JP2015040285A - Liquid crystal composition and liquid crystal display using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal composition achieving both of a high nematic phase-isotropic liquid phase transition temperature in addition to a large refractive index anisotropy and a low viscosity, and a liquid crystal display using the same.SOLUTION: The liquid crystal composition includes: 3 to 35 mass% of a compound having two benzene rings connected as a first component; 3 to 60 mass% of a compound having two cyclohexane rings connected as a second component; and one or a plurality of compounds represented by a general formula (3) as a third component; and has a negative dielectric anisotropy. The liquid crystal display uses the liquid crystal composition.

Description

  The present invention relates to a liquid crystal composition and further to a liquid crystal display device using the liquid crystal composition.

  Liquid crystal display elements are used in various measuring instruments, automobile panels, word processors, electronic notebooks, printers, computers, televisions, watches, advertisement display boards, as well as watches and calculators. In addition, the liquid crystal display device has a structure in which a liquid crystal composition is filled between a pair of substrates on which opposed transparent electrodes are formed, and a voltage passing between the electrodes changes the alignment state of the liquid crystal to pass through the light. The pattern that appears due to the difference in the amount of light passing therethrough is displayed. Typical liquid crystal display methods include TN (twisted nematic) type, STN (super twisted nematic) type, VA (hereinafter also referred to as vertical alignment) type using TFT (thin film transistor), and IPS ( In-plane switching) type. The liquid crystal composition used in these liquid crystal display elements is stable against external factors such as moisture, air, heat, light, etc., and exhibits a liquid crystal phase in the widest possible temperature range centering on room temperature, and has low viscosity. And a low driving voltage is required.

  For example, the VA type widely used for a liquid crystal TV or the like generally uses a liquid crystal composition having a negative Δε, and is widely used for a TN type or a touch panel used for a PC monitor or the like. In general, a liquid crystal composition mainly having a positive Δε is used for the IPS type. As a matter of course, there is a demand for a liquid crystal composition that exhibits low voltage driving, high-speed response, and a wide operating temperature range in all driving methods, not limited to these IPS and VA types. In order to meet such requirements, a large dielectric anisotropy difference (Δε), a large refractive index anisotropy difference (Δn), a small viscosity (η), and a high nematic phase-isotropic liquid phase transition temperature ( Tni) is generally required.

  Furthermore, from the setting of Δn × d, which is the product of Δn and the cell gap (d), it is necessary to adjust Δn of the liquid crystal composition to an appropriate range according to the cell gap. In addition, when a liquid crystal display element is applied to a television or the like, high-speed response is important, and therefore a liquid crystal composition having a small rotational viscosity coefficient (γ1) is required.

  Therefore, since there is no single compound that satisfies these physical properties required for liquid crystal compositions, physical property values such as dielectric anisotropy (Δε) and refractive index anisotropy (Δn) for individual display elements. Is made up of several to several tens of compounds in order to obtain an optimum value.

  For example, the technique disclosed in Patent Document 1 is able to provide a matrix liquid crystal display based on the ECB effect, which has a wide operating temperature range, a short response time, or low voltage driving as compared with the prior art, and at the same time has a very large resistance value ( Patent Document 1 Paragraph “0013”). Specifically, Patent Document 1 discloses a liquid crystal composition having a difluorophenylcyclohexane skeleton compound having an alkyl group or an alkenyl group at the terminal as an essential component.

  Moreover, Patent Document 2 is given as another technique for the same purpose. Patent Document 2 discloses a composition of polar liquid crystal compounds represented by formulas I to IV and nonpolar liquid crystal compounds represented by formulas V to VIII. And it is said that the available parameter range can be remarkably expanded by this composition (paragraph “0028” in Patent Document 2).

JP 2007-231283 A JP 2006-169518 A

  Since both Patent Documents 1 and 2 are compositions composed only of a liquid crystal compound in which two to three cyclohexane rings and benzene rings are connected, a low viscosity (η) can be expected with certainty. There is a problem that it is difficult to obtain a liquid crystal composition in which the refractive index anisotropy (Δn) and Tni do not decrease while maintaining such a low viscosity state. Therefore, the liquid crystal composition according to the present invention solves this problem by combining an alkoxybiphenyl compound having a specific chemical structure, a low-viscosity bicyclohexyl compound, and a bicyclic difluorophenyl compound having a specific chemical structure. Objective.

  As a result of intensive studies in order to solve the above-mentioned problems, the present inventor has achieved high Tni and low viscosity by using the compounds of general formula (1), general formula (2) and general formula (3). Thus, the present invention has been completed.

  That is, the liquid crystal composition according to the present invention has the general formula (1) as the first component.

(In the formula, R ¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ² represents an alkoxy group having 1 to 5 carbon atoms or 2 to 2 carbon atoms. 1 type or 2 types or more of the compound represented by this represents 5 alkenyloxy groups,
General formula (2) as the second component

(Wherein R ³ and R ⁴ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms). ) Containing one or more compounds represented by
General formula (3) as the third component

(Wherein R ⁵ and R ⁶ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, M ¹ represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and one or two —CH ₂ — in the trans-1,4-cyclohexylene group represents an oxygen atom. And a compound represented by Z ¹ may be substituted with —O— so as not to be directly adjacent to each other, and Z ¹ represents —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O— or a single bond. One or more types are contained, and the dielectric anisotropy is negative.

The liquid crystal composition of the present invention has a sufficiently low viscosity (η) without lowering the refractive index anisotropy (Δn) and the nematic phase-isotropic liquid phase transition temperature (T _ni ).

FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display element according to the present invention. FIG. 2 is an enlarged plan view of the electrode layer 3 including the thin film transistor formed on the substrate in FIG. FIG. 3 is a cross-sectional view of the liquid crystal display element shown in FIG. 1 cut along the line I-I ′ in FIG. 2. FIG. 4 is an enlarged view of the thin film transistor in FIG.

  The liquid crystal composition of the present invention has the general formula (1) as the first component.

The compound represented by these is contained. In general formula (1), R ¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms. R ² represents an alkoxy group having 1 to 5 carbon atoms or an alkenyloxy group having 2 to 5 carbon atoms, preferably an alkoxy group having 1 to 5 carbon atoms.

  Examples of the “alkyl group having 1 to 5 carbon atoms” according to the present invention include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, a 3-pentyl group, and an isopentyl group. Group, neopentyl group, pentyl group and the like. In the present specification, examples of alkyl groups are common and are appropriately selected from the above examples depending on the number of carbon atoms of each alkyl group. In addition, the alkyl group having 1 to 8 carbon atoms according to the present invention is preferably linear or branched, and more preferably linear.

  Examples of the “alkoxy group having 1 to 5 carbon atoms” according to the present invention are preferably present at a position where at least one oxygen atom in the substituent is directly bonded to the ring structure. Group, propoxy group (n-propoxy group, i-propoxy group), butoxy group, pentyloxy group and the like, and a methoxy group or an ethoxy group is preferable.

  Examples of the “alkenyloxy group having 2 to 5 carbon atoms” according to the present invention include vinyloxy group, allyloxy group, 1-propenyloxy group, isopropenyloxy group, 2-butenyloxy group, 3-butenyloxy group, 1, Examples include 3-butadienyloxy group, 2-pentenyloxy group, and 3-pentenyloxy group. More preferable alkenyloxy groups according to the present invention include the formula (i) (vinyl group), formula (ii) (1-propenyl group), and formula (iii) (3-butenyl group) of the alkenyl moiety described below. And formula (iv) (3-pentenyl group):

(In the above formulas (i) to (iv), * represents a bonding site to an oxygen atom), and a structure represented by formula (iii) or formula (iv) is preferable.

