A positive dielectric anisotropic liquid crystal composition includes one or more compounds of formula I and one or more compounds of formula II: ##STR00001##
wherein R1 represents cyclopropyl, cyclobutyl or cyclopentyl, R2, R3 and R4 are as defined in the specification, and a liquid crystal display device. The liquid crystal composition has positive dielectric properties, a high charge retention ratio, a low rotary viscosity, a fast response time, and especially a high transmittance, and is suitable for manufacturing a TFT-LCD with a high transmittance and a fast response.

The disclosure belongs to the technical field of liquid crystal materials, and specifically relates to a polymerizable compound, a preparation method therefor, and the use thereof. The polymerizable compound has a structure as shown in general formula I. Compared with the existing polymerizable RM, the polymerizable compound has the advantages of a good solubility, a faster polymerization rate, a more complete extent of polymerization, and less residues, thereby improving the problem of poor display to a great extent.

##STR00001##

The disclosure belongs to the technical field of liquid crystal materials, and specifically relates to a polymerizable compound, a preparation method therefor, and the use thereof. The polymerizable compound has a structure as shown in general formula I. Compared with the existing polymerizable RM, the polymerizable compound has the advantages of a good solubility, a faster polymerization rate, a more complete extent of polymerization, and less residues, thereby improving the problem of poor display to a great extent.

##STR00001##

The Kerr effect depends very strongly on the temperature and is associated with high operating voltages. The present invention relates to an electrically controllable optical element which comprises a cell (D) filled with a starting mixture (K) and having two substrates (1a, 1b) and a conductive layer (2a, 2b) applied onto the inner surface of the respective substrate (1a, 1b), wherein the starting mixture (K) comprises a mixture of dipolar, rod-shaped molecules (5) and semi-mesogenes (4) as active constituents, and wherein the starting mixture (K) forms a thin layer having a wide-meshed, anisotropic network (9) produced by photo-polymerization between the structured or/and flat conductive layers (2a, 2b), which are applied onto a substrate (1a, 1b), in a thin-film cell (D). According to the invention, an optically active surface profile (O) is incorporated on the inner surface of a substrate (1a or 1b) or into the substrate (1a or 1b) or both substrates (1a and 1b).

The Kerr effect depends very strongly on the temperature and is associated with high operating voltages. The present invention relates to an electrically controllable optical element which comprises a cell (D) filled with a starting mixture (K) and having two substrates (1a, 1b) and a conductive layer (2a, 2b) applied onto the inner surface of the respective substrate (1a, 1b), wherein the starting mixture (K) comprises a mixture of dipolar, rod-shaped molecules (5) and semi-mesogenes (4) as active constituents, and wherein the starting mixture (K) forms a thin layer having a wide-meshed, anisotropic network (9) produced by photo-polymerization between the structured or/and flat conductive layers (2a, 2b), which are applied onto a substrate (1a, 1b), in a thin-film cell (D). According to the invention, an optically active surface profile (O) is incorporated on the inner surface of a substrate (1a or 1b) or into the substrate (1a or 1b) or both substrates (1a and 1b).

A liquid crystal mixture applied in light modulating devices includes at least one compound selected from the group of compounds of formula I, at least one compound selected from the group of compounds of formula II and/or formula III, and at least one chiral compound. A light modulating device includes the liquid crystal mixture, where the light modulating device has reduced haze in the transparent state while increased opacity in the light scattering state.
R.sub.1-MG.sub.1-X-MG.sub.2-R.sub.2  I ##STR00001##

A liquid crystal mixture applied in light modulating devices includes at least one compound selected from the group of compounds of formula I, at least one compound selected from the group of compounds of formula II and/or formula III, and at least one chiral compound. A light modulating device includes the liquid crystal mixture, where the light modulating device has reduced haze in the transparent state while increased opacity in the light scattering state.
R.sub.1-MG.sub.1-X-MG.sub.2-R.sub.2  I ##STR00001##

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

Provided is a polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when used in a liquid crystal display device. The compound is represented by formula (1):

##STR00001##

in which, for example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 and M.sup.2 are hydrogen; and R.sup.2 is a group represented by formulas (1a) to (1c):

##STR00002##

in which, Sp.sup.2 and Sp.sup.a are a single bond or alkylene having 1 to 10 carbons; S.sup.1 is >CH—; S.sup.2 is >C<; and X.sup.1 is —OH.

Provided is a polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when used in a liquid crystal display device. The compound is represented by formula (1):

##STR00001##

in which, for example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 and M.sup.2 are hydrogen; and R.sup.2 is a group represented by formulas (1a) to (1c):

##STR00002##

in which, Sp.sup.2 and Sp.sup.a are a single bond or alkylene having 1 to 10 carbons; S.sup.1 is >CH—; S.sup.2 is >C<; and X.sup.1 is —OH.