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  • Patent number: 4293434
    Abstract: The invention describes nematic compositions for electrooptical devices for modulation of the transmitted or incident light and for the rendition of numbers, symbols and images as orientation in the spectroscopy and gas chromatography.
    Type: Grant
    Filed: February 13, 1979
    Date of Patent: October 6, 1981
    Assignee: VEB Werk fur Fernsehelektronik Berlin im VEB Kombinat Mikroelektronik
    Inventors: Hans-Joachim Deutscher, Herrmann Schubert, Christina Seidel, Dietrich Demus, Horst Kresse
  • Patent number: 4610805
    Abstract: Nematic liquid crystalline mixtures, which can be used in optoelectronic components. Compounds are provided which influence the characteristics of mixtures in the direction of high clarification temperatures at simultaneous favorable switching times. It has been found that compounds of the general formula ##STR1## wherein n, m=1 to 10 in nematic mixtures in quantities of 5 to 40% considerably increase the clarification points without significantly increasing the viscosity, so that favorable switching times are obtained. The new mixtures can be used for the production of optoelectronic components (displays) for watches, computers and other devices.
    Type: Grant
    Filed: January 29, 1985
    Date of Patent: September 9, 1986
    Assignee: VEB Werk fur Fernsehelektronik im VEB Kombinat Mikroelektronik
    Inventors: Michael Schellenberger, Sabine Richter, Hans-Joachim Deutscher, Horst Zaschke, Dietrich Demus
  • Patent number: 4519936
    Abstract: The invention relates to nematic liquid crystals in electro-optical components for the modulation of light as well as for the representation of numerals, signs and images and to a method for producing the same.It is the object of the invention to create nematic liquid crystals which are well suited for electro-optical devices, preferably for two-frequency operation.It has been found that pure or mixed 2-n-alkyl-1, 4-bis-[4-acyloxy]-benzenes of the general formula ##STR1## wherein R.sup.3 =n-C.sub.m H.sub.2m+1, with m=3 to 14, are well suited for utilization in electro-optical components.It was found that 2-n-alkyl-1,4-bis-[acyloxy]-benzene which is well suited for electro-optical components, and especially for two-frequency operations, can be produced by the conversion of a correspondingly substituted benzoic acid or cyclohexane carboxylic acid or a reaction-capable derivative thereof with the corresponding 2-n-alkylhydroquinone--also in the form of its phenylate--at a temperature ranging from 0.degree. C.
    Type: Grant
    Filed: July 20, 1982
    Date of Patent: May 28, 1985
    Assignee: VEB Werk fuer Fernsehelektronik im Kombinat Mikroelektronik
    Inventors: Dietrich Demus, Wolfgang Weissflog, Horst Kresse