WO2015098493A1 - Liquid-crystal display element and manufacturing method therefor - Google Patents

Abstract

This invention addresses the problem of providing an IPS/FFS liquid-crystal display element that exhibits a high transmittance and a high response speed and uses an n-type liquid-crystal composition that does not cause display problems such as white areas, uneven alignment, or burn-in. In said liquid-crystal display element, a liquid-crystal layer containing a liquid-crystal composition is sandwiched between a pair of substrates consisting of a first substrate, which has pixel electrodes and a common electrode formed on top of a substrate with an insulating layer interposed therebetween, and a second substrate. The liquid-crystal layer contains a polymer obtained by curing a polymerizable compound that has a single reactive group and/or a polymerizable compound that has two or more reactive groups. The aforementioned liquid-crystal composition exhibits negative dielectric anisotropy and contains at least one compound selected from the group of compounds that exhibit negative dielectric anisotropy and can be represented by general formulas (LC3) through (LC5) and at least one compound selected from the group of compounds that can be represented by general formula (L).

Description

Liquid crystal display element and manufacturing method thereof

The present invention relates to a liquid crystal display element of IPS mode and FFS mode using a nematic liquid crystal composition having a negative dielectric anisotropy and having characteristics of high transmittance characteristics and high-speed response.

Because of its excellent display quality, active matrix liquid crystal display elements are on the market for mobile terminals, liquid crystal televisions, projectors, computers, and the like. In the active matrix method, TFT (thin film transistor) or MIM (metal insulator metal) is used for each pixel, and it is important that the liquid crystal compound or liquid crystal composition used in this method has a high voltage holding ratio. Is being viewed. In order to obtain wider viewing angle characteristics, liquid crystal display elements combined with VA (Vertical Alignment) mode, IPS (In Plane Switching) mode, OCB (Optically Compensated Bend, Optically Compensated Birefringence) mode, and brighter display In order to achieve this, an ECB (Electrically Controlled Birefringence) mode reflective liquid crystal display device has been proposed. In order to deal with such a liquid crystal display element, new liquid crystal compounds or liquid crystal compositions have been proposed at present.

Currently, as a liquid crystal display for smart phones, a fringe field switching mode liquid crystal display device (FFS mode liquid crystal display device; FFS mode liquid crystal display device), which is a type of IPS mode liquid crystal display device with high quality and excellent visual characteristics. Is widely used (see Patent Document 1 and Patent Document 2). The FFS mode is a method introduced to improve the low aperture ratio and transmittance of the IPS mode, and the liquid crystal composition used has a positive dielectric anisotropy because it is easy to reduce the voltage. Materials using p-type liquid crystal compositions are widely used. In addition, since most of the applications of the FFS mode are portable terminals, there is a strong demand for further power saving, and liquid crystal element manufacturers are actively developing such as adopting an array using IGZO.

On the other hand, it is known that the transmittance can also be improved by changing the liquid crystal material currently using the p-type liquid crystal composition to an n-type liquid crystal composition having a negative dielectric anisotropy. (See Patent Document 3). This is because when the n-type liquid crystal composition is used, the polarization direction of the n-type liquid crystal composition is in the molecular minor axis direction, so the influence of the fringe electric field only rotates the liquid crystal molecules along the major axis. In this case, the molecular long axis is maintained in a parallel arrangement, so that the transmittance does not decrease.

However, the n-type liquid crystal composition is generally used as a liquid crystal composition for VA. However, in the VA mode, the IPS mode, and the FFS mode, any of the alignment direction, the electric field direction, and the required optical characteristics can be used. Therefore, even if the liquid crystal composition used for VA is simply diverted, it is difficult to construct a high-performance liquid crystal display element as required today. The IPS mode and the FFS mode Therefore, there is a demand for providing an n-type liquid crystal composition optimized for the above.

JP-A-11-202356 JP 2003-233083 A JP 2002-31812 A

An object of the present invention is to use an n-type liquid crystal composition that exhibits high transmittance characteristics and high-speed response in an IPS mode and FFS mode liquid crystal display element and does not cause display defects such as white spots, alignment unevenness, and burn-in. The object is to provide a liquid crystal display element.

The inventors of the present invention have made extensive studies in order to solve the above-mentioned problems, and as a result of investigating the configurations of various liquid crystal compositions that are optimal for IPS mode and FFS mode liquid crystal display elements, they have a polymerizable group having one reactive group. The usefulness of a liquid crystal composition containing a compound and / or a polymerizable compound having two or more reactive groups was found, and the present invention was completed.

That is, the present invention
A liquid crystal display in which a liquid crystal layer containing a liquid crystal composition is sandwiched between a pair of substrates including a first substrate having a pixel electrode and a common electrode formed on an insulating layer through an insulating layer and a second substrate The liquid crystal layer includes a polymerizable compound having one reactive group and / or a cured product which is a polymer of a polymerizable compound having two or more reactive groups, and the liquid crystal The composition has a negative dielectric anisotropy;
The following general formula (LC3) to general formula (LC5)

^(Wherein, represents an alkyl group of ^{R LC31, R LC32, R LC41} , R LC42, R LC51 and ^{R LC52} is 1 to 15 carbon atoms independently, one in the alkyl group or two or more The CH ₂ group may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent to the alkyl group. one or more hydrogen atoms in may be optionally substituted by a halogen ^{atom, a LC31, a LC32, a} LC41, a LC42, a LC51 and ^{a LC52} are independently any of the following Structure of

(In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen atoms. And one or more hydrogen atoms in the structure may be substituted with Cl, CF _3, or OCF ₃ ), Z ^LC31 , Z ^{LC32, Z LC41, Z LC42,} Z LC51 and ^{Z LC51} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—, Z ⁵ represents a CH ₂ group or an oxygen atom, X ^LC41 represents a hydrogen atom or a fluorine atom, m ^{LC31, m LC32, m LC41,} m L ^{42, m LC51} and ^{m LC52} each independently represent ^{0 ~ 3, m LC31 + m} LC32, m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or ^{3, A LC31 ~ A LC52,} Z LC31 ~ When there are a plurality of Z ^LC52s , they may be the same or different. At least one compound selected from the group of compounds having negative dielectric anisotropy represented by:
And the following general formula (L)

(Wherein R ^L1 and R ^L2 each independently represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently Optionally substituted by —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,
OL represents 0, 1, 2 or 3;
B ^L1 , B ^L2 and B ^L3 each independently represent (a) a 1,4-cyclohexylene group (one —CH ₂ — present in this group or two or more —CH ₂ — not adjacent to each other). May be replaced by —O—) and (b) a 1,4-phenylene group (one —CH═ present in this group or two or more —CH═ not adjacent to each other —N May be replaced by =.)
Represents a group selected from the group consisting of: The above groups (a) and (b) may be each independently substituted with a cyano group, a fluorine atom or a chlorine atom,
L ^L1 and L ^L2 are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —OCF ₂ -, -CF ₂ O-, -CH = NN-CH-, -CH = CH-, -CF = CF- or -C≡C-
When OL is 2 or 3 and a plurality of L ^L2 are present, they may be the same or different, and when OL is 2 or 3 and a plurality of B ^L3 is present, they are the same However, the compounds represented by general formula (LC3) to general formula (LC5) are excluded. The liquid crystal display element containing the at least 1 sort (s) of compound chosen from the compound group represented by this is provided.

The IPS mode and FFS mode liquid crystal display elements of the present invention are excellent in transmittance characteristics and high-speed response, have few display defects, and have excellent display characteristics. The liquid crystal display element of the present invention is useful for display elements such as liquid crystal TVs and monitors.

It is a disassembled perspective view which shows typically the structure of the one aspect | mode of a liquid crystal display element. It is an example of the top view which expanded the area | region of II of the electrode layer 3 containing the thin-film transistor formed on the board | substrate in FIG. FIG. 3 is an example of a cross-sectional view of the liquid crystal display element taken along the line III-III in FIG. 2. FIG. 6 is another example of a plan view in which a region II of the electrode layer 3 including a thin film transistor formed on the substrate in FIG. 1 is enlarged. FIG. 3 is another example of a cross-sectional view of the liquid crystal display element taken along the line III-III in FIG. It is the top view to which the electrode structure of the liquid crystal display element was expanded.

As described above, the present invention has found an n-type liquid crystal composition that is optimal for IPS mode and FFS mode liquid crystal display elements. Hereinafter, first, embodiments of the liquid crystal layer in the present invention will be described.
(Liquid crystal layer)
(Polymerizable compound having a reactive group)
The liquid crystal layer in the liquid crystal display element of the present invention contains a cured product which is a polymerizable compound having one reactive group and / or a polymer of a polymerizable compound having two or more reactive groups. The polymerizable compound having a reactive group may or may not contain a mesogenic moiety.

In the polymerizable compound having a reactive group, the reactive group is preferably a substituent having photopolymerizability. In particular, when the vertical alignment film is formed by thermal polymerization, the reaction of the polymerizable compound having a reactive group can be suppressed during the thermal polymerization of the vertical alignment film material. Substituents are particularly preferred.

As the polymerizable compound, a polymerizable compound represented by the general formula (III) and / or the general formula (IV) is preferable.

Specific examples of the polymerizable compound having one reactive group include the following general formula (III)

(Wherein X ³ represents a hydrogen atom or a methyl group, Sp ³ represents a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ) _t — (wherein t is 2 to And an oxygen atom is bonded to an aromatic ring. V represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic group having 5 to 30 carbon atoms. The alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom in the range where the oxygen atom is not adjacent to each other, and the alkyl group having 5 to 20 carbon atoms (the alkylene group in the group is an oxygen atom) May be substituted with an oxygen atom in a range not adjacent to each other)) or may be substituted with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkylene group having 1 to 8 carbon atoms). The polymerizable compound represented is preferred.

In the general formula (III), X ³ represents a hydrogen atom or a methyl group. However, a hydrogen atom is preferable when importance is attached to the reaction rate, and a methyl group is preferred when importance is placed on reducing the residual amount of reaction. preferable.

In the general formula (III), Sp ³ represents a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ) _t — (wherein _t represents an integer of 2 to 7, Represents a bond to an aromatic ring, but the carbon chain is preferably not so long, a single bond or an alkylene group having 1 to 5 carbon atoms is preferable, and a single bond or 1 to 3 carbon atoms is preferable. An alkylene group is more preferred. Further, when Sp ³ represents —O— (CH ₂ ) _t —, t is preferably 1 to 5, and more preferably 1 to 3.

In the general formula (III), V represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and an alkylene group in the polyvalent alkylene group. May be substituted with an oxygen atom in the range where the oxygen atom is not adjacent, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted with an oxygen atom within the range where the oxygen atom is not adjacent) .) Or may be substituted with a cyclic substituent, and is preferably substituted with two or more cyclic substituents.

More specifically, the polymerizable compound represented by the general formula (III) is represented by the general formula (X1a).

(In the formula, A ¹ represents a hydrogen atom or a methyl group,
A ² represents a single bond or an alkylene group having 1 to 8 carbon atoms (one or two or more methylene groups in the alkylene group are each independently an oxygen atom, assuming that oxygen atoms are not directly bonded to each other, -CO-, -COO- or -OCO- may be substituted, and one or more hydrogen atoms in the alkylene group are each independently substituted with a fluorine atom, a methyl group or an ethyl group. May be)
A ³ and A ⁶ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group are such that oxygen atoms are not directly bonded to each other) And each independently may be substituted with an oxygen atom, —CO—, —COO— or —OCO—, and one or more hydrogen atoms in the alkyl group are each independently a halogen atom. Which may be substituted with an atom or an alkyl group having 1 to 17 carbon atoms).
A ⁴ and A ⁷ are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group are such that oxygen atoms are not directly bonded to each other) And each independently may be substituted with an oxygen atom, —CO—, —COO— or —OCO—, and one or more hydrogen atoms in the alkyl group are each independently a halogen atom. Which may be substituted with an atom or an alkyl group having 1 to 9 carbon atoms).
p represents 1 to 10,
B ¹ , B ² and B ³ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group are In addition, as the oxygen atoms are not directly bonded to each other, each may be independently substituted with an oxygen atom, —CO—, —COO— or —OCO—, and one or more of the alkyl groups may be substituted. And each of the hydrogen atoms may be independently substituted with a halogen atom or a trialkoxysilyl group having 3 to 6 carbon atoms.

