JP7326959B2 - Composition and liquid crystal display element using the same - Google Patents

Description

The present invention relates to a liquid crystal composition suitable for active matrix devices and active matrix devices containing this composition. In particular, the present invention relates to liquid crystal compositions having negative dielectric anisotropy and devices containing the same in IPS mode, FFS mode, ECB mode, TN mode, OCB mode, PSA mode, and the like.

Liquid crystal display elements are used in watches, calculators, various household electric appliances, industrial measuring instruments, automobile panels, mobile phones, smart phones, notebook PCs, tablet PCs, televisions, and the like. Typical liquid crystal display methods are TN (twisted nematic) type, STN (super twisted nematic) type, GH (guest-host) type, IPS (in-plane switching) type, and FFS (fringe field switching) type. , OCB (optically compensated birefringence) type, ECB (voltage controlled birefringence) type, VA (vertical alignment) type, CSH (color super homeotropic) type, FLC (ferroelectric liquid crystal), and the like. Examples of drive systems include static drive, multiplex drive, simple matrix system, and active matrix (AM) system driven by TFTs (thin film transistors), TFDs (thin film diodes), and the like. Among these display methods, the IPS type, FFS type, ECB type, VA type, CSH type, etc. are characterized by using a liquid crystal composition exhibiting a negative dielectric anisotropy (Δε).

Among these, the FFS type display method by AM drive is particularly adopted in mobile devices such as smartphones and tablet PCs from the viewpoint of wide viewing angle, high transmittance, low power consumption, and optimum compatibility with touch panels. Furthermore, it is also being adopted for automobile panels and liquid crystal televisions. In liquid crystal compositions required for smart phones, tablet PCs, automotive panels, etc., which are assumed to be used outdoors, the nematic phase-isotropic liquid phase transition temperature (T _ni ) is high, and the solid layer-nematic phase transition temperature is high. Low temperature (T _cn ), excellent low-temperature storage stability are essential, and sufficiently low rotational viscosity (γ ₁ ) is required. It has been required to achieve both storage stability.

Liquid crystal compositions using compounds (N3-3) and (N3-4) (see Patent Document 1) having the following skeletons have been disclosed as liquid crystal compositions exhibiting a negative dielectric anisotropy value. ing.

However, this liquid crystal composition is a liquid crystal composition for VA, PSA, PSVA, IPS or ECB modes, and is not intended for use in the FFS type display system. However, the high T _ni , low T _cn , and excellent low-temperature storage stability required in the above have not yet been solved.

As a liquid crystal composition having a negative dielectric anisotropy and operating in a wide temperature range that can withstand outdoor use such as automobile panels, compounds having the following skeleton (I ) and (II) (see Patent Document 2).

However, this liquid crystal composition is a liquid crystal material for a passive matrix (PM) drive system, and does not have a fast response speed and a high VHR that can withstand use in an FFS type display system based on AM drive.

WO2015/050035 WO2013/179966

The problem to be solved by the present invention is to provide a composition having a negative Δε, a liquid crystal phase in a wide temperature range, no precipitation or phase change at low temperatures, good storage stability, specific resistance and VHR. The object is to provide a liquid crystal composition which has a high thermal stability and high stability against heat and light. Furthermore, by using this, it is intended to provide a liquid crystal display element which is excellent in high-speed response, has a wide operating temperature range, suppresses the occurrence of burn-in, and has excellent contrast.

The present inventors have investigated various liquid crystal compounds and various chemical substances, and have found that the above problems can be solved by combining specific liquid crystal compounds, and have completed the present invention.

That is, the present invention provides the following general formula (i)

(wherein R ⁱ¹ and R ⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or more —CH ₂ — in said group each independently represent an oxygen atom; may be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO- as long as they are not adjacent to each other.)
It is an object of the present invention to provide a liquid crystal composition having a negative dielectric anisotropy, containing four or more compounds represented by the following, having a nematic phase-isotropic liquid transition temperature of 80° C. or higher. A further object of the present invention is to provide a liquid crystal display device using the composition.

The liquid crystal composition of the present invention has a wide liquid crystal temperature range, low viscosity, good storage stability without precipitation or phase change at low temperatures, and extremely small changes in resistivity and voltage holding rate due to heat and light. , the practicality of the product is high. Further, a liquid crystal display device using the composition has a wide operating temperature range, high-speed response, excellent reliability, and good storage stability. In particular, when used in an FFS type or IPS type display element, the transmittance is high and the black luminance is reduced, so that a high contrast can be exhibited and the occurrence of burn-in can be suppressed, which is very useful.

