-, -CO-or-S-;

V¹、V²and V³Independently of the other being methine or nitrogen, V¹、V²And V³At least one of which contains nitrogen;

W¹is-O-or-S-;

W²is carbon, sulfur or silicon;

wherein, in the formula (X-14), in Q¹In the case of methine, U¹And U²At least one of which is-O-, -CO-or-S-.

Item 3. the liquid crystal composition according to item 1 or item 2, having at least one compound selected from the group consisting of compounds represented by formulae (1-1) to (1-6) as the first additive;

in the formulae (1-1) to (1-6),

R¹is hydrogen or alkyl with 1 to 10 carbon atoms, the R¹In (1), at least one-CH₂-may be substituted by-O-,at least one- (CH)₂)₂-may be substituted by-CH ═ CH-, at least one hydrogen may be substituted by fluorine or chlorine;

ring A¹To ring A⁴Is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl or 1, 3-dioxane-2, 5-diyl, said ring A¹To ring A⁴Wherein at least one hydrogen may be substituted with fluorine, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms;

b and c are independently 0, 1 or 2;

Z¹to Z³Independently a single bond, - (CH)₂)₂-、-CH＝CH-、-C≡C-、-CH₂O-or-OCH₂-；

Sp¹is a single bond or alkylene with 1 to 5 carbon atoms, and Sp¹In (1), at least one-CH₂-may be substituted by-O-at least one- (CH)₂)₂-may be substituted by-CH ═ CH-, at least one hydrogen may be substituted by fluorine or chlorine;

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

in the formulae (1-1) to (1-6),

at P¹And P²At least one of the compounds has the formula (1-p1), the formula (1-p2) and the formula (1)-p3),

Sp²is a single bond or alkylene with 1 to 7 carbon atoms, and Sp²In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-or a group represented by the formula (1-a)₂)₂-may be substituted with-CH ═ CH-, at least one hydrogen may be substituted with fluorine, chlorine, a group represented by formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5);

wherein, in the case where b and c are both 0,

Sp²is alkylene with 1 to 7 carbon atoms, and Sp²In (1), at least one-CH₂At least one-CH which may be substituted by a group represented by the formula (1-a)₂-may be substituted by-O-, -CO-or-COO-, at least one- (CH)₂)₂-may be substituted with-CH ═ CH-, at least one hydrogen may be substituted with a group represented by formula (1-p1), formula (1-p2) or formula (1-p3), and at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5);

item 4. the liquid crystal composition according to any one of item 1 to item 3, having at least one compound selected from the group consisting of compounds represented by formulae (1-7) to (1-90) as the first additive;

in the formulae (1-7) to (1-90),

R¹an alkyl group having 1 to 10 carbon atoms;

Z¹to Z³Independently is a single bond or- (CH)₂)₂-；

Sp¹Is a single bond or alkylene with 1 to 5 carbon atoms, and Sp¹In (1), at least one-CH₂-may be substituted by-O-;

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

Y¹¹to Y²¹Independently hydrogen, fluorine, alkyl of carbon number 1 to 5, alkenyl of carbon number 2 to 5 or alkoxy of carbon number 1 to 4;

Sp²is a single bond or alkylene with 1 to 7 carbon atoms, and Sp²In (1), at least one-CH₂-may be substituted with-O-or a group represented by formula (1-a), at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3) or formula (1-p 4);

in the formula (1-p1), the formula (1-p2), the formula (1-p3) and the formula (1-p4),

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

in the formulae (1-7) to (1-90),

Sp³and Sp⁴Independently is a single bond or alkylene with 1 to 5 carbon atoms, and Sp³And Sp⁴In (1), at least one-CH₂-may be substituted by-O-;

X¹is a polar group having a heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, and silicon.

Item 5. the liquid crystal composition according to any one of item 1 to item 4, wherein a proportion of the first additive is in a range of 0.03 parts by mass to 10 parts by mass based on a mass of the liquid crystal composition containing no additive.

Item 6. the liquid crystal composition according to any one of item 1 to item 5, containing at least one compound selected from the compounds represented by formula (2) as a first component;

in the formula (2), the reaction mixture is,

R¹¹and R¹²Independently hydrogen, alkyl of carbon number 1 to 12, alkoxy of carbon number 1 to 12, alkenyl of carbon number 2 to 12, alkenyloxy of carbon number 2 to 12, or alkyl of carbon number 1 to 12 in which at least one hydrogen is substituted by fluorine or chlorine;

ring D and ring F are independently 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 E 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;

Z¹³and Z¹⁴Independently a single bond, ethylene, methyleneoxy, or carbonyloxy;

e is 0, 1,2 or 3, f is 0 or 1, and the sum of e and f is 3 or less.

Item 7. the liquid crystal composition according to item 6, containing at least one compound selected from the group of compounds represented by formulae (2-1) to (2-35) as the first component;

in the formulae (2-1) to (2-35),

R¹¹and R¹²Is 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 8 the liquid crystal composition of item 6 or item 7, wherein the proportion of the first component ranges from 10% by mass to 90% by mass based on the mass of the liquid crystal composition containing no additive.

Item 9. the liquid crystal composition according to any one of item 1 to item 8, containing at least one compound selected from the compounds represented by formula (3) as a second component;

in the formula (3), the reaction mixture is,

R¹³and R¹⁴Independently 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 atomsAn alkyl group having 1 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine;

ring G and ring I are independently 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene or 2, 5-difluoro-1, 4-phenylene;

Z¹⁵independently a single bond, ethylene or carbonyloxy;

g is 1,2 or 3.

Item 10. the liquid crystal composition according to item 9, which contains at least one compound selected from the group consisting of compounds represented by formulae (3-1) to (3-13) as the second component;

in the formulae (3-1) to (3-13),

R¹³and R¹⁴Is 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 11. the liquid crystal composition of item 9 or item 10, wherein the proportion of the second component is in a range of 10 to 90 mass% based on the mass of the liquid crystal composition containing no additive.