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

The compound represented by formula (1.1) to formula (1.4) or formula (1.8) is more preferable.

  In the liquid crystal composition according to the present invention, the lower limit of the content of the first component is, for example, 3% by mass as one embodiment of the present invention with respect to the total amount (100% by mass) of the liquid crystal composition of the present invention. It is. Moreover, in another embodiment of this invention, it is 5 mass%. Or in another embodiment of the present invention, it is 7 mass%. Alternatively, in another embodiment of the present invention, it is 10% by mass. Moreover, in another embodiment of this invention, it is 12 mass%. Furthermore, in another embodiment of this invention, it is 15 mass%.

  Furthermore, in the liquid crystal composition according to the present invention, the upper limit value of the content of the first component is, for example, 35% by mass in one embodiment of the present invention with respect to the total amount of the liquid crystal composition of the present invention. Moreover, in another embodiment of this invention, it is 30 mass%. Furthermore, in another embodiment of this invention, it is 25 mass%. Furthermore, in another embodiment of this invention, it is 20 mass%.

  The liquid crystal composition of the present invention has the general formula (2) as the second component.

The compound represented by these is contained. In general formula (2), R ³ and R ⁴ are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. Represents an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 3 carbon atoms. More preferred.

  Examples of the “alkyl group having 1 to 8 carbon atoms” according to the present invention include methyl, ethyl, propyl, butyl, isopropyl, isobutyl, t-butyl, 3-pentyl, and isopentyl. Group, neopentyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. In the present specification, examples of alkyl groups are common and are appropriately selected from the above examples depending on the number of carbon atoms of each alkyl group. In addition, the alkyl group having 1 to 8 carbon atoms according to the present invention is preferably linear or branched, and more preferably linear.

  Examples of the “alkenyl group having 2 to 8 carbon atoms” according to the present invention are vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl. Group, 2-pentenyl group, 3-pentenyl group, 2-hexenyl group and the like. More preferable alkenyl groups according to the present invention include the following formula (i) (vinyl group), formula (ii) (1-propenyl group), formula (iii) (3-butenyl group) and formula (iv) ) (3-pentenyl group):

(In the above formulas (i) to (iv), * represents a bonding site to a ring structure), and a structure represented by formula (i) or formula (ii) is preferable.

  More specifically, the compound represented by the general formula (2) is preferably a compound described below.

  Among the compounds represented by the general formula (2) according to the present invention, the compounds represented by the general formula (3.1), the general formula (3.3), and the formula (3.4) are more preferable. .

When it is desired to produce a liquid crystal display element having a low viscosity and a high-speed response, it is preferable to use a larger amount of the formula (3.1). However, when a liquid crystal display element having a high Tni and capable of stable display even at a high temperature is desired. It is preferable to increase the content of the compounds represented by the formulas (3.3) to (3.4).
Moreover, Formula (3.6), Formula (3.7), Formula (3.11), Formula (3.13), Formula (3.18), Formula (3.21), Formula (3.23) The compounds represented by formula (3.26), formula (3.28) and formula (3.30) are also preferred.

  In the liquid crystal composition according to the present invention, the lower limit of the content of the second component is, for example, 3% by mass as one embodiment of the present invention with respect to the total amount (100% by mass) of the liquid crystal composition of the present invention. It is. Moreover, in another embodiment of this invention, it is 5 mass%. Or in another embodiment of the present invention, it is 7 mass%. Alternatively, in another embodiment of the present invention, it is 10% by mass. Moreover, in another embodiment of this invention, it is 12 mass%. Furthermore, in another embodiment of this invention, it is 15 mass%. Moreover, in another embodiment of this invention, it is 20 mass%. Furthermore, in another embodiment of this invention, it is 25 mass%.

  Furthermore, in the liquid crystal composition according to the present invention, the upper limit of the content of the second component is, for example, 60% by mass in one form of the present invention with respect to the total amount of the liquid crystal composition of the present invention. Moreover, in another embodiment of this invention, it is 55 mass%. Furthermore, in another embodiment of this invention, it is 50 mass%. Furthermore, in another embodiment of this invention, it is 45 mass%. Furthermore, in another embodiment of this invention, it is 40 mass%. Furthermore, in another embodiment of this invention, it is 35 mass%. Furthermore, in another embodiment of this invention, it is 30 mass%.

  The liquid crystal composition of the present invention has the general formula (3) as the third component.

The compound represented by these is contained. In general formula (3), R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. R ⁵ is preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and an alkyl group having 2 to 5 carbon atoms or an alkyl group having 2 to 4 carbon atoms. An alkenyl group is more preferable, and R ⁶ is preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.

  Examples of the “alkyl group having 1 to 8 carbon atoms” according to the present invention include methyl, ethyl, propyl, butyl, isopropyl, isobutyl, t-butyl, 3-pentyl, and isopentyl. Group, neopentyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. In the present specification, examples of alkyl groups are common and are appropriately selected from the above examples depending on the number of carbon atoms of each alkyl group. In addition, the alkyl group having 1 to 8 carbon atoms according to the present invention is preferably linear or branched, and more preferably linear.

  Examples of the “alkoxy group having 1 to 8 carbon atoms” according to the present invention are preferably present at a position where at least one oxygen atom in the substituent is directly bonded to the ring structure. Group, propoxy group (n-propoxy group, i-propoxy group), butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, etc., but ethoxy group, propoxy group, butoxy group or pentyl An oxy group is preferred.

  Examples of the “alkenyl group having 2 to 8 carbon atoms” according to the present invention are vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl. Group, 2-pentenyl group, 3-pentenyl group, 2-hexenyl group and the like. More preferable alkenyl groups according to the present invention include the following formula (i) (vinyl group), formula (ii) (1-propenyl group), formula (iii) (3-butenyl group) and formula (iv) ) (3-pentenyl group):

(In the above formulas (i) to (iv), * represents a bonding site to the ring structure), but the structure represented by formula (i), formula (ii) or formula (iii) is preferable.

In General Formula (3), M ¹ represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and one or two — in the trans-1,4-cyclohexylene group CH ₂ — may be substituted with —O— so that oxygen atoms are not directly adjacent to each other, but is preferably a trans-1,4-cyclohexylene group or a 1,4-phenylene group.

In the general formula (3), ^{Z 1} is _{-CH 2 CH 2 -, - OCH} 2 -, - CH 2 O- or represents a single bond, _-CH 2 O-or a single bond, more preferably a single bond is more preferable .

  The compound represented by the general formula (3) according to the present invention is preferably a compound represented by the general formula (IV-a).

(In the general formula (IV-a), R ^4a and R ^4b are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a carbon atom. Represents an alkenyl group of 2 to 8, A ¹ represents a 1,4-cyclohexylene group, a 1,4-phenylene group or a tetrahydropyran-2,5-diyl group, and Z ⁴¹ represents —CH ₂ CH ₂ —. , -OCH ₂ -, - represents a _CH 2 O- or a single bond).
In the general formula (IV-a), R ^4a preferably represents an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and represents an alkyl group having 1 to 8 carbon atoms. It is more preferable to represent, and it is still more preferable to represent an alkyl group having 3 to 5 carbon atoms.

