Patent ID: 6565933
Filing Date: 2003-05-20
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 straight-chain alkyl or alkoxy having 2 to 7 carbon atoms or alkenyl radical having 2 to 10 carbon atoms which is unsubstituted or monosubstituted by CN, 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€ƒâ€”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]ocrylene, 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€”{overscore (C)}Câ€”, â€”(CH2)4â€”, â€”CH&boxH;CHâ€”CH2CH2â€” or a single bond, Y is F, Cl, 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 mixture further comprises one or more compounds of formulae RI-RII where R0 is n-alkyl, oxaalky, fluoroalkyl or alkenyl, each having up to 9 carbon atoms, alkenyl and alkenyl* are each independently of one another, vinyl, 1E-alkenyl, 3E-alkenyl or 4-alkenyl having up to 9 carbon atoms.