Patents by Inventor Sylvia Deresch

Sylvia Deresch has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4358393
    Abstract: Nematic liquid crystals are employed in electro-optical devices for the modulation of the transmittant or incident light and for the black and white or colored rendition of numerals, symbols and pictures.The object of the invention is the use of nematic liquid crystals having a high positive dielectric anisotropy, a low threshold and operating voltage and high clear points and a process for making these compounds.It was found that as liquid crystals for electro-optical devices mixtures are useful which, as an essential component, contain one or several compounds from the class of 5-cyano-2-[4-acyloxyphenyl]-pyrimidines of the formula ##STR1## wherein R.sup.1 is ##STR2## C.sub.5 H.sub.11 -- or C.sub.n H.sub.2n+1 O-- R.sup.2 is C.sub.n H.sub.2n+1 ; C.sub.n H.sub.2n+1 O; C.sub.n H.sub.2n+1 S; F; Cl; Br; CF.sub.3 ; C.sub.n H.sub.2n+1 COO; C.sub.n H.sub.2n+1 OCOO; CN; NO.sub.2 ; C.sub.n H.sub.2n+1 NH; or C.sub.n H.sub.2n+1 (CH.sub.3)N, n is 1 to 10, andR.sup.3 is C.sub.n H.sub.2n+1,n is 1 to 10.
    Type: Grant
    Filed: April 30, 1980
    Date of Patent: November 9, 1982
    Assignee: VEB Werk fur Fernsehelektronik im VEB Kombinat Mikroelektronik
    Inventors: Horst Zaschke, Dietrich Demus, Sylvia Deresch