In the general formula (IV-a), R ^4b more preferably represents an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, and an alkyl group having 3 to 5 carbon atoms or It is more preferable to represent an alkoxy group having 2 to 4 carbon atoms, and it is even more preferable to represent an alkyl group having 3 or 5 carbon atoms or an alkoxy group having 2 or 4 carbon atoms.

In the general formula (IV-a), A ¹ represents a 1,4-cyclohexylene group, a 1,4-phenylene group or a tetrahydropyran-2,5-diyl group, but a 1,4-cyclohexylene group or 1 , 4-phenylene group is preferable, and more specifically, when the response speed is important in a display device and a liquid crystal display produced using the liquid crystal composition of the present invention, it represents a 1,4-phenylene group. In the case where the operating temperature range is important, that is, when a high operating temperature range (T _ni is high) is required, it is preferable to represent a 1,4-cyclohexylene group.

In the general formula ^{(IV-a), Z 41} is _{-CH 2 CH 2 -, - OCH} 2 -, - CH 2 O- or represents a single bond, _-CH 2 O-or a single bond, and more specifically For the display element and liquid crystal display produced using the liquid crystal composition of the present invention, when importance is attached to reliability (stability over time), it is preferable to represent a single bond, and a drive voltage at a low voltage is set. In the case of emphasis, it is preferable to represent —CH ₂ O—.

  The compound represented by the general formula (IV-a) is specifically the following general formula (IV-a-1) and / or general formula (IV-b-1)

(In formula (IV-a-1) and / or general formula (IV-a-2) and / or general formula (IV-e-1) and / or general formula (IV-f-1), R ^4a And R ^4b each independently represents 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. A compound is preferred. Further, when R ^4a and R ^4b are alkenyl groups, the number of carbon atoms is preferably 4 to 5.

  Specifically, the compound represented by the general formula (3) according to the present invention is represented by the following formulas (4.1) to (4.37).

The compounds represented by formula (4.1) to formula (4.5) and formula (4.15), formula (4.19), formula (4.20) and formula (4.22) are preferred. The compound represented by the formula (4.26) is more preferable, the formula (4.1), the formula (4.5), the formula (4.15), the formula (4.22), and the formula (4.23). The compounds represented by formula (4.1) to formula (4.4) are particularly preferred.

  More specifically, when the refractive index anisotropy Δn required for the liquid crystal composition of the present invention is relatively low (less than 0.1), the equations (4.1) to (4.4)) When the required refractive index anisotropy Δn is relatively high (0.1 or more), the compounds represented by formula (4.5) and formula (4.15) Is most preferred.

  When the compound represented by the general formula (IV-a) according to the present invention has an alkenyl group, specifically, the following formulas (4.38) to (4.51)

(In the above formulae, R ^4b independently represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 4 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.)
It is preferable that it is a compound chosen from the group represented by these.

  In the liquid crystal composition according to the present invention, the lower limit of the content of the third component is, for example, 3% by mass as one embodiment of the present invention with respect to the total amount (100% by mass) of the liquid crystal composition of the present invention. It is. Moreover, in another embodiment of this invention, it is 5 mass%. Or in another embodiment of the present invention, it is 7 mass%. Alternatively, in another embodiment of the present invention, it is 10% by mass. Moreover, in another embodiment of this invention, it is 12 mass%. Furthermore, in another embodiment of this invention, it is 15 mass%.

  Furthermore, in the liquid crystal composition according to the present invention, the upper limit of the content of the third component is, for example, 50% by mass in one embodiment of the present invention with respect to the total amount of the liquid crystal composition of the present invention. Moreover, in another embodiment of this invention, it is 45 mass%. Furthermore, in another embodiment of this invention, it is 40 mass%. Furthermore, in another embodiment of this invention, it is 35 mass%. Furthermore, in another embodiment of this invention, it is 30 mass%. Furthermore, in another embodiment of this invention, it is 25 mass%. Furthermore, in another embodiment of this invention, it is 20 mass%.

  The liquid crystal composition of the present invention has the general formula (4) as the fourth component.

The compound represented by these can be contained. In General Formula (4), R ⁷ and R ⁸ are each independently an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, or an alkenyl having 2 to 15 carbon atoms. Represents a group, preferably an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and having 1 to 5 carbon atoms. It is more preferable that the alkyl group is an alkoxy group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. The alkyl group, alkoxy group and alkenyl group are preferably linear or branched, and more preferably linear. Examples of the “alkyl group having 1 to 15 carbon atoms”, the “alkoxy group having 1 to 15 carbon atoms”, and the “alkenyl group having 2 to 15 carbon atoms” according to the present invention are as described above. Because there are, it is omitted here.

In the general formula (4), M ² represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and one or two — in the trans-1,4-cyclohexylene group CH ₂ — may be substituted with —O— so that oxygen atoms are not directly adjacent to each other, but is preferably a trans-1,4-cyclohexylene group or a 1,4-phenylene group. In the general formula (4), ^{Z 2} is _{-CH 2 CH 2 -, - OCH} 2 -, - CH 2 O- or represents a single bond, preferably a _-CH 2 O-or a single bond. In general formula (4), n1 and n2 each independently represent 0, 1 or 2, n1 + n2 represents 1 or 2, but n1 + n2 is preferably 1.

  The compound represented by the general formula (4) according to the present invention includes the general formula (IV-b), the general formula (IV-c), and the general formula (IV-d).

A compound selected from the group consisting of:
Formula (IV-b)

^In, independently each ^{R 4c} and ^{R 4d,} an alkyl group having 1 to 15 carbon atoms, represents an alkenyl group or an alkoxy group having a carbon number of 1 to 15 carbon atoms 2 to ^{15, R 4C} is It is preferably 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, an alkyl group having 1 to 8 carbon atoms, or 2 to 2 carbon atoms. More preferably, it is an alkenyl group having 8 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and still more preferably an alkyl group having 3 to 5 carbon atoms. R ^4d is preferably 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, and an alkyl group or carbon having 1 to 8 carbon atoms. More preferably, it is an alkoxy group having 1 to 8 atoms, more preferably an alkyl group having 3 to 5 carbon atoms or an alkoxy group having 2 to 4 carbon atoms, and an alkyl group having 3 or 5 carbon atoms. Or it is still more preferable that it is a C2-C4 alkoxy group. Z ⁴² is _{-CH 2 CH 2 -, - OCH} 2 -, - CH 2 O- or represents a single bond, preferably a _-CH 2 O-or a single bond.

  The compound represented by the general formula (IV-b) is specifically a compound represented by any of the following formulas (4.52) to (4.69)

However, the compounds represented by formula (4.52) to formula (4.55) and formula (4.58) to formula (4.61) are more preferable, and formula (4.52) to formula (4) .54) is more preferred, and compounds represented by formula (4.52) and formula (4.54) are particularly preferred.

  When the compound represented by formula (IV-b) according to the present invention has an alkenyl group, specifically, the following formulas (4.70) to (4.82)

(Wherein R ^4b represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 4 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms).
Formula (IV-c)

^In, R ^4e, are independently ^{R 4f} are each an alkyl group having 1 to 15 carbon atoms, an alkenyl group having a carbon number of 2 to 15, or an alkoxy group having 1 to 15 carbon ^{atoms, R 4e} is It is preferably an alkyl group having 1 to 10 carbon atoms, and R ^4f is preferably an alkoxy group having 1 to 10 carbon atoms, R ^4e is an alkyl group having 1 to 5 carbon atoms, and R ^4f is More preferably, it is an alkoxy group having 1 to 5 carbon atoms.