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 formula (4) as a second additive;

in the formula (4), the reaction mixture is,

ring J and ring L are independently cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1, 3-dioxan-2-yl, pyrimidin-2-yl or pyridin-2-yl, wherein at least one hydrogen in ring J and ring L 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 wherein at least one hydrogen is substituted with fluorine or chlorine;

ring K is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-1, 2-diyl, naphthalene-1, 3-diyl, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl, naphthalene-1, 7-diyl, naphthalene-1, 8-diyl, naphthalene-2, 3-diyl, naphthalene-2, 6-diyl, naphthalene-2, 7-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, and at least one of the ring K is hydrogen, hydrogen-substituted alkyl having 1 to 12 carbon atoms, or halogen, 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;

Z⁶and Z⁷Independently a single bond or alkylene having 1 to 10 carbon atoms, Z⁶And Z⁷In (1), at least one-CH₂-may be substituted by-O-, -CO-, -COO-or-OCO-, at least one-CH₂-CH₂-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;

Sp⁵、Sp⁶and Sp⁷Independently is a single bond or alkylene with 1 to 10 carbon atoms, and Sp⁵、Sp⁶And Sp⁷In (1), at least one-CH₂At least one-CH which may be substituted by-O-, -COO-, -OCO-or-OCOO-)₂-CH₂-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;

i. j and k are independently 0, 1,2,3 or 4, the sum of i, j and k being 1 or more;

P⁹、P¹⁰and P¹¹Independently a group selected from the polymerizable groups represented by the formulae (P-7) to (P-11);

in formulae (P-7) to (P-11), M⁵、M⁶And M⁷Independently hydrogen, fluorine or alkyl of carbon number 1 to 5, M⁵、M⁶And M⁷In (1), at least one-CH₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine.

Item 13. the liquid crystal composition according to item 12, containing at least one compound selected from the group consisting of the compounds represented by formulae (4-1) to (4-29) as the second additive;

in the formulae (4-1) to (4-29),

Sp⁵、Sp⁶and Sp⁷Independently 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-, -COO-, -OCO-or-OCOO-)₂-CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one of these groups being substituted by fluorine or chlorine;

P¹²、P¹³and P¹⁴Independently a polymerizable group selected from the group represented by the formulae (P-7) to (P-9);

in formulae (P-7) to (P-9), M⁵、M⁶And M⁷Independently hydrogen, fluorine or alkyl of carbon number 1 to 5, M⁵、M⁶And M⁷In (1), at least one-CH₂-may be substituted by-O-and at least one hydrogen may be substituted by fluorine or chlorine.

Item 14. the liquid crystal composition of item 12 or item 13, wherein a proportion of the second additive is in a range of 0.03 to 10 parts by mass based on a mass of the liquid crystal composition containing no additive.

Item 15. a liquid crystal display element containing the liquid crystal composition according to any one of items 1 to 14.

Item 16 the liquid crystal display device according to item 15, wherein an operation mode of the liquid crystal display device is an IPS mode, a VA mode, an FFS mode, or an FPA mode, and a driving method of the liquid crystal display device is an active matrix method.

Item 17. a polymer stable alignment type liquid crystal display element comprising the liquid crystal composition according to any one of items 1 to 14, or a polymerizable compound in the liquid crystal composition, polymerized.

Item 18. use of a liquid crystal composition according to any one of items 1 to 14 in a liquid crystal display element.

Item 19. use of a liquid crystal composition according to any one of items 1 to 14 in a liquid crystal display element of a polymer stabilized alignment type.

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 of compounds, although the compound described in paragraph [0013] of Japanese patent laid-open No. 2006-199941 is a liquid crystalline compound 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, ECB mode, OCB mode, IPS mode, FFS mode, VA mode, or FPA mode. (i) A permeable element comprising said 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 properties of the component compounds and the main effects of the compounds on the composition will be described. Third, the combination of ingredients in the composition, the preferred proportions of the ingredients, 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 a liquid crystalline compound selected from the compounds (2) and (3), and may further contain other liquid crystalline compounds, additives, and the like. The "other liquid crystalline compound" is a liquid crystalline compound different from the compound (2) and the compound (3). Such compounds are mixed into 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 properties can be further adjusted by mixing other liquid crystalline compounds, the composition a is superior to the composition B.

Second, 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
Anisotropy of dielectric constant	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

The main effects of the component compounds on the properties of the composition are as follows. The compound (1) and the compound (4) provide a polymer by polymerization, which shortens the response time of the element and improves the afterimage of the image. The compound (2) increases the dielectric anisotropy and lowers the lower limit temperature. The compound (3) lowers the viscosity or raises the upper limit temperature. In addition, 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 hexa-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. From the viewpoint of alignment of liquid crystal molecules, the polymer of the compound (1) is presumed to be more effective than the polymer of the compound (4) because it has an interaction with the substrate surface.

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

The preferable proportion of the compound (1) is about 0.03 parts by mass or more in order to improve the long-term stability of alignment based on the mass of the liquid crystal composition containing no additive, and the preferable proportion of the compound (1) is about 10 parts by mass or less in order to prevent display failure of the element. Further preferred is a range of about 0.1 to about 2 parts by mass. A particularly preferred ratio is in the range of about 0.2 parts by mass to about 1.0 parts by mass.

The preferable proportion of the compound (2) is about 10% by mass or more in order to improve the dielectric anisotropy based on the mass of the liquid crystal composition containing no additive, and the preferable proportion of the compound (2) is about 90% by mass or less in order to lower the lower limit temperature. Further, the preferable ratio is in the range of about 20 to about 85 mass%. A particularly preferred ratio is in the range of about 30% 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, based on the mass of the liquid crystal composition containing no additive. Further, the preferable ratio is in the range of about 15% by mass to about 75% by mass. A particularly preferred ratio is in the range of about 15% to about 60% by mass.

The polymerizable compound such as the compound (4) is added to the composition for the purpose of being suitable for a polymer-stabilized alignment type device. The preferable proportion of the polymerizable compound is about 0.03 parts by mass or more in order to shorten the response time, and about 10 parts by mass or less in order to prevent the display failure of the element, based on the mass of the liquid crystal composition containing no additive. Further preferred is a range of about 0.1 parts by mass to about 3.0 parts by mass. A particularly preferred ratio is in the range of about 0.3 parts by mass to about 1.0 parts by mass.

Fourth, preferred embodiments of the component compounds will be described. First, two liquid crystalline compounds (a first component and a second component) are summarized and described. Next, the first additive and the second additive will be described in the order named.

