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:
May. 07, 1991
Filed:
Nov. 17, 1987
Arthur Boller, Binningen, CH;
Richard Buchecker, Zurich, CH;
Hans-Jurgen Fromm, Tokyo, JP;
Stephen Kelly, Mohlin, CH;
Martin Schadt, Seltisberg, CH;
Alois Villiger, Basel, CH;
Hoffmann-La Roche Inc., Nutley, NJ (US);
Abstract
A ferroelectric liquid crystal mixture containing at least one compound of the formula ##STR1## wherein n stands for the number 0 or 1; X.sup.1 represents a single covalent bond, --COO-- or --OOC-- and X.sup.2 represents a single covalent bond, --COO--, --OOC--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 -- or --CH.sub.2 O--; rings A.sup.1, A.sup.2 and A.sup.3 each independently signify 1,4-phenylene optionally substituted with cyano, halogen or lower alkyl or pyrimidin-2,5-diyl, pyrazin-2,5-diyl, when n is 1, trans-1,4-cyclohexylene or trans-m-dioxan-2,5-diyl; with the proviso that one of the rings present stands for pyrimidin-2,5-diyl or pyrazin-2,5-diyl when a further ring signifies trans-1,4-cyclohexylene or when n stands for the number 0 and X.sup.1 stands for a single covalent bond; and R.sup.1 signifies an optionally halogen-substituted alkenyl group with up to 18 carbon atoms in which optionally 1 or 2 non-adjacent CH.sub.2 groups are replaced by --O-- and/or a C.dbd.C double bond; with the proviso that R.sup.1 is different from 3,7-dimethyl-6-octenyloxy; R.sup.2 signifies an optionally halogen-substituted alkyl group with up to 18 carbon atoms in which optionally 1 or 2 non-adjacent CH.sub.2 groups are replaced by --O-- and/or a C.dbd.C double bond; with the proviso that residues R.sup.1 and/or R.sup.2 attached to an aromatic ring have at least 2 chain atoms between the aromatic ring and a C.dbd.C double bond present; as well as novel compounds falling under formula I and novel ferroelectric liquid crystal devices employing the compounds according to the invention.