  The compound represented by the general formula (IV-c) is specifically a compound represented by any of the following formulas (4.82) to (4.87)

Compounds selected from the group consisting of are preferred. Compounds represented by formula (4.82) to formula (4.86) are more preferred, compounds represented by formula (4.82) to formula (4.85) are more preferred, and formula (4.82) And a compound represented by the formula (4.83) is particularly preferable.

  When the compound represented by the general formula (IV-c) according to the present invention has an alkenyl group, specifically, the following formulas (4.88) to (4.91)

(Wherein R ^4b represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 4 to 5 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms).
Formula (IV-d)

R ^4g and R ^4h each independently represents an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms, It is preferably 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, an alkyl group having 1 to 5 carbon atoms, or 2 to 5 carbon atoms. An alkenyl group or an alkoxy group having 1 to 5 carbon atoms is more preferable. A ² represents a 1,4-cyclohexylene group or a 1,4-phenylene group, and is preferably a 1,4-cyclohexylene group. Z ⁴³ represents a single bond, —CH ₂ CH ₂ —, —OCH ₂ — or —CH ₂ O—, and preferably a single bond. n represents 0 or 1, but 0 is preferable when the response speed is important, and 1 is preferable when the operating temperature range is important, that is, when a high operating temperature range is required. The 1,4-cyclohexyl group in the present application is preferably a trans-1,4-cyclohexyl group.

  Specifically, the compound represented by the general formula (IV-d) according to the present invention is represented by the following general formulas (IV-d-1) to (IV-d-2).

(In the ^{formula, R 4g} represents the same meaning as ^{R 4g} in the general formula ^{(IV-d), R 4h} the general formula (. Represents the same meaning as ^{R 4h} in IV-d)) a compound represented by preferable.

R ^4g and R ^4h in the general formulas (IV-d-1) to (IV-d-2) according to the present invention are each independently an alkyl group having 1 to 15 carbon atoms, or a group having 2 to 15 carbon atoms. Represents an alkenyl group or an alkoxy group having 1 to 15 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms, and an alkyl group having 2 to 5 carbon atoms Or more preferably an alkenyl group having 2 to 5 carbon atoms, still more preferably an alkyl group having 2 to 5 carbon atoms, and more preferably a straight chain, and R ^4g and R ^4h are both alkyl groups. In this case, the number of carbon atoms is preferably different.

  Specifically, the compound represented by formula (IV-d-1) according to the present invention is preferably a compound represented by formula (4.92) to formula (4.103).

  Among the compounds represented by the general formula (4) according to the present invention, compounds selected from the group consisting of compounds represented by the formulas (4.92) to (4.96) are more preferable.

  In the liquid crystal composition according to the present invention, the lower limit of the content of the fourth component is, for example, 3% by mass as one embodiment of the present invention with respect to the total amount (100% by mass) of the liquid crystal composition of the present invention. It is. Moreover, in another embodiment of this invention, it is 5 mass%. Or in another embodiment of the present invention, it is 7 mass%. Alternatively, in another embodiment of the present invention, it is 10% by mass. Moreover, in another embodiment of this invention, it is 12 mass%. Furthermore, in another embodiment of this invention, it is 15 mass%.

  Furthermore, in the liquid crystal composition according to the present invention, the upper limit value of the content of the fourth component is, for example, 50% by mass in one embodiment of the present invention with respect to the total amount of the liquid crystal composition of the present invention. Moreover, in another embodiment of this invention, it is 45 mass%. Furthermore, in another embodiment of this invention, it is 40 mass%. Furthermore, in another embodiment of this invention, it is 35 mass%. Furthermore, in another embodiment of this invention, it is 30 mass%. Furthermore, in another embodiment of this invention, it is 25 mass%. Furthermore, in another embodiment of this invention, it is 20 mass%.

  The liquid crystal composition of the present invention includes, as other components, general formula (5-1) to general formula (5-5).

The compound selected from the group which consists of a compound represented by these can be contained. In general formula (5-1) to general formula (5-5), R ⁹ , R ¹⁰ , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are each independently the number of carbon atoms. 1 to 8 alkyl groups, and one or two or more non-adjacent —CH ₂ — in the alkyl group are each independently —CH═CH—, —O—, —CO—, —COO—. Alternatively, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms is preferable. Examples of the alkenyl group having 2 to 5 carbon atoms are vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl group, and 2-pentenyl group. , 3-pentenyl group, 2-hexenyl group and the like. More preferable alkenyl groups according to the present invention include the following formula (i) (vinyl group), formula (ii) (1-propenyl group), formula (iii) (3-butenyl group) and formula (iv) ) (3-pentenyl group):

(In the above formulas (i) to (iv), * represents a bonding site to the ring structure), but the structure represented by formula (i), formula (ii) or formula (iii) is preferable. R ¹¹ and R ¹² each independently represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and is preferably an alkyl group having 2 to 5 carbon atoms. X ¹ represents a hydrogen atom, a fluorine atom or a methyl group, preferably a hydrogen atom or a fluorine atom.

  More specifically, the compound represented by the general formula (5-1) is preferably a compound described below.

  Among the compounds represented by the general formula (5-1) according to the present invention, compounds represented by the formula (3.40) to the formula (3.47) are more preferable.

  More specifically, the compound represented by the general formula (5-2) is preferably a compound described below.

    Among the compounds represented by the general formula (5-2) according to the present invention, a compound represented by the formula (3.56), the formula (3.58) or the formula (3.63) is more preferable. .

  More specifically, the compound represented by the general formula (5-3) is preferably a compound described below.

    Among the compounds represented by the general formula (5-3) according to the present invention, compounds represented by the formula (3.65), the formula (3.71), and the formula (3.72) are more preferable. .

  More specifically, the compound represented by the general formula (5-4) is preferably a compound described below.

    Among the compounds represented by the general formula (5-4) according to the present invention, a compound represented by the formula (3.74) or the formula (3.78) is more preferable.

  More specifically, the compound represented by the general formula (5-5) is preferably a compound described below.

  Among the compounds represented by the general formula (5-5) according to the present invention, the formula (3.100), the formula (3.101), the formula (3.102), the formula (3.103), the formula (3) .104), formula (3.105), formula (3.106), formula (3.109), formula (3.110) (3.113), formula (3.114), formula (3.111). The compounds represented by formula (3.112), formula (3.115) and formula (3.116) are more preferred, and formula (3.100), formula (3.101) and formula (3.103) are preferred. , Formula (3.104), Formula (3.105), Formula (3.106), Formula (3.109), Formula (3.110), Formula (3.111), Formula (3.112), The compounds represented by formula (3.113), formula (3.114), formula (3.115) and formula (3.116) are more preferable.

  In the liquid crystal composition according to the present invention, the lower limit value of the content of other components is, for example, 0 mass in one embodiment of the present invention, for example, relative to the total amount (100 mass%) of the liquid crystal composition of the present invention. %. In one embodiment of the present invention, the content is 3% by mass. Moreover, in another embodiment of this invention, it is 5 mass%. Or in another embodiment of the present invention, it is 7 mass%. Alternatively, in another embodiment of the present invention, it is 10% by mass. Moreover, in another embodiment of this invention, it is 12 mass%. Moreover, in another embodiment of this invention, it is 15 mass%. Moreover, in another embodiment of this invention, it is 18 mass%. Furthermore, in another embodiment of this invention, it is 20 mass%.

