Liquid crystal element, projector, and head-up display

Abstract

To steadily form a small pretilt in a liquid crystal element provided with an inorganic alignment film on the surface of a substrate.SOLUTION: Provided is a liquid crystal element provided with a first substrate, a second substrate, and a liquid crystal layer held between the first substrate and the second substrate, with an inorganic alignment film provided on the surface of the first substrate and / or the second substrate. The liquid crystal layer contains a liquid crystal composition whose dielectric anisotropy (Δε) is positive, and the liquid crystal composition contains a pyrimidine compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a liquid crystal element, a projector, and a head-up display. [Background technology]

[0002] LCOS (Liquid Crystal on Silicon) elements are known as small liquid crystal elements capable of producing high-definition images. LCOS elements are basically used in projection type displays, but when used in projectors or in-vehicle HUDs (Head Up Displays), an inorganic alignment film with higher light resistance than polyimide resins used in general alignment films is used because very strong light is incident on the liquid crystal element. Patent Document 1, for example, is an example of such an LCOS element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-206212 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since inorganic alignment films are formed by oblique deposition of SiO2 or the like, it is easy to control a large pretilt angle as in the vertical alignment mode, but it is not possible to stably form a small pretilt angle as in the horizontal alignment mode. An object of the present invention is to stably form a small pretilt angle in a liquid crystal element having an inorganic alignment film on the surface of a substrate. [Means for solving the problem]

[0005] As a result of intensive research, the inventors have discovered that in a liquid crystal element having an inorganic alignment film on the surface of a substrate, the above-mentioned problems can be solved by having a liquid crystal composition constituting a liquid crystal layer contain a pyrimidine compound, and have thus completed the present invention. An example of the configuration of the present invention that solves the above problem is as follows.

[0006] Item 1. A first substrate; A second substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate; A liquid crystal element comprising: An inorganic alignment film is provided on a surface of the first substrate and / or the second substrate, The liquid crystal layer contains a liquid crystal composition having a positive dielectric anisotropy (Δε), The liquid crystal composition comprises a pyrimidine compound.

[0007] Item 2. The pyrimidine compound is represented by the following general formula (P):

[0008] [ka] (In general formula (P), R P1 represents an alkyl group having 1 to 20 carbon atoms, S P1 each independently represents a hydrogen atom or a halogen atom, n P1 represents an integer between 0 and 1.) 2. The liquid crystal device according to item 1, wherein the compound is represented by the formula:

[0009] Item 3. A liquid crystal device according to item 1 or 2, wherein the inorganic component in the inorganic alignment film is one or more selected from the group consisting of silicon oxide (SiO2) and aluminum oxide (Al2O3).

[0010] Item 4. The liquid crystal device according to any one of Items 1 to 3, wherein the liquid crystal composition contains a chiral agent.

[0011] Item 5. The liquid crystal element according to item 4, wherein d / p is 0.001 to 0.40.

[0012] Item 6. A projector using the liquid crystal element according to any one of items 1 to 5.

[0013] Item 7. A head-up display using the liquid crystal element according to any one of items 1 to 5. Effect of the Invention

[0014] According to the present invention, the liquid crystal layer contains a liquid crystal composition containing a pyrimidine compound, which facilitates horizontal alignment of the liquid crystal compound, i.e., makes it possible to reduce the pretilt angle, and enables smooth switching of the alignment state when a voltage is applied to the liquid crystal layer. Furthermore, the liquid crystal element according to the present invention has a good response time and can suppress the occurrence of twisted domains. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (First Substrate and Second Substrate) A liquid crystal element according to the present invention comprises a first substrate and a second substrate, which substrates form a cell. Specifically, a first substrate and a second substrate are disposed opposite each other with a liquid crystal layer sandwiched therebetween to form a cell, with the liquid crystal layer being sandwiched between the substrates. The first substrate and the second substrate may be a glass substrate, a silicon substrate, or the like. Examples of the glass substrate include non-alkali glass and soda glass. Silicon substrates include silicon wafers used in the manufacture of semiconductor products. From the viewpoint of manufacturability, the thickness of the substrate is preferably 0.1 to 2 mm, and more preferably 0.5 to 1.5 mm. The shape of the substrate is not particularly limited, but a square, rectangular or the like is preferred. When the substrate has a square or rectangular shape, its size is preferably 0.5 to 10 cm square, and more preferably 1 to 5 cm square.

[0016] The distance between the substrates can be ensured by using a spacer or the like. Examples of the spacer include granular spacers such as glass particles, plastic particles, and alumina particles, and resin spacer pillars formed by photolithography.

[0017] The first substrate and / or the second substrate has an inorganic alignment film on the surface. From the viewpoint of light resistance, it is preferable that both the first substrate and the second substrate have an inorganic alignment film. Moreover, the first substrate and / or the second substrate preferably has an inorganic alignment film on the surface in contact with the liquid crystal layer. Examples of inorganic components in the inorganic alignment film include silicon oxide (SiO2) and aluminum oxide (Al2O3). The inorganic alignment film preferably contains, as an inorganic component, one or more materials selected from the group consisting of silicon oxide (SiO2) and aluminum oxide (Al2O3). The inorganic alignment film can be formed, for example, by obliquely evaporating an inorganic component onto the substrate surface using a vacuum deposition apparatus so that a desired pretilt angle can be imparted to the liquid crystal compound.

[0018] Additionally, the first substrate and / or the second substrate may have a plurality of electrodes on the surface. The electrodes include an ITO electrode and a reflective pixel electrode.

[0019] (Liquid crystal layer) A liquid crystal element according to the present invention comprises a liquid crystal layer sandwiched between a first substrate and a second substrate. The liquid crystal layer may be made of a liquid crystal composition or may contain a liquid crystal composition.

[0020] The liquid crystal composition according to the present invention has a positive dielectric anisotropy (Δε) at 25° C. (2≦Δε). The dielectric anisotropy (Δε) at 25° C. of the liquid crystal layer (liquid crystal composition) according to the present invention is th), it is preferably 2.0 to 30.0, more preferably 4.0 to 25.0, even more preferably 6.0 to 20.0, and even more preferably 6.0 to 16.5. The dielectric anisotropy (Δε) can be measured by an LCR meter (manufactured by Keysight Corporation).

[0021] Liquid crystal phase upper limit temperature (T ni ) is the temperature at which the liquid crystal composition undergoes phase transition from a nematic phase to an isotropic phase. T ni The measurement is performed by preparing a preparation in which the liquid crystal composition is sandwiched between a slide glass and a cover glass, and observing the preparation under a polarizing microscope while heating the preparation on a hot stage. It can also be measured by differential scanning calorimetry (DSC). The unit used is "℃". T ni The higher the temperature, the more the nematic phase can be maintained even at high temperatures, and the wider the operating temperature range can be. The upper limit temperature (T ni From the viewpoint of maintaining the liquid crystal phase even when the temperature of the liquid crystal element is increased by the incidence of strong light, the temperature is preferably 60°C or higher, more preferably 60 to 150°C, more preferably 65°C to 145°C, and even more preferably 70°C to 140°C.