Further, the polymerizable compound represented by the general formula (III) is specifically the general formula (X1b).

(Wherein A ⁸ represents a hydrogen atom or a methyl group,
6-membered rings T ¹ , T ² and T ³ are each independently

(Where q represents an integer of 1 to 4),
q represents 0 or 1,
Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —COO—, —OCO—, —C≡C—, —CH═CH—. , —CF═CF—, — (CH ₂ ) ₄ —, —CH ₂ CH ₂ CH ₂ O—, —OCH ₂ CH ₂ CH ₂ —, —CH ₂ ═CHCH ₂ CH ₂ — or —CH ₂ CH ₂ CH = CH-
Y ³ represents a single bond, —COO— or —OCO—,
B ⁸ represents a hydrocarbon group having 1 to 18 carbon atoms. And a compound represented by

Furthermore, the polymerizable compound represented by the general formula (III) is specifically the general formula (X1c).

(Wherein R ⁷⁰ represents a hydrogen atom or a methyl group, and R ⁷¹ represents a hydrocarbon group having a condensed ring).

Specific examples of the polymerizable compound having two or more reactive groups are those represented by the general formula (IV)

(Wherein X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms or —O— (CH ₂ ) _s — (wherein _s represents an integer of 2 to 7 and an oxygen atom is bonded to an aromatic ring), and U is a linear or branched chain having 2 to 20 carbon atoms Represents a valent alkylene group or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which the oxygen atom is not adjacent to each other. May be substituted with an alkyl group of ˜20 (the alkylene group in the group may be substituted with an oxygen atom in the range where the oxygen atom is not adjacent) or a cyclic substituent, and k is an integer of 1 to 5 The polymerizable compound represented by .
In the general formula (IV), X ¹ and X ² each independently represent a hydrogen atom or a methyl group. However, when importance is attached to the reaction rate, a hydrogen atom is preferable, and importance is placed on reducing the residual amount of the reaction. In this case, a methyl group is preferred.

In the general formula (IV), Sp ¹ and Sp ² are each independently a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ) _s — (wherein s is 2 to 7 Wherein the oxygen atom is bonded to the aromatic ring), the carbon chain is preferably not so long, a single bond or an alkylene group having 1 to 5 carbon atoms is preferable, and a single bond or An alkylene group having 1 to 3 carbon atoms is more preferred. Also, when Sp ¹ and Sp ² represent —O— (CH ₂ ) _s —, s is preferably 1 to 5, more preferably 1 to 3, and at least one of Sp ¹ and Sp ² is a single bond. More preferably, it is particularly preferable that both are single bonds.

In the general formula (IV), U represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and an alkylene group in the polyvalent alkylene group May be substituted with an oxygen atom in the range where the oxygen atom is not adjacent, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted with an oxygen atom within the range where the oxygen atom is not adjacent) ), May be substituted with a cyclic substituent, and is preferably substituted with two or more cyclic substituents.

In the general formula (IV), U specifically preferably represents the following formulas (IVa-1) to (IVa-5), and the formulas (IVa-1) to (IVa-3) It is more preferable to represent, and it is particularly preferable to represent the formula (IVa-1).

(In the formula, both ends shall be bonded to Sp ¹ or Sp ^2. )
When U has a ring structure, at least one of the Sp ¹ and Sp ² preferably represents a single bond, and it is also preferable that both are single bonds.

In the above general formula (IV), k represents an integer of 1 to 5, but k is preferably a bifunctional compound of 1 or k is a trifunctional compound of 2, more preferably a bifunctional compound. .

Specifically, the compound represented by the general formula (IV) is preferably a compound represented by the following general formula (IVb).

(Wherein X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms or —O— (CH ₂ ) _s — (wherein _s represents an integer of 2 to 7 and an oxygen atom is bonded to an aromatic ring), Z ¹ represents —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ —, —CF ₂ CF ₂ —, —CH═CH—COO—, —CH═CH—OCO—, — _{COO-CH = CH -, -} OCO-CH = CH -, - COO-CH 2 CH 2 -, - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO -, - CH 2 CH 2 -OCO- _{, -COO-CH 2 -, -} OCO-CH 2 -, - CH 2 -COO -, - CH ^{-OCO -, - CY 1 = CY} 2 -, - C≡C- or a single bond, C represents 1,4-phenylene group, represents trans-1,4-cyclohexylene group or a single bond, in formula All 1,4-phenylene groups may have any hydrogen atom substituted with a fluorine atom.)
In the general formula (IVb), X ¹ and X ² each independently represent a hydrogen atom or a methyl group, both of which are diacrylate derivatives each representing a hydrogen atom, or both are dimethacrylate derivatives having a methyl group. A compound in which one represents a hydrogen atom and the other represents a methyl group is also preferable. As for the polymerization rate of these compounds, diacrylate derivatives are the fastest, dimethacrylate derivatives are slow, asymmetric compounds are in the middle, and a preferred embodiment can be used depending on the application. In the general formula (IVb), Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ) s—, at least one of which is a single bond A compound in which both represent a single bond or one in which one represents a single bond and the other represents an alkylene group having 1 to 8 carbon atoms or —O— (CH ₂ ) _s — is preferable. In this case, an alkylene group having 1 to 4 carbon atoms is preferable, and s is preferably 1 to 4.

In the general formula (IVb), Z ¹ represents —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ —, — CF ₂ CF ₂ —, —CH═CH—COO—, —CH═CH—OCO—, —COO—CH═CH—, —OCO—CH═CH—, —COO—CH ₂ CH ₂ —, —OCO— CH ₂ CH ₂ —, —CH ₂ CH ₂ —COO—, —CH ₂ CH ₂ —OCO—, —COO—CH ₂ —, —OCO—CH ₂ —, —CH ₂ —COO—, —CH ₂ —OCO —, —CY ¹ ═CY ² —, —C≡C— or a single bond, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ —, —CF ₂ CF ₂ — or a single bond is preferred, and —CO O—, —OCO— or a single bond is more preferred, and a single bond is particularly preferred.
In the general formula (IVb), C represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a single bond in which any hydrogen atom may be substituted with a fluorine atom. -A phenylene group or a single bond is preferred.
When C represents a ring structure other than a single bond, Z ¹ is preferably a linking group other than a single bond. When C is a single bond, Z ¹ is preferably a single bond.

As described above, in the general formula (IVb), it is preferable that C represents a single bond and the ring structure is formed of two rings. Specific examples of the polymerizable compound having a ring structure include the following general formula: Compounds represented by (IV-1) to (IV-6) are preferred, compounds represented by general formulas (IV-1) to (IV-4) are particularly preferred, and compounds represented by general formula (IV-2) Most preferred are the compounds

Specifically, the compound represented by the general formula (IV) is also preferably a compound represented by the following general formula (IVc).

(In the formula, X ¹ , X ² and X ³ each independently represent a hydrogen atom or a methyl group, and Sp ¹ , Sp ² and Sp ³ each independently represents a single bond having 1 to 8 carbon atoms. An alkylene group or —O— (CH ₂ ) _s — (wherein _s represents an integer of 2 to 7 and an oxygen atom is bonded to an aromatic ring), and Z ¹¹ and Z ¹² are each independently —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —CF ₂ O—, —OCF ₂ —, —CH ₂ CH ₂ —, —CF ₂ CF ₂ —, —CH═ CH—COO—, —CH═CH—OCO—, —COO—CH═CH—, —OCO—CH═CH—, —COO—CH ₂ CH ₂ —, —OCO—CH ₂ CH ₂ —, —CH _{2 CH 2 -COO -, - CH 2} CH 2 -OCO -, - COO-CH 2 -, - _{CO-CH 2 -, - CH} 2 -COO -, - CH 2 -OCO -, - CY 1 = CY 2 -, - C≡C- or a single bond, J is a 1,4-phenylene group, trans - It represents a 1,4-cyclohexylene group or a single bond, and all 1,4-phenylene groups in the formula may have an arbitrary hydrogen atom substituted with a fluorine atom.)
The total content of the cured product that is a polymer of the polymerizable compound represented by the general formula (III) and / or the general formula (IV) is 0.05 to 5% by mass in the liquid crystal layer. Is preferable, 0.05 to 4% by mass is more preferable, and 0.1 to 2% by mass is particularly preferable.

As a method for polymerizing a polymerizable compound having a reactive group, an appropriate polymerization rate is desirable in order to obtain good alignment performance of liquid crystals, and therefore active energy rays such as ultraviolet rays or electron beams are used singly or in combination or sequentially. A method of polymerizing by irradiation is preferred. When ultraviolet rays are used, a polarized light source or a non-polarized light source may be used. In addition, when the polymerization is performed in a state where a liquid crystal composition containing a polymerizable compound, which will be described later, is sandwiched between two substrates, at least the substrate on the irradiation surface side has appropriate transparency to the active energy rays. Must be given. Moreover, after polymerizing only a specific part using a mask during light irradiation, the orientation state of the unpolymerized part is changed by changing conditions such as an electric field, a magnetic field, or temperature, and further irradiation with active energy rays is performed. Then, it is possible to use a means for polymerization. In particular, when ultraviolet exposure is performed, it is preferable to perform ultraviolet exposure while applying an alternating electric field to the polymerizable compound-containing liquid crystal composition. The alternating electric field to be applied is preferably an alternating current having a frequency of 10 Hz to 10 kHz, more preferably a frequency of 60 Hz to 10 kHz, and the voltage is selected depending on a desired pretilt angle of the liquid crystal display element. That is, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage.

The temperature at the time of irradiation is preferably within a temperature range in which the liquid crystal state of the liquid crystal composition described later is maintained. Polymerization is preferably performed at a temperature close to room temperature, that is, typically at a temperature of 15 to 35 ° C. As a lamp for generating ultraviolet rays, a metal halide lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or the like can be used. Moreover, as a wavelength of the ultraviolet-rays to irradiate, it is preferable to irradiate the ultraviolet-ray of the wavelength range which is not the absorption wavelength range of a liquid crystal composition, and it is preferable to cut and use an ultraviolet-ray as needed. Intensity of ultraviolet irradiation is ^preferably from 0.1mW / cm 2 ~ 100W / cm 2, 2mW / cm 2 ~ 50W / cm 2 is more preferable. The amount of energy of ultraviolet rays to be irradiated can be adjusted as appropriate, but is preferably 10 mJ / cm ² to 500 J / cm ^{2, and} more preferably 100 mJ / cm ² to 200 J / cm ² . When irradiating with ultraviolet rays, the intensity may be changed. The time for irradiating with ultraviolet rays is appropriately selected depending on the intensity of the irradiated ultraviolet rays, but is preferably from 10 seconds to 3600 seconds, and more preferably from 10 seconds to 600 seconds.
(Liquid crystal composition)
The liquid crystal layer in the liquid crystal display element of the present invention contains a liquid crystal composition composed of a compound represented by the following formula.
Specifically, the general formula (LC3) to the general formula (LC5)

^(Wherein, represents an alkyl group of ^{R LC31, R LC32, R LC41} , R LC42, R LC51 and ^{R LC52} is 1 to 15 carbon atoms independently, one in the alkyl group or two or more The CH ₂ group may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent to dr. one or more hydrogen atoms in the group may be optionally substituted by a halogen ^{atom, a LC31, a LC32, a} LC41, a LC42, a LC51 and ^{a LC52} each independently any of the following Structure

(In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen atoms. And one or more hydrogen atoms in the structure may be substituted with Cl, CF _3, or OCF ₃ ), Z ^LC31 , Z ^{LC32, Z LC41, Z LC42,} Z LC51 and ^{Z LC51} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—, Z ⁵ represents a CH ₂ group or an oxygen atom, X ^LC41 represents a hydrogen atom or a fluorine atom, m ^{LC31, m LC32, m LC41,} m L ^{42, m LC51} and ^{m LC52} each independently represent ^{0 ~ 3, m LC31 + m} LC32, m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or ^{3, A LC31 ~ A LC52,} Z LC31 ~ When there are a plurality of Z ^LC52s , they may be the same or different. 1 type or 2 types or more of at least 1 type of compounds chosen from the compound group which has negative dielectric constant anisotropy represented by this.

