摘要:
Novel liquid crystal materials which are trans-4-alkylcyclohexane-1-carboxylic acid esters are provided having the general formula: ##STR1## where R is a normal or branched chain alkyl group, which may also contain a chiral center, containing up to ten carbon atoms and X is selected from the groups: ##STR2## where A is a cyano group, a normal or branched chain alkyl group, which may also contain a chiral center, containing up to ten carbon atoms or an alkoxy group in which the alkyl group is as defined immediately above, and where Y is a halogen, preferably chlorine, or hydrogen.
摘要:
There is disclosed a liquid crystal polyacrylate mono- or co-polymers having a repeat unit (I), wherein R.sub.1 and R.sub.2 are independently alkyl or hydrogen, R.sub.3 is alkyl, hydrogen or chlorine, m is 0 or an integer 1-20, W is a linkage group COO, OOC or O and X is a mesogenic group. ##STR1##
摘要:
Novel liquid crystal materials are provided having the general formula ##STR1## where A is a 4-alkylphenyl group and B is a 2-(6-alkyl)naphthyl group, or vice versa, wherein the alkyl groups in A and B may be the same or different. These materials have a dielectric anisotropy sign change at moderate frequencies, i.e., in the range 1kHz to 50kHz and are thus useful for twisted nematic device cells of the frequency switching type.
摘要:
The invention relates to an anisotropic polymer film or polymer net-work obtainable by photopolymerization of at least one mesogene-containing compound, having two side chains attached to a mesogenic core structure one of which is polymerizable, the other of which is capable of forming association dimers by hydrogen bonds.
摘要:
A family of new compounds suitable for adding to cyanobiphenyls and other liquid crystal compounds to give mixtures having extended liquid crystal temperature ranges is characterised by the formula ##STR1## or, a simple substituted derivative thereof, where A is (CH.sub.2).sub.n, (CH.sub.2).sub.n O O(CH.sub.2).sub.n, n being an integer in the range 1-4, either X is hydrogen or an alkyl, alkoxy or alkanoyloxy group and Y is a cyano group or Y is hydrogen or an alkyl, alkoxy or alkanoyloxy group and X is a cyano group.The mixtures so produced may be used in known kinds of liquid crystal electro-optic devices.
摘要:
A cholesteric liquid crystal display device (10) comprises a layer of cholesteric liquid crystal material (11) supported by at least one substrate (13; electrode layers (14,15) on opposite sides of the layer of cholesteric liquid crystal material (11); and a light absorptive or reflective layer (17) on the rear side of the layer of cholesteric liquid crystal material (11). To provide non-uniform reflection of light, there is a layer (18) of reflective flakes (19) on the front side of the light absorptive or reflective layer (17), or the reflective layer is shaped to be non-planar.
摘要:
In a cholesteric liquid crystal display device (24), to drive a surface-stabilized layer of cholesteric liquid crystal material into the focal conic state, there is applied drive signal comprising a series of pulses (30, 34, 35, 36, 37, 38, 41). At least one initial pulse has sufficient energy to drive the layer of cholesteric liquid crystal material into the homeotropic state and the subsequent pulses have time-averaged energies which reduce to a minimum level at which the layer of cholesteric liquid crystal material is driven into the focal conic state. This produces a focal conic state of particularly low reflectance, which allows a high contrast ratio to be achieved.
摘要:
Novel phenylcyclohexanes of the formula I in which n is 0 to 7, Q1 and Q2 are H, or one of these radicals is alternatively CH3, r is 0, 1, 2, 3, 4 or 5, A is trans-1,4-cyclohexylene, 1,4-phenylene, 3-fluoro-1,4-phenylene or a single bond, X is F, Cl, —CF3, —CN, —OCF3 or —OCHF2, and Y and Z are each, independently of one another, H or F, with the proviso that, in the case where A is a single bond, Q1=Q2=H and simultaneously X=CN, Y and/or Z are F.
摘要:
The invention relates to multireactive polymerizable mesogenic compounds of formula I R1—MG—R2 I wherein R1, R2 and MG have the meaning given in claim 1, to a polymerizable mesogenic composition comprising at least two components, at least one which is a compound of formula I, to a linear or crosslinked polymer obtainable by polymerization of one or more compounds of formula I or of a polymerizable composition comprising one or more compounds of formula I and to the use of a compound of formula I, or a polymerizable composition or polymer obtainable thereof, in optical elements such as polarizers, optical retardation or compensation films, alignment layers, colour filters or holographic elements, in liquid crystal displays such as PDLC, polymer gel or polymer stabilized cholesteric texture (PSCT) displays, in adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics or liquid crystal pigments, for decorative and security applications, and for nonlinear optics or optical information storage.
摘要:
The invention relates to an alignment layer comprising a polymerized liquid crystal material with homeotrophic orientation, to methods of its preparation, to polymerizable liquid crystal compositions and liquid crystal polymers used for the preparation of the alignment layer, to liquid crystal devices comprising the alignment layer, and to a method of controlling the electrooptical steepness of a liquid crystal display comprising at least one alignment layer by varying the surface anchoring energy of the alignment layer.