Patent ID: 6596350
Filing Date: 2003-07-22
Classification: C09K

Abstract:
A liquid-crystalline medium comprising a mixture of polar compounds having positive dielectric anisotropy, wherein said mixture comprises one or more compounds of formula I, in whichR is H, an alkyl or alkenyl radical having 1 to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF3 or at least nonsubstituted by halogen, it also being possible for one or more CH2 groups in these radicals to be replaced, in each case independently of one another, by â€”Oâ€”, â€”COâ€”, â€”COâ€”Oâ€”, â€”Oâ€”COâ€”, â€”Sâ€” or â€”Oâ€”COâ€”Oâ€” in such a way that O atoms are not linked directly to one another,A1 (a) is a trans-1,4-cyclohexylene radical in which, in addition, one or more non-adjacent CH2 groups may be replaced, in each case independently, by â€”Oâ€” or â€”Sâ€”, or a 1,4-cyclohexenylene radical, (b) is a 1,4-phenylene radical, in which, in addition, one or two CH groups may be replaced by N, (c) is a radical from the group consisting of 1,4-bicyclo[2.2.2]octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydro-naphthalene-2,6-diyl and 1,2,3,4-tetrahydro-naphthalene-2,6-diyl, wherein the radicals (a) and (b) may be monosubstituted or polysubstituted by CN, CH3 or F, Z1 is â€”COâ€”Oâ€”, â€”Oâ€”COâ€”, â€”CH2â€”Oâ€”, â€”OCH2â€”, â€”CH2CH2â€”, â€”CF2Oâ€”, â€”OCF2â€”, â€”CH&boxH;CHâ€”, â€”Câ‰¡Câ€”, â€”(CH2)4â€”, â€”CH&boxH;CHâ€”CH2CH2â€” or a single bond, Y is F, halogenated alkyl having 1 to 6 carbon atoms, halogenated alkenyl having up to 6 carbon atoms, or halogenated alkoxy having 1 to 6 carbon atoms, L is H or F, and m is 0 or 1; and wherein said medium also comprises one or more compounds of formulae XVII-XXII in which 1,4-phenylene rings may be substituted by CN, chlorine or fluorine, andR0 is n-alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 9 carbon atoms, X0 is F, Cl, halogenated alkyl having 1 to 6 carbon atoms, halogenaed alkenyl having up to 6 carbon atoms or halogenated alkoxy having 1 to 6 carbon atoms, X0â€² is F or Cl, and Y1 is H or F.