Here, R ^LC31 to R ^LC52 are each independently preferably an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. Is most preferably the following structure:

(In the formula, it shall be bonded to the ring structure at the right end.)
A ^LC31 to A ^LC52 each independently preferably has the following structure:

Z ^LC31 to Z ^LC51 each independently has a single bond, —CH ₂ O—, ^{—COO—, —OCO—} , —CH ₂ CH ₂ —, —CF ₂ O—, —OCF ₂ — or —OCH ₂ —. preferable.

In the liquid crystal composition, one or more compounds selected from the compound group represented by the general formula (LC3), the general formula (LC4), and the general formula (LC5) are contained in the liquid crystal composition. As a lower limit, 10 mass% or more, preferably 20 mass% or more, more preferably 25 mass% or more, particularly preferably 28 mass% or more, most preferably 30 mass% or more, and an upper limit value is 85 mass%. % Or less, preferably 75% by mass or less, more preferably 70% by mass or less, particularly preferably 67% by mass or less, and most preferably 65% by mass or less.

Compounds represented by general formula (LC3), general formula (LC4), and general formula (LC5) are represented by general formula (LC3-1), general formula (LC4-1), and general formula (LC5-1).

Wherein R ³¹ to R ³³ are alkyl groups having 1 to 8 carbon atoms, alkenyl groups having 2 to 8 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, or alkenyloxy groups having 2 to 8 carbon atoms. R ⁴¹ to R ⁴³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. Z ³¹ to Z ³³ are a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —. , —CH ₂ O—, —OCF ₂ — or —CF ₂ O—, X ⁴¹ represents a hydrogen atom or a fluorine atom, and Z ³⁴ represents —CH ₂ — or an oxygen atom. It is preferable to use a compound selected from the group.

In the general formulas (LC3-1) to (LC5-1), R ³¹ to R ³³ are alkyl groups having 1 to 8 carbon atoms, alkenyl groups having 2 to 8 carbon atoms, and 1 to 8 carbon atoms. Represents an alkoxy group or an alkenyloxy group having 2 to 8 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and an alkyl group having 2 to 5 carbon atoms. It is more preferably a group or an alkenyl group having 2 to 4 carbon atoms, more preferably an alkyl group having 3 to 5 carbon atoms or an alkenyl group having 2 carbon atoms, and an alkyl group having 3 carbon atoms. It is particularly preferred to represent.

R ⁴¹ to R ⁴³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, It preferably represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 4 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms. More preferably, it represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, more preferably represents an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and has 2 carbon atoms. It is particularly preferred to represent an alkoxy group.

Z ³¹ to Z ³³ are a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, — CH ₂ O—, —OCF ₂ — or —CF ₂ O— represents a single bond, —CH ₂ CH ₂ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or — It preferably represents CF ₂ O—, and more preferably represents a single bond or —CH ₂ O—.

In the liquid crystal composition, one or more compounds selected from the group of compounds represented by general formula (LC3-1), general formula (LC4-1), and general formula (LC5-1) are used, and 0 to 50 5% to 50% by weight, preferably 5 to 40% by weight, more preferably 5 to 30% by weight, and more preferably 8 to 27% by weight. More preferably, the content is 10 to 25% by mass.

Specifically, the compound represented by the general formula (LC3-1) is preferably a compound represented by the following general formula (LC3-11) to general formula (LC3-14).

(Wherein R ³¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ^41a represents an alkyl group having 1 to 5 carbon atoms.)
Specifically, the compound represented by the general formula (LC4-1) is preferably a compound represented by the following general formula (LC4-11) to general formula (LC4-14).

(Wherein R ³² represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^42a represents an alkyl group having 1 to 5 carbon atoms, and X ⁴¹ represents a hydrogen atom or Represents a fluorine atom.)
Specifically, the compound represented by the general formula (LC5-1) is preferably a compound represented by the following general formula (LC5-11) to general formula (LC5-14).

(Wherein R ³³ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^43a represents an alkyl group having 1 to 5 carbon atoms, and Z ³⁴ represents —CH ₂ -Or represents an oxygen atom.)
In general formula (LC3-11), general formula (LC3-13), general formula (LC4-11), general formula (LC4-13), general formula (LC5-11), and general formula (LC5-13), R ³¹ to R ³³ are preferably the same embodiments as in formulas (LC3-1) to (LC5-1). R ^41a to R ^41c are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and particularly preferably an alkyl group having 2 carbon atoms.

In general formula (LC3-12), general formula (LC3-14), general formula (LC4-12), general formula (LC4-14), general formula (LC5-12), and general formula (LC5-14), R ³¹ to R ³³ are preferably the same embodiment as in general formula (II-1). R ^41a to R ^41c are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 3 carbon atoms, and particularly preferably an alkyl group having 3 carbon atoms.

Among general formulas (LC3-11) to (LC5-14), in order to increase the absolute value of dielectric anisotropy, general formula (LC3-11), general formula (LC4-11), Formula (LC5-11), general formula (LC3-13), general formula (LC4-13) and general formula (LC5-13) are preferred, and general formula (LC3-11), general formula (LC4-11), general formula Formula (LC5-11) is more preferred.

The liquid crystal layer in the liquid crystal display element of the present invention preferably contains one or more compounds represented by the general formulas (LC3-11) to (LC5-14), and contains one or two compounds. It is preferable to contain one or two compounds represented by the general formula (LC3-1).

The compounds represented by general formula (LC3), general formula (LC4), and general formula (LC5) are represented by general formula (LC3-2), general formula (LC4-2), and general formula (LC5-2). )

Wherein R ⁵¹ to R ⁵³ are an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. R ⁶¹ to R ⁶³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. B ¹ to B ^{3 each} represents a 1,4-phenylene group or trans-1,4-cyclohexylene group which may be fluorine-substituted, Z ⁴¹ to Z ⁴³ each represents a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O— the ^{stands, X 42} represents a hydrogen atom or a fluorine atom, ^{Z 4} Preferably from or an oxygen atom) compound selected from the group consisting of compounds represented by _- is -CH 2..

In the general formula (LC3-2), general formula (LC4-2), and general formula (LC5-2), R ⁵¹ to R ⁵³ are each an alkyl group having 1 to 8 carbon atoms, and an alkenyl having 2 to 8 carbon atoms. Group, an alkoxy group having 1 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. More preferably, it represents an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, and more preferably represents an alkyl group having 3 to 5 carbon atoms or an alkenyl group having 2 carbon atoms. And particularly preferably an alkyl group having 3 carbon atoms.

R ⁶¹ to R ⁶³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, It preferably represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 4 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms. More preferably, it represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, more preferably represents an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and has 2 carbon atoms. It is particularly preferred to represent an alkoxy group.

B ³¹ to B ³³ each represents a 1,4-phenylene group or trans-1,4-cyclohexylene group, which may be substituted with fluorine, but is an unsubstituted 1,4-phenylene group or trans-1,4- A cyclohexylene group is preferred, and a trans-1,4-cyclohexylene group is more preferred.

Z ⁴¹ to Z ⁴³ are a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, — CH ₂ O—, —OCF ₂ — or —CF ₂ O— represents a single bond, —CH ₂ CH ₂ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or — It preferably represents CF ₂ O—, and more preferably represents a single bond or —CH ₂ O—.

The compounds represented by the general formula (LC3-2), the general formula (LC4-2), and the general formula (LC5-2) are contained in the liquid crystal composition in an amount of 0 to 60% by mass, and 10 to 60% by mass. However, it is more preferably 20 to 50%, more preferably 25 to 45% by mass, more preferably 28 to 42%, and even more preferably 30 to 40%.

Specifically, the compound represented by the general formula (LC3-2) is preferably a compound represented by the following general formula (LC3-21) to general formula (LC3-26).

(Wherein R ⁵¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ^61a represents an alkyl group having 1 to 5 carbon atoms. Preferred is the same embodiment as R ⁵¹ and R ⁶¹ in 2).
Specifically, the compound represented by the general formula (LC4-2) is preferably a compound represented by the following general formula (LC4-21) to general formula (LC4-26).

(Wherein R ⁵² represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^62a represents an alkyl group having 1 to 5 carbon atoms, and X ⁴² represents a hydrogen atom or (It represents a fluorine atom, but an embodiment similar to R ⁵² and R ⁶² in formula (LC4-2) is preferred.)
Specifically, the compound represented by the general formula (LC5-2) is preferably a compound represented by the following general formula (LC5-21) to general formula (LC5-26).

(Wherein R ⁵³ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^63a represents an alkyl group having 1 to 5 carbon atoms, and W ² represents —CH ₂ -Represents an oxygen atom, but an embodiment similar to R ⁵³ and R ⁶³ in formula (LC5-2) is preferred.)
General formula (LC3-21), General formula (LC3-22), General formula (LC3-25), General formula (LC4-21), General formula (LC4-22), General formula (LC4-25), General formula In (LC5-21), general formula (LC5-22), and general formula (LC5-25), R ⁵¹ to R ⁵³ represent general formula (LC3-2), general formula (LC4-2), and general formula (LC Similar embodiments in LC5-2) are preferred. R ^61a to R ^63a are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and particularly preferably an alkyl group having 2 carbon atoms.

General formula (LC3-23), general formula (LC3-24) and general formula (LC3-26), general formula (LC4-23), general formula (LC4-24) and general formula (LC4-26), general formula (LC5-23), general formula (LC5-24), and general formula (LC5-26), R ⁵¹ to R ⁵³ represent general formula (LC3-2), general formula (LC4-2), and general formula (LC5- Similar embodiments in 2) are preferred. R ^61a to R ^63a are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 3 carbon atoms, and particularly preferably an alkyl group having 3 carbon atoms.

Among general formulas (LC3-21) to (LC5-26), in order to increase the absolute value of dielectric anisotropy, general formula (LC3-21), general formula (Lc3-22) and general formula Formula (LC3-25), Formula (LC4-21), Formula (LC4-22) and Formula (LC4-25), Formula (LC5-21), Formula (LC5-22) and Formula (LC LC5-25) is preferred.

The compounds represented by the general formula (LC3-2), the general formula (LC4-2) and the general formula (LC5-2) can be contained in one kind or two or more kinds, but B ¹ to B ³ are 1, It is preferable to contain at least one compound each representing a 4-phenylene group and a compound in which B ¹ to B ³ represent a trans-1,4-cyclohexylene group.

In addition, the compound represented by the general formula (LC3) includes the following general formula (LC3-a) and general formula (LC3-b)

^Wherein R ^7a1 and R ^7a2 , R ^8a1 and R ^8a2 are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Or an alkenyloxy group having 2 to 8 carbon atoms, wherein one or more hydrogen atoms in the alkyl group, alkenyl group, alkoxy group or alkenyloxy group may be substituted with a fluorine atom, The methylene group in the alkenyl group, alkoxy group or alkenyloxy group may be substituted with an oxygen atom unless the oxygen atom is continuously bonded, and may be substituted with a carbonyl group unless the carbonyl group is bonded continuously. Often,
n ^a2 represents 0 or 1, A ^1a2 represents a 1,4-cyclohexylene group, a 1,4-phenylene group or a tetrahydropyran-2,5-diyl group, and is represented by the general formulas (Ia1) and (Ia2) One or more hydrogen atoms in the 1,4-phenylene group therein may be substituted with fluorine atoms. )
It is preferable to use a compound selected from the group of compounds represented by:

The compounds represented by the general formula (LC3-a) are specifically the following formulas (LC3-a-1) to (LC3-a-8)

The compounds represented by formula (LC3-a-1) to (LC3-a-4) are more preferred, and the compounds represented by formula (LC3-a-1) and formula (LC3-a- The compound represented by 3) is more preferred, and the compound represented by the formula (LC3-a-1) is particularly preferred.