(A) Liquid crystalline compound

In the formulae (2) and (3), R¹¹And R¹²Independently hydrogen, alkyl of carbon number 1 to 12, alkoxy of carbon number 1 to 12, alkenyl of carbon number 2 to 12, alkenyloxy of carbon number 2 to 12, or alkyl of carbon number 1 to 12 in which at least one hydrogen is substituted by fluorine or chlorine. For improved stability, R is preferred¹¹Or R¹²R is an alkyl group having 1 to 12 carbon atoms and is preferable for improving the dielectric anisotropy¹¹Or R¹²R is an alkoxy group having 1 to 12 carbon atoms, and is preferably selected to reduce viscosity and to lower the threshold voltage¹¹Or R¹²Is an alkenyl group having 2 to 12 carbon atoms. R¹³And R¹⁴Independently an alkyl group of carbon number 1 to 12, an alkoxy group of carbon number 1 to 12, an alkenyl group of carbon number 2 to 12, an alkyl group of carbon number 1 to 12 in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group of carbon number 2 to 12 in which at least one hydrogen is substituted with fluorine or chlorine. Preferred R for reducing viscosity¹³Or R¹⁴An alkenyl group having 2 to 12 carbon atoms, and R is preferably selected for the purpose of improving stability¹³Or R¹⁴Is an alkyl group having 1 to 12 carbon atoms.

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

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy. Further preferred alkoxy groups for reducing the 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. Further 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. Among alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl, trans-form is preferable from the viewpoint of reducing viscosity and the like. Among alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl, cis-form is preferred.

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

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

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. Further preferable examples for lowering the viscosity are 2, 2-difluorovinyl group or 4, 4-difluoro-3-butenyl group.

Ring D and ring F are independently 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 D or F is preferably a 1, 4-cyclohexylene group for the purpose of reducing viscosity, a tetrahydropyran-2, 5-diyl group for the purpose of improving dielectric anisotropy, and a 1, 4-phenylene group for the purpose of improving optical anisotropy.

Ring E 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 ring E is preferably 2, 3-difluoro-1, 4-phenylene.

Ring G and ring I are independently 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 G or ring I is 1, 4-cyclohexylene, and for lowering the lower temperature limit, the preferred ring G or ring I is 1, 4-phenylene.

Z¹³And Z¹⁴Independently a single bond, ethylene, vinylene, methyleneoxy, or carbonyloxy. For reducing the viscosity, preferred is Z¹³Or Z¹⁴Is a single bond, and Z is preferably a bond for improving dielectric anisotropy¹³Or Z¹⁴Is methyleneoxy. Z¹⁵Independently a single bond, ethylene, vinylene, methyleneoxy, or carbonyloxy. For reducing the viscosity, preferred is Z¹⁵Is a single bond.

e is 0, 1,2 or 3, f is 0 or 1, and the sum of e and f is 3 or less. For lowering the viscosity, e is preferably 1, and for raising the upper limit temperature, e is preferably 2 or 3. For lowering the viscosity, f is preferably 0, and for lowering the lower limit temperature, f is preferably 1. g is 1,2 or 3. For lowering the viscosity, g is preferably 1, and for raising the upper limit temperature, g is preferably 2 or 3.

(B) First additive

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

R¹is hydrogen or C1-10 alkaneGroup R is¹In (1), at least one-CH₂-may be substituted by-O-or-S-, at least one- (CH)₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro. Preferred R¹Is an alkyl group having 1 to 7 carbon atoms.

Ring A¹And ring A²Independently 1, 2-cyclopropylene, 1, 3-cyclobutylene, 1, 3-cyclopentylene, 1, 4-cyclohexylene, 1, 4-cycloheptylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, decahydronaphthalene-2, 6-diyl, 1,2,3, 4-tetrahydronaphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, said ring A being¹And ring A²In (b), at least one hydrogen may be substituted with fluorine, chlorine, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkenyloxy group having 2 to 9 carbon atoms, and at least one hydrogen of the alkyl group, the alkenyl group, the alkoxy group, and the alkenyloxy group of the substituent may be substituted with fluorine or chlorine. Preferred ring A¹And ring A²Is 1, 4-cyclohexylene, 1, 4-phenylene or 2-fluoro-1, 4-phenylene, at least one hydrogen of these rings may be substituted by fluorine or an alkyl group having 1 to 5 carbon atoms.

a is 0, 1,2,3 or 4. Preferably a is 1,2 or 3. b and c are independently 0, 1 or 2. Preferably b or c is 1 or 2.

Z¹Independently a single bond or alkylene having 1 to 6 carbon atoms, Z¹In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro. Preferred Z¹Is a single bond, -CH₂-CH₂-、-CH₂O-、-OCH₂-, -COO-or-OCO-. Further preferred is Z¹Is a single bond.

P¹And P²Independently of one another is a polymerizable group, P¹And P²Is a group selected from the group consisting of the groups represented by the formula (1-p1), the formula (1-p2), the formula (1-p3), the formula (1-p4) and the formula (1-p 5). The wavy lines of formulae (1-p1) to (1-p5) indicate the sites to which bonds are bonded.

In the formulae (1-p1) to (1-p5),

Sp¹is a single bond or alkylene with 1 to 15 carbon atoms, and Sp¹In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro. Preferred is Sp¹Is a single bond or alkylene having 1 to 7 carbon atoms.

R²Is an alkyl group having 1 to 5 carbon atoms. Preferred R²Has 1 to 3 carbon atoms. Further preferred is R²The number of carbon atoms of (2) is 1, and in the above case, the reactivity is high, and the ability to align liquid crystal molecules and the voltage holding ratio when used in a liquid crystal display device can be maintained.

R³Is a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 8 carbon atoms. Preferred R³Has a carbon number of 1 to 5. Further preferred is R²The number of carbon atoms of (2) is 1, and in the above case, the reactivity is high, and the ability to align liquid crystal molecules and the voltage holding ratio when used in a liquid crystal display device can be maintained.

Y¹Is chlorine, fluorine or bromine. Preferred is Y¹Is fluorine. At Y¹In the case of fluorine, the solubility is high.

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

Sp²is a single bond or alkylene with 1 to 10 carbon atoms, and Sp²In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-, -OCOO-or a group represented by the formula (1-a)₂)₂-may be substituted with-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4), or formula (1-p 5). Preferred is Sp²Is a single bond or alkylene group having 1 to 7 carbon atoms,the Sp²In (1), at least one-CH₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-or a group represented by the formula (1-a)₂)₂-may be substituted with-CH ═ CH-, at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5).

Wherein, in the case where b and c are both 0,

Sp²is a single bond or alkylene with 1 to 10 carbon atoms, and Sp²In (1), at least one-CH₂At least one-CH which may be substituted by a group represented by the formula (1-a)₂At least one- (CH) which may be substituted by-O-, -CO-, -COO-, -OCO-or-OCOO-₂)₂-may be substituted with-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted with a group represented by formula (1-p1), formula (1-p2) or formula (1-p3), and at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5). Preferred is Sp²Is alkylene with 1 to 7 carbon atoms, and Sp²In (1), at least one-CH₂At least one-CH which may be substituted by a group represented by the formula (1-a)₂-may be substituted by-O-, -CO-or-COO-, at least one- (CH)₂)₂-may be substituted with-CH ═ CH-, at least one hydrogen may be substituted with a group represented by formula (1-p1), formula (1-p2) or formula (1-p3), and at least one hydrogen may be substituted with a group represented by fluorine, chlorine, formula (1-p1), formula (1-p2), formula (1-p3), formula (1-p4) or formula (1-p 5). The wavy line of formula (1-a) indicates the site to which the bond is bonded.

