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    12.
    发明专利
    未知

    公开(公告)号：NO172985B

    公开(公告)日：1993-06-28

    申请号：NO892983

    申请日：1989-07-20

    Applicant: HOECHST AG

    Inventor： SCHEROWSKY GUENTER ,  GAY JUERGEN ,  WINGEN RAINER ,  DUEBAL HANS ROLF ,  ESCHER CLAUS ,  HEMMERLING WOLFGANG ,  INOGUSCHI YOSHIO ,  MUELLER INGRID ,  OHLENDORF DIETER

    IPC: G02F1/13 ,  C07D317/22 ,  C07D317/24 ,  C07D317/36 ,  C07D317/72 ,  C07D405/12 ,  C07D405/14 ,  C07D407/12 ,  C07D409/12 ,  C07D409/14 ,  C07D417/12 ,  C07D417/14 ,  C09K19/34 ,  C09K19/54 ,  C09K19/58 ,  G02F1/137 ,  G02F1/33 ,  C07D317/34

    Abstract: Optically active 1,3-dioxolane derivates of the general formula which carry a mesogenic radical in the 4-position are suitable as dopes in - in particular ferroelectric - liquid-crystal mixtures. The symbols in the general formula have the following meanings: R has a structure analogous to the moiety of the general formula on the right of X or is an alkyl or alkylene radical, which may be substituted, R , R and R are H or alkyl (R is alternatively alkenyl), which may also be substituted [R and R , together with the C(2) of the dioxolane ring, may alternatively be cycloaliphatic or keto groups], j, l and n are zero, 1 or 2, and k and m are zero or 1, with the proviso that n is zero if k is zero, m is zero if n is zero, and 1 , -A and -A are an aromatic, heterocyclic or aliphatic ring system, -M and -M are -CO-O, -O-CO, -CH2CH2, -CH=CH, -CH2O, -OCH2 or -C IDENTICAL C and X is O, S or O-CO-O. The particular advantage of the compounds of the general formula (I) is that they are able to induce a high twisting power in the cholesteric phase, but without significantly affecting the magnitude of the spontaneous polarisation already present in the mixture in the smectic C phase. They are therefore suitable for pitch compensation, in particular for ferroelectric liquid-crystal mixtures.

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