When four or more compounds represented by the general formula (LC3-a) are used, the compounds represented by the formulas (LC3-a-1) to (LC3-a-4) should be used in combination. And the content of the compound represented by the formula (LC3-a-1) to the formula (LC3-a-4) is 50% by mass or more in the compound represented by the general formula (LC3-a) It is preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 85% by mass or more, and most preferably 90% by mass or more.

When three types of compounds represented by the general formula (LC3-a) are used, the compounds represented by the formulas (LC3-a-1) to (LC3-a-3) may be used in combination. Preferably, the content of the compound represented by the formula (LC3-a-1) to the formula (LC3-a-3) is 50% by mass or more in the compound represented by the general formula (LC3-a). Is preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 85% by mass or more, and most preferably 90% by mass or more.

When two types of compounds represented by the general formula (LC3-a) are used, the compounds represented by the formula (LC3-a-1) and the formula (LC3-a-3) may be used in combination. Preferably, the content of the compound represented by the formula (LC3-a-1) and the formula (LC3-a-3) is 50% by mass or more in the compound represented by the general formula (LC3-a). Is preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 85% by mass or more, and most preferably 90% by mass or more.

The compounds represented by the general formula (LC3-b) are specifically the following general formulas (LC3-b-1) to (LC3-b-9)

(Wherein R ⁷ has the same meaning as R ^7a2 in formula (LC3-b), and R ⁸ has the same meaning as R ^8a2 in formula (LC3-b).)
The compound represented by these is preferable.

When a compound represented by the general formula (LC3-b) is used, it is preferable to use a compound represented by the formula (LC3-b-1), but the compound represented by the formula (LC3-b-1) The content of the compound is preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass or more in the compound represented by the general formula (LC3-b). Is more preferably 85% by mass or more, and most preferably 90% by mass or more.

R ^7a2 and R ^8a2 in formula (LC3-b) are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or carbon Represents an alkenyloxy group having 2 to 8 atoms, preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, preferably an alkyl group or carbon atom having 2 to 5 carbon atoms More preferably, it represents an alkenyl group having 2 to 5 carbon atoms, more preferably an alkyl group having 2 to 5 carbon atoms, more preferably a straight chain, and when both R ⁷ and R ⁸ are alkyl groups The number of carbon atoms is preferably different from each other.

Further More specifically, compound R ^8a2 represents compounds or R ^7a2 is butyl R ^7a2 represents R ^8a2 ethyl group represents a propyl group represents an ethyl group are preferred.

In addition, the compound represented by the general formula (LC3-1) is selected from one or more compounds and the compound group represented by the general formula (LC3-a) and the general formula (LC3-b). It is preferable to use at least one kind of compound in combination, and in particular, one or more compounds represented by the above general formula (LC3-1) and a compound represented by the above general formula (LC3-a) It is preferable to use at least one compound selected from among them in combination. At least one compound selected from the compound represented by the general formula (LC3-1) and the compound group represented by the general formula (LC3-a) and / or the general formula (LC3-b) (in particular, In the case of using together with the compound represented by the general formula (LC3-a)), in the IPS mode and the FFS mode, which are the modes of the present invention, containing a cured product that is a polymer of the polymerizable compound described above, A liquid crystal display element having the highest transmittance can be obtained as compared with the case where the cured product is not contained.

The compound represented by the general formula (LC4) is preferably a compound represented by the following general formula (LC4-a) to general formula (LC4-c), and the compound represented by the general formula (LC5) is Compounds represented by formula (LC5-a) to general formula (LC5-c) are preferred.

^{(Wherein, R LC41,} R ^LC42 and ^{X LC41} each independently represent the same meaning as ^{R LC41, R LC42} and ^{X LC41} in the general formula ^{(LC4), R LC51} and ^{R LC52} is the general independently It represents the same meaning as ^{R LC51} and ^{R LC52} in formula ^{(LC5), Z LC4a1, Z} LC4b1, Z LC4c1, Z LC5a1, Z LC5b1 and ^{Z LC5c1} each independently represent a single bond, -CH = CH -, - C≡ C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O— is represented.
^{R LC41,} R LC42, R ^LC51 and ^{R LC52} each independently represents an alkyl group of 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, the number alkenyl group or a carbon atom of 2 to 7 carbon atoms 2 It preferably represents ˜7 alkenyloxy groups.

Z ^LC4a1 to Z ^LC5c1 each independently preferably represents a single bond, —CH ₂ O—, ^{—COO—, —OCO—} , —CH ₂ CH ₂ —, and more preferably represents a single bond.

General formula (LC3-a), General formula (LC3-b), General formula (LC4-a), General formula (LC4-b), General formula (LC4-c), General formula (LC5-a), General formula The compound represented by (LC5-b) and general formula (LC5-c) is contained in the liquid crystal composition in an amount of 0 to 60% by mass, preferably 10 to 60% by mass, but 20 to 50%. The content is more preferably 25 to 45% by mass, more preferably 28 to 42%, still more preferably 30 to 40%.

In addition, the liquid crystal composition in the present invention contains one or more compounds represented by the general formula (L) as the second component.

(Wherein R ^L1 and R ^L2 each independently represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently Optionally substituted by —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,
OL represents 0, 1, 2 or 3;
B ^L1 , B ^L2 and B ^L3 are each independently (a) a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ groups not adjacent to each other). May be substituted with an oxygen atom or a sulfur atom).
(B) 1,4-phenylene group (one CH group present in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom), and (c) 1 , 4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl A group or a group selected from the group consisting of a chroman-2,6-diyl group, but one or more hydrogen atoms contained in the group (a), group (b) or group (c) Each may be substituted with F, Cl, CF ₃ or OCF ₃ ,
L ^L1 and L ^L2 are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —OCF ₂ -, -CF ₂ O-, -CH = NN-CH-, -CH = CH-, -CF = CF- or -C≡C-
When OL is 2 or 3 and a plurality of L ^L2 are present, they may be the same or different, and when OL is 2 or 3 and a plurality of B ^L3 is present, they are the same However, the compounds represented by general formula (LC3) to general formula (LC5) are excluded. )
The compound represented by the general formula (L) is represented by the following general formula (II)

(Wherein R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or 2 to 2 carbon atoms) 8 represents an alkenyloxy group, A represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group, k represents 1 or 2, and when k is 2, two A's are the same. Or may be different.) Is preferably selected from the group of compounds represented by:

As a content rate in the liquid crystal composition of the compound represented by the general formula (II), the lower limit is preferably 5% by mass, more preferably 10% by mass, further preferably 15% by mass, and particularly preferably 20% by mass. 25% by mass is most preferable, and the upper limit is preferably 70% by mass, 65% by mass is next preferable, 55% by mass is more preferable, 50% by mass is further preferable, 47% by mass is particularly preferable, and 45% by mass. Is most preferred.

Specific examples of the compound represented by the general formula (II) include compounds represented by a group of compounds represented by the following general formula (II-a) to general formula (II-f).

Wherein R ¹¹ to R ¹⁶ and R ²¹ to R ²⁶ are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Or an alkenyloxy group having 2 to 8 carbon atoms.)
The compound selected from the group of compounds represented by general formula (II-a) to general formula (II-f) preferably contains 1 to 10 types, particularly preferably 1 to 8 types, 1 to 5 types are particularly preferably contained, and 2 or more types of compounds are also preferably contained.

R ¹¹ to R ¹⁶ and R ²¹ to R ²⁶ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 2 to 8 carbon atoms. And more preferably an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkoxy group having 2 to 5 carbon atoms. (I) to formula (iv)

(In the formula, it shall be bonded to the ring structure at the right end.)
The structure represented by these is preferable.

R ¹¹ and R ²¹ , R ¹² and R ²² , R ¹³ and R ²³ , R ¹⁴ and R ²⁴ , R ¹⁵ and R ²⁵ , R ¹⁶ and R ²⁶ may be the same or different, but different substitutions It is preferable to represent a group.

From these points, for example, as a compound represented by the general formula (II), the following general formula (II-a-1)

(Wherein R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents 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). It is preferable to contain at least one compound selected from the group of compounds represented by:

More specifically, the compound represented by the general formula (II-a-1) is preferably a compound described below.

When the compound represented by the general formula (II-a-1) is contained, the lower limit of the content of the compound represented by the general formula (II-a-1) in the liquid crystal composition is 5 mass. %, More preferably 15% by weight, still more preferably 20% by weight, particularly preferably 23% by weight, most preferably 25% by weight, and the upper limit is preferably 70% by weight, more preferably 60% by weight, and 55% by weight. % By weight is more preferred, 52% by weight is particularly preferred and 50% by weight is most preferred. More specifically, when emphasizing the response speed, the lower limit is preferably 20% by mass, more preferably 30% by mass, still more preferably 35% by mass, particularly preferably 38% by mass, and most preferably 35% by mass. Preferably, the upper limit is preferably 70% by mass, more preferably 60% by mass, even more preferably 55% by mass, particularly preferably 52% by mass, and most preferably 50% by mass. The value is preferably 5% by mass, more preferably 15% by mass, still more preferably 20% by mass, particularly preferably 23% by mass, most preferably 25% by mass, and the upper limit is preferably 60% by mass, 50% by mass. Is more preferable, 45% by mass is further preferable, 42% by mass is particularly preferable, and 40% by mass is most preferable. The proportion of the compound represented by the general formula (II-a-1) is represented by the general formula (II-a-1) in the total content of the compound represented by the general formula (II) in the liquid crystal composition. The lower limit of the content of the compound is preferably 60% by mass, more preferably 70% by mass, still more preferably 75% by mass, particularly preferably 78% by mass, most preferably 80% by mass, and the upper limit is 90%. % By mass is preferable, 95% by mass is more preferable, 97% by mass is further preferable, 99% by mass is particularly preferable, and 100% by mass is preferable.

The compounds represented by the general formula (II-a) to the general formula (II-f) other than the compound represented by the general formula (II-a-1) are more specifically described below. Compounds are preferred.

Among these, formula (II-a-1-1), formula (II-a-1-5), formula (II-a1) to formula (II-a6), formula (II-b2), formula (II Compounds represented by -b6), formula (II-d1), formula (II-d2), formula (II-d3), formula (II-e2), and formula (II-f2) are preferred.

The liquid crystal composition in the present invention includes at least one compound selected from the group of compounds represented by general formula (LC3) to general formula (LC5), and a compound represented by general formula (L) as an essential component. And at least one compound selected from the group of compounds represented by general formula (LC3) to general formula (LC5) contained in the liquid crystal composition, and a compound represented by general formula (L) The total content is preferably 80 to 100% by mass, more preferably 85 to 100% by mass, still more preferably 90 to 100% by mass, particularly preferably 95 to 100% by mass, and most preferably 97 to 100% by mass.

The liquid crystal composition of the present invention preferably does not contain a compound having a structure in which oxygen atoms such as a peracid (—CO—OO—) structure are bonded in the molecule.

When importance is attached to the reliability and long-term stability of the liquid crystal composition, the content of the compound having a carbonyl group is preferably 5% by mass or less with respect to the total mass of the liquid crystal composition, and 3% by mass or less. More preferably, it is more preferably 1% by mass or less, and most preferably not substantially contained.

It is preferable to increase the content of a compound in which all the ring structures in the molecule are 6-membered rings, and the content of the compound in which all the ring structures in the molecule are 6-membered rings is based on the total mass of the liquid crystal composition It is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and only a compound in which all the ring structures in the molecule are 6-membered rings. Most preferably, the liquid crystal composition is constituted.

In order to suppress deterioration due to oxidation of the liquid crystal composition, it is preferable to reduce the content of the compound having a cyclohexenylene group as a ring structure, and the content of the compound having a cyclohexenylene group is determined based on the total mass of the composition. The content is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably substantially not contained.

In order to suppress deterioration due to oxidation of the liquid crystal composition, it is preferable to reduce the content of the compound having —CH═CH— as a linking group, and the content of the compound is 10% relative to the total mass of the composition. It is preferable to set it as mass% or less, It is more preferable to set it as 5 mass% or less, It is still more preferable not to contain substantially.

