Patent ID: 6696111
Filing Date: 2004-02-24
Classification: C07C,C09K

Abstract:
A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, comprising one or more compounds of the formula IA and/or formula IB in whichRa and Rb are each, independently of one another, an alkenyl radical having up to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals may each, independently of one another, be replaced by â€”Oâ€”, â€”Sâ€”, â€ƒâ€”COâ€”, â€”COâ€”Oâ€”, â€”Oâ€”COâ€” or â€”Oâ€”COâ€”Oâ€” in such a way that O atoms are not linked directly to one another, Ya and Yb are each, independently of one another, F, Cl, SF5, NCS, or a halogenated alkyl, alkoxy, alkenyl or alkenyloxy radical having up to 5 carbon atoms, La and Lb are each, independently of one another, H or F, Za and Zb are each, independently of one another, â€”COOâ€”, â€”CH2Oâ€”, â€”OCH2â€”, â€”C2F4â€”, â€”CF2Oâ€”, â€”OCF2â€” or a single bond, and c and d are each, independently of one another, 1 or 2; wherein said medium further comprises one or more compounds selected from formulae II, III, IV, V, VI, VII and VIII: whereinR0 in each case is, independently, alkyl, oxaalkyl, fluoroalkyl or alkenyl, each having up to 9 carbon atoms, X0 in each case is, independently, F, Cl, halogenated alkyl or alkoxy having 1 to 6 carbon atoms, or halogenated, alkenyl or alkenyloxy having up to 6 carbon atoms, Z0 in each case is, independently, â€”C4H8â€”, â€”C2F4â€”, â€”OCH2â€”, â€”CH2Oâ€”, â€”CF2Oâ€”, â€”OCF2â€” or â€”CF&boxH;CFâ€”, Y1 and Y2 are in each case, independently of one another, H or F, and r is 0 or 1.