[0022] Liquid crystal phase lower limit temperature (T →n ) is the temperature at which a liquid crystal composition undergoes phase transition from another phase (glass phase, smectic phase, crystalline phase) to the nematic phase. T →n is measured by filling a glass capillary with the liquid crystal composition, immersing it in a refrigerant at -70°C to cause the liquid crystal composition to undergo a phase transition to another phase, and observing the change while increasing the temperature. It can also be measured by differential scanning calorimetry (DSC). The unit used is "℃". T →n The lower the temperature, the more the nematic phase can be maintained even at low temperatures, and therefore the operating temperature range can be made wider. The liquid crystal phase lower limit temperature (T →n ) is preferably 10°C or lower, more preferably -70 to 0°C, and even more preferably -50 to -5°C, from the viewpoint of the driving temperature.

[0023] Δn (refractive index anisotropy) correlates with Δn in the visible light region used in projectors and head-up displays, which will be described later. The larger Δn is, the greater the phase modulation power for the target wavelength is, so the thickness (d) of the liquid crystal layer can be made thinner, which is particularly suitable for projectors and head-up displays that require a fast response time. The extraordinary refractive index (n e ) and ordinary refractive index (n o ) difference (n e -n o ) is calculated. Also, Δn can be obtained from a phase difference measuring device. The relationship between the retardation Re, the thickness (d) of the liquid crystal layer, and Δn is Δn=Re / d. In measuring Δn, first, a liquid crystal composition is injected into a glass cell with a polyimide alignment film that has been subjected to an anti-parallel rubbing treatment, and the thickness (d) of the liquid crystal layer is measured. Then, the in-plane Re is measured using a retardation film / optical material inspection device RETS-100 (manufactured by Otsuka Electronics Co., Ltd.). The measurement is performed at 25°C and 589 nm, and has no units. The liquid crystal layer (liquid crystal composition) according to the present invention preferably has Δn at 25° C. and 589 nm of 0.10 or more, preferably 0.15 to 0.35, and more preferably 0.20 to 0.30, from the viewpoint of obtaining a large phase modulation power.

[0024] The rotational viscosity (γ1) is the viscosity related to the rotation of liquid crystal molecules. γ1 can be measured by filling the liquid crystal composition into a glass cell having a cell gap of about 10 μm, applying a voltage of 50 V, and using an LCM-2 (manufactured by Toyo Corporation). In the case of a liquid crystal composition having a positive dielectric anisotropy, a horizontally aligned cell is used, whereas in the case of a liquid crystal composition having a negative dielectric anisotropy, a vertically aligned cell is used. The measurement is carried out at 25°C and the unit is mPa·s. The smaller γ1 is, the faster the response speed of the liquid crystal composition becomes, and therefore, it is suitable for any liquid crystal element. The rotational viscosity (γ1) of the liquid crystal layer (liquid crystal composition) according to the present invention at 25° C. is preferably 150 to 1000 mPa·s, more preferably 200 to 750 mPa·s, and even more preferably 250 to 350 mPa·s, from the viewpoint of response speed.

[0025] By adding a chiral agent, which will be described later, to the liquid crystal composition, a twist pitch (p) can be induced. The twist pitch (p) of the liquid crystal layer (liquid crystal composition) according to the present invention is preferably from 5 to 1500 μm, more preferably from 10 to 200 μm, and even more preferably from 10.5 to 150 μm, from the viewpoint of horizontal alignment. The twist pitch (p) can be calculated by injecting a liquid crystal composition containing a predetermined amount of chiral agent into a wedge-shaped liquid crystal cell having two anti-parallel rubbed substrates with the distance between the substrates gradually changing, and using the tilt angle θ of the wedge-shaped liquid crystal cell (tilt of the upper substrate) and the distance L between the disclination lines of the wedge-shaped liquid crystal cell measured with a length measuring device, etc., as p=2×L×tan θ.

[0026] The liquid crystal composition according to the present invention contains a pyrimidine compound. It is known that the surface of inorganic alignment films containing silicon oxide (SiO2) etc. is covered with hydroxyl groups (-OH). Pyrimidine compounds are known to be highly basic and hydrophilic, which is believed to result in the adsorption of the pyrimidine compound onto the surface of the inorganic alignment film, resulting in a small pretilt angle and improved horizontal alignment. The pyrimidine compound is preferably a compound represented by the following general formula (P).

[0027] [ka]

[0028] In general formula (P), R P1 represents an alkyl group having 1 to 20 carbon atoms.

[0029] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0030] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0031] R P1 Specific examples of the alkyl group having 1 to 20 carbon atoms include those represented by the formula (R P1 -1)~(R P1 -6) and the like.

[0032] [ka]

[0033] Formula (R P1 -1)~(R P1 -6), the black dots represent bonds to the ring structure.

[0034] In addition, R v1 As for T ni From the viewpoint of adjusting the refractive index anisotropy, a linear alkyl group having 1 to 6 carbon atoms is preferable.

[0035] In general formula (P), S P1 each independently represents a hydrogen atom or a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. From the viewpoint of ensuring large dielectric anisotropy and reliability, a fluorine atom is preferred.

[0036] In general formula (P), n P1 represents an integer from 0 to 1.

[0037] The compound represented by general formula (P) is preferably a compound represented by the following general formulas (P-1) to (P-3).

[0038] [ka]

[0039] In general formulas (P-1) to (P-3), R P1 is R in the above general formula (P). P1 The preferred groups are also the same as those mentioned above.

[0040] The compound represented by general formula (P-1) is preferably a compound represented by the following structural formulas (P-1.1) to (P-1.2).

[0041] [ka]

[0042] The compound represented by general formula (P-2) is preferably a compound represented by the following structural formula (P-2.1).

[0043] [ka]

[0044] The compound represented by general formula (P-3) is preferably a compound represented by the following structural formula (P-3.1).

[0045] [ka]

[0046] The type of compound represented by general formula (P), general formulas (P-1) to (P-3), structural formulas (P-1.1) to (P-1.2), structural formula (P-2.1) or structural formula (P-3.1) used in the liquid crystal composition is one or more types, preferably 1 to 5 types, preferably 1 to 4 types, preferably 1 to 3 types, preferably 1 to 2 types, and preferably 1 type.

