The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 14, 1982
Filed:
Oct. 03, 1980
Dietrich Demus, Halle, DD;
Wolfgang Weissflog, Halle-Neustadt, DD;
Horst Zaschke, Halle, DD;
Rudolf Wolff, Halle, DD;
Horst Kresse, Halle, DD;
Abstract
The invention relates to liquid-crystalline nematic mixtures which are used in electro-optical components, as well as to methods for their preparation. The object of the invention is liquid-crystalline mixtures for electro-optical arrangements possessing high positive electrical anisotropy at a high clarification point, as well as methods for their preparation. According to the invention, liquid-crystalline nematic mixtures are used, wherein at least one component is a 1,4-disubstituted benzene derivative and the other compound is an ester of 4-[2,2-dicyano-ethenyl]-phenol of the general formula ##STR1## wherein R.sup.1 denotes added groups of various characters such as alkyl or alkoxy for example, X is aromatic, cycloaliphatic or a heterocyclic ring system such as phenyl or cyclohexyl for example; and Y is a connector such as carbonyloxy, azomethine, azoxy. These are prepared by reaction with reactive acid derivatives, particularly acid chlorides, or by a Knoevenagel-condensation by reacting respective 4-subst.-benzoic acid-[4-formyl-phenyl esters] or 4-alkyl-cyclohexanecarboxylic acid-[4-formyl-phenyl esters] with malonic acid dinitrile.