JP6061040B2 - Nematic liquid crystal composition and liquid crystal display device using the same - Google Patents

Description

  The present invention relates to a nematic liquid crystal composition having a positive dielectric anisotropy (Δε) useful as an electro-optical liquid crystal display material.

  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. Typical liquid crystal display methods include TN (twisted nematic) type, STN (super twisted nematic) type, VA type characterized by vertical alignment using TFT (thin film transistor) and horizontal alignment. IPS (In-Plane Switching) type / FFS 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. Furthermore, the liquid crystal composition has several to several tens of kinds of compounds in order to optimize the dielectric anisotropy (Δε) and the refractive index anisotropy (Δn) for each display element. It is composed of

A liquid crystal composition having a negative Δε is used for a vertical alignment type display, and a liquid crystal composition having a positive Δε is used for a horizontal alignment type display such as a TN type, STN type, or IPS type. In recent years, a driving method has been reported in which a liquid crystal composition having a positive Δε is vertically aligned when no voltage is applied and an IPS type / FFS type electric field is applied, and the necessity of a liquid crystal composition having a positive Δε is reported. Is growing further. On the other hand, low voltage driving, high-speed response, and a wide operating temperature range are required in all driving systems. That is, Δε is positive, the absolute value is large, the viscosity (η) is small, and a high nematic phase-isotropic liquid phase transition temperature (T _ni ) is required. Further, 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 applying a liquid crystal display element to a television or the like, since high-speed response is important, a liquid crystal composition having a small γ ₁ is required.

  There is a disclosure of a liquid crystal composition using a compound represented by the formula (A-1) or (A-2), which is a liquid crystal compound having a positive Δε as a constituent component of the liquid crystal composition (Patent Document 1 to Patent Document 4), these liquid crystal compositions have not yet achieved a sufficiently low viscosity.

  On the other hand, in order to improve the performance of liquid crystal displays, there are disclosures of inventions relating to compounds having various groups other than those having a fluorine atom or a trifluoromethoxy group as polar groups and compositions containing the same. (Patent Documents 5 to 18) However, these liquid crystal compositions have not yet achieved sufficiently low viscosity.

WO96 / 032365 JP 09-157202 A WO98 / 023564 JP 2003-183656 A Special table hei 3-505742 Special table hei 6-500343 Special table hei 7-509025 Special table hei 8-500366 Special table hei 8-507771 Special table hei 8-510220 JP-A-6-40988 JP-A-6-329573 JP-A-7-82561 JP-A-7-145099 JP 2004-115800 A JP 2006-321804 A JP 2008-189927 A Special table 2011-516628

The problem to be solved by the present invention is adjusted to a desired refractive index anisotropy (Δn), and suppresses a decrease in the nematic phase-isotropic liquid phase transition temperature (T _ni ) and an increase in the minimum temperature of the nematic phase. Thus, there is provided a liquid crystal composition having a sufficiently low viscosity (η) and a positive dielectric anisotropy (Δε) without deteriorating the temperature range of the nematic phase.

  The present inventor has studied various fluorobenzene derivatives and found that the above problem can be solved by combining specific compounds, and has completed the present invention.

  The present invention is a liquid crystal composition having positive dielectric anisotropy, wherein the liquid crystal composition contains one or more compounds selected from compounds represented by the general formula (LC0),

(In the formula, R ⁰¹ represents an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are —O—, —CH, so that oxygen atoms are not directly adjacent to each other. ═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ —, which may be substituted with one or more of the alkyl groups The hydrogen atom may be optionally halogen-substituted, and A ⁰¹ is independently any one of the following structures

(In the structure, X ^{104 to} X ¹⁰⁸ each independently represent —H, —Cl, —F, —CF _3, or —OCF ₃ ), and A ⁰² represents any one of the following structures:

(In the structure, X ^{109 to} X ¹¹³ each independently represent —H, —Cl, —F, —CF ₃ or —OCF ₃ ), and X ^{101 to} X ¹⁰³ each independently represent —H. , -Cl, -F, represents -CF ₃ or -OCF ^{_3, Y 01} and ^{Y 02} each independently represent -Cl, -F, a -CF ₃ or -OCF ^{_3, Z 02} is _-CH 2 O —, —OCH ₂ — or —CF ₂ O—, wherein Z ⁰¹ and Z ⁰³ are each independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH _{2) 4 -, - OCF 2} - or _-CF 2 O-a ^{represents, m 01} and ^{m 02} each independently represents an integer of ^{0~2, m} 01 ⁺ m ⁰² each independently 0, 1, 2 or represents ^{3, a 01, X 101,} X 102, Z 01 and / or ^{Z 03} is If the number present, they may be the same or different. The liquid crystal composition further comprises one or more compounds selected from the group of compounds represented by formulas (LC1) to (LC5).