[0047] The lower limit of the total content of the compounds represented by general formula (P), general formulas (P-1) to (P-3), structural formulas (P-1.1) to (P-1.2), structural formula (P-2.1) or structural formula (P-3.1) in 100 mass% of the liquid crystal composition is preferably 0.5 mass% or more, preferably 1.5 mass% or more, preferably 5 mass% or more, preferably 10 mass% or more, preferably 15 mass% or more, and preferably 20 mass% or more.

[0048] The upper limit of the total content of the compounds represented by general formula (P), general formulas (P-1) to (P-3), structural formulas (P-1.1) to (P-1.2), structural formula (P-2.1) or structural formula (P-3.1) in 100 mass% of the liquid crystal composition is preferably 35 mass% or less, preferably 30 mass% or less, preferably 25 mass% or less, preferably 20 mass% or less, preferably 15 mass% or less, preferably 10 mass% or less, and preferably 5 mass% or less.

[0049] The total content of the compounds represented by general formula (P), general formulas (P-1) to (P-3), structural formulas (P-1.1) to (P-1.2), structural formula (P-2.1) or structural formula (P-3.1) in 100% by mass of the liquid crystal composition is preferably 0.5 to 35% by mass, more preferably 1.5 to 30% by mass, and even more preferably 5 to 25% by mass.

[0050] The compound represented by the general formula (P) (including its sub-concepts) can be synthesized by using a known synthesis method.

[0051] From the viewpoint of ensuring a large dielectric anisotropy, the liquid crystal composition may further contain one or more compounds represented by the following general formula (i) having a cyano group (-CN).

[0052] [ka]

[0053] In general formula (i), R i1 represents an alkyl group having 1 to 20 carbon atoms.

[0054] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0055] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0056] R i1 Specific examples of the alkyl group having 1 to 20 carbon atoms include those represented by the formula (R i1 -1)~(R i1 -6) and the like.

[0057] [ka]

[0058] Formula (R i1 -1)~(R i1 -6) In the middle, the black dot is A i1 Represents a bond to .

[0059] In addition, R i1 As for T ni From the viewpoint of adjusting the refractive index anisotropy, a linear alkyl group having 1 to 6 carbon atoms is preferable.

[0060] In general formula (i), A i1 and A i2 each independently represents the following group (a) and group (b): (a) a 1,4-cyclohexylene group (in which one -CH2- or two or more non-adjacent -CH2- may be replaced by -O- and / or -S-). (b) 1,4-phenylene group represents a group selected from the group consisting of:

[0061] Also, A i1 and A i2 One or more hydrogen atoms therein may each be independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0062] A i2 The halogen atom may be substituted at any of the positions shown in the following formula (A i2 -SP-1)~(A i2 -SP-2).

[0063] [ka]

[0064] Formula (A i2 -SP-1)~(A i2 -SP-2) Medium, S i1 Each independently represents a halogen atom, and the white dots represent Z i1 The black dots represent bonds to Z. i1 Or it represents a bond to a cyano group (-CN).

[0065] More specifically, A i1 is expressed by the following formula (A i1 -1)~(A i1 -2) is preferable.

[0066] [ka]

[0067] Formula (A i1 -1)~(A i1-2) Medium, white dot is R i1 The black dots represent bonds to Z. i1 Represents a bond to .

[0068] More specifically, A i2 is expressed by the following formula (A i2 -1)~(A i2 -3) is preferable.

[0069] [ka]

[0070] Formula (A i2 -1)~(A i2 -3) Middle, white dot is Z i1 The black dots represent bonds to Z. i1 Or it represents a bond to a cyano group (-CN).

[0071] In general formula (i), Z i1 represents a single bond, -C(=O)-O- or -OC(=O)-.

[0072] In general formula (i), n i1 represents an integer of 1 to 2.

[0073] The compound represented by general formula (i) is preferably a compound represented by the following general formulas (i-1) to (i-6).

[0074] [ka]

[0075] In general formulas (i-1) to (i-6), R i1 and S i1 is R in the above general formula (i). i1 and S i1 The preferred groups are also the same as those mentioned above.

[0076] The compound represented by general formula (i-1) is preferably a compound represented by the following structural formula (i-1.1).

[0077] [ka]

[0078] The compound represented by general formula (i-2) is preferably a compound represented by the following structural formula (i-2.1).

[0079] [ka]

[0080] The compound represented by general formula (i-3) is preferably a compound represented by the following structural formula (i-3.1).

[0081] [ka]

[0082] The compound represented by general formula (i-4) is preferably a compound represented by the following structural formula (i-4.1).

[0083] [ka]

[0084] The compound represented by general formula (i-5) is preferably a compound represented by the following structural formula (i-5.1).

[0085] [ka]

[0086] The compound represented by general formula (i-6) is preferably a compound represented by the following structural formulas (i-6.1) to (i-6.4).

[0087] [ka]

[0088] The type of compound represented by general formula (i), general formulas (i-1) to (i-6), structural formula (i-1.1), structural formula (i-2.1), structural formula (i-3.1), structural formula (i-4.1), structural formula (i-5.1) or structural formula (i-6.1) to (i-6.4) used in the liquid crystal composition is one or more types, preferably 1 to 5 types, preferably 1 to 4 types, preferably 1 to 3 types, preferably 1 to 2 types, and preferably 1 type.

[0089] The lower limit of the total content of the compounds represented by general formula (i), general formulas (i-1) to (i-6), structural formulas (i-1.1), structural formula (i-2.1), structural formula (i-3.1), structural formula (i-4.1), structural formula (i-5.1), or structural formulas (i-6.1) to (i-6.4) in 100 mass% of the liquid crystal composition is preferably 1 mass% or more, preferably 5 mass% or more, preferably 10 mass% or more, preferably 15 mass% or more, preferably 20 mass% or more, preferably 25 mass% or more, preferably 30 mass% or more, preferably 35 mass% or more, preferably 40 mass% or more, preferably 45 mass% or more, and preferably 50 mass% or more.

[0090] The upper limit of the total content of the compounds represented by general formula (i), general formulas (i-1) to (i-6), structural formulas (i-1.1), structural formula (i-2.1), structural formula (i-3.1), structural formula (i-4.1), structural formula (i-5.1), or structural formulas (i-6.1) to (i-6.4) in 100% by mass of the liquid crystal composition is preferably 85% by mass or less, preferably 80% by mass or less, preferably 75% by mass or less, preferably 70% by mass or less, preferably 65% ​​by mass or less, preferably 60% by mass or less, preferably 55% by mass or less, preferably 50% by mass or less, preferably 45% by mass or less, preferably 40% by mass or less, preferably 35% by mass or less, preferably 30% by mass or less, preferably 25% by mass or less, preferably 20% by mass or less, preferably 15% by mass or less, preferably 10% by mass or less, and preferably 5% by mass or less.