X¹Is a polar group having a heteroatom selected from the group consisting of nitrogen, oxygen, sulfur, phosphorus, and silicon. Preferred X¹Is a polar group having a heteroatom selected from the group consisting of oxygen. More preferred X¹Is a polar group represented by any one of the formulae (X-1) to (X-27).

In the formulae (X-1) to (X-27),

J¹and J²Independently hydrogen, or a linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms, and J¹And J²In (1), at least one-CH₂-may be substituted by-O-.

J³Is hydrogen, or a linear alkyl group having 1 to 20 carbon atoms or a branched alkyl group having 3 to 20 carbon atoms, and J³In (1), at least one-CH₂-may be substituted by-O-, -COO-or-OCO-.

J⁴And J⁵Independently hydrogen or an alkyl group having 1 to 8 carbon atoms.

Q¹Is methine or nitrogen, and herein, hydrogen of the methine group may be substituted with an alkyl group having 1 to 6 carbon atoms.

U¹And U²Independently is-CH₂-, -O-, -CO-or-S-.

V¹、V²And V³Independently of the other being methine or nitrogen, V¹、V²And V³At least one of which contains nitrogen.

W¹is-O-or-S-.

W²Carbon, sulfur or silicon.

The wavy lines of the formulae (X-1) to (X-27) indicate the sites bonded thereto.

(C) Second additive

In the formula (4), the reaction mixture is,

ring J and ring L are cyclohexyl, cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1, 3-dioxan-2-yl, pyrimidin-2-yl or pyridin-2-yl, wherein at least one hydrogen in ring J and ring L 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 wherein at least one hydrogen is substituted with fluorine or chlorine. Preferred ring J or ring L is cyclohexyl or phenyl. Ring K is 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-1, 2-diyl, naphthalene-1, 3-diyl, naphthalene-1, 4-diyl, naphthalene-1, 5-diyl, naphthalene-1, 6-diyl, naphthalene-1, 7-diyl, naphthalene-1, 8-diyl, naphthalene-2, 3-diyl, naphthalene-2, 6-diyl, naphthalene-2, 7-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, pyrimidine-2, 5-diyl or pyridine-2, 5-diyl, and at least one of the ring K is hydrogen, hydrogen-substituted alkyl having 1 to 12 carbon atoms, or halogen, 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 K is cyclohexyl or phenyl.

Z⁶And Z⁷Is a single bond or alkylene having 1 to 10 carbon atoms, the Z⁶And Z⁷In (1), at least one-CH₂-may be substituted by-O-, -CO-, -COO-or-OCO-, at least one-CH₂-CH₂-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. Preferred Z⁶Or Z⁷Is a single bond, -CH₂CH₂-、-CH₂O-、-OCH₂-, -COO-or-OCO-. Further preferred is Z⁶Or Z⁷Is a single bond.

Sp⁵、Sp⁶And Sp⁷Is a single bond or alkylene with 1 to 10 carbon atoms, and Sp⁵、Sp⁶And Sp⁷In (1), at least one-CH₂At least one-CH which may be substituted by-O-, -COO-, -OCO-or-OCOO-)₂-CH₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro. Preferred is Sp⁵、Sp⁶And Sp⁷Is a single bond or alkylene with 1 to 5 carbon atoms, and Sp⁵、Sp⁶And Sp⁷In (1), at least one-CH₂-may be substituted by-O-.

P⁹、P¹⁰And P¹¹Is a polymerizable group selected from the group of groups represented by the formulae (P-7) to (P-11). Preferred P⁹、P¹⁰Or P¹¹Is a group represented by the formula (P-7), the formula (P-8) or the formula (P-9). Further preferred is P⁹、P¹⁰Or P¹¹Is a group represented by the formula (P-7) or the formula (P-8). Especially preferred P⁹、P¹⁰Or P¹¹Is a group represented by the formula (P-7). A preferred group represented by formula (P-7) is-OCO-CH ═ CH₂or-OCO-C (CH)₃)＝CH₂. The wavy lines of the formulae (P-7) to (P-11) indicate the bonding sites.

In formulae (P-7) to (P-11), M⁵、M⁶And M⁷Is hydrogen, fluorine or alkyl with 1 to 5 carbon atoms, the M⁵、M⁶And M⁷In (1), at least one-CH₂-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 preferred⁵、M⁶Or M⁷Is hydrogen, methyl or-CH₂-O-CH₃. Further preferred is M⁵Is hydrogen, methyl or-CH₂-O-CH₃Further preferred is M⁶Or M⁷Is hydrogen.

h is 0, 1 or 2. Preferably h is 0 or 1. i. j and k are independently 0, 1,2,3 or 4, and the sum of i, j and k is 1 or more. Preferably i, j or k is 1 or 2.

Fifth, preferred component compounds are shown. Preferred compounds (1) are the compounds (1-7) to (1-90) described in the above item 5. Of these compounds, it is preferable that at least one of the first additives is a compound (1-8), a compound (1-12), a compound (1-14), a compound (1-18), a compound (1-20), a compound (1-22), a compound (1-24), a compound (1-26), a compound (1-28), a compound (1-30), a compound (1-36), a compound (1-38), a compound (1-40), a compound (1-42), a compound (1-44), a compound (1-46), a compound (1-52), a compound (1-54), a compound (1-55), a compound (1-56), a compound (1-59), a compound (1-61), The compound (1-62), the compound (1-65), the compound (1-67), the compound (1-68), the compound (1-71), the compound (1-73), the compound (1-77), the compound (1-78), the compound (1-79), the compound (1-83), the compound (1-84), the compound (1-85), the compound (1-89), and the compound (1-90). Preferably, at least two of the first additives are a combination selected from the group consisting of the compounds (1-12) and the compounds (1-14), the compounds (1-28) and the compounds (1-30), and the compounds (1-44) and the compounds (1-46).

Preferred compounds (2) are the compounds (2-1) to (2-35) described in the above item 7. 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 includes 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 2-8), and the compounds (2-8), A combination of the compound (2-7) and the compound (2-14), or the compound (2-10) and the compound (2-14).