  Furthermore, in the liquid crystal composition according to the present invention, the upper limit value of the content of other components is, for example, 65% by mass in one embodiment of the present invention with respect to the total amount of the liquid crystal composition of the present invention. Moreover, in another embodiment of this invention, it is 60 mass%. Moreover, in another embodiment of this invention, it is 55 mass%. Moreover, in another embodiment of this invention, it is 50 mass%. Moreover, in another embodiment of this invention, it is 45 mass%. Furthermore, in another embodiment of this invention, it is 40 mass%. Furthermore, in another embodiment of this invention, it is 35 mass%. Furthermore, in another embodiment of this invention, it is 30 mass%. Furthermore, in another embodiment of this invention, it is 25 mass%. Furthermore, in another embodiment of this invention, it is 22 mass%.

  The liquid crystal composition of the present invention is represented by a compound represented by general formula (1), a compound represented by general formula (2), a compound represented by general formula (3), and general formula (4). Compound, compound represented by general formula (5-1), compound represented by general formula (5-2), compound represented by general formula (5-3), represented by general formula (5-4) The total content of the compound represented by formula (5-5) is preferably 90 to 100% by mass, more preferably 92 to 100% by mass, and 95 to 100% by mass. Is more preferable.

  The value of the dielectric anisotropy Δε of the liquid crystal composition according to the present invention is preferably −2.0 to −6.0 at 25 ° C., and preferably −2.5 to −5.0. More preferably, it is particularly preferably from −2.5 to −4.0, but more specifically, when the response speed is important, the value of the dielectric anisotropy Δε is −2.5 to −3. .4 is preferable from the viewpoint of response speed, and when the driving voltage is important, it is preferably -3.4 to -4.0.

  The value of the refractive index anisotropy Δn of the liquid crystal composition according to the present invention is preferably 0.08 to 0.160 at 25 ° C., more preferably 0.090 to 0.130. More specifically, when it corresponds to a thin cell gap (cell gap of 3.4 μm or less), it is preferably 0.100 to 0.130, and when it corresponds to a thick cell gap (cell gap of 3.5 μm or more). It is preferably 0.080 to 0.100.

The upper limit of the rotational viscosity (γ ₁ ) of the liquid crystal composition according to the present invention is preferably 165 (mPa · s) or less, more preferably 130 (mPa · s) or less, and particularly preferably 120 (mPa · s) or less. . On the other hand, the lower limit of the rotational viscosity (γ ₁ ) is preferably 20 (mPa · s) or more, more preferably 30 (mPa · s) or more, still more preferably 40 (mPa · s) or more, and 50 (mPa · s). s) or more is more preferable, 60 (mPa · s) or more is further more preferable, and 70 (mPa · s) or more is particularly preferable.

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

(In the above 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 liquid crystal composition according to the present invention, in the case of using the active matrix display device, preferably has a ^{10 11 (Ω} · m) or more in specific resistance, ^{10 12 (Ω} · m) and more preferably, ^{10 13} (Ω · m) or more is more preferable, and 10 ¹⁴ (Ω · m) or more is more preferable.

The liquid crystal composition according to the present invention can use a nematic phase-isotropic liquid phase transition temperature (T _NI ) in a wide range, but the phase transition temperature (T _NI ) is 60 to 120 ° C. It is preferable that it is 70-110 degreeC, and 75-100 degreeC is especially preferable.

  In addition to the above-mentioned components, the liquid crystal composition according to the present invention has other components such as a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, a chiral agent, an antioxidant, an ultraviolet absorber, and a polymerizable monomer, depending on applications. May be contained. Of these other components, the antioxidant and the ultraviolet absorber are not particularly limited, and known ones can be used.

  The liquid crystal composition according to the present invention preferably further contains a polymerizable monomer. That is, the polymerizable monomer according to the present invention has the general formula (6):

(In General Formula (6), X ⁶¹ and X ⁶² each independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² each independently represent a single bond or 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 ² 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 — (Wherein Y ¹ and Y ² each independently represents a fluorine atom or a hydrogen atom), —C≡C— or a single bond;
B represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a single bond, and all 1,4-phenylene groups in the formula may be substituted with any hydrogen atom by a fluorine atom. good. )
The bifunctional monomer represented by these is preferable.

In the above general formula (6), X ⁶¹ and X ⁶² are both preferably diacrylate derivatives each representing a hydrogen atom and both dimethacrylate derivatives having a methyl group, one representing a hydrogen atom and the other representing a methyl group. A compound representing is also preferred. 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 PSA display element, a dimethacrylate derivative is particularly preferable.

In the general formula (6), 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 —. It is preferable that at least one is a single bond, and a compound in which both represent a single bond or an embodiment 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, the alkyl group of 1-4 is preferable, and 1-4 is preferable for s.

In the general formula (6), Z ² represents —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 preferable, —COO—, —OCO— or a single bond is more preferable, and a single bond is particularly preferable.

In the general formula (6), B 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 preferable. When B represents a ring structure other than a single bond, Z ² is preferably a linking group other than a single bond. When B is a single bond, Z ² is preferably a single bond.

  In the liquid crystal composition according to the present invention, the content of the polymerizable monomer represented by the general formula (6) is 0.05 to 1% by mass with respect to the total amount (100% by mass) of the liquid crystal composition. Is preferable, 0.1 to 0.5% by mass is more preferable, 0.1 to 0.4% by mass is further preferable, 0.1 to 0.3% by mass is particularly preferable, and 0.15 to 0.3% by mass. % Is most preferred.

  The content of the polymerizable monomer is preferably 0.1 to 0.3% by mass from the viewpoint of a balance between display characteristics and reliability of the liquid crystal display element.

From these points, in general formula (6), the ring structure between Sp ¹ and Sp ² is specifically preferably the structure described below.

  In the general formula (6), when B represents a single bond and the ring structure is formed of two rings, the following formulas (VIa-1) to (VIa-5)

(In the general formulas (VIa-1) to (VIa-5), both ends shall be bonded to Sp ¹ or Sp ² ). It is preferable that the general formulas (VIa-1) to (VIa -3) is more preferable, and formula (VIa-1) is particularly preferable.

  The polymerizable monomers containing these skeletons are optimal in PSA type liquid crystal display elements because of their alignment regulating power after polymerization, and a good alignment state can be obtained, so that display unevenness is suppressed or does not occur at all.

  From the above, as the polymerizable monomer according to the present invention, the formula (6.1) to the formula (6.4) are particularly preferable, and the formula (6.2) is most preferable.

(In the above formulas (6.1) to (6.4), Sp ² represents an alkylene group having 2 to 5 carbon atoms.)
In the case of adding a monomer to the liquid crystal composition of the present invention, the polymerization proceeds even when no polymerization initiator is present, 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.

  Therefore, it is preferable that stabilizers, such as antioxidant and UV absorber, in the liquid crystal composition according to the present invention are 100 ppm to 1% by mass.

  Moreover, it was confirmed that the liquid crystal composition containing the liquid crystal composition and / or polymerizable monomer according to the present invention is also effective for suppressing the dropping marks. Here, the “drop mark” is defined as a phenomenon in which a mark in which a liquid crystal composition is dropped appears in white when black is displayed. Hereinafter, the dropping marks will be briefly described.