[0091] The total content of the compounds represented by general formula (i), general formulas (i-1) to (i-6), structural formula (i-1.1), structural formula (i-2.1), structural formula (i-3.1), structural formula (i-4.1), structural formula (i-5.1) or structural formula (i-6.1) to (i-6.4) in 100% by mass of the liquid crystal composition is preferably 1 to 85% by mass, more preferably 5 to 80% by mass, and even more preferably 10 to 75% by mass.

[0092] The compound represented by the general formula (i) (including sub-concepts) can be synthesized by using a known synthesis method.

[0093] From the viewpoint of ensuring a large dielectric anisotropy while also ensuring reliability, the liquid crystal composition may further contain one or more compounds represented by the following general formula (ii) having a fluoro group (-F).

[0094] [ka]

[0095] In general formula (ii), R ii1 represents an alkyl group having 1 to 20 carbon atoms.

[0096] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0097] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0098] R ii1 Specific examples of the alkyl group having 1 to 20 carbon atoms include those represented by the formula (R ii1 -1)~(R ii1 -6) and the like.

[0099] [ka]

[0100] Formula (R ii1 -1)~(R ii1 -6) In the middle, the black dot is A ii1 Represents a bond to .

[0101] In addition, R ii1 As for T ni From the viewpoint of adjusting the refractive index anisotropy, a linear alkyl group having 1 to 6 carbon atoms is preferable.

[0102] In general formula (ii), A ii1 and A ii2 each independently represents the following group (a), group (b) and group (c): (a) a 1,4-cyclohexylene group (in which one -CH2- or two or more non-adjacent -CH2- may be replaced by -O- and / or -S-). (b) 1,4-phenylene group (c) a naphthalene-2,6-diyl group, a naphthalene-1,4-diyl group (one -CH= or two or more -CH= present in the naphthalene-2,6-diyl group or the naphthalene-1,4-diyl group may be replaced by -N=). represents a group selected from the group consisting of:

[0103] Also, A ii1 and A ii2 One or more hydrogen atoms therein may each be independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0104] A ii1 The halogen atom may be substituted at any of the positions shown in the following formula (A ii1 -SP-1).

[0105] [ka]

[0106] Formula (A ii1 -SP-1) Medium, S ii1 Each independently represents a halogen atom, and the white dots represent R ii1 The black dots represent bonds to Z. ii1 Represents a bond to .

[0107] A ii2 The halogen atom may be substituted at any of the positions shown in the following formula (A ii2 -SP-1)~(A ii2 -SP-3).

[0108] [ka]

[0109] Formula (A ii2 -SP-1)~(A ii2 -SP-3) Medium, S ii1Each independently represents a halogen atom, and the white dots represent Z ii1 The black dots represent bonds to Z. ii1 or a bond to a fluoro group (-F).

[0110] More specifically, A ii1 is expressed by the following formula (A ii1 -1)~(A ii1 -3) is preferable.

[0111] [ka]

[0112] formula(A ii1 -1)~(A ii1 -3) Middle, white point is R ii1 The black dots represent bonds to Z. ii1 Represents a bond to .

[0113] More specifically, A ii2 is expressed by the following formula (A ii2 -1)~(A ii2 -5) is preferable.

[0114] [ka]

[0115] Formula (A ii2 -1)~(A ii2 -5) In the middle, the white dot is Z ii1 The black dots represent bonds to Z. ii1 or a bond to a fluoro group (-F).

[0116] In general formula (ii), Z ii1 represents a single bond or -C≡C-.

[0117] In general formula (ii), n ii1 represents an integer from 1 to 3.

[0118] The compound represented by general formula (ii) is preferably a compound represented by the following general formulas (ii-1) to (ii-4).

[0119] [ka]

[0120] In general formulas (ii-1) to (ii-4), R ii1 and S ii1 is R in the above general formula (ii). ii1 and S ii1 The preferred groups are also the same as those mentioned above.

[0121] The compound represented by general formula (ii-1) is preferably a compound represented by the following structural formula (ii-1.1).

[0122] [ka]

[0123] The compound represented by general formula (ii-2) is preferably a compound represented by the following structural formula (ii-2.1).

[0124] [ka]

[0125] The compound represented by general formula (ii-3) is preferably a compound represented by the following structural formulas (ii-3.1) to (ii-3.2).

[0126] [ka]

[0127] The compound represented by general formula (ii-4) is preferably a compound represented by the following structural formulas (ii-4.1) to (ii-4.2).

[0128] [ka]

[0129] The compounds represented by general formula (ii), general formulas (ii-1) to (ii-4), structural formula (ii-1.1), structural formula (ii-2.1), structural formula (ii-3.1) to (ii-3.2) or structural formula (ii-4.1) to (ii-4.2) used in the liquid crystal composition are one or more kinds, preferably 1 to 5 kinds, preferably 1 to 4 kinds, preferably 1 to 3 kinds, preferably 1 to 2 kinds, and preferably 1 kind.

[0130] The lower limit of the total content of the compounds represented by general formula (ii), general formulas (ii-1) to (ii-4), structural formulas (ii-1.1), structural formula (ii-2.1), structural formulas (ii-3.1) to (ii-3.2), or structural formulas (ii-4.1) to (ii-4.2) in 100 mass% of the liquid crystal composition is preferably 1 mass% or more, more preferably 5 mass% or more, more preferably 10 mass% or more, more preferably 15 mass% or more, and more preferably 20 mass% or more.

[0131] The upper limit of the total content of the compounds represented by general formula (ii), general formulas (ii-1) to (ii-4), structural formulas (ii-1.1), structural formula (ii-2.1), structural formulas (ii-3.1) to (ii-3.2), or structural formulas (ii-4.1) to (ii-4.2) in 100% by mass of the liquid crystal composition is preferably 35% by mass or less, more preferably 30% by mass or less, more preferably 25% by mass or less, more preferably 20% by mass or less, and more preferably 15% by mass or less.

[0132] The total content of the compounds represented by general formula (ii), general formulas (ii-1) to (ii-4), structural formula (ii-1.1), structural formula (ii-2.1), structural formula (ii-3.1) to (ii-3.2) or structural formula (ii-4.1) to (ii-4.2) in 100% by mass of the liquid crystal composition is preferably 1 to 35% by mass, more preferably 5 to 30% by mass, and even more preferably 10 to 25% by mass.

[0133] The compound represented by the general formula (ii) (including its sub-concepts) can be synthesized by using a known synthesis method.

[0134] The liquid crystal composition may further contain one or more compounds represented by the following general formula (iii) having -CH=NN=CH- from the viewpoint of reducing viscosity.

[0135] [ka]

[0136] In general formula (iii), R iii1 and R iii2 each independently represents an alkyl group having 1 to 20 carbon atoms.

[0137] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0138] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0139] One or more -CH2- groups in the alkyl group may each independently be replaced by -CH=CH-.