The present invention provides the following general formula (i)

(wherein R ⁱ¹ and R ⁱ² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or more —CH ₂ — in said group each independently represent an oxygen atom; may be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO- as long as they are not adjacent to each other.)
A liquid crystal composition having a negative dielectric anisotropy, containing four or more compounds represented by the following, having a nematic phase-isotropic liquid transition temperature of 80° C. or higher, and a liquid crystal display device using the same is.

In general formula (i), R ⁱ¹ is an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. is preferably an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms or an alkenyloxy group having 2 to 5 carbon atoms, and has a low viscosity. For this purpose, an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms is more preferable. The alkenyl group having 2 to 5 carbon atoms is preferably selected from groups represented by any one of formulas (R1) to (R5) described later, and formula (R1) or formula (R2) is particularly preferred.

R ⁱ² is preferably an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 atoms, preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and has low viscosity. For this purpose, an alkyl group having 1 to 3 carbon atoms is more preferable, and for a large Δn, an alkoxy group having 1 to 3 carbon atoms is more preferable.

In the liquid crystal composition of the present invention, _four or more compounds represented by general formula (i) are contained. It is preferable to contain. The combination of multiple types of compounds represented by general formula (i) is not particularly limited, but a combination of a compound in which R ⁱ¹ is an alkyl group and a compound in which R i2 is an alkenyl group, and/or R ⁱ² is A combination of a compound that is an alkyl group and a compound that is an alkoxy group is preferred.

Preferred lower limits for the content of the compound represented by formula (i) are 10%, 20%, 30%, and 40% with respect to the total amount of the liquid crystal composition of the present invention. , 50%, 55%, 60%, 65%, 70%, 75%, 80%. The upper limit of the preferred content is 95%, 85%, 75%, 65%, 55%, 45%, 35%, 30%, 25% , 20%, and 15%.

In the liquid crystal composition of the present invention, one It is preferable to contain one type or two or more types. These compounds correspond to compounds having negative dielectric anisotropy. These compounds have a negative sign of Δε and an absolute value of more than 2. The Δε of the compound is a value extrapolated from the measured value of the dielectric anisotropy of a composition obtained by adding the compound to a composition that is dielectrically neutral at 25°C.

In the formula, R ²¹ and R ²² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or more —CH ₂ — in the group each independently represent an oxygen atom. may be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO- as long as are not adjacent to each other, and Z ¹ is each independently single bond, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -OCF ₂ -, -CF ₂ O-, -CH=CH-, -CF=CF represents - or -C≡C-, and each m independently represents 1 or 2; Examples of groups that R ²¹ and R ²² can take include an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and an alkenyloxy group having 2 to 8 carbon atoms. and the like.

R ²¹ is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and still more preferably an alkyl group having 1 to 4 carbon atoms. However, when Z ¹ represents other than a single bond, R ²¹ is preferably an alkyl group having 1 to 3 carbon atoms.

R ²² is preferably an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Preferred are alkoxy groups having 1 to 4 carbon atoms.
R ²¹ and R ²² can also be an alkenyl group, and a group represented by any one of formulas (R1) to (R5) (the black dots in each formula represent a carbon atom in the ring structure) to It is preferably selected, and formula (R1) or formula (R2) is preferable, but the content of compounds in which R ²¹ and R ²² are alkenyl groups should be as low as possible, and in many cases it is preferable not to include them.

Z ¹ is each independently a single bond, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -OCF ₂ -, -CF ₂ O-, - represents CH=CH-, -CF=CF- or -C≡C-, preferably a single bond, -CH ₂ CH ₂ -, -OCH ₂ - or -CH ₂ O-, and a single bond or -CH ₂ O - is more preferred.
When m is 1, ^Z1 is preferably a single bond.
When m is 2, Z ¹ is preferably -CH ₂ CH ₂ -, -CH ₂ O-.

Fluorine atoms in compounds represented by general formulas (N-01), (N-02), (N-03), (N-04) and (N-05) are substituted with chlorine atoms which are the same halogen group. It's okay to be. However, the content of the compound substituted with a chlorine atom should be as small as possible, preferably not contained.

The hydrogen atoms present on the rings of the compounds represented by general formulas (N-01), (N-02), (N-03), (N-04) and (N-05) are further fluorine atoms or It may be substituted with a chlorine atom. However, the content of the compound substituted with a chlorine atom should be as small as possible, preferably not contained.

The compounds represented by the general formulas (N-01), (N-02), (N-03), (N-04) and (N-05) have a negative Δε and an absolute value greater than 3. A compound is preferred. Specifically, R ²² preferably represents an alkoxy group having 1 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms.

As compounds represented by general formula (N-01), general formula (N-01-1), general formula (N-01-2), general formula (N-01-3) and general formula (N-01 -4)

(Wherein, R ²¹ has the same meaning as described above, and R ²³ each independently represents an alkoxy group having 1 to 4 carbon atoms.) It is preferable to contain two or more kinds.

