Patent ID: 6605323
Filing Date: 2003-08-12
Classification: C09K

Abstract:
A monostable ferroelectric active matrix display comprising a liquid-crystal layer in the form of a monodomain having an unambiguously defined direction of the layer normals z of the smC* phase, wherein the layer normals z and the preferential direction n of the nematic or cholesteric phase (N* phase) form an angle of more than 5Â°, where the liquid-crystal layer comprises at least one compound of the formula (I)R1(-A1-M1)a(-A2-M2)b-A3-(M4-A4)c(-M5-A5)d-R2 where:A3 is a mono-fluorinated, mono-, di- or trinuclear nitrogen containing aromatic, R1 and R2 are, independently of one another, identical or different and are each hydrogen or an alkyl or alkyloxy radical having 2-16 carbon atoms, where one or two â€”CH2â€” groups may be replaced by â€”CH&boxH;CHâ€”, â€”OC(&boxH;O)â€”, â€”O&boxH;)Câ€”Oâ€”, â€”Si(CH3)2â€” or cyclopropane-1,2diyl and one or more H atoms may be replaced by F with the proviso that R1 and R2 cannot both be hydrogen or the group M7-R7 where R7 is a group having at least one asymmetric carbon atom which is either part of an alkyl group having 3-16 carbon atoms, where one to four â€”CH2â€” groups may be replaced by â€”Oâ€”, â€”OC(&boxH;O)â€” or â€”(O&boxH;)Câ€”Oâ€” and one of the substituents of the asymmetric carbon atom must be â€”CH3â€”CF3â€”OCH3, Cl, F or CN, or part of a 3- to 7-membered carbocycle, where one or two nonadjacent â€”CH2â€” groups may be replaced by â€”Oâ€” or one â€”CH2â€” group may be replaced by â€”OC(&boxH;O)â€” or â€”(O&boxH;)Câ€”Oâ€”, where M7 is a single bond, if the asymmetric carbon atom is part of an alkyl chain, and a single bond, â€”OCH2â€”, â€”CH2Oâ€”, â€”OC(&boxH;O)â€” or â€”C(&boxH;O)Oâ€”, if the asymmetric carbon atom is part of the carbocycle defined under R7 A1, A2, A4 and A5 are, independently of one another, identical or different and are each 1,4-phenylene, unsubstituted, monosubstituted or disubstituted by F or Cl, 1,3-phenylene, unsubstituted, monosubstituted or disubstituted by F, cyclohex-1-ene-1,4-diyl, cyclohex-2ene-1,4-diyl, 1-alkyl-1-silacyclohexane-1,4-diyl, bicyclo[2.2.2]octane-1,4-diyl, indane-2,6diyl or naphthalene-2,6-diyl M1, M2, M4 and M5 are, independently of one another, identical or different and are each a single bond, â€”OC(&boxH;O)â€”, â€”(O&boxH;)Câ€”Oâ€”, â€”OCH2â€”, â€”CH2â€”Oâ€”, â€”CH2CH2â€”, â€”CH2CH2CH2CH2â€” or â€”Câ‰¡Câ€”a, b, c and d are each zero or 1 with the proviso that 1&lE;{a+b+c+d}&lE;3 and the understanding that (Ax-Mx) is a single bond when the corresponding index is zero.