[0140] For example, R iii1 and R iii2 can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH2-CH2- in the alkyl group with -CH=CH-.

[0141] The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.

[0142] The alkenyl group preferably has 2-10, and more preferably 2-6, carbon atoms.

[0143] R iii1 and R iii2 Specific examples of the alkyl group having 1 to 20 carbon atoms (including substituted alkyl groups) in the formula (R iii1 / 2 -1)~(R iii1 / 2 -11) and the like.

[0144] [ka]

[0145] Formula (R iii1 / 2 -1)~(R iii1 / 2 -11) In the middle, the black dot is A iii1 Or A iii2 Represents a bond to .

[0146] In addition, R iii1 and R iii2 From the viewpoint of the viscosity of the liquid crystal composition, a linear alkenyl group having 1 to 6 carbon atoms is preferable.

[0147] In general formula (iii), A iii1 and A iii2 each independently represents the following group (a) and group (b): (a) a 1,4-cyclohexylene group (in which one -CH2- or two or more non-adjacent -CH2- may be replaced by -O- and / or -S-). (b) 1,4-phenylene group represents a group selected from the group consisting of:

[0148] Also, A iii1 and A iii2 One or more hydrogen atoms therein may each be independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0149] More specifically, A iii1 is expressed by the following formula (A iii1 -1)~(Aiii1 -2) is preferable.

[0150] [ka]

[0151] Formula (A iii1 -1)~(A iii1 -2) Medium, white dot is R iii1 The black dots represent bonds to the -CH=NN=CH- group.

[0152] More specifically, A iii2 is expressed by the following formula (A iii2 -1)~(A iii2 -2) is preferable.

[0153] [ka]

[0154] Formula (A iii2 -1)~(A iii2 -2) In the figure, the white dots represent bonds to -CH=NN=CH-, and the black dots represent R iii2 Represents a bond to .

[0155] The compound represented by general formula (iii) is preferably a compound represented by the following general formula (iii-1).

[0156] [ka]

[0157] In general formula (iii-1), R iii1 and R iii2 is R in the above general formula (iii). iii1 and R iii2 The preferred groups are also the same as those mentioned above.

[0158] The compound represented by general formula (iii-1) is preferably a compound represented by the following structural formula (iii-1.1).

[0159] [ka]

[0160] The compounds represented by general formula (iii), general formula (iii-1) and structural formula (iii-1.1) used in the liquid crystal composition are one or more kinds, preferably 1 to 5 kinds, preferably 1 to 4 kinds, preferably 1 to 3 kinds, preferably 1 to 2 kinds, and preferably 1 kind.

[0161] The lower limit of the total content of the compounds represented by general formula (iii), general formula (iii-1), and structural formula (iii-1.1) in 100 mass% of the liquid crystal composition is preferably 1 mass% or more, more preferably 5 mass% or more, and even more preferably 10 mass% or more.

[0162] The upper limit of the total content of the compounds represented by general formula (iii), general formula (iii-1), and structural formula (iii-1.1) in 100% by mass of the liquid crystal composition is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0163] The total content of the compounds represented by general formula (iii), general formula (iii-1), and structural formula (iii-1.1) in 100% by mass of the liquid crystal composition is preferably 1 to 25% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass.

[0164] The compound represented by the general formula (iii) (including its sub-concepts) can be synthesized by using a known synthesis method.

[0165] The liquid crystal composition may further contain one or more compounds represented by the following general formula (iv) having -C≡C-, in order to ensure a large refractive index anisotropy.

[0166] [ka]

[0167] In general formula (iv), R iv1 and R iv2 each independently represents an alkyl group having 1 to 20 carbon atoms.

[0168] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0169] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0170] One or more -CH2- groups in the alkyl group may each independently be substituted by -O- or -CH=CH-.

[0171] However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.

[0172] For example, R iv1 and R iv2 can represent an alkoxy group having 1 to 19 carbon atoms by replacing one -CH2- in the alkyl group with -O-.

[0173] The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.

[0174] The alkoxy group preferably has 2-10, and more preferably 2-6, carbon atoms.

[0175] Also, R iv1 and R iv2 can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH2-CH2- in the alkyl group with -CH=CH-.

[0176] The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.

[0177] The alkenyl group preferably has 2-10, and more preferably 2-6, carbon atoms.

[0178] R iv1 and R iv2 Specific examples of the alkyl group having 1 to 20 carbon atoms (including substituted alkyl groups) in the formula (R iv1 / 2 -1)~(R iv1 / 2 -16) groups.

[0179] [ka]

[0180] Formula (R iv1 / 2 -1)~(R iv1 / 2 -16) In the middle, the black dot is A iv1 Or A iv2 Represents a bond to .

[0181] In addition, R iv1 and R iv2 As for T ni From the viewpoint of adjusting the refractive index anisotropy, a linear alkyl group having 1 to 6 carbon atoms, a linear alkoxy group having 1 to 6 carbon atoms, or a linear alkenyl group having 1 to 6 carbon atoms is preferred.

[0182] In general formula (iv), A iv1 and A iv2 each independently represents the following group (a) and group (b): (a) a 1,4-cyclohexylene group (in which one -CH2- or two or more non-adjacent -CH2- may be replaced by -O- and / or -S-). (b) 1,4-phenylene group represents a group selected from the group consisting of:

[0183] Also, A iv1 and A iv2 One or more hydrogen atoms therein may each be independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0184] A iv2 The halogen atom may be substituted at any of the positions shown in the following formula (A iv2 -SP-1).

[0185] [ka]

[0186] Formula (A iv2 -SP-1) Medium, S iv1 represents a halogen atom, the white dot represents a bond to -C≡C-, and the black dot represents R iv2 Represents a bond to .

[0187] More specifically, A iv1 is expressed by the following formula (A iv1 -1)~(A iv1 -2) is preferable.

[0188] [ka]

[0189] Formula (A v1 -1)~(A v1 -2) Medium, white dots are R iv1 or Z iv1 The black dots represent bonds to Z. iv1 Represents a bond to .

[0190] More specifically, A iv2 is expressed by the following formula (A iv2 -1)~(A iv2 -3) is preferable.

[0191] [ka]

[0192] Formula (A iv2 -1)~(A iv2 -3) In the figure, the white dots represent bonds to -C≡C-, and the black dots represent R iv2 Represents a bond to .

[0193] In general formula (iv), Z iv1 represents a single bond, -C≡C-, -C(=O)-O- or -OC(=O)-.

[0194] In general formula (iv), n iv1 represents an integer of 1 to 3, and preferably an integer of 1 or 2.

[0195] The compound represented by general formula (iv) is preferably a compound represented by the following general formulas (iv-1) to (iv-5).