  Due to the recent expansion of the use of liquid crystal display elements, there have been significant changes in their usage and manufacturing methods, and in order to respond to these, characteristics other than the conventionally known basic physical property values are also optimal. It came to be demanded. That is, VA type and IPS type liquid crystal display elements using a liquid crystal composition have been widely used, and super large display elements having a size of 50 type or more have come to be used. As the substrate size is increased, the liquid crystal composition is injected into the substrate from the conventional vacuum injection method to the drop injection (ODF: One Drop Fill) method (see JP-A-6-235925). The problem that the drop marks when the composition is dropped on the substrate causes the display quality to deteriorate has surfaced. Furthermore, PS liquid crystal display elements (polymer stabilized) and PSA liquid crystal display elements (polymer sustained alignment, polymer sustaining alignment) have been developed for the purpose of high-speed response to the generation of pretilt angles of liquid crystal materials in liquid crystal display elements. (See Japanese Patent Application Laid-Open No. 2002-357830), the problem of dripping marks is a larger problem.

  That is, the display element of PS or PSA is characterized by adding a monomer to the liquid crystal composition and curing the monomer in the composition. In the active matrix liquid crystal composition, usable compounds are specified because of the necessity of maintaining a high voltage holding ratio, and use of compounds having an ester bond in the compound is limited. Monomers used for PSA liquid crystal display elements are mainly acrylates, and those having an ester bond in the compound are generally used, and such compounds are not normally used as liquid crystal compounds for active matrix (special features). (See Kai 2002-357830). Such foreign matter induces the generation of dripping marks, and the deterioration of the yield of the liquid crystal display element due to display failure is a problem. In addition, when adding additives such as antioxidants and light absorbers to the liquid crystal composition, deterioration of yield becomes a problem.

  In order to suppress such a drop mark, the drop mark generated in relation to the alignment control film is suppressed by forming a polymer layer in the liquid crystal phase layer by polymerization of a polymerizable monomer mixed in the liquid crystal composition. A method is disclosed (see JP 2006-58755 A). However, in this method, there is a problem of display burn-in caused by the polymerizable monomer added to the liquid crystal, and the effect is not sufficient for suppressing dripping marks, and the basic characteristics as a liquid crystal display element are maintained. However, there is a demand for the development of a liquid crystal display element that does not easily cause image sticking or dripping marks.

  A liquid crystal composition containing a polymerizable monomer according to the present invention (hereinafter also referred to as a polymerizable monomer-containing liquid crystal composition) is useful for a liquid crystal display element, particularly useful for a liquid crystal display element for active matrix driving, It can be used for a liquid crystal display element for PSA mode, PSVA mode, VA mode, IPS mode or ECB mode.

  The polymerizable monomer-containing liquid crystal composition of the present invention is provided with a liquid crystal alignment ability by polymerizing the polymerizable monomer contained therein by ultraviolet irradiation, and controls the amount of light transmitted using the birefringence of the liquid crystal composition. Used for liquid crystal display elements. As liquid crystal display elements, AM-LCD (active matrix liquid crystal display element), TN (nematic liquid crystal display element), STN-LCD (super twisted nematic liquid crystal display element), OCB-LCD and IPS-LCD (in-plane switching liquid crystal display element) However, it is particularly useful for AM-LCDs, and can be used for transmissive or reflective liquid crystal display elements.

  Further, referring to the liquid crystal display element described later and the contents of FIGS. 1 to 4, the two substrates 2 and 8 of the liquid crystal cell used in the liquid crystal display element are made of a transparent material having flexibility such as glass or plastic. One can be an opaque material such as silicon. Moreover, the transparent substrates 2 and 8 having the transparent electrodes (layers) 6 and 14 can be obtained, for example, by sputtering indium tin oxide (ITO) on the transparent substrates 2 and 8 such as glass plates.

  The substrates 2 and 8 on which the transparent electrodes (layers) and TFTs are formed are opposed so that the transparent electrodes (layers) 6 and 14 are on the inside. In that case, you may adjust the space | interval of a board | substrate via a spacer (not shown). At this time, it is preferable to adjust so that the thickness of the light control layer obtained may be set to 1-100 micrometers, and 1.5-10 micrometers is more preferable (refer FIGS. 1-4).

  When a polarizing plate is used, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so that the contrast is maximized. In addition, when there are two polarizing plates 1 and 9, the polarizing axis of each polarizing plate can be adjusted so that the viewing angle and contrast are good (see FIGS. 1 to 4). Furthermore, a retardation film for widening the viewing angle can also be used. Examples of the spacer include glass particles, plastic particles, alumina particles, and a photoresist material. Thereafter, a sealant such as an epoxy thermosetting composition is screen-printed on the substrates with a liquid crystal inlet provided, the substrates are bonded together, and heated to thermally cure the sealant.

  The method of introducing the polymerizable monomer-containing liquid crystal composition into the liquid crystal composition containing space containing the liquid crystal composition formed by bonding the two substrates facing each other as described above is a normal vacuum injection method. Alternatively, an ODF method or the like can be used. However, in the method of introducing the polymerizable monomer-containing liquid crystal composition by the vacuum injection method, although the drop mark does not occur, there is a problem that the injection mark remains, but in the present invention, the ODF method is used. The display element can be suitably used.

  As a method for polymerizing the polymerizable monomer according to the present invention, in order to obtain good alignment performance of liquid crystal, an appropriate polymerization rate is desirable. Therefore, active energy rays such as ultraviolet rays or electron beams are used singly or in combination or in sequence. A method of polymerizing by irradiating is preferable. 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 the polymerizable monomer-containing liquid crystal composition is sandwiched between two substrates, at least the substrate on the irradiation surface side must be given appropriate transparency to the active energy rays. I must. 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 monomer-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. In the MVA mode liquid crystal display element, it is preferable to control the pretilt angle from 80 degrees to 89.9 degrees from the viewpoint of alignment stability and contrast.

The temperature when irradiating active energy rays such as ultraviolet rays or electron beams is preferably within the temperature range in which the liquid crystal state of the liquid crystal composition of the present invention 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.

  The second aspect of the present invention is a liquid crystal display element using the liquid crystal composition according to the present invention. FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display element. Further, in FIG. 1, for convenience of explanation, each component is illustrated separately. FIG. 2 is an enlarged plan view of a region surrounded by II line 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. 3 is a cross-sectional view of the liquid crystal display element shown in FIG. 1 taken along the line III-III in FIG. FIG. 4 is an enlarged view of a thin film transistor which is a region IV in FIG. The liquid crystal display element according to the present invention will be described below with reference to FIGS.

  The configuration of the liquid crystal display element 10 according to the present invention includes a first substrate 8 provided with a transparent electrode (layer) 6 (also referred to as a common electrode 6) made of a transparent conductive material, as shown in FIG. A second substrate 2 including a thin film transistor layer 3 on which a pixel electrode made of a transparent conductive material and a thin film transistor for controlling the pixel electrode included in each pixel are formed; and the first substrate 8 and the second substrate 2 A liquid crystal display element having a liquid crystal composition (or liquid crystal layer 5) sandwiched therebetween, wherein the alignment of liquid crystal molecules in the liquid crystal composition when no voltage is applied is substantially perpendicular to the substrates 2 and 8; Thus, the liquid crystal composition of the present invention is used as the liquid crystal composition. As shown in FIGS. 1 and 3, the second substrate 2 and the first substrate 8 may be sandwiched between a pair of polarizing plates 1 and 9. Further, in FIG. 1, a color filter 7 is provided between the first substrate 8 and the common electrode 6. Further, a pair of alignment films 4 may be formed on the surfaces of the transparent electrodes (layers) 6 and 14 so as to be adjacent 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. Good.

