摘要:
Liquid crystal display elements based on a twisted nematic cell are almost free from interference colors and show only a very little angular dependence of the contrast, if the product of the layer thickness and the optical anisotropy of the liquid crystalline dielectric has a value of 150 to 600 nanometers.
摘要:
Diketones of the formula ##STR1## wherein R.sub.1 is alkyl, perfluoroalkyl or alkoxy, each of 1-18 carbon atoms; R.sub.2 is alkyl or perfluoroalkyl, each of 1-12 carbon atoms; and X is 1,4-trans-cyclohexylene, 1,4-phenylene or 4,4'-cyclohexylphenyl are liquid crystalline compounds.
摘要:
Partially hydrogenated oligo-1,4-phenylenes of the formula ##STR1## wherein n is 1 or 2, the rings A and B are identical or different and are trans-4-alkylcyclohexyl or 4-alkylcyclohex-1-enyl, and the alkyl groups in each case are of up to 10 carbon atoms, have valuable liquid crystalline properties.
摘要:
Fluorophenylcyclohexanes of the formula ##STR1## wherein R is alkyl of 1 to 17 carbon atoms and Z is carbonyl or methylene, are valuable components for use in liquid crystal dielectrics.
摘要:
Cyclohexane derivatives of the formula ##STR1## wherein the rings A and B are identical or different and are each a 1,4-disubstituted phenyl or cyclohexyl ring; X is --CO--O -- or --O--CO--; R.sub.1 is alkyl of 1-8 carbon atoms; and R.sub.2 is alkyl of 1-8 carbon atoms, and when the ring B is phenyl, R.sub.2 is alkyl, alkoxy or alkanoyloxy, each of up to 8 carbon atoms, or --CN, have valuable liquid crystalline properties.
摘要:
The optically active medium of an electro-optical cell sandwiched between a pair of crossed polarizers is a thin layer of liquid crystal with a positive dielectric anisotropy and a negative anisotropy of the diamagnetic susceptibility. The medium is positioned between two planar transparent electrodes across which a potential difference establishes, in the liquid crystal layer, an electric field perpendicular to the electrode layers. A magnet is provided for establishing in the medium a magnetic field that has a predetermined orientation relative to the electric field. When both fields are parallel, the threshold voltage of the cell is increased. The presence of such a magnetic field, when the electric field is switched off, reduces the turn-off time of the cell. When the fields are perpendicular to each other, the color of the display can be controlled in accordance with the magnitude of the magnetic field.
摘要:
A liquid crystalline dielectric composition contains 0.001-5% by weight of a monocyclic or bicyclic amino compound of the formula ##STR1## wherein R.sub.1 and R.sub.2 each are hydrogen or collectively are CH.sub.2 --(CH.sub.2 --Z--CH.sub.2).sub.p --CH.sub.2 ; X is --CH.sub.2 or --CO--; Y is --Z--CH.sub.2 --CH.sub.2 -- or ##STR2## Z is O, S, or NH; m and n are 0, 1 or 2; p is 1, 2 OR 3; OR AN ACID ADDITION SALT OR METAL SALT CHELATE COMPLEX THEREOF.
摘要:
Organic solvents containing less than 0.2 atom percent of .sup.13 C and which preferably are at least partially deuterated are produced from .sup.13 C-depleted gaseous carbon compounds and are advantageously employed as solvents for .sup.13 C NMR spectroscopy.
摘要翻译:含有少于0.2原子%的13 C且优选至少部分氘代的有机溶剂由13C-贫化的气态碳化合物制备,并且有利地用作13 C NMR光谱的溶剂。
摘要:
Organic solvents containing less than 0.2 atom percent of .sup.13 C and which preferably are at least partially deuterated are produced from .sup.13 C-depleted gaseous carbon compounds and are advantageously employed as solvents for .sup.13 C NMR spectroscopy.
摘要翻译:含有少于0.2原子%的13 C且优选至少部分氘代的有机溶剂由13C-贫化的气态碳化合物制备,并且有利地用作13 C NMR光谱的溶剂。