When emphasizing improvements of improvement and T _NI viscosity, that a hydrogen atom to reduce the content of the compound having the optionally substituted 2-methyl-1,4-diyl group halogen in the molecule The content of the compound having a 2-methylbenzene-1,4-diyl group in the molecule is preferably 10% by mass or less with respect to the total mass of the composition, and is 5% by mass or less. It is more preferable that it is not substantially contained.

When the compound contained in the composition of the present invention has an alkenyl group as a side chain, when the alkenyl group is bonded to cyclohexane, the alkenyl group preferably has 2 to 5 carbon atoms. When the alkenyl group is bonded to benzene, the alkenyl group preferably has 4 to 5 carbon atoms, and the unsaturated bond of the alkenyl group and benzene are preferably not directly bonded. In the case where importance is attached to the stability of the liquid crystal composition, it is preferable to reduce the content of the compound having an alkenyl group as a side chain and a 2,3-difluorobenzene-1,4-diyl group, It is preferable to make content of the said compound into 10 mass% or less with respect to the total mass of the said composition, it is more preferable to set it as 5 mass% or less, and it is still more preferable not to contain substantially.

The value of the dielectric anisotropy Δε of the liquid crystal composition in the present invention has a negative dielectric anisotropy, and the absolute value of the dielectric anisotropy is 2 or more. The value of the dielectric anisotropy Δε is preferably −2.0 to −6.0 at 25 ° C., more preferably −2.5 to −5.0, and −2.5 to -4.0 is particularly preferable. More specifically, it is preferably -2.5 to -3.4 when the response speed is important, and -3 when the drive voltage is important. It is preferable that it is from .4 to -4.0.

The value of the refractive index anisotropy Δn of the liquid crystal composition in the present invention is preferably 0.08 to 0.13 at 25 ° C., more preferably 0.09 to 0.12. More specifically, it is preferably 0.10 to 0.12 when corresponding to a thin cell gap, and preferably 0.08 to 0.10 when corresponding to a thick cell gap.

The rotational viscosity (γ ₁ ) of the liquid crystal composition in the invention is preferably 150 or less, more preferably 130 or less, and particularly preferably 120 or less.

In the liquid crystal composition of the present invention, it is preferable that Z as a function of rotational viscosity and refractive index anisotropy shows a specific value.

(In the formula, γ ₁ represents rotational viscosity, and Δn represents refractive index anisotropy.)
Z is preferably 13000 or less, more preferably 12000 or less, and particularly preferably 11000 or less.

The nematic phase-isotropic liquid phase transition temperature (T _ni ) of the liquid crystal composition in the present invention is 60 ° C. or higher, preferably 75 ° C. or higher, more preferably 80 ° C. or higher, and still more preferably 90 ° C. It is above ℃.

The liquid crystal composition of the present invention needs to have a specific resistance of 10 ¹² (Ω · m) or more, preferably 10 ¹³ (Ω · m), more preferably 10 ¹⁴ (Ω · m) or more.

The liquid crystal composition of the present invention may contain a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, an antioxidant, an ultraviolet absorber, etc. in addition to the above-mentioned compounds. When chemical stability is required, it is preferable not to have a chlorine atom in the molecule. When stability to light such as ultraviolet rays of the liquid crystal composition is required, conjugation represented by a naphthalene ring or the like. It is desirable that the molecule does not have a condensed ring having a long length and an absorption peak in the ultraviolet region.

In the liquid crystal composition of the present invention, the polymerization proceeds even in the absence of a polymerization initiator, but may contain a polymerization initiator in order to accelerate the polymerization. Examples of the polymerization initiator include benzoin ethers, benzophenones, acetophenones, benzyl ketals, acylphosphine oxides, and the like. Further, a stabilizer may be added in order to improve storage stability. Examples of the stabilizer that can be used include hydroquinones, hydroquinone monoalkyl ethers, tert-butylcatechols, pyrogallols, thiophenols, nitro compounds, β-naphthylamines, β-naphthols, nitroso compounds, and the like. It is done.
(Liquid crystal display element)
The liquid crystal display element of the present invention contains a liquid crystal composition between a pair of substrates composed of a first substrate having a pixel electrode and a common electrode formed on the substrate via an insulating layer and a second substrate. The liquid crystal layer is sandwiched.

Embodiments of the liquid crystal display element according to the present invention include an IPS type liquid crystal display element (In Plane Switching mode Liquid Crystal Display) or an FFS which is a kind of IPS type liquid crystal display device having a thin film transistor and a specific liquid crystal composition. Type liquid crystal display element (Fringe field switching mode liquid crystal display).

An IPS liquid crystal display element, which is a preferred embodiment of the liquid crystal display element according to the present invention, includes a first substrate, a second substrate, and the first substrate and the second substrate that are arranged to face each other. A plurality of gate wirings and data wirings arranged in a matrix on the first substrate, a thin film transistor provided at an intersection of the gate wirings and the data wirings, with a liquid crystal layer containing a liquid crystal composition interposed therebetween And a pixel electrode made of a transparent conductive material driven by the transistor, wherein the thin film transistor is provided in conduction with the gate electrode, a semiconductor layer provided via the gate electrode and an insulating layer, and the semiconductor layer A thin film transistor having a source electrode and a drain electrode provided at each intersection of a gate wiring and the data wiring; a pixel electrode connected to the thin film transistor; A common electrode provided on the first substrate or the second substrate and spaced apart from the pixel electrode, and the liquid crystal layer between the first transparent insulating substrate and the second transparent insulating substrate and the liquid crystal layer. An alignment film that induces homogeneous alignment with respect to the liquid crystal composition, and the shortest path connecting the common electrode adjacent to the pixel electrode from the pixel electrode is formed on the first or second substrate On the other hand, it is preferable that the pixel electrode and the common electrode are arranged so as to have a parallel direction component.

The shortest path connecting the pixel electrode to the common electrode adjacent to the pixel electrode has a parallel component with respect to the first or second substrate, and is disposed at a distance closest to the pixel electrode from the pixel electrode. The direction vector indicating the shortest path connecting the common electrodes has a parallel direction component with respect to the first or second substrate. For example, when the pixel electrode and the counter electrode overlap each other in the vertical direction with respect to the first or second substrate, the shortest path connecting the common electrode adjacent to the pixel electrode from the pixel electrode is the first Or, since it is perpendicular to the second substrate, it does not correspond to a component having a parallel component with respect to the first or second substrate. That is, the pixel electrode and the counter electrode are arranged so as not to overlap in the vertical direction with respect to the first or second substrate. The counter electrode may be provided on the first substrate or may be provided on the second substrate.

By providing the common electrode and the pixel electrode so as not to overlap each other in the vertical direction with respect to one or the second substrate, an electric field (E) generated between the common electrode and the pixel electrode is planar. Can have ingredients. Therefore, for example, when an alignment film that induces homogeneous alignment with respect to the liquid crystal composition is used for the alignment layer, the alignment layer is aligned in the plane direction that is the alignment direction of the alignment film before voltage is applied between the common electrode and the pixel electrode. The liquid crystal molecules block light, and when a voltage is applied, the liquid crystal molecules rotate horizontally with respect to the substrate by the electric field (E) applied in the plane direction, and block the light by arranging along the electric field direction. An element can be provided.

An FFS type liquid crystal display element, which is an embodiment of a liquid crystal display element according to the present invention, includes a first substrate, a second substrate, and a space between the first substrate and the second substrate that are arranged to face each other. Sandwiching a liquid crystal layer containing a liquid crystal composition, a plurality of gate wirings and data wirings arranged in a matrix on the first substrate, a thin film transistor provided at an intersection of the gate wirings and the data wirings, A pixel electrode made of a transparent conductive material driven by the transistor, wherein the thin film transistor is electrically connected to the gate electrode, the oxide semiconductor layer provided through the gate electrode and the insulating layer, and the oxide semiconductor layer A source electrode and a drain electrode provided on the first transparent insulating substrate, a common electrode provided apart from the pixel electrode on the first transparent insulating substrate, and the first transparent insulating substrate and the second transparent insulating substrate. So A liquid crystal layer provided between each of the liquid crystal layers and adjacent to the liquid crystal layer, having an alignment film that induces a homogeneous alignment with respect to the liquid crystal composition, and a shortest separation distance d between the adjacent common electrode and the pixel electrode; Is preferably shorter than the shortest separation distance G between the alignment films.

Note that in this specification, a liquid crystal display element in which the shortest separation distance d between the common electrode and the pixel electrode is longer than the shortest separation distance G between the alignment layers is referred to as an IPS liquid crystal display element. An element in which the shortest distance d from the electrode is shorter than the shortest distance G between the alignment layers is referred to as FFS. Accordingly, the only requirement for the FFS method is that the shortest separation distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the alignment layers. Therefore, the surface of the common electrode and the surface of the pixel electrode There is no limitation on the positional relationship in the thickness direction. Therefore, in the FSS mode liquid crystal display element according to the present invention, the pixel electrode may be provided closer to the liquid crystal layer than the common electrode as shown in FIGS. 1 to 5, and the pixel electrode and the common electrode as shown in FIG. May be provided on the same surface.
(Alignment film)
In the liquid crystal display element of the present invention, the liquid crystal composition is aligned on the first substrate and the surface in contact with the liquid crystal composition on the second substrate. It can be placed between the liquid crystal layers.

As the alignment film material, transparent organic materials such as polyimide, polyamide, BCB (Penzocyclobutene Polymer), polyvinyl alcohol and the like can be used. Particularly, p-phenylenediamine, 4,4′-diaminodiphenylmethane, etc. Aliphatic or alicyclic tetracarboxylic anhydrides such as aliphatic or alicyclic diamines, butanetetracarboxylic anhydride, 2,3,5-tricarboxycyclopentylacetic anhydride, pyromellitic dianhydride A polyimide alignment film obtained by imidizing a polyamic acid synthesized from an aromatic tetracarboxylic anhydride such as a product is preferable. In this case, rubbing is generally used as a method for imparting orientation, but when used for a vertical orientation film or the like, it can be used without imparting orientation.

As the alignment film material, a material containing chalcone, cinnamate, cinnamoyl or azo group in the compound can be used, and it may be used in combination with materials such as polyimide and polyamide. In this case, the alignment film is rubbed. Or a photo-alignment technique may be used.

The alignment film is generally formed by applying the alignment film material on a substrate by a method such as spin coating to form a resin film, but a uniaxial stretching method, Langmuir-Blodgett method, or the like can also be used. .

As an embodiment according to the present invention, an example of an FFS type liquid crystal display element will be described below with reference to FIGS. FIG. 1 is an exploded perspective view schematically showing a structure of one embodiment of a liquid crystal display element, which is a so-called FFS type liquid crystal display element. A liquid crystal display element 10 according to the present invention includes a first polarizing plate 1, a first substrate 2, an electrode layer (also referred to as a thin film transistor layer) 3 including a thin film transistor, an alignment film 4, and a liquid crystal composition. It is preferable that the liquid crystal layer 5, the alignment film 4, the color filter 6, the second substrate 7, and the second polarizing plate 8 are sequentially stacked. As shown in FIG. 1, the first substrate 2 and the second substrate 7 may be sandwiched between a pair of polarizing plates 1 and 8. Further, in FIG. 1, a color filter 6 is provided between the second substrate 7 and the alignment film 4. Further, a pair of alignment films 4 may be formed on the (transparent) electrode (layer) 3 so as to be close to the liquid crystal layer 5 according to the present invention and to directly contact the liquid crystal composition constituting the liquid crystal layer 5.

The FFS mode liquid crystal display element uses a fringe electric field. When the shortest separation distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the alignment layers, the common electrode and the pixel electrode A fringe electric field is formed between them, and the horizontal and vertical alignments of the liquid crystal molecules can be used efficiently. That is, in the case of the FFS liquid crystal display element, a horizontal electric field formed in a direction perpendicular to a line forming the comb-teeth of the pixel electrode 21 and a parabolic electric field can be used.