The liquid crystal composition of the present invention preferably contains a compound represented by general formula (i) and compounds represented by general formulas (N-01-1) and (N-01-4).
When a high VHR is required, that is, when high reliability is required, in other words, when it is important to obtain a liquid crystal display element free from display defects, general formula (N-01-3) It is preferred that it does not contain a compound that is

As compounds represented by general formula (N-02), general formula (N-02-1), general formula (N-02-2), and general formula (N-02-3)

(Wherein, R ²¹ has the same meaning as described above, and R ²³ each independently represents an alkoxy group having 1 to 4 carbon atoms.) It is preferable to contain two or more kinds.

The liquid crystal composition of the present invention preferably contains a compound represented by general formula (i) and a compound represented by general formula (N-02-1).

The liquid crystal composition of the present invention preferably contains a compound represented by general formula (i) and a compound represented by general formula (N-02-3).

The liquid crystal composition of the present invention includes a compound represented by the general formula (i), a compound represented by the general formula (N-01-1), a compound represented by the general formula (N-01-4) and general It is particularly preferred to contain the compound represented by formula (N-02-1) at the same time.

The liquid crystal composition of the present invention includes a compound represented by the general formula (i), a compound represented by the general formula (N-01-1), a compound represented by the general formula (N-01-4) and general It is particularly preferred to contain the compound represented by formula (N-02-3) at the same time.

As a compound represented by the general formula (N-03), the general formula (N-03-1)

(wherein R ²¹ has the same meaning as described above, and R ²³ represents an alkoxy group having 1 to 4 carbon atoms).

The liquid crystal composition of the present invention is preferably a combination of the compound represented by general formula (i) and the compound represented by general formula (N-03-1).
The liquid crystal composition of the present invention includes a compound represented by the general formula (i), a compound represented by the general formula (N-01-1), a compound represented by the general formula (N-01-4) and general It is particularly preferred to contain the compound represented by formula (N-03-1) at the same time.

As a compound represented by general formula (N-04), general formula (N-04-1)

(wherein R ²¹ has the same meaning as described above, and R ²³ represents an alkoxy group having 1 to 4 carbon atoms).

The liquid crystal composition of the present invention includes a compound represented by the general formula (i), a compound represented by the general formula (N-01-1), a compound represented by the general formula (N-01-4) and general It is particularly preferred to contain the compound represented by formula (N-04-1) at the same time.

The compound represented by general formula (N-05) is preferably a compound selected from the group of compounds represented by formulas (N-05-1) to (N-05-3).

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by the general formula (N-01) is 0%, 1%, 5%, and 10%. , 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% is. The upper limit of the preferred content is 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20% , 15%, and 10%.

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by the general formula (N-02) is 0%, 1%, 5%, and 10%. , 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% is. The upper limit of the preferred content is 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20% , 15%, and 10%.

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by the general formula (N-03) is 0%, 1%, 5%, and 10%. , 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% is. The upper limit of the preferred content is 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20% , 15%, and 10%.

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by the general formula (N-04) is 0%, 1%, 5%, and 10%. , 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80% is. The upper limit of the preferred content is 95%, 85%, 75%, 65%, 55%, 45%, 35%, 25%, 20% , 15%, and 10%.

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by formula (N-05) is 0%, 2%, 5%, and 8%. Yes, 10%, 13%, 15%, 17%, 20%. Preferred upper limits of the content are 30%, 28%, 25%, 23%, 20%, 18%, 15% and 13%.

The liquid crystal composition of the present invention contains 0.1% to 15% of the compound represented by general formula (i) and 1% to 20% of the compound represented by general formula (N-01-1). However, it contains 1% to 30% of the compound represented by the general formula (N-01-4) and 1% to 20% of the compound represented by the general formula (N-04-1). preferable.

The liquid crystal composition of the present invention may further contain one or more compounds represented by general formula (N-06).

(In the formula, R ²¹ and R ²² have the same meanings as described above.)
The compound represented by the general formula (N- ₀₆ ) is effective when it is desired to adjust various physical properties. can be done.

With respect to the total amount of the liquid crystal composition of the present invention, the preferred lower limit of the content of the compound represented by formula (N-06) is 0%, 2%, 5%, and 8%. Yes, 10%, 13%, 15%, 17%, 20%. The upper limit of the preferred content is 30%, 28%, 25%, 23%, 20%, 18%, 15%, 13%, 10% and 5%.