Preferred compounds (3) are the compounds (3-1) to (3-13) described in the above item 10. 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 compounds (4) are the compounds (4-1) to (4-29) described in the above item 13. 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 (4-3), the compound (4-17), the compound (4-18), the compound (4-24), or the compound (4-25). 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), or the compound (4-2) and the compound (4-25).

Sixth, additives 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 (torsion angle). Examples of such compounds are compound (6-1) to compound (6-5). The preferable proportion of the optically active compound is about 5 parts by mass or less based on the weight of the liquid crystal composition containing no additive. Further, the preferable ratio is in the range of about 0.01 to about 2 parts by mass.

In order to prevent a decrease in specific resistance caused by heating in the atmosphere, or to maintain a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after the device is used for a long time, an antioxidant is added to the composition. 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 in 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. The preferable proportion of the antioxidant is about 50ppm or more in order to obtain the above effect, and about 600ppm or less in order not to lower the upper limit temperature or not to raise the lower limit temperature, based on the weight of the liquid crystal composition containing no additive. Even more preferred ratios range from about 100ppm to about 300 ppm.

Preferable examples of the ultraviolet absorber are benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Further, 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 preferred proportion of these absorbers 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, based on the weight of the liquid crystal composition containing no additives. Even more 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 preferred proportion of these matting agents is about 50ppm or more for obtaining the above-mentioned effects, and about 20000ppm or less for not raising the lower limit temperature, based on the weight of the liquid crystal composition containing no additives. Even more 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 preferred proportion of the pigment ranges from about 0.01 parts by mass to about 10 parts by mass based on the weight of the liquid crystal composition containing no additive.

In order to prevent foaming, an antifoaming agent such as dimethyl silicone oil or methylphenyl silicone oil is added to the composition. The preferable proportion of the defoaming agent is about 1ppm or more for obtaining the above-described effects, and about 1000ppm or less for preventing display defects, based on the weight of the liquid crystal composition containing no additive. Even more preferred ratios range from 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. Other polymerizable compounds different from 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 together with the compound (1), the compound (4), the compound (5-1), the compound (5-2) and the compound (5-3). 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. Further preferable 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 in 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. The alignment of the liquid crystal molecules is stabilized, and thus 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 the polymerization, suitable types and suitable amounts of initiators are known to the person 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 to about 5 parts by mass based on the mass of the polymerizable compound. Further, the preferable ratio is in the range of about 1 part by mass to about 3 parts 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, -NH₂At least one of partial structures such as NH and N-.

Seventh, a method for synthesizing the component compound will be explained. These compounds can be synthesized by known methods. The synthesis method is exemplified. The synthesis of compound (1) is described in the section of the 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 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 methods described in the following written description: organic Synthesis (Organic Synthesis), Inc. (John Wiley & Sons, Inc.), (Organic Reactions), Inc. (John Wiley & Sons, Inc.)), (Organic Synthesis), Integrated Circuit (Pergeman Press), New Experimental chemistry lecture (Bolus), etc. The compositions are prepared by known methods from the compounds obtained in the manner described. 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 a 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 also 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 compositions are useful in AM elements. Further, the present invention can be applied to a PM element. The composition can be used for AM elements and PM elements with modes of PC, TN, STN, ECB, OCB, IPS, FFS, VA, FPA and the like. Particularly preferred is an AM element for use in a 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 of a reflective type, a transmissive type or a semi-transmissive type. Preferably for use in transmissive devices. But also for amorphous silicon-TFT elements or polysilicon-TFT elements. It is also applicable to a Nematic Curvilinear Aligned Phase (NCAP) type element prepared by microencapsulating the composition, 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. If necessary, additives may be further added. Injecting the composition into a component. 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. By the polymerization, a composition containing a polymer is produced. Polymer-stabilized oriented devices are fabricated in this order.

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 malfunction 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.

In the case of using a polar compound having a polymerizable group (i.e., a polymerizable compound) such as the compound (1), an alignment film is not required on the substrate of the element. Elements without alignment films were fabricated from substrates that were not subjected to alignment treatment in the order described in the preceding two paragraphs.

In the order, the compound (1) is 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 this state, a polymer maintaining the orientation 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 malfunction 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 with reference to examples. The present invention is not limited to 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 determined by the following methods.

NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for the measurement. In that¹In the measurement of H-NMR, a sample was dissolved in CDCl₃The measurement was performed at room temperature in a deuterated solvent at 500MHz for 16 cumulative times. Tetramethylsilane was used as an internal standard. In that¹⁹In the measurement of F-NMR, CFCl was used₃As an internal standard, the number of times is accumulated to 24 times. In the description of 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 (multiplex), 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 ℃. For separation of component compounds, a capillary column DB-1 (length 30m, inner diameter 0.32mm, film thickness 0.25 μm; fixing liquid phase is dimethylpolysiloxane; non-polar) manufactured by Agilent Technologies Inc. was used. After the column was held at 200 ℃ for 2 minutes, it was heated 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. Capillary columns manufactured by Shimadzu corporation, CBP1-M50-025 (length 50M, inner diameter 0.25mm, film thickness 0.25 μ M) were also used for the purpose of preventing overlapping of compound peaks.

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 a smectic phase (or crystal) 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 obtained 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 society of electronic Information Technology Industries (Japan Electronics and Information Technology Industries Association; referred to as 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 including a polarizing microscope, and heated at a rate of 1 ℃ per minute. 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 placing the sample in a glass bottle and keeping the bottle in a freezer at 0 ℃, -10 ℃, -20 ℃, -30 ℃ and-40 ℃ for 10 days. For example, when the sample maintains a nematic phase at-20 ℃ and changes to a crystalline or smectic phase at-30 ℃, T is measured_CIs reported 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): the measurement was carried out by using a rotational viscosity ratio measuring system LCM-2 of Toyang technology (TOYO Corporation) 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. The values of rotational viscosity were obtained using these measured values and the dielectric anisotropy. 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 primary prism in one direction, the sample was dropped onto the primary prism. The refractive index n/is measured when the direction of polarization is parallel to the direction of rubbing. The refractive index n ″) 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.. di-elect cons.; measured at 25 ℃): the value of the dielectric anisotropy is calculated from the formula Δ ∈/∈ ″. The dielectric constants (. epsilon./. epsilon. mu.j) were measured in the following manner.

1) Measurement of dielectric constant (. epsilon. /): a solution of octadecyltriethoxysilane (0.16mL) in ethanol (20mL) was applied to 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 light. A sine wave (0.5V, 1kHz) was applied to the cell, and the dielectric constant (. epsilon. /) in the long axis direction of the liquid crystal molecules was measured after 2 seconds.