FIG. 2 is an enlarged plan view of a region II of an electrode layer 3 (or also referred to as a thin film transistor layer 3) including a thin film transistor formed on the substrate in FIG. In the vicinity of the intersection where the gate line 26 and the data line 25 intersect each other, the thin film transistor including the source electrode 27, the drain electrode 24 and the gate electrode 28 serves as a switching element for supplying a display signal to the pixel electrode 21. It is provided in connection with. As an example, FIG. 1 shows a configuration in which a flat plate-like common electrode 22 is formed on one surface of a back surface of a comb-like pixel electrode 21 via an insulating layer (not shown). The surface of the pixel electrode 21 may be covered with a protective insulating film and an alignment film layer. Note that a storage capacitor 23 for storing a display signal supplied through the data wiring 25 may be provided in a region surrounded by the plurality of gate wirings 26 and the plurality of data wirings 25. Further, a common line 29 is provided in parallel with the gate wiring 26. The common line 29 is connected to the common electrode 22 in order to supply a common signal to the common electrode 22.

FIG. 3 is an example of a cross-sectional view of the liquid crystal display element taken along the line III-III in FIG. The first substrate 2 on which the electrode layer 3 including the alignment layer 4 and the thin film transistor (11, 12, 13, 14, 15, 16, 17) is formed on the surface, and the second substrate on which the alignment layer 4 is formed on the surface The substrate 7 is spaced apart from the alignment layer at a predetermined interval G, and the liquid crystal layer 5 containing the liquid crystal composition is filled in this space. A gate insulating film 12 is formed on a part of the surface of the first substrate 2, a common electrode 22 is formed on a part of the surface of the gate insulating film 12, and the common electrode 22 and the thin film transistor 20 are further formed. An insulating film 18 is formed so as to cover it. A pixel electrode 21 is provided on the insulating film 18, and the pixel electrode 21 is in contact with the liquid crystal layer 5 through the alignment layer 4. Therefore, the minimum distance d between the pixel electrode and the common electrode can be adjusted as the (average) film thickness of the gate insulating film 12. In other words, in the embodiment of FIG. 2, the distance in the horizontal direction on the substrate between the pixel electrode and the common electrode is zero. The electrode width of the comb-like portion of the pixel electrode 21: l and the width of the gap of the comb-like portion of the pixel electrode 21: m are such that all the liquid crystal molecules in the liquid crystal layer 5 can be driven by the generated electric field. It is preferable to form the width.

As shown in FIGS. 1 to 5, in the case of the FFS mode liquid crystal display element in which the shortest separation distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the alignment layers, the major axis direction is When a voltage is applied to the liquid crystal molecules arranged parallel to the alignment direction of the alignment layer, an equipotential line of a parabolic electric field is formed between the pixel electrode 21 and the common electrode 22 between the pixel electrode 21 and the common electrode 22. The liquid crystal molecules in the liquid crystal layer 5 rotate in the liquid crystal layer 5 along the formed electric field and function as a switching element. More specifically, for example, when an alignment film that induces homogeneous alignment with respect to the liquid crystal composition is used for the alignment layer, the plane direction that is the alignment direction of the alignment film before voltage is applied between the common electrode and the pixel electrode When the liquid crystal molecules arranged in the light block and block the light, the common electrode and the pixel electrode are separated from each other on the same substrate (or electrode layer). And the vertical component electric field (fringe field) derived from the edges of these electrodes is generated when the shortest separation distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the alignment layers. Even liquid crystal molecules having a low dielectric anisotropy can be driven. Therefore, in the liquid crystal composition, the amount of the compound having a large dielectric anisotropy (Δε) can be reduced as much as possible, so that the liquid crystal composition itself can contain a large amount of a low-viscosity compound.

Further, the rubbing direction of the alignment film 4 in the embodiment of the liquid crystal display element according to the present invention is a direction perpendicular to the line forming the comb shape of the pixel electrode 21 (direction in which a horizontal electric field is formed) as the x axis. Then, it is preferable that the angle θ formed by the x-axis and the major axis direction of the liquid crystal molecules 30 is approximately 0 to 45 °. In the second embodiment, the same liquid crystal composition as that described in the first embodiment is used as the liquid crystal composition, that is, a liquid crystal composition having negative dielectric anisotropy is used. Used. In a state where no voltage is applied, the liquid crystal molecules are arranged so that the major axis direction thereof is parallel to the alignment direction of the alignment film 4. When a voltage is applied, the liquid crystal molecules having negative dielectric anisotropy rotate so that the major axis direction thereof is perpendicular to the generated electric field direction. Although the liquid crystal molecules located near the pixel electrode 21 are easily affected by the fringe electric field, the liquid crystal molecules having negative dielectric anisotropy are oriented in the major axis direction because the polarization direction is on the minor axis of the molecule. It does not rotate in a direction perpendicular to the film 4, and the major axis direction of all the liquid crystal molecules 30 in the liquid crystal layer 5 can be maintained parallel to the alignment film 4. Therefore, the FFS type liquid crystal display element using liquid crystal molecules having negative dielectric anisotropy can obtain excellent transmittance characteristics.

FIG. 4 is another form of a plan view in which the region II of the electrode layer 3 including the thin film transistor (also referred to as the thin film transistor layer 3) formed on the substrate in FIG. 1 is enlarged. In the vicinity of the intersection where the gate line 26 and the data line 25 intersect each other, the thin film transistor including the source electrode 27, the drain electrode 24 and the gate electrode 28 serves as a switching element for supplying a display signal to the pixel electrode 21. It is provided in connection with. Further, the pixel electrode 21 may have a structure cut out by at least one notch, and an example thereof is shown in FIG. The pixel electrode 21 has a shape in which the center and both ends of a rectangular flat plate are cut out by a triangular cutout, and the remaining region is cut out by eight rectangular cutouts. Reference numeral 22 denotes a comb tooth body (not shown). The surface of the pixel electrode may be covered with a protective insulating film and an alignment film layer. Note that a storage capacitor 23 for storing a display signal supplied through the data wiring 24 may be provided in a region surrounded by the plurality of gate wirings 25 and the plurality of data wirings 24. Note that the shape and number of the notches are not particularly limited.

FIG. 5 shows another example of a cross-sectional view of the liquid crystal display element taken along the line III-III in FIG. That is, the difference from the structure of the liquid crystal display element shown in FIG. 3 is that the liquid crystal display element shown in FIG. 2 has a common electrode as a flat plate and a pixel electrode as a comb. On the other hand, as described above, in the liquid crystal display element shown in FIG. 4, the pixel electrode 21 has a rectangular flat plate whose center and both ends are cut out by a triangular cutout, and a remaining area is 8. It has a shape cut out by two rectangular cutouts, and the common electrode has a comb-like structure. Therefore, the minimum separation distance d between the pixel electrode and the common electrode is equal to or greater than the (average) film thickness of the gate insulating film 12 and less than the alignment layer separation distance G. Further, in FIG. 5, the common electrode has a comb-like structure, but the common electrode may be a flat plate in this embodiment. In any case, the FFS mode liquid crystal display element according to the present invention only needs to satisfy the condition that the shortest separation distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the alignment layers. Further, in the configuration of the liquid crystal display element shown in FIG. 5, the pixel electrode 21 is covered with the protective film 18, but in the configuration of the liquid crystal display element shown in FIG. 2, the pixel electrode 21 is covered with the alignment layer 4. . In the present invention, the pixel electrode may be covered with either a protective film or an alignment film.

In FIG. 5, a polarizing plate is formed on one surface of the first substrate 2, and a gate insulating film 12 is formed so as to cover the comb-like common electrode 22 formed on a part of the other surface. A pixel electrode 21 is formed on a part of the surface of the gate insulating film 12, and an insulating film 18 is formed so as to cover the pixel electrode 21 and the thin film transistor 20. Further, an alignment layer 4, a liquid crystal layer 5, an alignment layer 4, a color filter 6, a second substrate 7 and a polarizing plate 8 are laminated on the insulating film 18. Therefore, the minimum separation distance d between the pixel electrode and the common electrode is adjusted by both electrode positions, the electrode width of the comb-like portion of the pixel electrode 21: l, or the width of the gap of the comb-like portion of the pixel electrode 21: m. can do.

As shown in FIG. 5, when the pixel electrode protrudes from the common electrode to the second substrate side and both are provided in parallel on the first substrate, the pixel electrode is disposed between the common electrode and the pixel electrode. Therefore, an electric field (E) having a thickness direction component can be applied at the same time because an electric field having a planar direction component is formed and the height in the thickness direction is different between the surface of the pixel electrode and the surface of the common electrode.

Note that the FFS mode liquid crystal display element uses a fringe electric field, and is particularly limited as long as the shortest distance d between the adjacent common electrode and the pixel electrode is shorter than the shortest distance G between the alignment layers. For example, as shown in FIG. 6, the pixel electrode 41 and the common electrode 42 are provided on the same surface on the first substrate 2. The configuration may be such that the plurality of tooth portions and the plurality of tooth portions of the comb-like common electrode 42 are separated and meshed. In this case, an IPS liquid crystal display element can be obtained by making the distance between the tooth portion of the common electrode 42 and the tooth portion of the pixel electrode 41 longer than the shortest distance G between the alignment layers, and the tooth portion of the common electrode 42 and the pixel electrode 41. If the distance from the teeth is shorter than the shortest distance G between the alignment layers, an FFS type liquid crystal display element utilizing a fringe electric field can be obtained.
(Thin film transistor)
The thin film transistor shown in FIGS. 3 and 5 includes a gate electrode 11 formed on the surface of the substrate 2, a gate insulating layer 12 that covers the gate electrode 11 and covers substantially the entire surface of the substrate 2, A semiconductor layer 13 formed on the surface of the gate insulating layer 12 so as to face the gate electrode 11; a protective film 14 provided so as to cover a part of the surface of the semiconductor layer 113; the protective layer 14; A drain electrode 16 which covers one side end of the semiconductor layer 13 and is in contact with the gate insulating layer 12 formed on the surface of the substrate 2, the other of the protective film 14 and the semiconductor layer 13 A source electrode 17 provided so as to cover a side end portion of the substrate 2 and to be in contact with the gate insulating layer 12 formed on the surface of the substrate 2, the drain electrode 16, and the source electrode It has 7 and the insulating protective layer 18 provided to cover the, the.

Further, in the thin film transistor shown in FIG. 5, an insulating film 18 is formed so as to cover the pixel electrode 21 and the thin film transistor 20. Since the insulating film 18 also separates the liquid crystal layer 5 from the semiconductor layer 13 using an oxide semiconductor, the influence of oxygen released from the oxide semiconductor film on the liquid crystal layer can be reduced.

1 to 5 includes a first polarizing plate 1, a first substrate 2, a pixel electrode layer (also referred to as a thin film transistor layer) 3 including a thin film transistor, and an alignment film 4. A layer 5 containing a liquid crystal composition, an alignment film 4, a common electrode 6, a color filter 6, a second substrate 7, and a polarizing plate 8 are sequentially stacked.

Hereinafter, some examples of the best mode of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Further, “%” in the compositions of the following Examples and Comparative Examples means “% by mass”.

In the examples, the measured characteristics are as follows.

T _ni : Nematic phase-isotropic liquid phase transition temperature (° C.)
Δn: refractive index anisotropy at 25 ° C. Δε: dielectric anisotropy at 25 ° C. η: viscosity at 20 ° C. (mPa · s)
γ ₁ : rotational viscosity at 25 ° C. (mPa · s)
d _gap : _gap between the first substrate and the second substrate of the cell (μm)
VHR: Voltage holding ratio at 70 ° C. (%)
(The ratio of the measured voltage to the initial applied voltage in% when the liquid crystal composition was injected into a cell having a cell thickness of 3.5 μm and measured under the conditions of 5 V applied, frame time 200 ms, and pulse width 64 μs)
Burn-in:
The burn-in evaluation of the liquid crystal display element is based on the following four-level evaluation of the afterimage level of the fixed pattern when the predetermined fixed pattern is displayed in the display area for 1000 hours and then the entire screen is uniformly displayed. went.