The liquid crystal composition of the present invention has general formulas (NU-01) to (NU-06)

(wherein R ^NU11 , R ^NU12 , R ^NU21 , R ^NU22 , R ^NU31 , R ^NU32 , R ^{NU41 , R NU42 ,} R ^NU61 and R ^NU62 each independently represent an alkyl group having 1 to 8 carbon atoms; and one or more —CH ₂ — in said group are independently —CH═CH—, —C≡C—, —O—, —CO—, as long as oxygen atoms are not adjacent to each other. —COO— or —OCO— may be substituted.) contains one or more compounds selected from the group of compounds represented by

More specifically, the groups that can be taken by ^RNU11 , ^RNU12 , ^RNU21 , ^RNU22 , ^RNU31 , ^{RNU32, RNU41, RNU42 , RNU61 and RNU62} are alkyl groups having 1 to 8 carbon atoms. Examples thereof include an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkenyloxy group having 2 to 8 carbon atoms, and an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms. An alkoxy group having 5 carbon atoms or an alkenyl group having 2 to 3 carbon atoms is preferable, and an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 3 carbon atoms is more preferable. When emphasizing response speed, at least one of R ^NU11 , R ^NU21 , R ^NU31 and R ^NU41 is preferably an alkenyl group having 2 to 3 carbon atoms, and compounds having such an alkenyl group are , preferably 10% or more, preferably 20% or more, preferably 25% or more, preferably 30% or more, preferably 40% or more, preferably 45% or more, relative to the total amount of the liquid crystal composition of the present invention. % or more is preferable. When a high VHR is important, the alkenyl group-containing compound is preferably 40% or less, preferably 35% or less, and preferably 30% or less.

In order to achieve both high speed and high reliability, it is preferable to use only the general formula (NU-01) as the compound having an alkenyl group, where R ^NU11 is an alkyl group having 2 to 4 carbon atoms, R ^NU12 is particularly preferably an alkenyl group having 2 to 3 carbon atoms.

In order to achieve both high speed and high reliability, it is preferable to use the general formula (NU-01) as the compound having an alkenyl group, where R ^NU11 is an alkyl group having 2 to 4 carbon atoms, R ^NU12 is particularly preferably an alkenyl group having 2 to 3 carbon atoms.
In order to achieve both high speed and high reliability, it is preferable to use general formula (NU-01) and general formula (NU-04) as compounds having an alkenyl group, where R ^NU11 has 2 carbon atoms. It is particularly preferred that R ^NU12 is an alkenyl group having 2 to 3 carbon atoms, R ^NU41 is an alkenyl group having 2 to 3 carbon atoms, and R ^NU42 is an alkyl group having 2 to 3 carbon atoms. is preferred.

The liquid crystal composition of the present invention preferably contains compounds represented by general formulas (NU-01) and (NU-02).

The liquid crystal composition of the present invention preferably contains compounds represented by general formulas (NU-01) and (NU-03).

The liquid crystal composition of the invention preferably contains a compound represented by general formula (NU-04).

The liquid crystal composition of the present invention preferably contains a compound represented by general formula (NU-06).

The liquid crystal composition of the invention preferably contains a compound represented by general formula (NU-01).

The liquid crystal composition of the present invention preferably contains compounds represented by general formulas (NU-01) and (NU-06).

The content of the compound represented by the general formula (NU-01) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 25 to 45% by mass. preferable.

The content of the compound represented by the general formula (NU-02) is preferably 3 to 30% by mass, more preferably 5 to 25% by mass, and further preferably 5 to 20% by mass. preferable.

The content of the compound represented by the general formula (NU-03) is preferably 0 to 20% by mass, more preferably 0 to 15% by mass, and further preferably 0 to 10% by mass. preferable.

The content of the compound represented by the general formula (NU-04) is preferably 3 to 30% by mass, more preferably 3 to 20% by mass, and further preferably 3 to 10% by mass. preferable.

The content of the compound represented by the general formula (NU-06) is preferably 1 to 30% by mass, more preferably 3 to 20% by mass, and further preferably 3 to 10% by mass. preferable.

The liquid crystal composition of the present invention may contain one or more polymerizable compounds.

The liquid crystal composition of the present invention may contain one or more polymerizable compounds represented by general formula (RM) as polymerizable compounds.

(wherein R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ , R ¹⁰⁷ and R ¹⁰⁸ are each independently P ¹³ —S ¹³ —, a carbon which may be substituted with a fluorine atom an alkyl group having 1 to 18 atoms, an alkoxy group having ¹ to 18 carbon atoms which may be substituted with a fluorine atom, a fluorine ^atom or a hydrogen ^atom ; Then, formula (Re-1) to formula (Re-9)

(wherein R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ each independently represent an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom, m ^r5 , m ^r7 , ^nr5 and ^nr7 each independently represent 0, 1, or 2, and ^mr5 , ^mr7 , ^nr5 and/or ^nr7 represent a single bond when they represent 0.)
represents a polymerizable group represented by S ¹¹ , S ¹² and S ¹³ each independently represents a single bond or an alkylene group having 1 to 15 carbon atoms, and one —CH in the alkylene group ₂ - or two or more non-adjacent -CH ₂ - may be replaced with -O-, -OCO- or -COO-, and when a plurality of P ¹³ and S ¹³ are present, each may be different. )
A liquid crystal composition containing a polymerizable compound represented by the general formula (RM) is suitable for producing a PSA-type or PSVA-type liquid crystal display device. It is also suitable for manufacturing an NPS type liquid crystal display element. It is also suitable for producing a PI-less type liquid crystal display device that does not have an alignment film.

