Liquid crystal Schiffs bases
AssigneeHoffmann-La Roche Inc.
InventorsArthur Boller, Hanspeter Scherrer
Life of this patent
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Abstract
Liquid crystal substances or compounds of the formula ##STR1## wherein R is as hereinafter set forth, as well as compositions and electro-optical apparatuses containing them are described.
Claims22
A nematic composition which comprises two or more compounds of the formula ##STR11## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, isohexyl, n-hexyl, n-heptyl or n-octyl.
A nematic composition which comprises a Schiffs' base of the formula ##STR12## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isohexyl, n-heptyl or n-octyl,
- or mixtures thereof and one or more nematic compounds having a positive anisotropy.
A nematic composition which comprises a compound of the formula ##STR13## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isohexyl, n-heptyl or n-octyl,
- or mixtures thereof, and a compound of the formula ##STR14## wherein R.sub.1 is straight-chain lower alkyl of 4 to 7 carbon atoms.
A nematic composition which comprises a compound of the formula ##STR15## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isohexyl, n-heptyl or n-octyl,
- or mixtures thereof, and a compound of the formula ##STR16## wherein R.sub.2 is straight-chain lower alkyl of 4 to 7 carbon atoms or straight-chain lower alkanoyl of 2 to 8 carbon atoms.
A nematic composition which comprises a compound of the formula ##STR17## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isohexyl, n-heptyl or n-octyl,
- or mixtures thereof, and a compound of the formula ##STR18## wherein R.sub.2 is straight-chain lower alkyl of 4 to 8 carbon atoms or straight-chain lower alkoxy of 5 to 8 carbon atoms.
A dielectric for electro-optical purposes, which comprises a nematic Schiffs' base of the formula ##STR19## wherein R is ethyl, n-propyl, n-butyl, n-pentyl, isohexyl, n-hexyl, n-heptyl or n-octyl,
- or mixtures thereof and one or more nematic compounds having positive anisotropy.
Dependencies are inferred from the claim text.