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:
Oct. 05, 1993
Filed:
Apr. 01, 1992
Hoffmann-La Roche Inc., Nutley, NJ (US);
Abstract
Optically active compounds of the formula ##STR1## wherein R.sup.1 and R.sup.2 each are alkyl with at least 2 carbon atoms; A.sup.1, A.sup.2 and A.sup.3 each are unsubstituted, cyano-, halogen- or methyl-substituted 1,4-phenylene, optionally having one or two CH groups replaced by nitrogen, unsubstituted, cyano- or methyl-substituted trans-1,4-cyclohexylene, the cyclohexylene optionally having one or two CH.sub.2 groups replaced by oxygen; Z.sup.1 and Z.sup.2 each are a single covalent bond, --COO--, --OOC--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O--, --C.tbd.C--, --COS-- or --SOC--; m stands for the number 0 or 1; n is an integer of 0 to 4; X is oxygen or a methylene group; and each C* represents a chiral carbon atom, one of the chiral carbon atoms has the R-configuration while the other has the S-configuration. The compounds are used in liquid crystalline mixtures to compensate the temperature dependence of the threshold potential of liquid crystal cells.