(In the formula, R ^{11 to} R ⁴¹ each independently represent an alkyl group having 1 to 15 carbon atoms, and one or two or more —CH ₂ — in the alkyl group is not directly adjacent to an oxygen atom. May be substituted with -O-, -CH = CH-, -CO-, -OCO-, -COO-, -C≡C-, -CF ₂ O- or -OCF _2- , One or two or more hydrogen atoms in the above may be optionally substituted with halogen, and R ⁵¹ and R ⁵² each independently represents an alkyl group having 1 to 15 carbon atoms, and one of the alkyl groups Or two or more —CH ₂ — are substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent. well Te, when ^{a 51} or ^{a 53} described later cyclohexane ring -OCF _3, -CF , May be -OCF = CF ₂ or _{^{-OCH = CF 2, A 11 ~A}} 42 are each independently either the following structures

(In the structure, one or more —CH ₂ — of the cyclohexane ring may be substituted with —O— so that the oxygen atom is not directly adjacent to each other, and X ⁶¹ and X ⁶² are each independently — H, -Cl, -F, represents a -CF ₃ or -OCF _3.) ^represent, respectively, a 51 ^{to a 53} independently of any of the following structures

(Wherein one or more —CH ₂ CH ₂ — in the cyclohexane ring may be substituted with —CH═CH—, —CH ₂ O— or —OCH ₂ —, One or two or more of —CH═ may be substituted with —N═ so that the nitrogen atom is not directly adjacent to each other), and X ^{11 to} X ⁴³ are each independently —H, —Cl. , -F, -CF ₃ or -OCF ₃ , Y ^{11 to} Y ⁴¹ are -Cl, -F, -CF ₃ , -OCF ₃ , -CF ₂ CF ₃ , -CHFCF ₃ , -OCF ₂ CF ₃ , —OCHFCF ₃ or —OCF═CF ₂ , each of Z ^{31 to} Z ⁴² is independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) _{4. -, - OCH 2 -, -} CH 2 O -, - OCF 2 - or _-CF 2 O The stands, at least one of ^{Z 31} and ^{Z 32} present is not a single ^{bond, Z 51} and ^{Z 52} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH _{2 -, - (CH 2)} 4 -, - OCH 2 -, - CH 2 O -, - COO -, - OCO -, - OCF 2 - or _-CF 2 O-a ^represents, m 21 ^{~m 51} each Each independently represents an integer of 0 to 3, m ³¹ + m ³² and m ⁴¹ + m ⁴² each independently represent 1, 2, 3 or 4; and A ²³ , A ³¹ , A ³² , A ⁴¹ , A ⁴² , When a plurality of A ⁵² , Z ³¹ , Z ³² , Z ⁴¹ , Z ⁴² and / or Z ⁵² are present, they may be the same or different. However, any one of A ³¹ and A ³² present is

(In the structure, one or more —CH ₂ — of the cyclohexane ring may be substituted with —O— so that the oxygen atom is not directly adjacent.)
And any one of A ⁴¹ and A ⁴² present is

(In the structure, one or more —CH ₂ — of the cyclohexane ring may be substituted with —O— so that the oxygen atom is not directly adjacent.)
It is. And a liquid crystal display element using the liquid crystal composition.

The liquid crystal composition of the present invention is characterized in that Δε is positive and its absolute value can be increased. Also, η is low, rotational viscosity (γ ₁ ) is small, liquid crystallinity is excellent, and a stable liquid crystal phase is exhibited over a wide temperature range. Further, it is a practical and reliable liquid crystal composition that is chemically stable to heat, light, water, and the like and can be driven at a low voltage.

  The liquid crystal composition in the present invention contains one or more compounds selected from the compounds represented by the general formula (LC0), and further compounds represented by the general formulas (LC1) to (LC5). 1 type, or 2 or more types of compounds chosen from the compound group which consists of these are contained. A liquid crystal composition containing the compound represented by the general formula (LC0) and the compounds represented by the general formula (LC1) to the general formula (LC5) exhibits a stable liquid crystal phase even at a low temperature. It can be said that.

In general formula (LC0) to general formula (LC5), R ^{01 to} R ⁵² each independently represents an alkyl group having 1 to 15 carbon atoms, and one or more CH ₂ in the alkyl group. The groups are selected from —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ — so that the oxygen atom is not directly adjacent. 1 or 2 or more hydrogen atoms in the alkyl group may be optionally halogen-substituted, but 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 is preferable, and a straight chain is preferable. In particular, any one of R ⁵¹ and R ⁵² is preferably an alkenyl group having 2 to 8 carbon atoms. When R ^{01 to} R ⁵² are alkenyl groups, Formula (R1) to Formula (R5)

(The black dot in each formula represents the connection point with the ring.)
It is preferable to be selected from the group represented by any of the above. When A ¹¹ , A ²¹ , A ³¹ , A ⁴¹ , A ⁵¹ , A ⁵³ is a trans-1,4-cyclohexylene group, Formula (R1), Formula (R2), and Formula (R4) are more preferable. It is more preferable that at least one of R ⁵¹ and R ⁵² in the general formula (LC5) contains one or more compounds each of which is an alkenyl group of any one of the formulas (R1) to (R5).

A ⁰¹ is one of the following structures

In the case where a plurality of A ⁰¹ are present, they may be the same or different. X ^{104 to} X ¹⁰⁸ in the above structure each independently represent —H, —Cl, —F, —CF _3, or —OCF _3, and are preferably —H or —F. ^A02 is one of the following structures

Represents.
X ^{109 to} X ¹¹³ in the above structure each independently represent —H, —Cl, —F, —CF ₃ or —OCF ₃ , preferably —H or —F, and —F. Is more preferable. Y ⁰¹ and Y ⁰² in the above structure each independently represent —Cl, —F, —CF ₃ or —OCF ₃ , preferably —F or —OCF ₃ , and more preferably —F. preferable.

A ^{11 to} A ⁴² are each independently a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group, 3,5-difluoro-1,4-phenylene. Group or tetrahydropyran-2,5-diyl group is preferred. When A ^{11 to} A ⁴² contain a tetrahydropyran group, A ¹¹ , A ²¹ , A ³¹ and A ³² are preferable.