[0196] [ka]

[0197] In general formulas (iv-1) to (iv-5), R iv1 , R iv2 and S iv1 is R in the above general formula (iv). iv1 , R iv2 and S iv1 The preferred groups are also the same as those mentioned above.

[0198] The compound represented by general formula (iv-1) is preferably a compound represented by the following structural formulas (iv-1.1) to (iv-1.5).

[0199] [ka]

[0200] The compound represented by general formula (iv-2) is preferably a compound represented by the following structural formula (iv-2.1).

[0201] [ka]

[0202] The compound represented by general formula (iv-3) is preferably a compound represented by the following structural formulas (iv-3.1) to (iv-3.2).

[0203] [ka]

[0204] The compound represented by general formula (iv-4) is preferably a compound represented by the following structural formula (iv-4.1).

[0205] [ka]

[0206] The compound represented by general formula (iv-5) is preferably a compound represented by the following structural formulas (iv-5.1) to (iv-5.2).

[0207] [ka]

[0208] The number of types of the compounds represented by general formula (iv), general formulae (iv-1) to (iv-5), structural formulae (iv-1.1) to (iv-1.5), structural formula (iv-2.1), structural formulae (iv-3.1) to (iv-3.2), structural formula (iv-4.1) or structural formulae (iv-5.1) to (iv-5.2) used in the liquid crystal composition is one or more, preferably 1 to 15, and more preferably 1 to 10.

[0209] The lower limit of the total content of the compounds represented by general formula (iv), general formulae (iv-1) to (iv-5), structural formulae (iv-1.1) to (iv-1.5), structural formulae (iv-2.1), structural formulae (iv-3.1) to (iv-3.2), structural formula (iv-4.1), or structural formulae (iv-5.1) to (iv-5.2) in 100 mass% of the liquid crystal composition is preferably 1 mass% or more, preferably 3 mass% or more, preferably 5 mass% or more, preferably 10 mass% or more, preferably 30 mass% or more, preferably 35 mass% or more, preferably 60 mass% or more, preferably 65 mass% or more, and preferably 70 mass% or more.

[0210] The upper limit of the total content of the compounds represented by general formula (iv), general formulae (iv-1) to (iv-5), structural formulae (iv-1.1) to (iv-1.5), structural formulae (iv-2.1), structural formulae (iv-3.1) to (iv-3.2), structural formula (iv-4.1), or structural formulae (iv-5.1) to (iv-5.2) in 100 mass% of the liquid crystal composition is preferably 80 mass% or less, preferably 75 mass% or less, preferably 45 mass% or less, preferably 40 mass% or less, preferably 15 mass% or less, preferably 10 mass% or less, and preferably 5 mass% or less.

[0211] The total content of the compounds represented by general formula (iv), general formulae (iv-1) to (iv-5), structural formulae (iv-1.1) to (iv-1.5), structural formulae (iv-2.1), structural formulae (iv-3.1) to (iv-3.2), structural formula (iv-4.1) or structural formulae (iv-5.1) to (iv-5.2) in 100% by mass of the liquid crystal composition is preferably 1 to 80% by mass, more preferably 3 to 75% by mass, and even more preferably 5 to 70% by mass.

[0212] The compound represented by the general formula (iv) (including its sub-concepts) can be synthesized by using a known synthesis method.

[0213] The liquid crystal composition may further contain one or more compounds represented by the following general formula (v) in order to adjust the magnitude of the dielectric anisotropy.

[0214] [ka]

[0215] In general formula (v), R v1 and R v2 each independently represents an alkyl group having 1 to 20 carbon atoms.

[0216] The alkyl group having 1 to 20 carbon atoms is a linear, branched or cyclic alkyl group, and is preferably a linear alkyl group.

[0217] The alkyl group having 1 to 20 carbon atoms preferably has 2 to 10 carbon atoms, and more preferably has 2 to 6 carbon atoms.

[0218] One or more -CH2- groups in the alkyl group may each independently be substituted by -O- or -CH=CH-.

[0219] However, when the alkyl group is substituted with a specific group, the oxygen atoms are not directly bonded to each other.

[0220] For example, R v1 and R v2 can represent an alkoxy group having 1 to 19 carbon atoms by replacing one -CH2- in the alkyl group with -O-.

[0221] The alkoxy group is a linear, branched or cyclic alkoxy group, and is preferably a linear alkoxy group.

[0222] The alkoxy group preferably has 2-10, and more preferably 2-6, carbon atoms.

[0223] Also, R v1 and Rv2 can represent an alkenyl group having 2 to 20 carbon atoms by replacing one or more -CH2-CH2- in the alkyl group with -CH=CH-.

[0224] The alkenyl group is a linear, branched or cyclic alkenyl group, and is preferably a linear alkenyl group.

[0225] The alkenyl group preferably has 2-10, and more preferably 2-6, carbon atoms.

[0226] R v1 and R v2 Specific examples of the alkyl group having 1 to 20 carbon atoms (including substituted alkyl groups) in the formula (R v1 / 2 -1)~(R v1 / 2 -16) and the like.

[0227] [ka]

[0228] Formula (R v1 / 2 -1)~(R v1 / 2 -16) In the middle, the black dot is A v1 Or A v2 Represents a bond to .

[0229] In addition, R v1 and R v2 As for T ni From the viewpoint of adjusting the refractive index anisotropy, a linear alkyl group having 1 to 6 carbon atoms, a linear alkoxy group having 1 to 6 carbon atoms, or a linear alkenyl group having 1 to 6 carbon atoms is preferred.

[0230] In general formula (v), A v1 and A v2 each independently represents the following group (a) and group (b): (a) a 1,4-cyclohexylene group (in which one -CH2- or two or more non-adjacent -CH2- may be replaced by -O- and / or -S-). (b) 1,4-phenylene group represents a group selected from the group consisting of:

[0231] Also, A v1 and A v2 One or more hydrogen atoms therein may each be independently substituted by a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0232] More specifically, A v1 is expressed by the following formula (A v1 -1)~(A v1 -2) is preferable.

[0233] [ka]

[0234] Formula (A v1 -1)~(A v1 -2) Medium, white dots are R v1 Also A v1 represents a bond to, and the black dot represents A v1 Or A v2 Represents a bond to .

[0235] More specifically, A v2 is expressed by the following formula (A v2 -1)~(A v2 -3) is preferable.

[0236] [ka]

[0237] Formula (A v2 -1)~(A v2 -3) Medium, white dots are A v1 The black dots represent bonds to R. v2 Represents a bond to .

[0238] In general formula (v), n v1represents an integer of 1 to 2.

[0239] The compound represented by general formula (v) is preferably a compound represented by the following general formulas (v-1) to (v-4).

[0240] [ka]

[0241] In general formulas (v-1) to (v-4), R v1 and R v2 R in the above general formula (v) v1 and R v2 The preferred groups are also the same as those mentioned above.