2) Measurement of dielectric constant (. epsilon. DELTA. -): the glass substrate that was sufficiently cleaned was coated with a polyimide solution. 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 the measurement, a Liquid Crystal Display (LCD) 5100 type luminance meter manufactured by Otsuka electronics Ltd was used. The light source is a halogen lamp. A sample was placed in a VA element of a normally black mode (normal black mode) in which the interval (cell gap) between two glass substrates was 4 μm and the rubbing directions were antiparallel, and the element was sealed with an adhesive hardened by ultraviolet rays. The voltage applied to the element (60Hz, square wave) was increased from 0V to 20V in a stepwise manner 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 was prepared in which the transmittance was 100% when the light amount reached the maximum and the transmittance was 0% when the light amount reached the minimum. The threshold voltage is represented by a voltage at which the transmittance becomes 10%.

(8) Voltage holding ratio (initial VHR; measured at 60;%): the VA cell using a glass substrate that was not subjected to alignment treatment was sealed with a sample. The gap between the two glass substrates (cell gap) was 3.5 μm. The element is sealed with an adhesive hardened by ultraviolet rays after the sample is injected. 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 represented 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. In the measurement, a VA device using a glass substrate which was not subjected to alignment treatment was used, and the gap (cell gap) between the two glass substrates was 3.5. mu.m. The sample was injected into the cell and 15J of 5 mw light was irradiated using UV2 as the light source. Then, the UV-VHR assay was performed 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, more 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. Utilization in measurementIn the VA device using the glass substrates which were not subjected to the alignment treatment, the gap (cell gap) between the two glass substrates was 3.5. mu.m. The sample was injected into the element and irradiated at 365nm with an intensity of 7.0mW/cm²For 90 minutes and heated in a thermostat at 60 ℃ for 12 hours. Then, the heated VHR was 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 more preferably 95% or more.

(11) Response time (. tau.; measured at 25 ℃ C.; ms): for the measurement, an LCD5100 type luminance meter manufactured by Otsuka electronics Co., Ltd 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 by ultraviolet rays. Applying a voltage of 30V to one side of the element, and irradiating 78mW/cm to the other side²Ultraviolet (405nm) rays 449 seconds (35J). 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 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 0V was applied to the cell, and the electrostatic capacitance and applied voltage were measured. The values of the measured electrostatic capacitance (C) and the applied voltage (V) were fitted using the equations (2.98) and (2.101) on page 75 of the handbook of liquid crystal devices (journal industries, press), 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 sample was injected into the container including the electrode. A DC voltage (10V) was applied to the vessel, and a DC current after 10 seconds was measured. The specific resistance was calculated from the following equation. (specific resistance) { (voltage) × (capacitance of container) }/{ (direct current) × (dielectric constant of vacuum) }.

(14) Pretilt angle measurement (Pt angle; degree): retts (RETS) -100 (manufactured by Otsuka Electron Co., LTD) was used for measurement of pretilt angle. In order to maintain the viewing angle characteristics of the VA mode display device, it is desirable to provide a pretilt angle of 1 degree or more under arbitrary conditions.

(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 on the electrode side before the stress was applied was measured (before), and after applying a square wave of 4.5V and 60Hz to the element for 20 minutes, the cell was buffered for 1 second, and after 1 second and 5 minutes, the liquid crystal alignment angle phi on the electrode side was measured again (after). 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.

Δ φ (deg.) φ (after) - φ (before)

These measurements are made with reference to Solid Films (Thin Solid Films) 455-456(2004) -596-600 of J.Hilfeke (J.Hilfaker), B.Jones (B.John), C.Herzinger (C.Herzinger), J.F.Elman (J.F.Elman), E.Monbamic (E.Montbach), D.Bryant (D.Bryant) and P.J.Bos (P.J.Bos). It can be said that the smaller the Δ Φ, the smaller the rate of change of the liquid crystal alignment axis, and 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 added polar compound is not precipitated at-10 ℃ for 10 days, and the nematic phase is maintained. Further preferably, the nematic phase is maintained at-20 ℃ for 10 days.

[ Synthesis example 1]

Synthesis of Compound (1-14-1)

Step 1

The compound (T-1) (100.0g), the compound (T-2) (58.6g) synthesized by a known method, sodium carbonate (68.1g), [1,1' -bis (diphenylphosphino) ferrocene ] palladium (II) dichloride (9.80g), dioxane (1000ml), and pure water (250ml) were put into a reactor and stirred at 80 ℃ 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: toluene ═ 4: 1) to obtain compound (T-3) (72.1 g; 77%).

Step 2

The known compound (T-3) (72.1g) and Tetrahydrofuran (THF) (500ml) were placed in a reactor, and n-butyllithium (1.6mol/L, hexane solution) (185.7ml) was added dropwise at-70 ℃ and stirred at-70 ℃ for 1 hour. A THF solution (150ml) of compound (T-4) (50.0g) was added dropwise thereto, and the mixture was stirred for 5 hours while warming to room temperature. 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 (vol. toluene: ethyl acetate ═ 19: 1) to obtain compound (T-5) (84.8 g; 90%).

Step 3

Aluminum chloride (29.7g) and toluene (400ml) were put into a reactor, and 1,1,3, 3-tetramethyldisiloxane (14.9g) was added dropwise at-70 ℃. A toluene (400ml) solution of compound (T-5) (84.8g) was added dropwise thereto, and the mixture was stirred at room temperature for 4 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 ═ 19: 1) to obtain compound (T-6) (61.7 g; 76%).

Step 4

Compound (T-6) (61.7g) and methylene chloride (500ml) were placed in a reactor, and boron tribromide (1.0mol/L, methylene chloride solution) (220ml) was added dropwise at 0 ℃ and stirred for 6 hours while warming to room temperature. 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 (vol. toluene: ethyl acetate: 9: 1) to obtain compound (T-7) (52.0 g; 87%).

Step 5

Compound (T-7) (50.0g), methylene chloride (500ml) and methanol (500ml) were placed in a reactor and cooled to 0 ℃. Benzyltrimethylammonium tribromide (116.8g) was added to the solution, which was allowed to warm 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 (vol. toluene: ethyl acetate: 9: 1) to obtain compound (T-8) (59.4 g; 82%).

Step 6

Compound (T-8) (59.4g), compound (T-9) (24.7g), potassium iodide (21.3g), potassium carbonate (32.3g), N-Dimethylformamide (DMF) (600ml) were put into a reactor and stirred at 80 ℃ 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 (vol. toluene: ethyl acetate: 9: 1) to obtain compound (T-10) (63.7 g; 82%).

