Novel liquid crystal mixtures
AssigneeHoffmann-La Roche Inc.
InventorsMartin Petrzilka, Martin Schadt
Life of this patent
Estimating the term…
Abstract
Liquid crystalline mixtures containing compounds of the formula ##STR1## wherein n stands for the number 0 or 1; X.sup.1 and X.sup.2 denote single covalent bonds or one of the symbols X.sup.1 and X.sup.2 also denotes --COO--, --OOC-- or --CH.sub.2 CH.sub.2 --; the rings A.sup.1, A.sup.2, and A.sup.3 represent 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also represents a 2,5-disubstituted pyrimidine ring or a trans-2,5-disubstituted m-dioxane ring; R.sup.1 signifies 4-alkenyl or on a cyclohexyl ring also 2Z-alkenyl; and R.sup.2 denotes alkyl, alkoxy, --CN or --NCS, as well as the manufacture of these compounds and the use for electro-optical purposes are described.
Claims10
A liquid crystalline mixture containing
- (a) a liquid crystalline carrier material;
- and
- (b) a compound of the formula:
- ##STR15## wherein n is the integer 0 or 1;
- X.sup.1 and X.sup.2 are single covalent bonds or one of X.sup.1 and X.sup.2 also is --COO--, --OOC-- or --CH.sub.2 CH.sub.2 --;
- the rings A.sup.1, A.sup.2 and A.sup.3 independently are 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also is 2,5-disubstituted pyrimidine or trans-2,5-disubstituted m-dioxane;
- R.sup.1 is 4-alkenyl or when positioned on a cyclohexyl ring R.sup.1 also can be 2Z-alkenyl;
- and R.sup.2 is alkyl, alkoxy, --CN or --NCS.
An electro-optical cell comprising:
- (a) two plate means;
- (b) a liquid crystal mixture disposed between the two plate means and including
- (i) a liquid crystalline carrier material;
- and
- (ii) a compound of the formula ##STR16## wherein n is the integer 0 or 1;
- X.sup.1 and X.sup.2 are single covalent bonds or one of X.sup.1 and X.sup.2 also is --COO--, --OOC-- or --CH.sub.2 CH.sub.2 --;
- the rings A.sup.1, A.sup.2 and A.sup.3 independently are 1,4-phenylene, 2-fluoro-1,4-phenylene or trans-1,4-cyclohexylene or one of these rings also is 2,5-disubstituted pyrimidine or trans-2,5-disubstituted m-dioxane;
- R.sup.1 is 4-alkenyl or when positioned on a cyclohexyl ring R.sup.1 also can be 2Z-alkenyl;
- and R.sup.2 is alkyl, alkoxy, --CN or --NCS;
- and
- (c) means for applying an electric potential to the two plate means.
Dependencies are inferred from the claim text.