  That is, the liquid crystal display element 10 according to the present invention includes a second polarizing plate 1, a second 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. The layer 5 including the alignment layer 4, the common electrode 6, the color filter 7, the first substrate 8, and the first polarizing plate 9 are sequentially stacked.

  As shown in FIGS. 2 and 3, the electrode layer 3 including the thin film transistor formed on the surface of the second substrate 2 has a gate wiring 25 for supplying a scanning signal and data for supplying a display signal. Pixel electrodes 21 are formed in a matrix in a region that intersects the wirings 24 and is surrounded by the plurality of gate wirings 25 and the plurality of data wirings 24. As a switching element for supplying a display signal to the pixel electrode 21, a thin film transistor including a source electrode 26, a drain electrode 23, and a gate electrode 27 is provided in the vicinity of the intersection where the gate line 25 and the data line 24 intersect each other. It is connected to the pixel electrode 21. Further, a storage capacitor 22 for storing a display signal supplied via the data wiring 24 is provided in a region surrounded by the plurality of gate wirings 25 and the plurality of data wirings 24.

  In the present invention, as shown in FIG. 2, the thin film transistor can be suitably used for a liquid crystal display element having an inverted staggered type, and the gate wiring 25 and the data wiring 24 are preferably metal films, and an aluminum wiring is used. Is particularly preferred. Further, the gate wiring 25 and the data wiring 24 overlap with each other through a gate insulating film.

  The color filter 7 is preferably formed with a black matrix (not shown) in a portion corresponding to the thin film transistor and the storage capacitor 22 from the viewpoint of preventing light leakage.

  A preferred embodiment of the structure of the thin film transistor of the liquid crystal display element according to the present invention includes, for example, a gate electrode 11 formed on the surface of the substrate 2 as shown in FIGS. A gate insulating layer 13 provided so as to cover substantially the entire surface of the substrate 2; a semiconductor layer 17 formed on the surface of the gate insulating layer 13 so as to face the gate electrode 11; and a surface of the surface of the semiconductor layer 17. A protective film 18 provided so as to cover a part of the protective film 18, covers one side edge of the protective layer 18 and the semiconductor layer 17, and contacts the gate insulating layer 13 formed on the surface of the substrate 2. The drain electrode 15 is provided on the other side edge of the protective film 18 and the semiconductor layer 17 and is in contact with the gate insulating layer 13 formed on the surface of the substrate 2. Source electrodes 19a and 19b, a transparent electrode 14 provided so as to cover the source electrodes 19a and 19b and to cover substantially the entire surface of the gate insulating layer 13 following the gate insulating layer 13, and the transparent electrode 14 , And a protective layer 101 (not shown in FIG. 3) provided so as to cover the source electrodes 19a and 19b.

  Further, as shown in FIGS. 3 and 4, an anodic oxide film 12 may be formed on the surface of the gate electrode 11 for the purpose of eliminating a step with the gate electrode. Furthermore, an ohmic contact layer 16 may be provided between the semiconductor layer 17 and the drain electrode 15 for the purpose of reducing the width and height of the Schottky barrier.

  As described above, in the process of manufacturing a liquid crystal display element, the occurrence of dripping marks is greatly affected by the injected liquid crystal material, but the influence is unavoidable depending on the configuration of the liquid crystal display element. In particular, the color filter 7 or the thin film transistor formed in the liquid crystal display element is a member in which only the thin alignment film 4 and the transparent electrodes 6 and 14 are separated from the liquid crystal composition as shown in FIG. Depending on the chemical structure of the pigment used in the color filter 7 or the combination of the chemical structure of the color filter resin and the liquid crystal compound having the specific chemical structure, the generation of dripping marks is affected.

  In particular, when the inverted staggered type as described above is used as the thin film transistor of the liquid crystal display device according to the present invention, the drain electrode 15 is formed so as to cover the gate electrode 11, so that the area of the drain electrode 15 tends to increase. It is in. In general, the drain electrode is usually formed of a metal material such as copper, aluminum, chromium, titanium, molybdenum, and tantalum and subjected to passivation treatment. However, as shown in FIGS. 3 and 4, for example, the protective film 18 is generally thin, the alignment film 4 is also thin, and there is a high possibility that the ionic substance is not blocked. Therefore, the dropping is caused by the interaction between the metal material and the liquid crystal composition. The generation of scars could not be avoided.

  However, in the liquid crystal display element including the liquid crystal composition according to the present invention, for example, from the viewpoint of a delicate balance between the liquid crystal display element member and the surface free energy or adsorption energy of the liquid crystal composition according to the present invention. It is considered that the problem of generation of marks can be reduced.

  The liquid crystal display device using the liquid crystal composition according to the present invention is useful for achieving both high-speed response and suppression of display failure, and is particularly useful for a liquid crystal display device for driving an active matrix, and includes a VA mode and a PSVA mode. , PSA mode, IPS mode, FFS mode or ECB mode.

  EXAMPLES The present invention will be described in further detail with reference to examples below, 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. γ1: Rotational viscosity at 25 ° C. (mPa · s)
Initial voltage holding ratio (initial VHR): Voltage holding ratio (%) at 343 K under conditions of frequency 6 Hz and applied voltage 5 V
After heat resistance test VHR: TEG (test element group) for evaluation of electro-optical characteristics in which a liquid crystal composition sample was enclosed was held in a thermostatic bath at 150 ° C. for 1 hour, and then measured under the same conditions as the VHR measurement method described above. .

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 ○ Very little afterimage but acceptable level △ There is afterimage unacceptable level × Afterimage is quite bad Drop mark:
Evaluation of the drop marks of the liquid crystal display device was performed by the following four-stage evaluation of the drop marks that appeared white when the entire surface was displayed in black.

◎ No afterimage ○ Very little afterimage but acceptable level △ With afterimage unacceptable level × With afterimage Quite poor process suitability:
The process suitability is that the liquid crystal is dropped by 50 pL at a time using a constant volume metering pump 100000 times in the ODF process, and the following “0 to 100 times, 101 to 200 times, 201 to 300 times, ... 99901 to 100,000 times ”was evaluated for changes in the amount of liquid crystal dropped 100 times each in the following four stages.

◎ Extremely small change (Stable liquid crystal display device can be manufactured)
○ Allowable level with slight change △ Level with change and unacceptable level (Yield deteriorated due to spots)
× There is a change and it is quite inferior (liquid crystal leakage and vacuum bubbles are generated)
Solubility at low temperature:
In order to evaluate the solubility at a low temperature, after preparing the liquid crystal composition, 1 g of the liquid crystal composition was weighed into a 2 mL sample bottle, and the next was “−20 ° C. (1 hour) in a temperature-controlled test tank. Hold) → Temperature rise (0.1 ° C./min)→0° C. (hold for 1 hour) → Temperature rise (0.1 ° C./min)→20° C. (hold for 1 hour) → Temperature drop (−0.1 ° C.) / Min) → 0 ° C. (hold for 1 hour) → temperature drop (−0.1 ° C./min)→−20° C. ”, and visually observe the occurrence of precipitates from the liquid crystal composition Then, the following four-stage evaluation was performed.

  A precipitate was not observed for 600 hours or more.

  ○ No precipitate was observed for 300 hours or more.

  Precipitates were observed within Δ150 hours.