[0242] The compound represented by general formula (v-1) is preferably a compound represented by the following structural formula (v-1.1).

[0243] [ka]

[0244] The compound represented by general formula (v-2) is preferably a compound represented by the following structural formulas (v-2.1) to (v-2.2).

[0245] [ka]

[0246] The compound represented by general formula (v-3) is preferably a compound represented by the following structural formulas (v-3.1) to (v-3.2).

[0247] [ka]

[0248] The compound represented by general formula (v-4) is preferably a compound represented by the following structural formulas (v-4.1) to (v-4.3).

[0249] [ka]

[0250] The compounds represented by general formula (v), general formulae (v-1) to (v-4), structural formula (v-1.1), structural formulae (v-2.1) to (v-2.2), structural formulae (v-3.1) to (v-3.2) or structural formulae (v-4.1) to (v-4.3) used in the liquid crystal composition are one or more kinds, preferably 1 to 5 kinds, preferably 1 to 4 kinds, preferably 1 to 3 kinds, and preferably 1 or 2 kinds.

[0251] The lower limit of the total content of the compounds represented by general formula (v), general formulas (v-1) to (v-4), structural formula (v-1.1), structural formulas (v-2.1) to (v-2.2), structural formulas (v-3.1) to (v-3.2), or structural formulas (v-4.1) to (v-4.3) in 100% by mass of the liquid crystal composition is preferably 1% by mass or more, more preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 15% by mass or more.

[0252] The upper limit of the total content of the compounds represented by general formula (v), general formulas (v-1) to (v-4), structural formula (v-1.1), structural formulas (v-2.1) to (v-2.2), structural formulas (v-3.1) to (v-3.2), or structural formulas (v-4.1) to (v-4.3) in 100% by mass of the liquid crystal composition is preferably 25% by mass or less, more preferably 20% by mass or less, more preferably 15% by mass or less, and more preferably 10% by mass or less.

[0253] The total content of the compounds represented by general formula (v), general formulas (v-1) to (v-4), structural formula (v-1.1), structural formulas (v-2.1) to (v-2.2), structural formulas (v-3.1) to (v-3.2), or structural formulas (v-4.1) to (v-4.3) in 100% by mass of the liquid crystal composition is preferably 1 to 25% by mass, more preferably 5 to 20% by mass, and even more preferably 10 to 15% by mass.

[0254] The compound represented by the general formula (v) (including sub-concepts) can be synthesized by using a known synthesis method.

[0255] The liquid crystal composition preferably contains a chiral agent from the viewpoint of improving the response time. The term "chiral agent" refers to an additive that can impart a twist to liquid crystal molecules and impart optical rotation to a liquid crystal composition, and the twist pitch (p) can be varied depending on the amount added. In the liquid crystal element according to the present invention, the chemical structure and the amount of the chiral agent used are not particularly limited as long as the chiral agent can impart a twist pitch (p) to the liquid crystal layer. The chiral agent may be a known one, and examples thereof include a compound having an asymmetric atom, a compound having axial chirality (atropisomer), and a compound having planar chirality. Of these, a compound having an asymmetric atom or a compound having axial chirality is preferred. In a compound having an asymmetric atom, the asymmetric atom is preferably an asymmetric carbon atom or an asymmetric heteroatom, and from the viewpoint of less prone to stereoinversion, an asymmetric carbon atom is preferred. The asymmetric atom may be introduced into a part of a chain structure or into a part of a cyclic structure. When a strong helical twisting power is particularly required, a compound having axial chirality is preferred. The chiral agent may or may not have a polymerizable group. The chiral agents may be used alone or in combination of two or more kinds. The content of the chiral agent in the liquid crystal composition can be set according to any desired twist pitch (p). The chiral agent may be either right-handed or left-handed, and can be appropriately selected depending on the application of the liquid crystal element. Specific examples of the chiral agent include compounds represented by the following structural formulas (Ch-1) to (Ch-3).

[0256] [ka]

[0257] As the chiral agent, a commercially available product or a synthesized product can be used.

[0258] Furthermore, the liquid crystal layer (liquid crystal composition) may contain additives, if necessary. Examples of the additives include a stabilizer, a dye compound, and a polymerizable compound. Examples of the stabilizer include hydroquinones, hydroquinone monoalkyl ethers, tert-butylcatechols, pyrogallols, thiophenols, nitro compounds, β-naphthylamines, β-naphthols, nitroso compounds, hindered phenols, and hindered amines.

[0259] Examples of the hindered phenols include compounds represented by the following formula (HP-1).

[0260] [ka]

[0261] Benzotriazoles include compounds represented by the following formula (BTA-1).

[0262] [ka]

[0263] When a stabilizer is used, the type of stabilizer used in the liquid crystal composition is one or more, preferably 1 to 10 types, preferably 1 to 8 types, preferably 1 to 6 types, preferably 1 to 4 types, and preferably 1 to 2 types. When stabilizers are used, the total content of the stabilizers in 100% by mass of the liquid crystal composition is preferably 0.005 to 1% by mass, more preferably 0.02 to 0.50% by mass, and even more preferably 0.03 to 0.35% by mass.

[0264] (Liquid crystal element) The thickness (d) of the liquid crystal layer of the liquid crystal element according to the present invention can be appropriately set depending on the application, but is preferably 1 to 50 μm, preferably 1.5 to 20 μm, and preferably 2 to 10 μm. The pretilt angle of the liquid crystal element according to the present invention is preferably less than 15° C., preferably 0 to 10°, preferably 0 to 5°, and preferably less than 0 to 3°, from the viewpoint of horizontal alignment. The thickness (d) of the liquid crystal layer and the pretilt angle can be measured by a phase difference measuring device Optipro (manufactured by Shintech Co., Ltd.). Optipro is a device that can measure the thickness and pretilt angle of a liquid crystal layer by measuring the Stokes parameters while changing the angle and polarization state of the measurement light incident on a liquid crystal element placed on a stage. The measurement was performed using the extraordinary refractive index (n e ) and ordinary refractive index (n o ) is required, and the extraordinary refractive index (ne) and ordinary refractive index (no) of the liquid crystal composition are determined under conditions of 25°C and 589 nm using an Abbe refractometer.

[0265] From the viewpoint of moving image display quality, the response time (Td) of the liquid crystal element according to the present invention is preferably less than 150 ms, preferably less than 125 ms, preferably less than 100 ms, preferably less than 50 ms, preferably less than 25 ms, preferably less than 10 ms. The response time can be measured by an optical property evaluation device OCA-100 (manufactured by Shintech Co., Ltd.). The OCA-100 is a device that measures the transmittance of measurement light incident on a liquid crystal element placed on a stage, and can measure the response time of the liquid crystal element by measuring the transient response time of the change in transmittance when the voltage applied to the liquid crystal element is turned ON / OFF. Here, Td indicates the transient response time when the voltage applied to the liquid crystal element is turned off. Specifically, a voltage that results in 100% transmittance is applied, and the transient response time when that voltage is switched to 0V is measured.

