The present invention relates to liquid-crystalline media (LC media) having negative or positive dielectric anisotropy, comprising a low-molecular-weight component and a polymerizable component. The polymerizable component comprises self-aligning, polymerizable mesogens (polymerizable self-alignment additives) which effect homeotropic (vertical) alignment of the LC media at a surface or the cell walls of a liquid-crystal display (LC display). The invention therefore also encompasses LC displays having homeotropic alignment of the LC medium without alignment layers. The invention discloses novel structures for polymerizable self-alignment additives which have a certain position of the functional groups.

A composition includes an aqueous mixture of birefringent small molecules and a birefringent polymer. The birefringent small molecules are of a structure:

##STR00001##

or a salt thereof.

The birefringent polymer is of a structure:

##STR00002##

or salt thereof,
where n is an integer in a range from 25 to 10,000.

The present invention relates to liquid-crystalline media (LC media) having negative or positive dielectric anisotropy, comprising a low-molecular-weight component and a polymerisable component. The polymerisable component comprises self-aligning, polymerisable mesogens (polymerisable self-alignment additives) which effect homeotropic (vertical) alignment of the LC media at a surface or the cell walls of a liquid-crystal display (LC display). The invention therefore also encompasses LC displays having homeotropic alignment of the LC medium without alignment layers. The invention discloses novel structures for polymerisable self-alignment additives which have a certain position of the functional groups.

The present invention relates to a process of preparing a light modulation element of the PS-ULH (polymer stabilised ULH) type, which allows to reduce the operational voltage and allows to improve the switching time of the light modulation element.

Material comprising a ferroelectric nematic phase, the material are disclosed. The material can include a mixture comprising first molecules and second molecules. At least one of a fluid of the first molecules and a fluid of the second molecules exhibits a ferroelectric nematic phase. The first molecules and second molecules are miscible. The first molecules can induce a polar orientational order of said second molecules.

The invention relates to a liquid-crystalline medium, preferably having a nematic phase and dielectric anisotropy of 0.5 or more, which comprises one or more compounds of formula Y

##STR00001##

in which the parameters have the meanings given in the text,
to the use thereof in an electro-optical display, particularly in an active-matrix display based on the IPS or FFS effect, to displays of this type which contain a liquid-crystalline medium of this type, and to the use of the compounds of formula Y for the improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds.

Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy and large dielectric anisotropy, or the liquid crystal composition having a suitable balance regarding at least two of the characteristics; and an AM device including the composition. The liquid crystal composition contains a specific compound having small optical anisotropy as a first component, and a specific compound having positive dielectric anisotropy 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 positive dielectric anisotropy as a fourth component, or a specific compound having negative dielectric anisotropy as a fifth component.

Provided are a liquid crystal compound having larger dielectric anisotropy and superb heating reliability in comparison with a similar compound, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. A compound is represented by formula (1).

##STR00001##

In formula (1), for example, R.sup.1 is alkyl having 1 to 15 carbons, ring A.sup.1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by halogen or tetrahydropyran-2,5-diyl; Z.sup.1 is a single bond or CF.sub.2O; L.sup.1 and L.sup.2 are hydrogen or halogen; Y.sup.1 and Y.sup.2 are hydrogen or halogen; and a is an integer from 1 to 4.

The present invention relates to a switch element, which is thermoresponsive and which switches between a less transmissive state for radiant energy and a more transmissive state for radiant energy, and which comprises a liquid-crystalline medium. The invention furthermore relates to the use of the switch element for the regulation of radiant energy flow between interior spaces and the environment and for the regulation of the temperature of interior spaces. The invention furthermore relates to a liquid-crystalline medium, characterised in that it comprises 5-95% of a compound of the formula (I), in particular for use in the switch elements according to the invention.

Liquid-crystalline (LC) media having positive dielectric anisotropy and liquid-crystal displays (LCDs) containing these media, especially displays addressed by an active matrix and in particular LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA type.