X Precipitates were observed within 75 hours.
In the examples, the following abbreviations are used for the description of compounds.
(Side chain)
-N -C _n H _{2n + 1} linear alkyl group with _n carbon atoms -On -OC _n H _{2n + 1} linear alkoxy group with n carbon atoms -V0 -C = CH ₂ vinyl group -V _n -C = CH—C _n H _{2n + 1} vinyl group (ring structure)

(Example 1 and Comparative Example 1)
A liquid crystal composition having the following composition was prepared and measured for physical properties. The results are shown in the following table.

  Using the liquid crystal composition of Example 1 and the liquid crystal composition of Comparative Example 1, a VA liquid crystal display element shown in FIG. This liquid crystal display element has an inverted staggered thin film transistor as an active element. The liquid crystal composition was injected by a dropping method, and image sticking, dropping marks, process suitability, solubility at low temperatures, and volatility were evaluated. The compositions of Example 1 and Comparative Example 1 and the experimental results of the evaluation are shown in Table 1 below.

  The symbol on the left side of the content is a description of the abbreviation for the above compound.

The liquid crystal composition LC-1 of Example 1 has a practical TNI as a liquid crystal composition for TV, has a large absolute value of dielectric anisotropy, has an optimal Δn, and low viscosity. I understand that. On the other hand, the liquid crystal composition LC- of Comparative Example 1 designed to have the same liquid crystal phase temperature range, the same dielectric anisotropy value, and the same refractive index anisotropy value as the composition of the example. Since A contains a compound (3-Ph-Ph-1) having an alkyl end group different from the compound represented by the general formula (1), the rotational viscosity γ1 was shown to increase. In each evaluation, the liquid crystal composition LC-1 of Example 1 showed good results, while the liquid crystal composition LC-A of Comparative Example 1 showed insufficient results.
(Example 2 and Comparative Example 2)
A liquid crystal composition having the following composition was prepared, its physical properties were measured, and various evaluations were performed. The results are shown in Table 2.

The liquid crystal composition LC-2 of Example 2 has a practical TNI as a liquid crystal composition for TV, has an absolute value of large dielectric anisotropy, has an optimal Δn, and low viscosity. I understand that. On the other hand, the liquid crystal composition LC- of Comparative Example 1 designed to have the same liquid crystal phase temperature range, the same dielectric anisotropy value, and the same refractive index anisotropy value as the composition of the example. Since B contains a compound (3-Ph-Ph-1) having an alkyl end group different from the compound represented by the general formula (1), the rotational viscosity γ1 was shown to increase. In each evaluation, the liquid crystal composition LC-2 of Example 2 showed good results, whereas the liquid crystal composition LC-B of Comparative Example 2 showed insufficient results.
(Examples 3 to 7)
A liquid crystal composition having the following composition was prepared, its physical properties were measured, and various evaluations were performed. The results are shown in Table 3.

In the liquid crystal compositions LC-3 to LC-7 of Examples 3 to 7, remarkably good results were obtained in characteristics and various evaluations.
(Examples 8 to 13)
A liquid crystal composition having the following composition was prepared, its physical properties were measured, and various evaluations were performed. The results are shown in Table 4.

In the liquid crystal compositions LC-8 to LC-13 of Examples 8 to 13, remarkable results were obtained in characteristics and various evaluations.
(Examples 14 to 19)
A liquid crystal composition having the following composition was prepared, its physical properties were measured, and various evaluations were performed. The results are shown in Table 5.

In the liquid crystal compositions LC-14 to LC-19 of Examples 14 to 19, remarkably good results were obtained in characteristics and various evaluations.
(Examples 20 to 24)
A liquid crystal composition having the following composition was prepared, its physical properties were measured, and various evaluations were performed. The results are shown in Table 6.

  In the liquid crystal compositions LC-20 to LC-24 of Examples 20 to 24, remarkably good results were obtained in characteristics and various evaluations.

  Each configuration in each embodiment described above, a combination thereof, and the like are examples, and the addition, omission, replacement, and other changes of the configuration can be made without departing from the spirit of the present invention. Further, the present invention is not limited by each embodiment, and is limited only by the scope of the claims.

  The liquid crystal composition according to the present invention is widely applicable to the fields of liquid crystal display elements and liquid crystal displays.

DESCRIPTION OF SYMBOLS 1 Second polarizing plate 2 Second substrate 3 Thin film transistor layer or electrode layer including thin film transistor 4 Alignment film 5 Liquid crystal layer 6 Pixel electrode (common electrode)
7 Color Filter 8 First Substrate 9 First Polarizing Plate 10 Liquid Crystal Display Element 11 Gate Electrode 12 Anodized Film 13 Gate Insulating Layer 14 Transparent Electrode (Layer)
DESCRIPTION OF SYMBOLS 15 Drain electrode 16 Ohmic contact layer 17 Semiconductor layer 18 Protective film 19a, 19b Source electrode 21 Pixel electrode 22 Storage capacitor 23 Drain electrode 24 Data wiring 25 Gate wiring 26 Source electrode 27 Gate electrode 101 Protective layer

Claims (9)

General formula (1) as the first component

(In the formula, R ¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ² represents an alkoxy group having 1 to 5 carbon atoms or 2 to 2 carbon atoms. 1 type or 2 types or more of the compound represented by this represents 5 alkenyloxy groups,
General formula (2) as the second component

(Wherein R ³ and R ⁴ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms). ) Containing one or more compounds represented by
General formula (3) as the third component

(Wherein R ⁵ and R ⁶ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, M ¹ represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and one or two —CH ₂ — in the trans-1,4-cyclohexylene group represents an oxygen atom. And a compound represented by Z ¹ may be substituted with —O— so as not to be directly adjacent to each other, and Z ¹ represents —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O— or a single bond. A liquid crystal composition containing one or more kinds and having a negative dielectric anisotropy. General formula (4) as the fourth component

(Wherein R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, or an alkenyl group having 2 to 15 carbon atoms). , M ² represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group, and one or two —CH ₂ — in the trans-1,4-cyclohexylene group represents an oxygen atom. May be substituted with —O— so that they are not directly adjacent, Z ² represents —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O— or a single bond, and n 1 and n 2 are each The liquid crystal composition according to claim 1, which independently represents 0, 1 or 2, and n1 + n2 represents 1 or 2. The liquid crystal composition according to claim 1 or 2, comprising 3 to 35% by mass of the compound represented by the general formula (1) and 3 to 60% by mass of the compound represented by the general formula (2). . As other components, general formula (5-1) to general formula (5-5)

(Wherein R ⁹ , R ¹⁰ , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represents an alkyl group having 1 to 8 carbon atoms, Or two or more non-adjacent —CH ₂ — may be each independently substituted by —CH═CH—, —O—, —CO—, —COO— or —OCO—. ¹¹ and R ¹² each independently represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X ¹ represents a hydrogen atom, a fluorine atom or a methyl group). The liquid crystal composition according to any one of claims 1 to 3, comprising one or more compounds selected from the group of compounds described below. Compound represented by general formula (1), compound represented by general formula (2), compound represented by general formula (3), compound represented by general formula (4), general formula (5-1) ), A compound represented by general formula (5-2), a compound represented by general formula (5-3), a compound represented by general formula (5-4), and general formula (5) The liquid crystal composition according to any one of claims 1 to 4, wherein the total content of compounds selected from the group consisting of compounds represented by -5) is 90 to 100% by mass. The liquid crystal composition according to any one of claims 1 to 5, comprising a reactive monomer. The liquid crystal display element using the liquid-crystal composition of any one of Claims 1-6. A liquid crystal display using the liquid crystal display element according to claim 7. An active matrix driving liquid crystal display using the liquid crystal display element according to claim 7.

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