Liquid-crystalline medium
AssigneeMerck Patent GmbH
InventorsBernhard Rieger, Reinhard Hittich, Volker Reiffenrath, Herbert Plach
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Abstract
The invention relates to a liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, characterized in that it contains one or more compounds of the general formula I ##STR1## in which X is fluorine, chlorine, CF.sub.3, OCF.sub.3 or OCHF.sub.2, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 7 carbon atoms.
Claims15
A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising one or more compounds of the formula I ##STR71## in which X is fluorine, chlorine, CF.sub.3, OCF.sub.3 or OCHF.sub.2, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms, and one or more compounds of the formulae II-IV ##STR72## in which the individual radical R is independently as defined above,
- X" is fluorine, chlorine, CF.sub.3 or OCF.sub.3,
- Y.sup.1 ' and Y.sup.2 ' are in each case F, and
- r is 0 to 1.
A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising one or more compounds of the formula ##STR75## in which X' is fluorine or chlorine and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms, one or more compounds selected from the group consisting of the formulae II, III and IV:
- ##STR76## in which the individual radicals R and X' are independently as defined above.
- Y.sup.1 and Y.sup.2 are in each case H or F, and
- r is 0 to 1, and
- one or more compounds selected from the group consisting of the formulae IX to XII:
- ##STR77## in which the individual radicals R, Y.sup.1, Y.sup.2 and r are independently as defined above, and
- X is F, Cl, CF.sub.3, OCF.sub.3 or OCHF.sub.2.
A liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, comprising one or more compounds of the formula I ##STR79## in which X is fluorine, chlorine, CF.sub.3, OCF.sub.3 or OCHF.sub.2, and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms and one or more compounds selected from the group consisting of the formulae V to VIII:
- ##STR80## in which R is independently as defined above,
- X" is fluorine, chlorine, CF.sub.3 or OCF.sub.3,
- Y.sup.1' and Y.sup.2' are in each case F, and
- r is 0 or 1.
Dependencies are inferred from the claim text.