A ^{51 to} A ⁵³ are each independently a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group or 2-fluoro-1,4-phenylene group. preferable.

Z ⁰² represents —OCH ₂ — or —CF ₂ O—. Z ⁰¹ and Z ⁰³ are each independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCF ₂ — or —CF ₂ O—. Represents a single bond, —CH ₂ CH ₂ —, —OCF ₂ — or —CF ₂ O—, more preferably a single bond or —CH ₂ CH ₂ —, and a single bond. It is particularly preferred.

Z ^{31 to} Z ⁴² are each independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—. , —OCF ₂ — or —CF ₂ O—, and at least one of Z ³¹ and Z ³² present is not a single bond, but a single bond, —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —CF ₂ O— is preferred, and one of Z ^{31 to} Z ⁴² present is —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or —. When CF ₂ O— is represented, the others are preferably single bonds.

Z ⁵¹ and Z ⁵² are each independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—. , -COO -, - OCO -, - OCF 2 - or represents a _-CF 2 O-, a single _{bond, -CH 2 CH 2 -, -} OCF 2 - or ^{Z 51} _{to -CF} 2 O-are preferably present When a plurality of Z ⁵² are present, at least one is preferably a single bond, more preferably all represent a single bond.

X ¹⁰³ represents —H, —Cl, —F, —CF _3, or —OCF ₃ , and —F is a large dielectric anisotropy (Δε) or similar dielectric anisotropy (Δε). In contrast, the viscosity (η) is remarkably low, which is particularly preferable.

X ^{101 to} X ¹⁰² each independently represent —H, —Cl, —F, —CF ₃ or —OCF ₃ , and —H or —F is preferred.

Y ⁰¹ and Y ⁰² each independently represent —Cl, —F, —CF ₃ or —OCF ₃ , preferably —F or —OCF ₃ , and more preferably —F. Y ^{11 to} Y ⁴¹ represent —Cl, —F, —CF ₃ , —OCF ₃ , —CF ₂ CF ₃ , —CHFCF ₃ , —OCF ₂ CF ₃ , —OCHFCF ₃ or —OCF═CF ₂ , It is preferably F or —OCF ₃ , and more preferably —F.

m ^{01 to} m ⁵¹ can each independently represent an integer of 0 to 3, but m ⁰¹ + m ⁰² is more preferably 1 or 2, m ²¹ is more preferably 0, and m ³¹ + m ³² is 1 or 2. Or 3 is more preferable, and m ⁴¹ + m ⁴² is more preferably 1 or 2.

  Specifically, the liquid crystal compound represented by the general formula (LC0) is represented by the following general formula (LC0-1) to general formula (LC0-36).

(Wherein X ^{114 to} X ¹¹⁷ each independently represent —H, —Cl, —F, —CF ₃ or —OCF ₃ , and R ⁰¹ , X ^{101 to} X ¹¹³ , and Y ¹⁰¹ are the same as in claim 1). It is preferably a compound represented by

  Specifically, the compound represented by the general formula (LC2) is represented by the following general formula (LC2-1) to general formula (LC2-14).

(In the formula, X ²³ , X ²⁴ , X ²⁵ and X ²⁶ each independently represent a hydrogen atom, Cl, F, CF ₃ or OCF ₃ , and X ²² , R ²¹ and Y ²¹ in the general formula (LC2) It is more preferable that it is a compound represented by the same meaning. The compound groups represented by general formula (LC2-1) to general formula (LC2-4) and general formula (LC2-9) to general formula (LC2-11) are more preferable.

  Specifically, the compound represented by the general formula (LC3) is represented by the following general formula (LC3-1) to general formula (LC3-58).

(Wherein X ^{33 to} X ³⁸ each independently represent H, Cl, F, CF ₃ or OCF ₃ , and R ³¹ , X ³²¹ and Y ³¹ represent the same meaning as in claim 1). It is preferable that it is a compound.

  Specifically, the compound represented by the general formula (LC4) is represented by the following general formula (LC4-1) to general formula (LC4-14).

(Wherein X ^{44 to} X ⁴⁷ each independently represent H, Cl, F, CF ₃ or OCF ₃ , and X ⁴² , X ⁴³ , R ⁴¹ and Y ⁴¹ represent the same meaning as in claim 1). It is preferable that it is a compound represented by these.

  Compounds represented by general formula (LC5) are represented by the following general formula (LC5-1) to general formula (LC5-26).

(Wherein R ⁵¹ and R ⁵² represent the same meanings in general formula (LC5)), and are preferably compounds represented by Among these, from general formula (LC5-1) to general formula (LC5-8), general formula (LC5-14), general formula (LC5-16), and general formula (LC5-18) to general formula (LC5-26) It is more preferable to use together the compound group represented by general formula (LC0) which is an essential component of this invention. A compound group in which at least one of R ⁵¹ and R ^{52 in} the general formula (LC5-1) and the general formula (LC5-4) is an alkenyl group, particularly any one of the alkenyl groups in the following formulas (R1) to (R5) More preferably.

  The compound represented by general formula (LC5) contains 1 type or 2 types or more, and it is preferable that content is 20-70 mass%, and it is more preferable that it is 30-70 mass%.

  The liquid crystal composition of the present invention contains a compound represented by general formula (LC0) and a compound selected from the group of compounds represented by general formula (LC1) to general formula (LC5). It is preferable that the compound represented by the compound group represented by the compound represented by the compound represented by the compound represented by General formula (LC4) and General formula (LC5) and the compound represented by General formula (LC5).

