Patent number: 5496500
Abstract: Liquid crystal compounds of formula (I) are described, where formula (I) is given as R.sub.1 --A--(X.sub.m --(B).sub.n --R.sub.2 where A is selected from nathyl, flourinated naphthyl, brominated naphthyl, B is selected from phenyl, methylated phenyl, brominated phenyl, fluorinated phenyl, thiophene, pyrimidine and pyridine, R.sub.1 and R.sub.2 are independently selected from alkyl, alkoxy, alkynyl, thioalkyl, Br, CN, SCN, NCS, perfluoroalkyl, perfluoroalkoxy and hydrogen, X is selected from C.tbd.C, COO and C.tbd.C, m is 0 or 1, n is 0 or 1 where m is 1 and n is 0 where m is 0; provided that where A is naphthyl, n is 1 and m is 0 then B is selected from methylated phenyl, brominated phenyl, thiophene, pyrimidine and pyridine; and further provided that where A is naphthyl, X is C.tbd.C, m is 1 and n is 1, then B is selected from thiophene, pyrimidine and pyridine.
Type:
Grant
Filed:
August 1, 1994
Date of Patent:
March 5, 1996
Assignee:
The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain & Northern Ireland
Inventors:
Kenneth J. Toyne, John W. Goodby, Alexander Seed, George W. Gray, Damien G. McDonnel, Edward P. Raynes, Sally E. Day, Kenneth J. Harrison, Michael Hird