Optically active cyano-biphenyl compounds and liquid crystal materials containing them
AssigneeThe Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorsGeorge William Gray, Damien Gerard McDonnell
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Abstract
Liquid crystal compounds are disclosed having the formula ##STR1## where p is an integer having a value from 0 to 5 inclusive. These materials are optically active and cholesterogenic and may be used in an electro-optical display device either on their own or in admixture with nematogenic materials having a formula ##STR2## where i has a value from 0 to 5 inclusive and j is 0 or 1. These last mentioned mixtures may be thermochromic and employed in a temperature sensing device.
Claims18
A liquid crystal material consisting essentially of an admixture of (1) one or more optically active biphenyl compounds having a positive optical rotation angle and having the formula:
- ##STR18## where p is an integer having a value of from 0 to 5 inclusive and (2) at least one optically active cholesterogenic compound different from (1) having a positive optical rotation angle and having the formula:
- ##STR19## where i is an integer having a value from 0 to 5 inclusive and j is 0 or 1.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(2"-methylbutyl)-4'-cyanobiphenyl and (+)-4-(3'"-methypentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(2"-methylbutyl)-4'-cyanobiphenyl and
- (+)-4-(4'"-methylhexyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(3"-methylpentyl)-4'-cyanobiphenyl and
- (+)-4-(3'"-methylpentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(3"-methylpentyl)-4'-cyanobiphenyl and
- (+)-4-(4'"-methylhexyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(4"-methylhexyl)-4'-cyanobiphenyl and
- (+)-4(3'"methylpentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(4"-methylhexyl)-4'-cyanobiphenyl and
- (+)-4(4'"-methylhexyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(2"-methylbutyl)-4"-cyanobiphenyl,
- (+)-4-(4"-methylhexyl)-4'-cyanobiphenyl and
- (+)-4-(3'"-methylpentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(2"-methylbutyl)-4'-cyanobiphenyl,
- (+)-4-(4"-methyl hexyl)-4'-cyanobiphenyl and
- (+)-4-(4'"-methyl hexyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(3"-methylpentyl)-4'-cyanobiphenyl,
- (+)-4(4"-methylhexyl)-4'-cyanobiphenyl and
- (+)-4-(3'"-methylpentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(4"-methylhexyl)-4'-cyanobiphenyl,
- (+)-4-(3"-methylpentyl)-4'-cyanobiphenyl and
- (+)-4-(3'"-methylpentyl)-4"-cyano-p-terphenyl.
A liquid crystal material consisting essentially of a mixture of
- (+)-4-(3"-methylpentyl)-4'-cyanobiphenyl,
- (+)-4-(2"-methylbutyl)-4'-cyanobiphenyl,
- (+)-4-(4"-methylhexyl)-4'-cyanobiphenyl and
- (+)-4-(4'"-methylhexyl)-4"-cyano-p-terphenyl.
A temperature sensing device containing a cholesteric liquid crystal material consisting essentially of in admixture (1) one or more optically active biphenyl compounds having a positive optical rotation angle and having the formula:
- ##STR20## wherein p is an integer having a value from 0 to 5 inclusive and (2) at least one optically active cholesterogenic compound different from (1) having a positive optical rotation angle and having the formula:
- ##STR21## wherein i is an integer having a value from 0 to 5 inclusive and j is 0 or 1,
- said liquid crystal material being sandwiched, in its Grandjean plane texture, between the inner surface area of two transparent slides.
Dependencies are inferred from the claim text.