  The liquid crystal composition of the present invention preferably has a viscosity η at 20 ° C. of 20 mPa · s or less.

  The liquid crystal composition of the present invention can contain one or more optically active compounds. Any optically active compound can be used as long as the liquid crystal molecules can be twisted and aligned. Usually, since this twist changes with temperature, a plurality of optically active compounds can be used to obtain a desired temperature dependency. In order not to adversely affect the temperature range and viscosity of the nematic liquid crystal phase, it is preferable to select and use an optically active compound having a strong twist effect. Specifically, such an optically active compound is preferably a liquid crystal such as cholesteric nonanate or a compound represented by the following general formula (Ch-1) to general formula (Ch-6).

(Wherein R _c1 , R _c2 and R ^* each independently represents an alkyl group having 1 to 15 carbon atoms, and one or two or more —CH ₂ — in the alkyl group has a direct oxygen atom. May be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O— or —OCF ₂ — so that they are not adjacent, One or more hydrogen atoms in the alkyl group may be optionally substituted with halogen, provided that R ^* has at least one branched chain group or halogen substituent having optical activity, and Z _c1 , Z _c2 , each independently, a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH ₂ —. _{, -CH 2 O -, - OCF} 2 - or _-CF 2 O-a _{represents, D 1,} D ₂ is Cyclohexane represents a ring or a benzene ring, one or two or more -CH 2 in the cyclohexane ring _- may have an oxygen atom which may be substituted with -O- so as not to directly adjacent, and the ring Note 1 Two or more —CH ₂ CH ₂ — may be substituted with —CH═CH—, —CF ₂ O— or —OCF ₂ —, and one or more —CH 2 in the benzene ring. ═ may be substituted with —N═ such that the nitrogen atom is not directly adjacent, one or more hydrogen atoms in the ring may be substituted with F, Cl, CH ₃ , t ₁ , t ₂ represents 0, 1, 2 or 3, and MG *, Q _c1 and Q _c2 have the following structures

(In the formula, D ₃ and D ₄ represent a cyclohexane ring or a benzene ring, and one or two or more —CH ₂ — in the cyclohexane ring are substituted with —O— so that the oxygen atom is not directly adjacent. And one or more —CH ₂ CH ₂ — in the ring note may be substituted with —CH═CH—, —CF ₂ O—, or —OCF ₂ —. One or more —CH═ may be substituted with —N═ such that the nitrogen atoms are not directly adjacent, and one or more hydrogen atoms in the ring are substituted with F, Cl, CH ₃ . May be used).

  The liquid crystal composition of the present invention may contain one or more polymerizable compounds, and the polymerizable compound contains a benzene derivative, a triphenylene derivative, a truxene derivative, a phthalocyanine derivative or a cyclohexane derivative at the center of the molecule. And a discotic liquid crystal compound having a structure in which a linear alkyl group, a linear alkoxy group or a substituted benzoyloxy group is radially substituted as its side chain.

  Specifically, the polymerizable compound is represented by the general formula (PC).

It is preferable that it is a polymeric compound represented by these. (Wherein P ₁ represents a polymerizable functional group, Sp ₁ represents a spacer group having 0 to 20 carbon atoms, and Q _p1 represents a single bond, —O—, —NH—, —NHCOO—, —OCONH— , -CH = CH-, -CO-, -COO-, -OCO-, -OCOO-, -OOCO-, -CH = CH-, -CH = CH-COO-, -OCO-CH = CH- or- C≡C—, p ₁ and p ₂ each independently represent 1, 2 or 3, MG _p represents a mesogenic group or a mesogenic support group, and R _p1 represents a halogen atom, a cyano group or a carbon atom Represents an alkyl group of 1 to 25, and one or more CH ₂ groups in the alkyl group are —O—, —S—, —NH—, —N so that the O atom is not directly adjacent to each other. _{(CH 3) -, - CO} -, - COO -, - OCO -, - OCOO -, - SCO-, May also be replaced by -COS- or -C≡C-, or _{R p1} is _P 2 _-Sp 2 _{-Q p2} - can be _{a, P 2, Sp 2, Q} p2 are each independently P ₁ , Sp ₁ and Q _p1 have the same meaning.)
More preferably, MG _p in the polymerizable compound general formula (PC) has the following structure:

It is a polymeric compound represented by these.
(Wherein C _{01 to} C ₀₃ are each independently 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, tetrahydropyran-2,5-diyl group, 1,3 -Dioxane-2,5-diyl group, tetrahydrothiopyran-2,5-diyl group, 1,4-bicyclo (2,2,2) octylene group, decahydronaphthalene-2,6-diyl group, pyridine-2 , 5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6-naphthylene group, phenanthrene -2,7-diyl group, 9,10-dihydrophenanthrene-2,7-diyl group, 1,2,3,4,4a, 9,10a-octahydrophenanthrene 2,7-diyl group or fluorene 2,7 Represents a -diyl group, 1,4-phenylene group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, 2,6-naphthylene group, phenanthrene-2,7-diyl group, 9,10 -Dihydrophenanthrene-2,7-diyl , 1,2,3,4,4a, 9,10a- octahydrophenanthrene 2,7-diyl group and 2,7-diyl group is 1 or more F as substituents, _Cl, CF _3, OCF 3 A cyano group, an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an alkanoyl group, an alkanoyloxy group, an alkenyl group having 2 to 8 carbon atoms, an alkenyloxy group, an alkenoyl group or an alkenoyloxy group. Z _p1 and Z _p2 are each independently —COO—, —OCO—, —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O—, —CH═CH—, —C≡C—. _{, -CH = CHCOO -, - OCOCH} = CH -, - CH 2 CH 2 COO -, - CH 2 CH 2 OCO -, - COOCH 2 CH 2 -, - OCOCH 2 CH 2 -, - CONH -, - NHCO- Or a single bond, ₃ represents 0, 1 or 2.)
Here, when Sp ₁ and Sp ₂ are each independently an alkylene group, the alkylene group may be substituted by one or more halogen atoms or CN, and one or two present in the group The above CH ₂ groups are —O—, —S—, —NH—, —N (CH ₃ ) —, —CO—, —COO—, —OCO—, —OCOO—, so that O atoms are not directly adjacent to each other. -SCO-, -COS-, or -C≡C- may be substituted. P ₁ and P ₂ are each independently the following general formula

