Phenyl-pyrimidines
AssigneeHoffman-La Roche Inc.
InventorsArthur Boller, Marco Cereghetti, Hanspeter Scherrer
Life of this patent
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Abstract
Phenyl-pyrimidines of the formula ##STR1## wherein R.sub.1 and R.sub.2 are as hereinafter set forth, are described. The end products are useful as liquid crystals.
Claims25
A nematic mixture for electro-optical purposes which comprises two or more compounds of the formula ##STR20## wherein one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 3 to 9 carbon atoms, straight-chain alkoxy of 2 to 9 carbon atoms or straight-chain alkanoyloxy of 2 to 9 carbon atoms.
A nematic mixture for electro-optical purposes which comprises one or more compounds of the formula ##STR21## wherein one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 3 to 9 carbon atoms, straight-chain alkoxy of 2 to 9 cabon atoms or straight-chain alkanoyloxy of 2 to 9 carbon atoms,
- and one or more nematic substances.
An optical cell comprising a liquid crystal means comprising one or more compounds selected from the group consisting of compounds of the formula ##STR34## wherein one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 3 to 9 carbon atoms, straight-chain alkoxy of 2 to 9 carbon atoms or straight-chain alkanoyloxy of 2 to 9 carbon atoms,
- in the liquid crystalline state disposed between two plate means at least one of which plate means is transparent;
- means for controlling the optical activity of the cell;
- and said liquid crystal means having a helical structure in the direction perpendicular to the plate means and the surfaces of the plate means being wall oriented.
An optical cell comprising a liquid crystal means comprising one or more compounds selected from the group consisting of compounds of the formula ##STR35## wherein one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 3 to 9 carbon atoms, straight-chain alkoxy of 2 to 9 carbon atoms or straight-chain alkanoyloxy of 2 to 9 carbon atoms, in the liquid crystalline state, and one or more nematic substances
- disposed between two plate means at least one of which plate means is transparent;
- means for controlling the optical activity of the cell;
- and said liquid crystal means having a helical structure in the direction perpendicular to the plate means and the surfaces of the plate means being wall oriented.
Dependencies are inferred from the claim text.