◎ No afterimage or very little but no problem level ○ Slightly afterimage is acceptable level △ No afterimage is acceptable level x Afterimage is fairly bad Transmission:
The transmittance in the liquid crystal display element is a value when the transmittance of the element after the liquid crystal composition is injected is measured with the transmittance of the element before the liquid crystal composition is injected as 100%.
(Side chain structure)
-N -C _n H _{2n + 1} linear alkyl group having n carbon atoms n- C _n H _{2n + 1-} linear alkyl group having n carbon atoms -On -OC _n H _{2n + 1} linear alkoxyl having n carbon atoms Group nO- C _n H _{2n + 1} O- linear alkoxyl group having n carbon atoms -V -CH = CH ₂
V- CH ₂ = CH-
-V1 -CH = CH-CH ₃
1V- CH ₃ —CH═CH—
_{-2V -CH 2 -CH 2 -CH = CH} 3
V2- CH ₃ = CH-CH ₂ -CH _2-
-2V1 -CH ₂ -CH ₂ -CH = CH-CH ₃
1V2- CH ₃ —CH═CH—CH ₂ —CH ₂
(Ring structure)
0d3- CH ₂ = CH-CH ₂ -CH _2-
-3d0 —CH ₂ —CH ₂ —CH═CH ₂
(Linked structure)
-VO- -COO-
-NO- -C _n H _2n O-
-T- -C≡C-
-N- -CH = NN-CH =
(Ring structure)

(Comparative Example 1)
An electrode structure is formed on at least one of the first and second substrates, a horizontal alignment film is formed on each facing side, and then a weak rubbing process is performed to create an FFS cell. A liquid crystal display element of Comparative Example 1 was prepared by sandwiching the following liquid crystal composition 1 between two substrates (d _gap = 3.0 μm, alignment film AL-1051) (d _gap = 3.0 μm) , Its VHR, and transmittance were measured. In addition, image sticking evaluation of the obtained liquid crystal display element was performed. The composition of the liquid crystal composition, its physical properties, the VHR of the liquid crystal display element, the transmittance, and the results of the burn-in evaluation are shown in the following table.
Example 1
A polymerizable liquid crystal composition 1A is prepared by adding 0.2% by mass of a polymerizable compound represented by the following general formula (IV-A) to 99.8% by mass of the liquid crystal composition 1: and uniformly dissolving the polymer compound. did.

An FFS cell was prepared in the same manner as in Comparative Example 1, and after the polymerizable liquid crystal composition 1A was sandwiched between the first substrate and the second substrate, a rectangular wave having a frequency of 1 kHz was applied to the cell. However, ultraviolet rays were irradiated with a high-pressure mercury lamp through a filter that cuts out ultraviolet rays of 320 nm or less. The cell surface is adjusted to have an irradiation intensity of 10 mW / cm ² and irradiated for 600 seconds to polymerize the polymerizable compound in the polymerizable liquid crystal composition to prepare a liquid crystal display element, and VHR, transmittance, and The seizure property was measured.
(Example 2)
A polymerizable liquid crystal composition 1B is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-B) to 99.7% by mass of the liquid crystal composition 1: and uniformly dissolving the polymer compound. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 1B was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
Example 3
A polymerizable liquid crystal composition 1C is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-C) to 99.7% by mass of the liquid crystal composition 1 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 1C was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
Example 4
A polymerizable liquid crystal composition 1D is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-D) to 99.7% by mass of the liquid crystal composition 1: and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 1D was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 5)
A polymerizable liquid crystal composition 1E is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-E) to 99.7% by mass of the liquid crystal composition 1: and uniformly dissolving the polymer compound. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 1E was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 1 to 5 show VHR equivalent to that of Comparative Example 1, and there is no afterimage even in burn-in evaluation, or even if it is very slight, maintaining high acceptable level and high transmittance improvement Was able to be realized.
(Comparative Examples 2 and 3)
In the same manner as in Comparative Example 1, the liquid crystal composition 2 and the liquid crystal composition 3 shown in the following table are sandwiched to prepare the liquid crystal display elements of Comparative Examples 2 and 3, and the VHR, transmittance, and burn-in evaluation of the liquid crystal display elements Went. The results are shown below.
(Example 6)
The polymerizable liquid crystal composition 2F is prepared by adding 0.2% by mass of a polymerizable compound represented by the following general formula (IV-F) to 99.8% by mass of the liquid crystal composition 2: and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell is created, the polymerizable liquid crystal composition 2F is sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition is polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 7)
A polymerizable liquid crystal composition 2G is prepared by adding 0.1% by mass of a polymerizable compound represented by the following general formula (IV-G) to 99.9% by mass of the liquid crystal composition 2: and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 2G was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 8)
Polymerizable compound 3H is prepared by adding 0.15% by mass of a polymerizable compound represented by the following general formula (IV-H) to 99.85% by mass of liquid crystal composition 3: and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 3H was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
Example 9
The polymerizable liquid crystal composition 3I is prepared by adding 0.15% by mass of a polymerizable compound represented by the following general formula (IV-I) to 99.85% by mass of the liquid crystal composition 3: and dissolving uniformly. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 3I was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 6 to 9 show VHR equivalent to Comparative Examples 2 and 3, and there is no afterimage even in the burn-in evaluation, or even if there is very little, maintaining an acceptable level and high transmission It was possible to improve the rate.
(Comparative Examples 4 and 5)
In the same manner as in Comparative Example 1, the liquid crystal composition 4 and the liquid crystal composition 5 shown in the following table were sandwiched to prepare the liquid crystal display elements of Comparative Examples 4 and 5, and the VHR, transmittance, and burn-in evaluation of the liquid crystal display elements Went. The results are shown below.
(Example 10)
A polymerizable liquid crystal composition 4A is prepared by uniformly adding 0.2% by mass of a polymerizable compound represented by the above general formula (IV-A) to 99.8% by mass of the liquid crystal composition 4: did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 4A was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 11)
A polymerizable liquid crystal composition 4B is prepared by adding 0.3% by mass of a polymerizable compound represented by the above general formula (IV-B) to 99.7% by mass of the liquid crystal composition 4: and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 4B was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
Example 12
A polymerizable liquid crystal composition 5C is prepared by adding 0.3% by mass of a polymerizable compound represented by the above general formula (IV-C) to 99.7% by mass of the liquid crystal composition 5 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 5C was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 13)
Polymerizable liquid crystal composition 5F is prepared by adding 0.2% by mass of a polymerizable compound represented by the above general formula (IV-F) to 99.8% by mass of liquid crystal composition 5 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 5F was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 10 to 13 show VHR equivalent to Comparative Examples 4 and 5, and there is no afterimage even in the burn-in evaluation, or even if there is very little, maintaining high acceptable level and high transmission It was possible to improve the rate.
(Comparative Example 6)
Similarly to Comparative Example 1, the liquid crystal composition 6 shown in the following table was sandwiched to prepare a liquid crystal display element of Comparative Example 6, and VHR, transmittance and burn-in evaluation of the liquid crystal display element were performed. The results are shown below.
(Example 14)
Polymerizable liquid crystal composition 6A is prepared by adding 0.2% by mass of the polymerizable compound represented by the above general formula (IV-A) to 99.8% by mass of liquid crystal composition 6 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 6A was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 15)
Polymerizable liquid crystal composition 6B is prepared by adding 0.3% by mass of a polymerizable compound represented by the above general formula (IV-B) to 99.7% by mass of liquid crystal composition 6 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 6B was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 14 and 15 showed VHR equivalent to that of Comparative Example 6, and there was no afterimage even in the burn-in evaluation, or even if it was very slight, maintaining an acceptable level, compared with Comparative Example. A particularly high transmittance improvement was achieved.
(Comparative Example 7)
Similarly to Comparative Example 1, the liquid crystal composition 7 shown in the following table was sandwiched to prepare a liquid crystal display element of Comparative Example 7, and VHR, transmittance and burn-in evaluation of the liquid crystal display element were performed. The results are shown below.
(Example 16)
A polymerizable liquid crystal composition 7C is prepared by adding 0.3% by mass of a polymerizable compound represented by the above general formula (IV-C) to 99.7% by mass of the liquid crystal composition 7 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 7C was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 17)
The polymerizable liquid crystal composition 7D is prepared by adding 0.3% by mass of the polymerizable compound represented by the above general formula (IV-D) to 99.7% by mass of the liquid crystal composition 7 and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 7D was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 18)
Polymerizable liquid crystal composition 7F is prepared by adding 0.2% by mass of the polymerizable compound represented by the above general formula (IV-F) to 99.8% by mass of the liquid crystal composition 7 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 7F was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 16 to 18 show VHR equivalent to that of Comparative Example 7, and there is no afterimage even in the burn-in evaluation, or even if it is very slight, maintaining an acceptable level, compared with Comparative Example. A particularly high transmittance improvement was achieved.
(Comparative Examples 8 and 9)
In the same manner as in Comparative Example 1, the liquid crystal composition 8 and the liquid crystal composition 9 shown in the following table are sandwiched to prepare the liquid crystal display elements of Comparative Examples 8 and 9, and the VHR, transmittance, and burn-in evaluation of the liquid crystal display elements Went. The results are shown below.
(Example 19)
A polymerizable liquid crystal composition 8A is prepared by adding 0.2% by mass of the polymerizable compound represented by the above general formula (IV-A) to 99.8% by mass of the liquid crystal composition 8 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell is prepared, the polymerizable liquid crystal composition 8A is sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition is polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 20)
The polymerizable liquid crystal composition 8B is prepared by adding 0.3% by mass of the polymerizable compound represented by the above general formula (IV-B) to 99.7% by mass of the liquid crystal composition 8 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 8B was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 21)
Polymerizable liquid crystal composition 9A is prepared by adding 0.2% by mass of the polymerizable compound represented by the above general formula (IV-A) to 99.8% by mass of liquid crystal composition 9 and uniformly dissolving it. did.

In the same manner as in Example 1, an FFS cell is prepared, the polymerizable liquid crystal composition 9A is sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition is polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 22)
The polymerizable liquid crystal composition 9C is prepared by adding 0.3% by mass of the polymerizable compound represented by the above general formula (IV-C) to 99.7% by mass of the liquid crystal composition 9 and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 9C was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 19 to 22 show VHR equivalent to Comparative Examples 8 and 9, and there is no afterimage even in the burn-in evaluation, or even if there is very little, maintaining high acceptable level and high transmission It was possible to improve the rate.
(Comparative Example 10)
Similarly to Comparative Example 1, the liquid crystal composition 10 shown in the following table was sandwiched to prepare a liquid crystal display element of Comparative Example 10, and VHR, transmittance, and burn-in evaluation of the liquid crystal display element were performed. The results are shown below.
(Example 23)
A polymerizable liquid crystal composition 10A is prepared by adding 0.2% by mass of a polymerizable compound represented by the following general formula (IV-A) to 99.8% by mass of the liquid crystal composition 10 and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 10A was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 24)
A polymerizable liquid crystal composition 10B is prepared by uniformly adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-B) to 99.7% by mass of the liquid crystal composition 10: did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 10B was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 25)
Polymerizable compound 10C is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-C) to 99.7% by mass of liquid crystal composition 10 and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 10C was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 26)
A polymerizable liquid crystal composition 10D is prepared by uniformly adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-D) to 99.7% by mass of the liquid crystal composition 10: did.

In the same manner as in Example 1, an FFS cell was prepared, the polymerizable liquid crystal composition 10D was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.
(Example 27)
A polymerizable liquid crystal composition 10E is prepared by adding 0.3% by mass of a polymerizable compound represented by the following general formula (IV-E) to 99.7% by mass of the liquid crystal composition 10 and uniformly dissolving. did.

In the same manner as in Example 1, an FFS cell was created, the polymerizable liquid crystal composition 10E was sandwiched, irradiated with ultraviolet rays, and a polymerizable compound in the polymerizable liquid crystal composition was polymerized to prepare a liquid crystal display element. VHR, transmittance, and burn-in were measured.

The liquid crystal display elements of Examples 23 to 27 show VHR equivalent to that of Comparative Example 10, and there is no afterimage even in the burn-in evaluation, or even if there is very little, while maintaining an acceptable level, very high transmission It was possible to improve the rate.