It is preferable that it is either.
(In the formula, R _p2 to R _p6 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms.)
More specifically, the polymerizable compound general formula (PC) is changed from the general formula (PC0-1) to the general formula (PC0-6).

(Wherein, p ₄ are each independently represents 1, 2 or 3.) Is preferably a polymerizable compound represented by. More specifically, from general formula (PC1-1) to general formula (PC1-9)

(Wherein p ₅ represents 0, 1, 2, 3 or 4). Among them, Sp ₁ , Sp ₂ , Q _p1 and Q _p2 are preferably a single bond, P ₁ and P ₂ are preferably the formula (PC0-a), and are an acryloyloxy group and a methacryloyloxy group. More preferably, p ₁ + p ₄ is preferably 2, 3 or 4, and R _p1 is preferably H, F, CF ₃ , OCF ₃ , CH ₃ or OCH ₃ . Furthermore, compounds represented by general formula (PC1-2), general formula (PC1-3), general formula (PC1-4) and general formula (PC1-8) are preferred.

Moreover, it is also preferable that MG _p in the general formula (PC) is a discotic liquid crystal compound represented by the general formula (PC1) -9.

(In the formula, each R ₇ independently represents P ₁ -Sp ₁ -Q _{p 1} or a substituent of the general formula (PC1-e), and R ₈₁ and R ₈₂ each independently represents a hydrogen atom, a halogen atom or methyl) R ₈₃ represents an alkoxy group having 1 to 20 carbon atoms, and at least one hydrogen atom in the alkoxy group is a substituent represented by the general formulas (PC0-a) to (PC0-d). Has been replaced.)
The amount of the polymerizable compound used is preferably 0.05 to 2.0% by mass.

  The liquid crystal composition of the present invention may further contain one or more antioxidants, and may further contain one or more UV absorbers. The antioxidant is preferably selected from the following general formula (E-1) and / or general formula (E-2).

(In the formula, R _e1 represents an alkyl group having 1 to 15 carbon atoms, and one or two or more —CH ₂ — in the alkyl group is —O—, — CH = CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O— or —OCF ₂ — may be substituted, and one or more in the alkyl group The hydrogen atom of may be optionally substituted with halogen,
Z _e1 and Z _e2 are each independently a single bond, —CH═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —COO—, —OCO—, —OCH. _2- , —CH ₂ O—, —OCF ₂ —, or —CF ₂ O—, and E ₁ represents a cyclohexane ring or a benzene ring, and one or more —CH ₂ — in the cyclohexane ring represents an oxygen atom. May be substituted with —O— so that they are not directly adjacent to each other, and one or more —CH ₂ CH ₂ — in the ring note may be —CH═CH—, —CF ₂ O— or —OCF. ₂ - as can be substituted, one or more -CH = nitrogen atom in the benzene ring are not directly adjacent with may be substituted with -N =, 1 in the ring One or more hydrogen atoms are F, Cl, may be substituted by _{CH 3, q 1} is 0, 1 It represents 2 or 3. )
The liquid crystal composition of the present invention can be used as a liquid crystal display device, particularly a liquid crystal display device for active matrix driving, for example, TN mode, OCB mode, ECB mode, IPS (including FFS electrode) mode or VA-IPS mode (including FFS electrode). Can be used. Here, the VA-IPS mode refers to a pixel electrode in which a liquid crystal material (Δε> 0) having a positive dielectric anisotropy is aligned perpendicularly to a substrate surface when no voltage is applied, and is arranged on the same substrate surface. This is a method of driving liquid crystal molecules by a common electrode. Since liquid crystal molecules are aligned in the direction of the curved electric field generated by the pixel electrode and the common electrode, pixel division and multi-domain can be easily formed, and response is also possible. There are excellent advantages. Non-Patent Document Proc. 13th IDW, 97 (1997), Proc. 13th IDW, 175 (1997), SID Sym. Digest, 319 (1998), SID Sym. Digest, 838 (1998), SID Sym. Digest, 1085 (1998), SID Sym. Digest, 334 (2000), Eurodisplay Proc. 142 (2009), various names such as EOC and VA-IPS are used, but in the present invention, they are hereinafter abbreviated as “VA-IPS”.

  In general, the threshold voltage (Vc) of the Fredericks transition in the TN and ECB systems is represented by the formula (I)

In the STN system, the formula (II)

The VA system is represented by the formula (III).

(Where Vc is the Frederick transition (V), Π is the circumference, d _cell is the distance between the first substrate and the second substrate (μm), d _gap is the distance between the pixel electrode and the common electrode (μm), d _ITO is the pixel electrode and / or common electrode width (μm), <r1>, <r2>, and <r3> are extrapolated lengths (μm), K11 is the spray elastic constant (N), and K22 is the twist elasticity. Constant (N), K33 represents the elastic constant (N) of the bend, and Δε represents the anisotropy of the dielectric constant.
On the other hand, in the VA-IPS system, the present inventors have found that the formula (IV) is applied.