Step 7

Compound (T-10) (63.7g), sodium hydrogencarbonate (16.1g), palladium acetate (4.30g), methyl acrylate (24.7g) and DMF (600ml) were placed in a reactor and stirred at 90 ℃ for 9 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 (vol. toluene: ethyl acetate 4: 1) to obtain compound (T-11) (42.0 g; 65%).

Step 8

Compound (T-11) (42.0g), a palladium catalyst (type pH) (0.70g), toluene (500ml), and isopropyl alcohol (IPA) (500ml) were put into a reactor and stirred under a hydrogen atmosphere for 24 hours. The reaction mixture was filtered, the solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (vol., toluene: ethyl acetate 4: 1) to obtain compound (T-12) (38.0 g; 90%).

Step 9

Lithium Aluminum Hydride (LAH) (2.54g) and Tetrahydrofuran (THF) (500ml) were put into a reactor, and a THF (500ml) solution of compound (T-12) (38.0g) was added at 0 ℃ and stirred at room temperature for 4 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 (vol. toluene: ethyl acetate ═ 1: 2) to obtain compound (T-13) (24.4 g; 70%).

Step 10

Compound (T-13) (24.4g), N-Dimethylaminopyridine (DMAP) (4.79g), 2-fluoroacrylic acid (10.5g), and methylene chloride (500ml) were put into a reactor and cooled to 0 ℃. N, N-Dicyclohexylcarbodiimide (DCC) (20.2g) was added thereto, and stirred at room temperature 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 (vol. toluene: ethyl acetate 4: 1) to obtain compound (T-14) (19.5 g; 65%).

11 th step

Compound (T-14) (19.5g), Pyridinium p-Toluenesulfonate (PPTS) (3.19g), THF (200ml) and methanol (200ml) were put into a reactor and stirred at 50 ℃ for 12 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 (vol. toluene: ethyl acetate: 1) to obtain compound (T-15) (14.6 g; 75%).

Step 12

Compound (T-15) (14.6g), N-Dimethylaminopyridine (DMAP) (1.16g), compound (T-16) (4.25g) synthesized by a known method, methylene chloride (500ml) were put into a reactor and cooled to 0 ℃. N, N-Dicyclohexylcarbodiimide (DCC) (4.71g) was added thereto, and stirred at room temperature 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 (vol. toluene: ethyl acetate 4: 1) to obtain compound (T-17) (10.5 g; 65%).

Step 13

Compound (T-17) (10.5g), pyridinium p-toluenesulfonate (PPTS) (1.55g), THF (100ml) and methanol (100ml) were placed in a reactor and stirred at 50 ℃ for 12 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 (vol. toluene: ethyl acetate: 1) to obtain compound (1-14-1) (6.6 g; 70%).

The compounds (Z-1) to (Z-23) described later 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 (Z-1) to (Z-23), and polymerizable compounds (RM-1) to (RM-11), which are listed in order.

[ composition M1]

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

[ composition M2]

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

[ composition M3]

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

[ composition M4]

NI＝88.5℃；Tc＜-30℃；Δn＝0.108；Δε＝-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；Δε＝-4.5；Vth＝1.69V；η＝31.4mPa·s.

[ composition M6]

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

[ composition M7]

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

[ composition M8]

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

[ composition M9]

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

[ composition M10]

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

[ composition M11]

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

[ composition M12]

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

[ composition M13]

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

[ composition M14]

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

[ composition M15]

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

[ composition M16]

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

[ composition M17]

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

[ composition M18]

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

[ composition M19]

NI＝75.9℃；Δn＝0.101；Δε＝-2.7.

[ composition M20]

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

[ composition M21]

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

[ composition M22]

NI＝75.3℃；Δn＝0.109；Δε＝-3.1；Vth＝2.29V.

[ composition M23]

NI＝73.5℃；Tc＜-20℃；Δn＝0.100；Δε＝-2.6.

[ composition M24]

NI＝74.8℃；Tc＜-20℃；Δn＝0.099；Δε＝-3.2.

[ composition M25]

NI＝71.1℃；Tc＜-20℃；Δn＝0.105；Δε＝-2.7.

[ composition M26]

NI＝75.6℃；Δn＝0.104；Δε＝-2.4.

[ composition M27]

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

[ composition M28]

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

The following polar compounds (Z-1) to (Z-23) were used as the first additives. The numbers in parentheses located at the rear correspond to the numbers of the compounds.

The following polymerizable compounds (RM-1) to (RM-11) were used as the second additive.

[ example 1]

The composition (M1) was added with the formula (Z-1) as a first additive in an amount of 0.5% by mass. The composition showed a nematic phase at room temperature, and the result of NI (. degree. C.) measurement was 72.6 ℃.

In order to confirm the low-temperature solubility of the formula (Z-1), the composition was stored in a refrigerator at-0 ℃ for 7 days, and as a result, the nematic phase was maintained.

Further, the composition was sealed in a VA element using a glass substrate which was not subjected to alignment treatment, and the vertical alignment of the composition on the substrate was confirmed, and as a result, the vertical alignment was exhibited. A voltage of 19.0V was applied to the VA device, and the intensity at 365nm was 7.0mW/cm²UV light for 1 minute. Subsequently, the same UV light was irradiated for 90 minutes without applying a voltage. The pretilt angle (Pt angle) was measured, and found to be 1.12 degrees.

Comparative example 1

For comparison, a compound represented by the following formula (S) was added to the composition (M1) at a ratio of 0.5% by mass. NI (. degree. C.) was confirmed in the same manner as in example 1, and the result was 72.4 ℃.

In addition, in order to confirm the low-temperature solubility of the formula (S), the composition was kept in a refrigerator at-0 ℃ for 7 days, and as a result, the nematic phase could not be maintained and crystals were precipitated.

The composition was sealed in a VA element using a glass substrate that was not subjected to alignment treatment, and the vertical alignment of the composition on the substrate was confirmed, resulting in the display of vertical alignment. The VA cell was irradiated with UV light for 90 minutes in the same manner as in example 1, and the pretilt angle (Pt angle) was measured, and found to be 0.30 degrees.

[ example 2 to example 37]

The kind of the composition and the concentration of the polar compound were changed to prepare a liquid crystal composition to which the first additive and the second additive were added, and the low temperature solubility and the Pt angle were measured by the same method as in example 1. Regarding the low-temperature solubility, the nematic phase was maintained at 0 ℃ for 7 days as "o", and the nematic phase was not maintained as "x", and the results are summarized in table 4.