Since the liquid crystal composition containing the compound represented by the general formula (i) and the polymerizable compound represented by the general formula (RM) has a moderately high polymerization rate, it imparts a desired pretilt angle with a short UV irradiation time. can do. Furthermore, the residual amount of the polymerizable compound after polymerization can be reduced. As a result, it is possible to improve the production efficiency of manufacturing PSA or PSVA liquid crystal display elements. In addition, there is an effect that display defects (for example, problems such as burn-in) due to changes in the pretilt angle do not occur or are extremely reduced. The display defect in this specification means a display defect caused by a change in the pretilt angle over time, a display defect caused by the residual amount of the unreacted polymerizable compound, and a display defect caused by a decrease in the voltage holding ratio. there is

In the above general formula (RM), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R 105 , R ¹⁰⁶ , ^{R 107 and} R ¹⁰⁸ are each independently substituted by P ¹³ —S ¹³ — and a fluorine atom. represents either an alkyl group having 1 to 18 carbon atoms which may be substituted, an alkoxy group having 1 to 18 carbon atoms which may be substituted with a fluorine atom, a fluorine atom or a hydrogen atom, but is an alkyl group and an alkoxy group. is preferably from 1 to 16, more preferably from 1 to 10, even more preferably from 1 to 8, even more preferably from 1 to 6, still more preferably from 1 to 3. be. In addition, the alkyl group and alkoxy group may be linear or branched, but are particularly preferably linear.

In the general formula (RM), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ , R ¹⁰⁷ and R ¹⁰⁸ are P ¹³ —S ¹³ —, a carbon atom which may be substituted with a fluorine atom It preferably represents either an alkoxy group having a number of 1 to 3, a fluorine atom or a hydrogen atom, and represents either P ¹³ —S ¹³ —, an alkoxy group having 1 to 3 carbon atoms, a fluorine atom or a hydrogen atom. is more preferred. The number of carbon atoms in the alkoxy group is preferably 1 or more and 3 or less, more preferably 1 or more and 2 or less, and particularly preferably 1.

P ¹¹ , P ¹² and P ¹³ may all be the same polymerizable group (formulas (Re-1) to (Re-9)) or different polymerizable groups.

In the above general formula (RM), P ¹¹ , P ¹² and P ¹³ are each independently represented by formula (Re-1), formula (Re-2), formula (Re-3) and formula (Re-4) , Formula (Re-5) or Formula (Re-7) is preferable, Formula (Re-1), Formula (Re-2), Formula (Re-3) or Formula (Re-4) is more preferred, formula (Re-1) is more preferred, and acrylic or methacrylic groups are even more preferred.

At least one of P ¹¹ and P ¹² is preferably represented by formula (Re-1), more preferably an acrylic group or a methacrylic group, still more preferably a methacrylic group, and P ¹¹ and P ¹² are methacryl is particularly preferred.

In the general formula (RM), S ¹¹ , S ¹² and S ¹³ are each independently preferably a single bond or an alkylene group having 1 to 5 carbon atoms, particularly preferably a single bond. When S ¹¹ , S ¹² and S ¹³ are single bonds, the residual amount of the polymerizable compound after ultraviolet irradiation is sufficiently small, and display defects due to changes in the pretilt angle are less likely to occur. Display defects of the display element do not occur or are extremely reduced. When S ¹¹ , S ¹² and S ¹³ have 1 to 3 carbon atoms, they are suitable for NPS type liquid crystal display devices.