(Where Vc is the Frederick transition (V), Π is the circumference, d _cell is the distance between the first substrate and the second substrate (μm), d _gap is the distance between the pixel electrode and the common electrode (μm), d _ITO is the width of the pixel electrode and / or common electrode (μm), <r>, <r ′>, <r3> are extrapolation lengths (μm), K33 is the bend elastic constant (N), Δε is the dielectric constant (Expression of anisotropy) From the formula (IV), the cell configuration is as small as possible for d _gap and as large as possible for d _ITO, and the absolute value of Δε of the liquid crystal composition to be used is increased. , K33 can be selected to reduce the drive voltage.

  The liquid crystal composition of the present invention can be adjusted to preferable Δε, K11, and K33.

The product (Δn · d) of the refractive index anisotropy (Δn) of the liquid crystal composition and the distance (d) between the first substrate and the second substrate of the display device is strongly related to viewing angle characteristics and response speed. . Therefore, the distance (d) tends to be as thin as 3 to 4 μm. The product (Δn · d) is preferably 0.31 to 0.33 in the TN mode, ECB mode, and IPS mode. In the VA-IPS mode, 0.20 to 0.59 is preferable in the case of vertical alignment with respect to both substrates, and 0.30 to 0.40 is particularly preferable. The tilt angle in the TN mode and ECB mode where the liquid crystal alignment when no voltage is applied needs to be substantially horizontal is preferably 0.5 to 7 °, and the liquid crystal alignment when no voltage is applied needs to be approximately perpendicular to the substrate surface. In the VA-IP mode, the tilt angle is preferably 85 to 90 °. In order to align the liquid crystal composition in this way, an alignment film made of polyimide (PI), polyamide, chalcone, cinnamate, cinnamoyl, or the like can be provided. Further, it is preferable to use an alignment film prepared by using a photo-alignment technique. The liquid crystal composition of the present invention containing the compound in which X ¹⁰³ in the general formula (LC0) is F can be easily aligned on the easy axis of the alignment film and can easily control a desired tilt angle.

  Furthermore, the liquid crystal composition of the present invention containing the compound represented by the general formula (PC) as the polymerizable compound is obtained by polymerizing the polymerizable compound contained in the liquid crystal composition with voltage applied or without voltage applied. The produced polymer stabilized liquid crystal display element for TN mode, OCB mode, ECB mode, IPS mode or VA-IPS mode can be provided.

  Hereinafter, although an example is given and this invention is further explained in full detail, this invention is not limited by these. Further, “%” in the compositions of the following examples and comparative examples means “mass%”.

The physical properties of the liquid crystal composition are expressed as follows.
T _NI : Nematic phase-isotropic liquid phase transition temperature (° C)
ε⊥: dielectric constant in the direction perpendicular to the molecular long axis direction at 25 ° C. Δε: dielectric anisotropy at 25 ° C. no: refractive index for ordinary light at 25 ° C. Δn: refractive index anisotropic at 25 ° C. sex
Vth: Applied voltage (V) in a cell having a cell thickness of 6 μm in which the transmittance changes by 10% when a rectangular wave with a frequency of 1 KHz is applied at 25 ° C.
η ₂₀ : Bulk viscosity at 20 ° C. (mPa · s)
γ ₁ : rotational viscosity (mPa · s)
The following abbreviations are used in compound descriptions.

(Example 1 and Comparative Example 1)
The content ratio and physical property values of the compound of the prepared liquid crystal composition of the present invention (Example 1) and the liquid crystal composition prepared for comparison (Comparative Example 1) are shown below.

The liquid crystal composition of Comparative Example 1 does not contain the compound represented by the general formula (LC0), but is substituted with a compound other than the compound represented by the general formula (LC0). The dielectric anisotropy (Δε) is made substantially the same, and _TN-I and Δn are made almost the same, but the liquid crystal composition of Example 1 has a lower viscosity. It can be seen that the combination of the present invention is very excellent.
(Example 2 to Example 4)
The liquid crystal compositions (Examples 2 to 4) prepared so as to have substantially the same Δε as in Example 1 and their physical properties are shown below.

Similar to the liquid crystal composition of Example 1, the viscosity was low.
(Example 5 and Comparative Example 2)
The content ratio and physical property values of the compound of the prepared liquid crystal composition of the present invention (Example 5) and the liquid crystal composition prepared for comparison (Comparative Example 2) are shown below.

The liquid crystal composition of Comparative Example 2 does not include the compound represented by the general formula (LC0), but is substituted with a compound other than the compound represented by the general formula (LC0). The dielectric anisotropy (Δε) is made substantially the same, and _TN-I and Δn are made almost the same, but the liquid crystal composition of Example 5 has a lower viscosity. It can be seen that the combination of the present invention is very excellent.
(Example 6 to Example 8)
The liquid crystal compositions (Examples 6 to 8) prepared so as to have substantially the same Δε as Example 5 and their physical properties are shown below.

Similar to the liquid crystal composition of Example 5, the viscosity was low.
(Example 9 and Comparative Example 3)
The content ratios and physical properties of the compounds of the prepared liquid crystal composition of the present invention (Example 9) and the liquid crystal composition prepared for comparison (Comparative Example 3) are shown below.