[0266] From the viewpoint of display uniformity, it is preferable that the alignment of the liquid crystal element according to the present invention is such that no twist domain occurs. The presence or absence of twisted domains can be visually observed by placing a liquid crystal element between polarizing plates arranged at right angles to each other.

[0267] In order to suppress the occurrence of unnecessary twist domains, d / p of the liquid crystal element according to the present invention is preferably 0.001 to 0.40, preferably 0.020 to 0.35, and preferably 0.025 to 0.34.

[0268] The liquid crystal element can be fabricated as follows. For example, a sealing material such as an epoxy-based thermosetting composition is applied to a first substrate with an injection port, the first substrate is bonded to a second substrate, and then the sealing material is thermally cured by heating to produce an empty cell. Next, a liquid crystal composition is sandwiched between the two substrates of the empty cell using a vacuum injection method, an ODF method, or the like, and the injection port is sealed with a sealant such as an acrylic thermosetting composition, thereby producing a liquid crystal element.

[0269] (projector) A projector according to the present invention is characterized by including the above-mentioned liquid crystal element. The structure of the projector according to the present invention can be applied by taking into consideration the matters described in, for example, JP-A-2007-294158.

[0270] (Head-up display) A head-up display according to the present invention is characterized by including the above-mentioned liquid crystal element. The structure of the head-up display according to the present invention can be applied by taking into consideration the matters described in, for example, JP-A-2021-60444. EXAMPLES

[0271] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way. The compositions of the following Examples and Comparative Examples contained each compound in the proportions shown in the table, and the contents are shown in "mass %". The compounds are described using the following abbreviations. In addition, compounds which can take either cis or trans form will represent the trans form unless otherwise specified. <Ring structure>

[0272] [ka]

[0273] <Terminal structure>

[0274] [Table 1] (Note that n in the table is a natural number. Also, the alkyl group represented by n is a straight-chain alkyl group.)

[0275] <Connection structure>

[0276] [Table 2]

[0277] (Preparation of Liquid Crystal Composition) LC-A and LC-01 to LC-09 shown in Table 3 were prepared.

[0278] [Table 3]

[0279] (Examples 1 to 13 and Comparative Example 1) (Liquid crystal element manufacturing) First, a non-alkali glass substrate (manufactured by Corning, EAGLE XG, 2 cm × 2 cm, thickness: 1.1 mm) with an ITO electrode formed on its surface and a silicon substrate (2 cm × 2 cm, thickness: 0.725 mm) with a reflective pixel electrode formed on its surface were placed in a vacuum deposition apparatus so that they were oblique to the direction in which the deposition material was scattered from the deposition source. Then, while maintaining the vacuum deposition apparatus in a vacuum, the temperature of the deposition source was heated to above the boiling point of the deposition material, thereby forming an inorganic alignment film made of silicon oxide (SiO2) on the entire surface of the ITO electrode formed on the non-alkali glass substrate and the entire surface of the reflective pixel electrode formed on the silicon substrate. Next, the two substrates were placed face to face with their inorganic alignment films facing each other, and an empty cell was created using a spacer (Micropearl, plastic particles, manufactured by Sekisui Chemical Co., Ltd.) and a sealing material (Structbond, epoxy-based thermosetting composition, manufactured by Mitsui Chemicals, Inc.). Next, liquid crystal compositions were prepared using the liquid crystal compositions, stabilizers, and chiral agents (compounds having axial asymmetry) shown in Table 3. The prepared empty cell was filled with the prepared liquid crystal composition, and then sealed with a sealant (manufactured by ThreeBond Co., Ltd., TB3026, acrylic photocurable composition) to produce liquid crystal elements 1 to 14 shown in Tables 4 and 5. The pretilt angle and response speed of each liquid crystal element were measured to confirm the presence or absence of twisted domains. Response speeds of less than 100 ms were rated as "good" and less than 10 ms as "excellent." In Examples 10 to 13, since the liquid crystal compositions contained a chiral agent, Δε, Δn, and γ1 could not be measured accurately. In addition, the thickness (d) of the liquid crystal layer in each liquid crystal element was 3.5 μm. As the stabilizer, a compound represented by the following formula (HP-1) was used as a hindered phenol.

[0280] [ka]

[0281] As the benzotriazole, a compound represented by the following formula (BTA-1) was used.

[0282] [ka]

[0283] As the chiral agent, a compound represented by the following formula (Ch-1) was used.

[0284] [ka]

[0285] [Table 4]

[0286] [Table 5]

[0287] From Comparative Example 1 and Example 1, when a liquid crystal composition containing a pyrimidine compound was used, the pretilt angle and the response time were good, and no twist domain was observed. Moreover, from Examples 2 to 13, it was confirmed that the same effects were obtained not only when various liquid crystal compositions were used, but also when a stabilizer and a chiral agent were used. In particular, it was confirmed that the response speed was improved when the chiral agent was used. This is believed to be because the helical state is spontaneously induced by the addition of the chiral agent, and the direction in which the liquid crystal molecules fall at the fall time is determined by the direction in which the helical state is released. [Industrial Applicability]

[0288] The liquid crystal element of the present invention can be used in projectors and head-up displays.

Claims

1. A first substrate; A second substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate; A liquid crystal element comprising: An inorganic alignment film is provided on a surface of the first substrate and / or the second substrate, The liquid crystal layer contains a liquid crystal composition having a positive dielectric anisotropy (Δε), The liquid crystal composition comprises a pyrimidine compound.

2. The pyrimidine compound is represented by the following general formula (P): 【Chemistry 1】 (In general formula (P), R Ｐ１ represents an alkyl group having 1 to 20 carbon atoms, S Ｐ１ each independently represents a hydrogen atom or a halogen atom, n Ｐ１ represents an integer of 0 to 1.) 2. The liquid crystal device according to claim 1, wherein the compound is represented by the formula:

3. The inorganic component in the inorganic alignment film is silicon oxide (SiO ２ ) and aluminum oxide (Al ２ O ３ 3. The liquid crystal device according to claim 1, wherein the compound is one or more selected from the group consisting of:

4. 4. The liquid crystal device according to claim 1, wherein the liquid crystal composition contains a chiral agent.

5. 5. The liquid crystal device according to claim 4, wherein d / p is from 0.001 to 0.

40.

6. A projector using the liquid crystal element according to any one of claims 1 to 5.

7. A head-up display using the liquid crystal device according to any one of claims 1 to 5.

Images