The lower limit of the content of the polymerizable compound represented by the general formula (RM) in the liquid crystal composition of the present invention is preferably 0.01% by mass, preferably 0.02% by mass, and preferably 0.03% by mass. 0.04% by weight is preferred, 0.05% by weight is preferred, 0.06% by weight is preferred, 0.07% by weight is preferred, 0.08% by weight is preferred, 0.09% by weight is preferred, and 0.07% by weight is preferred. 1% by weight is preferred, 0.12% by weight is preferred, 0.15% by weight is preferred, 0.17% by weight is preferred, 0.2% by weight is preferred, 0.22% by weight is preferred, 0.25% by weight % is preferred, 0.27% by weight is preferred, 0.3% by weight is preferred, 0.32% by weight is preferred, 0.35% by weight is preferred, 0.37% by weight is preferred, 0.4% by weight is Preferably 0.42% by weight, preferably 0.45% by weight, preferably 0.5% by weight, preferably 0.55% by weight. The upper limit of the content of the polymerizable compound represented by the general formula (RM) in the liquid crystal composition of the present invention is preferably 5% by mass, preferably 4.5% by mass, preferably 4% by mass, and 3.5% by mass. % is preferred, 3% by weight is preferred, 2.5% by weight is preferred, 2% by weight is preferred, 1.5% by weight is preferred, 1% by weight is preferred, 0.95% by weight is preferred, 0.9% by weight % is preferred, 0.85% by weight is preferred, 0.8% by weight is preferred, 0.75% by weight is preferred, 0.7% by weight is preferred, 0.65% by weight is preferred, 0.6% by weight is Preferably 0.55% by mass, preferably 0.5% by mass, preferably 0.45% by mass, preferably 0.4% by mass.

More specifically, in order to obtain a sufficient pretilt angle, a small residual amount of the polymerizable compound, or a high voltage holding ratio (VHR), the content is preferably 0.2 to 0.6% by mass. When the suppression of is important, the content is preferably 0.01 to 0.4% by mass. It is also preferable to increase the content up to 2% by mass in order to obtain a particularly fast response speed.

Moreover, when a plurality of polymerizable compounds represented by general formula (RM) are contained, the content of each is preferably 0.01 to 0.4% by mass. Therefore, in order to solve all these problems, it is particularly preferable to adjust the polymerizable compound represented by general formula (RM) in the range of 0.1 to 0.6% by mass.

As the polymerizable compound represented by the general formula (RM) according to the present invention, specifically, the compounds represented by the general formulas (RM-1) to (RM-10) are preferable, and the PSA type using these The liquid crystal display element has a small residual amount of the polymerizable compound, has a sufficient pretilt angle, and has no or very little defects such as poor alignment and poor display caused by changes in the pretilt.

In the formula, R ^M1 and R ^M2 each independently represent an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom, and each represents an alkyl group having 1 carbon atom or a hydrogen atom. is more preferred.

The liquid crystal composition of the present invention contains one or more compounds having a terphenyl structure or a tetraphenyl structure and a dielectric anisotropy Δε greater than +2, that is, a compound having a positive dielectric anisotropy. can do. The Δε of the compound is a value extrapolated from the measured value of the dielectric anisotropy of a composition obtained by adding the compound to a composition that is dielectrically neutral at 25°C. The compounds are used in combination according to desired properties such as solubility at low temperature, transition temperature, electrical reliability, and refractive index anisotropy. The reactivity of the polymerizable compound in the composition can be accelerated.

A compound having a terphenyl structure or a tetraphenyl structure and having a dielectric anisotropy Δε of more than +2 has a preferable lower limit of content of 0.1% with respect to the total amount of the liquid crystal composition of the present invention. , 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, 10% be. A preferable upper limit of the content is, for example, 20%, 15%, 10%, 9%, and 8% in one embodiment of the present invention with respect to the total amount of the liquid crystal composition of the present invention. , 7%, 6%, 5%, 4%, 3%.

Compounds having a terphenyl structure or a tetraphenyl structure and having a dielectric anisotropy greater than +2 that can be used in the liquid crystal composition of the present invention include, for example, formulas (M-8.51) to (M-8) .54), compounds represented by formulas (M-7.1) to (M-7.4), formulas (M-7.11) to (M-7.14) It is preferable to contain the compounds represented by formulas (M-7.21) to (M-7.24).

In order to increase the T _ni of the liquid crystal composition according to the present invention, the formulas (L-7.1) to (L-7.4) and the formulas (L-7.11) to (L-7.11) L-7.13), formula (L-7.21) to formula (L-7.23), formula (L-7.31) to formula (L-7.34), formula (L-7.41 ) to formula (L-7.44), formula (L-7.51) to formula (L-7.53) four-ring dielectrically almost zero (generally in the range of -2 to +2) compound May contain.

The liquid crystal composition of the present invention may contain ordinary nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, antioxidants, ultraviolet absorbers, light stabilizers, infrared absorbers, and the like, in addition to the compounds described above.

Antioxidants include hindered phenols represented by general formulas (H-1) to (H-4).

In general formulas (H-1) to (H-3), each R ^H1 is independently an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and 2 carbon atoms. represents an alkenyl group having from 1 to 10 or an alkenyloxy group having from 2 to 10 carbon atoms, wherein one —CH ₂ — or two or more non-adjacent —CH ₂ — present in the group are each independently — It may be substituted with O- or -S-, and one or more hydrogen atoms present in the group may be independently substituted with a fluorine atom or a chlorine atom. More specifically, it is an alkyl group having 2 to 7 carbon atoms, an alkoxy group having 2 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkenyloxy group having 2 to 7 carbon atoms. An alkyl group having 3 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms is more preferable.