TABLE 4 Low temperature solubility and pretilt angle of liquid crystal compositions

From the results in table 4, the liquid crystal composition to which the first additive was added exhibited good low-temperature solubility, and further was imparted with a Pt angle of 1 degree or more. On the other hand, the liquid crystal composition to which the first additive is not added has poor low-temperature solubility and a Pt angle of less than 1 degree. The results show that the liquid crystal composition of the present invention has excellent low-temperature solubility and a high Pt angle formation rate.

[ industrial applicability ]

The liquid crystal composition of the present invention can impart excellent low-temperature solubility and a suitable Pt angle. The liquid crystal display element containing the composition has the characteristics of short response time, large voltage holding ratio, low threshold voltage, large contrast ratio, long service life and the like, and therefore, the liquid crystal display element can be used in a liquid crystal projector, a liquid crystal television and the like.

Claims

1. A liquid crystal composition containing at least one compound selected from the group consisting of polar compounds represented by the 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 10 carbon atoms, the R¹In (1), at least one-CH₂-may be substituted by-O-or-S-, at least one- (CH)₂)₂-may be substituted by-CH ═ CH-or-C ≡ C-, at least one hydrogen may be substituted by fluoro or chloro;

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

b and c are independently 0, 1 or 2;

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

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

wherein, in the case where b and c are both 0,

2. the liquid crystal composition according to claim 1, wherein the polar group is represented by any one of formula (X-1) to formula (X-27);

in the formulae (X-1) to (X-27),

J⁴and J⁵Independently hydrogen or alkyl of carbon number 1 to 8;

U¹and U²Independently is-CH₂-, -O-, -CO-or-S-;

W¹is-O-or-S-;

W²is carbon, sulfur or silicon;

3. The liquid crystal composition according to claim 1 or 2, having at least one compound selected from the group consisting of compounds represented by formulae (1-1) to (1-6) as the first additive;

in the formulae (1-1) to (1-6),

R¹is hydrogen or alkyl with 1 to 10 carbon atoms, the R¹In (1), at least one-CH₂-may be substituted by-O-at least one- (CH)₂)₂-may be substituted by-CH ═ CH-, at least one hydrogen may be substituted by fluorine or chlorine;

b and c are independently 0, 1 or 2;

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

in the formulae (1-1) to (1-6),

wherein, in the case where b and c are both 0,

4. the liquid crystal composition according to claim 1 or 2, having at least one compound selected from the group consisting of compounds represented by formulae (1-7) to (1-90) as the first additive;

in the formulae (1-7) to (1-90),

R¹an alkyl group having 1 to 10 carbon atoms;

Z¹to Z³Independently is a single bond or- (CH)₂)₂-；

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

R²an alkyl group having 1 to 5 carbon atoms;

Y¹is chlorine, fluorine or bromine;

in the formulae (1-7) to (1-90),

5. The liquid crystal composition according to claim 1 or 2, wherein the proportion of the first additive is in the range of 0.03 to 10 parts by mass based on the mass of the liquid crystal composition containing no additive.

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

in the formula (2), the reaction mixture is,

R¹¹and R¹²Independently hydrogen, alkyl group with carbon number of 1 to 12, alkoxy group with carbon number of 1 to 12, alkenyl group with carbon number of 2 to 12, and alkenyloxy group with carbon number of 2 to 12Or an alkyl group of carbon number 1 to 12 in which at least one hydrogen is substituted by fluorine or chlorine;

e is 0, 1,2 or 3, f is 0 or 1, and the sum of e and f is 3 or less.

7. The liquid crystal composition according to claim 6, comprising at least one compound selected from the group of compounds represented by formulae (2-1) to (2-35) as the first component;

in the formulae (2-1) to (2-35),

R¹¹and R¹²Is hydrogen, alkyl group with 1 to 12 carbon atoms, alkoxy group with 1 to 12 carbon atoms, alkene with 2 to 12 carbon atomsA C1-12 alkyl group in which at least one hydrogen is substituted with fluorine or chlorine.

8. The liquid crystal composition according to claim 6, wherein the proportion of the first component is in the range of 10 to 90 mass% based on the mass of the liquid crystal composition containing no additive.

9. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from the group consisting of compounds represented by formula (3) as a second component;

in the formula (3), the reaction mixture is,

R¹³and R¹⁴Independently an alkyl group of carbon number 1 to 12, an alkoxy group of carbon number 1 to 12, an alkenyl group of carbon number 2 to 12, an alkyl group of carbon number 1 to 12 in which at least one hydrogen is substituted with fluorine or chlorine, or an alkenyl group of carbon number 2 to 12 in which at least one hydrogen is substituted with fluorine or chlorine;

Z¹⁵independently a single bond, ethylene or carbonyloxy;

g is 1,2 or 3.

10. The liquid crystal composition according to claim 9, comprising at least one compound selected from the group consisting of compounds represented by formulae (3-1) to (3-13) as the second component;

in the formulae (3-1) to (3-13),

R¹³and R¹⁴Is alkyl group with 1 to 12 carbon atoms, alkoxy group with 1 to 12 carbon atoms, alkenyl group with 2 to 12 carbon atomsAt least one alkyl group having 1 to 12 carbon atoms in which hydrogen is substituted by fluorine or chlorine, or at least one alkenyl group having 2 to 12 carbon atoms in which hydrogen is substituted by fluorine or chlorine.

11. The liquid crystal composition according to claim 9, wherein the proportion of the second component is in the range of 10 to 90 mass% based on the mass of the liquid crystal composition containing no additive.

12. The liquid crystal composition according to claim 1 or 2, comprising at least one compound selected from polymerizable compounds represented by formula (4) as a second additive;

in the formula (4), the reaction mixture is,

h is 0, 1 or 2;

13. The liquid crystal composition according to claim 12, comprising at least one compound selected from the group consisting of compounds represented by formulae (4-1) to (4-29) as the second additive;

in the formulae (4-1) to (4-29),

14. The liquid crystal composition according to claim 12, wherein the proportion of the second additive is in the range of 0.03 to 10 parts by mass based on the mass of the liquid crystal composition containing no additive.

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

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

17. A polymer-stabilized alignment type liquid crystal display element comprising the liquid crystal composition according to any one of claims 1 to 14, or a polymerizable compound in the liquid crystal composition, and polymerized.

18. Use of a liquid crystal composition according to any one of claims 1 to 14 in a liquid crystal display element.

19. Use of a liquid crystal composition according to any one of claims 1 to 14 in a liquid crystal display element of a polymer-stabilized alignment type.