The liquid crystal composition of Comparative Example 3 does not include the compound represented by the general formula (LC0), but is substituted with a compound other than the compound represented by the general formula (LC0). The dielectric anisotropy (Δε) is made substantially the same, and _TN-I and Δn are made almost the same, but the liquid crystal composition of Example 9 has a lower viscosity. It can be seen that the combination of the present invention is very excellent.
(Example 10 to Example 12)
The liquid crystal compositions (Examples 10 to 12) prepared so as to have substantially the same Δε as Example 9 and their physical properties are shown below.

Similar to the liquid crystal composition of Example 9, the viscosity was low.
(Example 13 and Comparative Example 4)
The content ratios and physical properties of the compounds of the prepared liquid crystal composition of the present invention (Example 13) and the liquid crystal composition prepared for comparison (Comparative Example 4) are shown below.

The liquid crystal composition of Comparative Example 4 does not include the compound represented by the general formula (LC0), but is substituted with a compound other than the compound represented by the general formula (LC0). The dielectric anisotropy (Δε) is made substantially the same, and _TN-I and Δn are made almost the same. However, the liquid crystal composition of Example 13 has a lower viscosity. It can be seen that the combination of the present invention is very excellent.
(Example 14 to Example 16)
The liquid crystal compositions (Examples 14 to 16) prepared so as to have substantially the same Δε as Example 13 and their physical properties are shown below.

Similar to the liquid crystal composition of Example 13, the viscosity was low.
(Example 17)
Using a first substrate in which a pair of transparent electrodes having a comb-shaped electrode structure is provided on the same substrate and a second substrate not having an electrode structure, a vertical alignment film is formed on each substrate, and the first substrate and An IPS empty cell having a gap interval of 4.0 microns was fabricated on the second substrate. The liquid crystal composition shown in Example 1 was injected into this empty cell to produce a liquid crystal display element. When the electro-optical characteristics of the display element were measured, the applied voltage at which the transmittance changed by 10% was 2.88v. The response speed when 7v was applied was 6.9 milliseconds, and the response speed when the voltage was turned off was 14.4 milliseconds.

  The polymerizable compound represented by the formula (PC-1) -3-1 with respect to 99% of the liquid crystal composition shown in Example 1

1% was added and uniformly dissolved to prepare a polymerizable liquid crystal composition CLC-A. The physical properties of CLC-A were almost the same as those of the liquid crystal composition shown in Example 1.

After CLC-A is sandwiched between the above IPS empty cells, UV light is irradiated to the liquid crystal cell by a high-pressure mercury lamp through a filter that cuts UV light of 300 nm or less while applying a rectangular wave of 1.8 V at a frequency of 1 KHz. did. The cell surface was adjusted to have an irradiation intensity of 20 mW / cm ² and irradiated for 600 seconds to obtain a vertically aligned liquid crystal display element in which the polymerizable compound in the polymerizable liquid crystal composition was polymerized. When the electro-optical characteristics of this display element were measured, the applied voltage at which the transmittance changed by 10% was 2.98 v. The response speed when 7v was applied was 4.8 milliseconds. Further, the response speed when the voltage was turned off was 5.0 milliseconds, which was very fast as compared with the liquid crystal display element produced only with the liquid crystal composition shown in Example 1.

Claims (16)

A liquid crystal composition having positive dielectric anisotropy, wherein the liquid crystal composition contains one or more compounds selected from compounds represented by the general formula (LC0);

(In the formula, R ⁰¹ represents an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group are —O—, —CH, so that oxygen atoms are not directly adjacent to each other. ═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF ₂ O—, —OCF ₂ —, which may be substituted with one or more of the alkyl groups The hydrogen atom may be optionally halogen substituted and A ⁰¹ is

(In the structure, X ^{104 to} X ¹⁰⁵ each independently represents —H, —Cl, —F, —CF ₃ or —OCF ₃ ), and A ⁰² represents the following structure:

(In the structure, X ^{109 to} X ¹¹⁰ each independently represent —H, —Cl, —F, —CF ₃ or —OCF ₃ ), X ^{101 to} X ¹⁰³ represent —F, Y ⁰¹ represents —Cl, —F, —CF ₃ or —OCF ₃ , Z ⁰² represents —OCH ₂ —, Z ⁰¹ and Z ⁰³ each independently represents a single bond, m ⁰¹ represents 0, m ⁰² represents an integer of 1 or 2, and when a plurality of A ⁰¹ and / or Z ⁰³ are present, they may be the same or different. ), And further the general formula (LC5)

(In the formula, R ⁵¹ and R ⁵² each independently represents an alkyl group having 1 to 15 carbon atoms, and one or two or more —CH ₂ — in the alkyl group is not directly adjacent to an oxygen atom. May be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C—, and —OCF when A ⁵¹ or A ⁵³ described later is a cyclohexane ring. ₃ , —CF ₃ , —OCF═CF _2, or —OCH═CF ₂ , and A ^{51 to} A ⁵³ are each independently any one of the following structures:

(Wherein one or more —CH ₂ CH ₂ — in the cyclohexane ring may be substituted with —CH═CH—, —CH ₂ O— or —OCH ₂ —, One or two or more —CH═ may be substituted with —N═ so that the nitrogen atoms are not directly adjacent to each other ), Z ⁵¹ and Z ⁵² are each independently a single bond, —CH ═CH—, —C≡C—, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O—, —COO—, —OCO—, —OCF ₂ — or — CF ₂ O-to ^{represent, m 51} represents any of integers from 0 to ^{3, when a 52} and / or ^{Z 52} is plurally present, they may be the same or different. The compound represented by general formula (LC5-3), general formula (LC5-6) to general formula (LC5-) includes one or more compounds represented by general formula (LC5). 8)

