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:
Sep. 18, 1984
Filed:
Jul. 02, 1982
Gunther Haas, Neckargemund, DE;
Georg Weber, Erzhausen, DE;
Merck Patent Gesellschaft mit beschrankter Haftung, Darmstadt, DE;
Abstract
A liquid crystalline dielectric useful in electro-optical display elements based on the guest-host effect, comprises a liquid crystalline compound and a pleochroitic dyestuff of the formula ##STR1## wherein X and Y are the same or different and each is hydrogen, chlorine or bromine; R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each independently is hydrogen, alkyl or alkoxyalkyl each of up to 8 C-atoms or a cyclic group Z, wherein Z is, ##STR2## and R is alkyl, alkoxy, alkoxyalkyl, alkoxyalkoxy or alkanoyloxy each of up to 8 C-atoms, with the proviso that at least one and at most two of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is cyclic group Z; and when two Z groups are present, either R.sub.1 and R.sub.2 or R.sub.3 and R.sub.4 are both a cyclic group Z; and, when R.sub.3 and R.sub.4 are both cyclic groups Z, these are in the 2- and 6- or 3- and 7-positions of the naphthalene structure.