Claims (14)

1. A liquid crystal display in which a liquid crystal layer containing a liquid crystal composition is sandwiched between a pair of substrates including a first substrate having a pixel electrode and a common electrode formed on an insulating layer through an insulating layer and a second substrate The liquid crystal layer includes a polymerizable compound having one reactive group and / or a cured product which is a polymer of a polymerizable compound having two or more reactive groups, and the liquid crystal The composition has a negative dielectric anisotropy;
   The following general formula (LC3) to general formula (LC5)
   

   

   ^(Wherein, represents an alkyl group of ^{R LC31, R LC32, R LC41} , R LC42, R LC51 and ^{R LC52} is 1 to 15 carbon atoms independently, one in the alkyl group or two or more The CH ₂ group may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent to the alkyl group. one or more hydrogen atoms in may be optionally substituted by a halogen ^{atom, a LC31, a LC32, a} LC41, a LC42, a LC51 and ^{a LC52} are independently any of the following Structure of
   

   

   (In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen atoms. And one or more hydrogen atoms in the structure may be substituted with Cl, CF _3, or OCF ₃ ), Z ^LC31 , Z ^{LC32, Z LC41, Z LC42,} Z LC51 and ^{Z LC51} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—, Z ⁵ represents a CH ₂ group or an oxygen atom, X ^LC41 represents a hydrogen atom or a fluorine atom, m ^{LC31, m LC32, m LC41,} m L ^{42, m LC51} and ^{m LC52} each independently represent ^{0 ~ 3, m LC31 + m} LC32, m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or ^{3, A LC31 ~ A LC52,} Z LC31 ~ When there are a plurality of Z ^LC52s , they may be the same or different. At least one compound selected from the group of compounds having negative dielectric anisotropy represented by:
   And the following general formula (L)
   

   

   (Wherein R ^L1 and R ^L2 each independently represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently Optionally substituted by —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,
   OL represents 0, 1, 2 or 3;
   B ^L1 , B ^L2 and B ^L3 each independently represent (a) a 1,4-cyclohexylene group (one —CH ₂ — present in this group or two or more —CH ₂ — not adjacent to each other). May be replaced by —O—) and (b) a 1,4-phenylene group (one —CH═ present in this group or two or more —CH═ not adjacent to each other —N May be replaced by =.)
   Represents a group selected from the group consisting of: The above groups (a) and (b) may be each independently substituted with a cyano group, a fluorine atom or a chlorine atom,
   L ^L1 and L ^L2 are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —OCF ₂ -, -CF ₂ O-, -CH = NN-CH-, -CH = CH-, -CF = CF- or -C≡C-
   When OL is 2 or 3 and a plurality of L ^L2 are present, they may be the same or different, and when OL is 2 or 3 and a plurality of B ^L3 is present, they are the same However, the compounds represented by general formula (LC3) to general formula (LC5) are excluded. The liquid crystal display element containing the at least 1 sort (s) of compound chosen from the compound group represented by this.
2. As a compound represented by the general formula (L), the following general formula (II)
   

   

   (Wherein R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or 2 to 2 carbon atoms) 8 represents an alkenyloxy group, A represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group, k represents 1 or 2, and when k is 2, two A's are the same. The liquid crystal display element of Claim 1 which contains 1 type (s) or 2 or more types of compounds represented by these.
3. As the compound represented by the general formula (LC3), the general formula (LC3-1)
   

   

   (Wherein R ³¹ represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, R ⁴¹ represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, and Z ³¹ to Z ³³ is a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, —CH ₂ O—. The liquid crystal display device according to claim 1, wherein the compound represented by the formula: —OCF ₂ — or —CF ₂ O— is contained in one or more compounds.
4. As a compound represented by the general formula (LC3), the following general formula (LC3-a) and general formula (LC3-b)
   

   

   ^Wherein R ^7a1 and R ^7a2 , R ^8a1 and R ^8a2 are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Or an alkenyloxy group having 2 to 8 carbon atoms, wherein one or more hydrogen atoms in the alkyl group, alkenyl group, alkoxy group or alkenyloxy group may be substituted with a fluorine atom, The methylene group in the alkenyl group, alkoxy group or alkenyloxy group may be substituted with an oxygen atom unless the oxygen atom is continuously bonded, and may be substituted with a carbonyl group unless the carbonyl group is bonded continuously. Often,
   n ^a2 represents 0 or 1, A ^1a2 represents a 1,4-cyclohexylene group, a 1,4-phenylene group or a tetrahydropyran-2,5-diyl group, and is represented by the general formulas (LC3-a) and ( One or more hydrogen atoms in the 1,4-phenylene group in LC3-b) may be substituted with fluorine atoms. The liquid crystal display element of Claim 3 containing the at least 1 sort (s) of compound chosen from the compound group represented by this.
5. The liquid crystal display element according to any one of claims 1 to 4, wherein the first substrate and the second substrate have an alignment film on a surface in contact with the liquid crystal layer.
6. The liquid crystal display element according to claim 5, wherein the alignment film is an alignment control film imparted with an alignment control ability by irradiation with substantially linearly polarized light.
7. The liquid crystal display element according to claim 5, wherein the alignment film includes a polyimide structure.
8. The polymerizable compound having one reactive group is represented by the following general formula (III):
   

   

   (Wherein X ³ represents a hydrogen atom or a methyl group, Sp ³ represents a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ) _t — (wherein t is 2 to And an oxygen atom is bonded to an aromatic ring. V represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic group having 5 to 30 carbon atoms. The alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom in the range where the oxygen atom is not adjacent to each other, and the alkyl group having 5 to 20 carbon atoms (the alkylene group in the group is an oxygen atom) May be substituted with an oxygen atom in a range not adjacent to each other)) or may be substituted with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkylene group having 1 to 8 carbon atoms). A polymerizable compound represented by:
   The polymerizable compound having two or more reactive groups is represented by the following general formula (IV):
   

   

   (Wherein X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms or —O— (CH ₂ ) _s — (wherein _s represents an integer of 2 to 7 and an oxygen atom is bonded to an aromatic ring), and U is a linear or branched chain having 2 to 20 carbon atoms Represents a valent alkylene group or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which the oxygen atom is not adjacent to each other. May be substituted with an alkyl group of ˜20 (the alkylene group in the group may be substituted with an oxygen atom in the range where the oxygen atom is not adjacent) or a cyclic substituent, and k is an integer of 1 to 5 Represents a polymerizable compound represented by The liquid crystal display device according to any one of claims 1 to 7.
9. The liquid crystal display device according to any one of claims 1 to 8, which is produced by a dropping method.
10. A liquid crystal layer containing a liquid crystal composition between a pair of substrates consisting of a first substrate on a base material and a second substrate having a pixel electrode and a common electrode formed on the substrate via an insulating layer. A method for producing a sandwiched liquid crystal display device, wherein the liquid crystal layer is a polymerizable compound having one reactive group and / or a polymer of a polymerizable compound having two or more reactive groups. The liquid crystal composition has a negative dielectric anisotropy,
    The following general formula (LC3) to general formula (LC5)
    

    

    ^(Wherein, represents an alkyl group of ^{R LC31, R LC32, R LC41} , R LC42, R LC51 and ^{R LC52} is 1 to 15 carbon atoms independently, one in the alkyl group or two or more The CH ₂ group may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent to the alkyl group. one or more hydrogen atoms in may be optionally substituted by a halogen ^{atom, a LC31, a LC32, a} LC41, a LC42, a LC51 and ^{a LC52} are independently any of the following Structure of
    

    

    (In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with oxygen atoms, and one or more CH groups in the 1,4-phenylene group may be nitrogen atoms. And one or more hydrogen atoms in the structure may be substituted with Cl, CF _3, or OCF ₃ ), Z ^LC31 , Z ^{LC32, Z LC41, Z LC42,} Z LC51 and ^{Z LC51} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O—, Z ⁵ represents a CH ₂ group or an oxygen atom, X ^LC41 represents a hydrogen atom or a fluorine atom, m ^{LC31, m LC32, m LC41,} m L ^{42, m LC51} and ^{m LC52} each independently represent ^{0 ~ 3, m LC31 + m} LC32, m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or ^{3, A LC31 ~ A LC52,} Z LC31 ~ When there are a plurality of Z ^LC52s , they may be the same or different. At least one compound selected from the group of compounds having negative dielectric anisotropy represented by:
    And the following general formula (L)
    

    

    (Wherein R ^L1 and R ^L2 each independently represents an alkyl group having 1 to 8 carbon atoms, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently Optionally substituted by —CH═CH—, —C≡C—, —O—, —CO—, —COO— or —OCO—,
    OL represents 0, 1, 2 or 3;
    B ^L1 , B ^L2 and B ^L3 each independently represent (a) a 1,4-cyclohexylene group (one —CH ₂ — present in this group or two or more —CH ₂ — not adjacent to each other). May be replaced by —O—) and (b) a 1,4-phenylene group (one —CH═ present in this group or two or more —CH═ not adjacent to each other —N May be replaced by =.)
    Represents a group selected from the group consisting of: The above groups (a) and (b) may be each independently substituted with a cyano group, a fluorine atom or a chlorine atom,
    L ^L1 and L ^L2 are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —OCF ₂ -, -CF ₂ O-, -CH = NN-CH-, -CH = CH-, -CF = CF- or -C≡C-
    When OL is 2 or 3 and a plurality of L ^L2 are present, they may be the same or different, and when OL is 2 or 3 and a plurality of B ^L3 is present, they are the same However, the compounds represented by general formula (LC3) to general formula (LC5) are excluded. And at least one compound selected from the group of compounds represented by formula (1), and by irradiating active energy rays in a state where liquid crystal molecules in the liquid crystal composition are aligned by an external field, A method for producing a liquid crystal display element, wherein an alignment state is fixed by curing a polymerizable compound having one reactive group and / or a polymerizable compound having two or more reactive groups.
11. As a compound represented by the general formula (L), the following general formula (II)
    

    

    (Wherein R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or 2 to 2 carbon atoms) 8 represents an alkenyloxy group, A represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group, k represents 1 or 2, and when k is 2, two A's are the same. The method for producing a liquid crystal display element according to claim 10, wherein the compound represented by 1) or 2 or more types is contained.
12. As the compound represented by the general formula (LC3), the general formula (LC3-1)
    

    

    (Wherein R ³¹ represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, R ⁴¹ represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms, and Z ³¹ to Z ³³ is a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —, —CH ₂ O—. , -OCF ₂ -or -CF ₂ O-.
    The manufacturing method of the liquid crystal display element of Claim 10 or Claim 11 containing 1 type, or 2 or more types of compounds represented by these.
13. As the compound represented by the general formula (LC3), the following general formula (LC3-a) and general formula (LC3-b)
    

    

    ^Wherein R ^7a1 and R ^7a2 , R ^8a1 and R ^8a2 are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Or an alkenyloxy group having 2 to 8 carbon atoms, wherein one or more hydrogen atoms in the alkyl group, alkenyl group, alkoxy group or alkenyloxy group may be substituted with a fluorine atom, The methylene group in the alkenyl group, alkoxy group or alkenyloxy group may be substituted with an oxygen atom unless the oxygen atom is continuously bonded, and may be substituted with a carbonyl group unless the carbonyl group is bonded continuously. Often,
    n ^a2 represents 0 or 1, A ^1a2 represents a 1,4-cyclohexylene group, a 1,4-phenylene group or a tetrahydropyran-2,5-diyl group, and is represented by the general formulas (LC3-a) and ( One or more hydrogen atoms in the 1,4-phenylene group in LC3-b) may be substituted with fluorine atoms. The manufacturing method of the liquid crystal display element of Claim 12 containing the at least 1 sort (s) of compound chosen from the compound group represented by this.
14. 14. The liquid crystal display according to claim 10, wherein the active energy ray is ultraviolet light, the intensity thereof is ² mW / cm ⁻² to 100 mW / cm ⁻² , and the total irradiation energy amount is 10 J to 300 J. Device manufacturing method.

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