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    1.
    发明专利
    未知

    公开(公告)号：DE59209008D1

    公开(公告)日：1997-12-11

    申请号：DE59209008

    申请日：1992-08-14

    Applicant: HOECHST AG

    Inventor： SCHLOSSER HUBERT DR ,  ILLIAN GERHARD DR ,  KALTBEITZEL ANKE DR ,  WINGEN RAINER DR

    IPC: C07D241/16 ,  C07D241/18 ,  C07D405/12 ,  C09K19/34 ,  C09K19/40 ,  C09K19/58 ,  G02F1/13

    Abstract: A 2-fluoropyrazine of the formula (I) in which the symbols have the following meanings: R and R , independently of one another, are, for example, H or straight-chain or branched alkyl, A , A , A and A are identical or different and are, for example, 1,4-phenylene, or M , M , M and M are identical or different and are, for example, -O- or -CO-O-, R , R , R and R are, independently of one another, for example H or straight-chain or branched alkyl, M is, for example, -O-CO- or a single bond, and k, l, m, n, o, p, q, r are zero or one, with the proviso that the sum of k+m+p+r is less than 4 and greater than zero, can advantageously be employed as a component of liquid-crystal mixtures.

    3.
    发明专利
    未知

    公开(公告)号：DE4100176A1

    公开(公告)日：1992-07-09

    申请号：DE4100176

    申请日：1991-01-05

    Applicant: HOECHST AG

    Inventor： ILLIAN GERHARD DR ,  HEMMERLING WOLFGANG DR ,  WINGEN RAINER DR

    IPC: C07D239/26 ,  C07D239/24 ,  C07D239/30 ,  C07D239/32 ,  C07D239/34 ,  C09K19/34 ,  G02F1/13

    Abstract: Disclosed is a liquid-crystalline bis-pyrimidinecyclohexane of general formula (I), in which R and R which may be the same or different, are for example a straight-chain or branched-chain alkyl and X and X , which may be the same or different, are H, F, Cl or CN, which is particularly suitable for use as a component in liquid-crystalline mixtures. In nematic and smectic liquid-crystalline mixtures, such compounds give low melting points and high-width phases.

    4.
    发明专利
    未知

    公开(公告)号：DE3925970A1

    公开(公告)日：1991-02-07

    申请号：DE3925970

    申请日：1989-08-05

    Applicant: HOECHST AG

    Inventor： ESCHER CLAUS DR ,  DUEBAL HANS-ROLF DR ,  FELDHUES MICHAEL DR ,  HARADA TAKAMASA ,  ILLIAN GERHARD DR ,  MECKLENBURG THOMAS DR ,  MURAKAMI MIKIO ,  OHLENDORF DIETER DR ,  PAMPUS KARL DR

    IPC: C08G61/12 ,  G02F1/1337 ,  G02F1/141 ,  G09F9/35

    Abstract: Switching and display elements based on ferroelectric liquid-crystals often exhibit a pronounced optical hysteresis which results in the appearance of so-called ghost images. This phenomenon can be markedly reduced or even suppressed if at least one of the two orienting layers are in direct contact with the electrodes and is composed of an electrically conductive polymer of the formula (I): (I) in which R1, R2=independently of each other, H, or straight-chain or branched alkyl or alkoxy containing 1-16 carbon atoms, or halogen, X=S, NH, Y-=BF4-, PF6-, PO43-, AsF6-, SbCl6-, SO42-, HSO4-, alkyl-SO3-, perfluoroalkyl-SO3-, aryl-SO3, F- or Cl-, and n is an integer from 4 to 100 and m is an integer from 1 to 30.

    5.
    发明专利
    未知

    公开(公告)号：DE3920625A1

    公开(公告)日：1991-01-03

    申请号：DE3920625

    申请日：1989-06-23

    Applicant: HOECHST AG

    Inventor： ESCHER CLAUS DR ,  HEMMERLING WOLFGANG DR ,  ILLIAN GERHARD DR ,  HARADA TAKAMASA ,  MURAKAMI MIKIO

    IPC: G02F1/1337 ,  C09K19/02 ,  C09K19/34 ,  C09K19/58 ,  G02F1/137 ,  G02F1/141

    Abstract: Liquid-crystalline materials are becoming increasingly important in electrooptical switching and display devices. Recently, ferroelectric liquid-crystalline mixtures have also been investigated widely and employed in displays. A particularly important physical parameter for describing FLC mixtures is the spontaneous polarisation (Ps). On the one hand, a high spontaneous polarisation results in short response times, but on the other hand, high Ps values result in optical hysteresis, which causes, inter alia, so-called "ghost images". The use of FLC mixtures of high spontaneous polarisation (Ps 20 nC/cm ) and a natural helical pitch of less than half the layer thickness in an SSFLC display having a layer thickness of from 1 to 10 mu m allows the problem of optical hysteresis to be circumvented, in spite of the high spontaneous polarisation. FLC mixtures in which Ps is > 40 nC/cm can also be switched under these conditions.

    10.
    发明专利
    未知

    公开(公告)号：DE3832503A1

    公开(公告)日：1990-03-29

    申请号：DE3832503

    申请日：1988-09-24

    Applicant: HOECHST AG

    Inventor： MUELLER INGRID DR ,  DUEBAL HANS-ROLF DR ,  ESCHER KLAUS DR ,  HEMMERLING WOLFGANG DR ,  ILLIAN GERHARD DR ,  MURAKAMI MIKIO ,  OHLENDORF DIETER DR ,  WINGEN RAINER DR

    IPC: G02F1/13 ,  C07D317/24 ,  C07D317/30 ,  C07D317/32 ,  C07D405/12 ,  C07D405/14 ,  C09K19/34 ,  C09K19/54 ,  G09F9/35

    Abstract: Novel optically active esters of 5-ethyl- and 5-vinyl-1,3- dioxolane-4-carboxylic acid, their use as dopes in liquid-crystal mixtures, and liquid-crystal mixtures containing the novel esters. Optically active 1,3-dioxolanyl derivatives of the general formula (I) are suitable as dopes in liquid-crystal mixtures. The symbols in the general formula have the following meanings: R has an analogous structure to the moiety on the right of X in the general formula or is an alkyl or alkylene radical, which may be substituted, R and R are H or alkyl, which may also be substituted [R and R are alternatively, together with the C(2) of the dioxolane ring, a cycloaliphatic radical] R is vinyl or ethyl, with the proviso that at least one radical R is vinyl or ethyl if R is analogous to the moiety on the right of X in the formula (I), -A , -A and -A are aromatic, heterocyclic or aliphatic ring systems, -M and -M are -CO-O, -O-CO, -CH2CH2, -CH=CH, -CH2O,-OCH2 or -C=C, and X is O, S or O-CO-O. The particular advantage of the compound of the general formula (I) is that it is able to induce high twisting power in a cholesteric phase.

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