A liquid crystal composition comprising one or more compounds selected from the group of compounds represented. As a compound represented by general formula (LC5), general formula (LC5-1)

2. The liquid crystal composition according to claim 1, comprising one or more compounds in which any of R ⁵¹ and R ^{52 in} the formula is an alkenyl group having 2 to 5 carbon atoms. General formula (LC1) to general formula (LC4)

(In the formula, R ^{11 to} R ⁴¹ each independently represent an alkyl group having 1 to 15 carbon atoms, and one or two or more —CH ₂ — in the alkyl group is not directly adjacent to an oxygen atom. May be substituted with -O-, -CH = CH-, -CO-, -OCO-, -COO-, -C≡C-, -CF ₂ O- or -OCF _2- , 1 or 2 or more hydrogen atoms may be optionally substituted with halogen, and A ^{11 to} A ⁴² are each independently any one of the following structures:

(In the structure, one or more —CH ₂ — of the cyclohexane ring may be substituted with —O— so that the oxygen atom is not directly adjacent to each other, and X ⁶¹ and X ⁶² are each independently — represents H, -Cl, -F, a representative.) the -CF ₃ or -OCF ^_3, X 11 ^{to X 43} each independently represent -H, -Cl, -F, a -CF ₃ or -OCF ₃ , ^Y 11 ^{to Y 41} represents _{-Cl, -F, -CF 3, -OCF} 3, -CF 2 CF 3, -CHFCF 3, -OCF 2 CF 3, a -OCHFCF _3, or -OCF = CF _2, Z ³¹ to Z ⁴² each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - OCH 2 -, - CH 2 O-, -OCF ₂ - or _-CF 2 O-a represents, ^{Z 31} and ^{Z 3} are present At least one of is not a single ^bond, m 21 ^{~m 42} each independently represents an integer of 0~3, ^m 31 ^{+ m 32} and m ⁴¹ + ^{m 42} each independently is 1, 2, 3 or 4 In the case where a plurality of A ²³ , A ³¹ , A ³² , A ⁴¹ , A ⁴² , Z ⁴¹ and / or Z ⁴² are present, they may be the same or different. However, any one of A ³¹ and A ³² present is

(In the structure, one or more —CH ₂ — of the cyclohexane ring may be substituted with —O— so that the oxygen atom is not directly adjacent.)
It is. The liquid crystal composition according to claim 1, comprising one or more compounds selected from the group of compounds represented by: Claim containing formula (LC2) general formula as the compound represented by (LC2-1) from general formula (LC2-14) 1 kind selected from the group consisting of compounds represented by two or more compounds 4. The liquid crystal composition according to 3 .

(Wherein X ²³ , X ²⁴ , X ²⁵ and X ²⁶ each independently represent a hydrogen atom, Cl, F, CF ₃ or OCF ₃ , and X ²² , R ²¹ and Y ²¹ have the same meaning as in claim 1. Represents.) Claim containing formula (LC3) general formula as the compound represented by (LC3-1) from general formula (LC3-58) 1 kind selected from the group consisting of compounds represented by two or more compounds 4. The liquid crystal composition according to 3 .

(Wherein X ^{33 to} X ³⁸ each independently represent H, Cl, F, CF ₃ or OCF ₃ , and R ³¹ , X ³²¹ and Y ³¹ represent the same meaning as in claim 1). Claim containing formula (LC4) general formula as the compound represented by (LC4-1) from general formula (LC4-14) 1 kind selected from the group consisting of compounds represented by two or more compounds 4. The liquid crystal composition according to 3 .

(Wherein X ^{44 to} X ⁴⁷ each independently represent H, Cl, F, CF ₃ or OCF ₃ , and X ⁴² , X ⁴³ , R ⁴¹ and Y ⁴¹ represent the same meaning as in claim 1). As a compound represented by general formula (LC5), general formula (LC5-2), general formula (LC5-4), general formula (LC5-5), general formula (LC5-9) to general formula (LC5-26) The liquid crystal composition according to any one of claims 1 to 6, comprising one or more compounds selected from the group consisting of compounds represented by:

(Wherein R ⁵¹ and R ⁵² represent the same meaning as in claim 1). At least one of A ¹¹ , A ^{21 to} A ²³ , A ^{31 to} A ³² , A ^{41 to} A ⁴² , A ^{51 to} A ⁵³ present in the general formula (LC1) to general formula (LC5) is tetrahydropyran-2, The liquid crystal composition according to any one of claims 3 to 7, comprising one or more compounds each having a 5-diyl group. The liquid crystal composition according to any one of claims 1 to 8, which contains 30 to 70% by mass of a compound represented by the general formula (LC5) and has a viscosity η at 20 ° C of 20 mPa · s or less. The liquid crystal composition according to any one of claims 1 to 9, comprising one or more optically active compounds. The liquid crystal composition according to any one of claims 1 to 10, comprising one or more polymerizable compounds. The liquid crystal composition according to any one of claims 1 to 11, comprising one or more antioxidants. The liquid crystal composition according to any one of claims 1 to 12, comprising one or more UV absorbers. The liquid crystal display element using the liquid-crystal composition as described in any one of Claims 1-13. A liquid crystal display element for driving an active matrix using the liquid crystal composition according to claim 1. A liquid crystal display element for a TN mode, an OCB mode, an ECB mode, an IPS mode, or a VA-IPS mode using the liquid crystal composition according to any one of claims 1 to 13.