In general formula (H-4), M ^H4 is an alkylene group having 1 to 15 carbon atoms (one or two or more —CH ₂ — in the alkylene group are — O—, —CO—, —COO—, —OCO—.), —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —CF ₂ O—, — OCF ₂ -, -CF ₂ CF ₂ -, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, - C≡C—, a single bond, a 1,4-phenylene group (any hydrogen atom in the 1,4-phenylene group may be substituted with a fluorine atom) or a trans-1,4-cyclohexylene group However, it is preferably an alkylene group having 1 to 14 carbon atoms, and a large number of carbon atoms is preferable in consideration of volatility, but it is preferable that the number of carbon atoms is not too large in consideration of viscosity. 2 to 12 carbon atoms are more preferred, 3 to 10 carbon atoms are more preferred, 4 to 10 carbon atoms are still more preferred, 5 to 10 carbon atoms are still more preferred, and 6 to 10 carbon atoms are even more preferred.

In general formulas (H-1) to (H-4), one or two or more non-adjacent —CH= in the 1,4-phenylene group may be replaced by —N=. Also, each hydrogen atom in the 1,4-phenylene group may be independently substituted with a fluorine atom or a chlorine atom.

In general formulas (H-2) and (H-4), one or two or more non-adjacent —CH ₂ — in the 1,4-cyclohexylene group are —O— or —S— may be replaced by Also, each hydrogen atom in the 1,4-cyclohexylene group may be independently substituted with a fluorine atom or a chlorine atom.

More specific examples include formulas (H-11) to (H-15).

When the liquid crystal composition of the present invention contains an antioxidant, it is preferably 10 mass ppm or more, preferably 20 mass ppm or more, and preferably 50 mass ppm or more. When the antioxidant is contained, the upper limit is 10000 ppm by mass, preferably 1000 ppm by mass, preferably 500 ppm by mass, and more preferably 100 ppm by mass.

The liquid crystal composition of the present invention has a nematic phase-isotropic liquid phase transition temperature (T _ni ) of 80°C to 120°C, more preferably 90°C to 120°C, particularly preferably 100°C to 110°C. In the present invention, a temperature of 80° C. or higher is expressed as having a high _Tni .

The liquid crystal composition of the present invention has a refractive index anisotropy (Δn) at 20° C. of 0.08 to 0.14, more preferably 0.09 to 0.13, more preferably 0.09 to 0.12. Especially preferred. More specifically, it is preferably 0.10 to 0.13 for a thin cell gap and 0.08 to 0.10 for a thick cell gap. In the present invention, 0.09 or more is expressed as large Δn.

The liquid crystal composition of the present invention has a rotational viscosity (γ ₁ ) at 20° C. of 50 to 160 mPa·s, preferably 55 to 160 mPa·s, more preferably 60 to 160 mPa·s, more preferably 80 mPa·s. to 150 mPa·s, preferably 90 to 140 mPa·s, preferably 90 to 130 mPa·s, and preferably 95 to 130 mPa·s.

The liquid crystal composition of the present invention has a dielectric anisotropy (Δε) at 20° C. of −2.0 to −8.0, preferably −2.0 to −6.0, more preferably −2.0 to -5.0 is more preferred, -2.5 to -4.0 is more preferred, and -2.5 to -3.5 is particularly preferred.

In addition to the compound represented by the general formula (i), the liquid crystal composition of the present invention has the general formula (N-01), the general formula (N-02), the general formula (N-03), the general formula (N- 04), contains one or more compounds selected from the group of compounds represented by general formulas (N-05) and (N-06), and further contains general formulas (NU-01) to (NU- 06) preferably contains one or more compounds selected from the group of compounds represented by , and the upper limits of the total content of these are 100% by mass, 99% by mass, 98% by mass, and 97% by mass. %, 96% by mass, 95% by mass, 94% by mass, 93% by mass, 92% by mass, 91% by mass, 90% by mass, 89% by mass, 88% by mass, 87% by mass, 86% by mass, 85% by mass, It is preferably 84% by mass, and the lower limits of the total of these contents are 78% by mass, 80% by mass, 81% by mass, 83% by mass, 85% by mass, 86% by mass, 87% by mass, and 88% by mass. %, 89% by mass, 90% by mass, 91% by mass, 92% by mass, 93% by mass, 94% by mass, 95% by mass, 96% by mass, 97% by mass, 98% by mass, and 99% by mass. .

