The instant invention relates to liquid crystalline media comprising a chiral component, component A, consisting of one or more chiral compounds, optionally, a bimesogenic component, component B, consisting of one or more bimesogenic compounds, a liquid crystalline component, component C, consisting of one or more liquid crystalline, respectively mesogenic compounds, and a reactive mesogenic component, component D, comprising, one or more reactive mesogenic compounds,
as defined in claim 1, to their stabilization by polymerization and to the polymer-stabilised liquid crystal materials, as well as to liquid crystal displays comprising these liquid crystal media, respectively these stabilized materials, especially to USH-displays and in particular to active matrix displays and, last not least, to the processes of preparation of the respective composite systems and of the displays comprising these systems.

Shown is a liquid crystal composition satisfying at least one of characteristics such as a high maximum temperature, a low minimum temperature, a large elastic constant, a suitable optical anisotropy and a large negative dielectric anisotropy, or has a suitable balance regarding at least two of the characteristics, and an AM device including the composition. The liquid crystal composition may contain a specific compound having a high maximum temperature, a low minimum temperature, a large elastic constant and a large negative dielectric anisotropy as a first component, a specific compound having a high maximum temperature or a small viscosity as a second component, a specific compound having negative dielectric anisotropy as a third component, or a specific compound having a polymerizable group as an additive component.

The present invention discloses a liquid crystal composition, comprising: at least a first compound selected from the group consisting of a compound of general Formula I-1, a compound of general Formula I-2, and a combination thereof, and at least a second compound selected from the group consisting of a compound of general Formula II-1, a compound of general Formula II-2, a compound of general Formula II3, a compound of general Formula II-4 and a combination thereof The liquid crystal composition provided in the present invention has the properties of appropriate optical and dielectric anisotropies, high clearing point, existence of a nematic phase over a wide range of temperature, low viscosity and good high-temperature stability. The liquid crystal composition is applicable to a liquid crystal display (LCD) device, to enable the LCD device to have such properties as short response time, excellent display effect at high temperature, and others.

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To provide a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and heat, or having a suitable balance regarding at least two of the characteristics; and an AM device having characteristics such as short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio and long service life. The composition has negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, a specific compound having small viscosity as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having negative dielectric anisotropy as a fourth component, or a specific compound having a polymerizable group as an additive component.

Disclosed are a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula IV. By compounding the four compounds, the composition can have advantages of a wide temperature range of nematic phase, a low viscosity and a low threshold voltage, and the liquid crystal display element can have a short response time and great power saving performance.

A liquid-crystalline media having a negative dielectric anisotropy and a high clearing point as specified herein, is suitable for use of in switchable optical cells in window elements, in particular laminated window elements.

Compounds of the formula I, liquid-crystalline media which contain at least one compound of the formula I and electro-optical displays which contain the LC mixtures, especially for the self-aligning VA, PSA, PS-VA, PVA, MVA, PM-VA, HT-VA or VA-IPS mode ##STR00001##
in which R.sub.1, R.sub.2, ring A.sub.1, Z.sub.1, Z.sub.2, Sp, P, L.sub.1, L.sub.2, r1, r2, r3, m, n, p1 and p2 have the meanings indicated above.

A liquid-crystal (LC) media having a negative dielectric anisotropy containing a compound of formula I ##STR00001##
and the use of the LC media for optical, electro-optical and electronic purposes, in particular in energy-efficient LC displays, especially in IPS, FFS, VA or PS-VA displays.

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH,

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in which Z.sup.1 denotes a single bond, —CH.sub.2CH.sub.2—, —CH═CH—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, —OCF.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —(CH.sub.2).sub.4—, —CHFCHF—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —C≡C—, —CF═CF—, —CH═CHCHO— or —CH.sub.2CF.sub.2O—,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

A liquid-crystal (LC) media having a negative dielectric anisotropy containing a compound of formula I

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and the use of the LC media for optical, electro-optical and electronic purposes, in particular in energy-efficient LC displays, especially in IPS, FFS, VA or PS-VA displays.