A liquid crystal display element using the liquid crystal composition of the present invention is particularly useful as a liquid crystal display element for active matrix driving, and includes VA, FFS, IPS, PSA, PSVA, PS-IPS or PS-FFS, NPS, PI- It can be used as appropriate for liquid crystal display elements such as less.

The following abbreviations are used for the description of compounds in Examples. Note that n represents a natural number.
(side chain)
-n -C _n H _2n+1 straight chain alkyl group having n carbon atoms n- C _n H _2n+1 - straight chain alkyl group having n carbon atoms -On -OC _n H _2n+1 straight chain having n carbon atoms alkoxyl group nO- C _n H _2n+1 O- straight-chain 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 _-CH2 - _CH2 -CH= _CH2
V2- CH ₂ =CH-CH ₂ -CH ₂ -
-2V1 _-CH2 - _CH2 -CH=CH- _CH3
1V2- CH ₃ -CH=CH-CH ₂ -CH ₂ -

(Connecting group)
_{-n- -CnH2n-}
-nO- -C _n H _2n -O-
-On- -O _{- CnH2n-}
-COO- -C(=O)-O-
-OCO- -OC(=O)-
-CF2O- _-CF2 -O-
-OCF2- -O- _CF2-

(ring structure)

The properties measured in the examples are as follows.

T _ni : nematic phase-isotropic liquid phase transition temperature (°C)
T _→n : Transition temperature to nematic phase (°C)
Δn: refractive index anisotropy at 25°C _nO : refractive index for ordinary light at 25°C Δε: dielectric anisotropy at 25°C _ε⊥ : dielectric constant in the direction perpendicular to the molecule at 25°C _γ1 : rotational viscosity at 25°C (mPa・s)
Low-temperature storage stability: About 0.5 g of the liquid crystal composition was placed in a vial and stored at -40°C. As a result, "A" was given when precipitation was not confirmed after 10 days, "B" when precipitation was confirmed after 1 week, and "C" when precipitation was confirmed after 3 days. . If the evaluation was B or higher, it was regarded as a pass.

(Examples 1 to 17 and Comparative Example 1)
The following compositions were prepared as examples and comparative examples. Each composition contains each compound listed in the table, and each compound contains the amount (g) listed in the table. Using these compositions, an FFS cell was produced and each physical property value was measured.

As shown in the above results, it was found that the examples exhibited a higher T _ni and excellent low-temperature storage stability than the comparative examples.

Claims (9)

The following general formula (i)

(wherein R ⁱ¹ and R ⁱ² are each independently an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or represents an alkenyloxy group of 8 to 8, wherein one or more —CH ₂ — in the group are each independently —CH═CH—, —C≡C—, —, as long as oxygen atoms are not adjacent to each other; may be substituted by O-, -CO-, -COO- or -OCO-.)
A liquid crystal composition having a negative dielectric anisotropy and containing four or more compounds represented by the formula and having a nematic phase-isotropic liquid transition temperature of 80° C. or higher. 2. The liquid crystal composition according to claim 1, wherein the compound represented by formula (i) contains one or more compounds in which R ⁱ² is an alkoxy group. 3. The liquid crystal composition according to claim 1, containing 20 to 30% of the compound represented by formula (i). 4. The liquid crystal composition according to any one of claims 1 to 3, containing 5 or more compounds represented by formula (i). 5. The liquid crystal composition according to claim 1, which has a nematic phase-isotropic liquid transition temperature of 100° C. or higher. The following general formulas (N-01), (N-02), (N-03), (N-04) and (N-05)

(In the formula, R ²¹ and R ²² each independently represent an alkyl group having 1 to 8 carbon atoms, and one or more —CH ₂ — in the group each independently represent an oxygen may be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO- as long as the atoms are not adjacent, and Z ¹ is each independently , single bond, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -OCF ₂ -, -CF ₂ O-, -CH=CH-, -CF= CF- or -C≡C-, and each m independently represents 1 or 2. Claims 1 to 5 containing one or more compounds selected from the group of compounds represented by The liquid crystal composition according to any one of . General formula (NU-06) from the following general formula (NU-01)

(wherein R ^NU11 , R ^NU12 , R ^NU21 , R ^NU22 , R ^NU31 , R ^NU32 , R ^{NU41 , R NU42 ,} R ^NU61 and R ^NU62 are each independently an alkyl group having 1 to 8 carbon atoms, represents an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, wherein one or two or more non-adjacent -CH ₂ groups in the group; - each independently may be substituted with -CH=CH-, -C≡C-, -O-, -CO-, -COO- or -OCO-.) selected from the group of compounds represented by 7. The liquid crystal composition according to any one of claims 1 to 6, which contains one or two or more compounds. A liquid crystal display device using the liquid crystal composition according to any one of claims 1 to 7. 9. The liquid crystal display device according to claim 8, wherein the drive system is the FFS system.