中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

102 records (took 0.022 seconds)

    63.
    发明专利
    未知

    公开(公告)号：PT96573A

    公开(公告)日：1991-10-15

    申请号：PT9657391

    申请日：1991-01-24

    Applicant: HOECHST AG

    Inventor： DUEBAL HANS-ROLF ,  MURAKAMI MIKIO ,  DROTLOFF HANSOTTO ,  BREKNER MICHAEL

    IPC: C09K19/56 ,  C08G65/40 ,  G02F1/1337 ,  C09D

    Abstract: The use of polyaryl ether ketones of the structural unit -O-A-O-B- gives alignment layers for liquid-crystal displays and switching elements which have high transparency, low water-absorption capacity and a particularly uniform alignment, both of smectic and nematic liquid crystals, and thus enable high contrast to be obtained.

    67.
    发明专利
    未知

    公开(公告)号：DE3925971A1

    公开(公告)日：1991-02-07

    申请号：DE3925971

    申请日：1989-08-05

    Applicant: HOECHST AG

    Inventor： ESCHER CLAUS DR ,  DUEBAL HANS-ROLF DR ,  HARADA TAKAMASA ,  HEMMERLING WOLFGANG DR ,  ILLIAN GERHARD DR ,  MUELLER INGRID DR ,  MURAKAMI MIKIO ,  OHLENDORF DIETER DR ,  WEGENER PETER DR ,  WINGEN RAINER DR

    IPC: C09K19/20 ,  C09K19/34 ,  C09K19/46

    Abstract: The novel liquid crystalline mixtures, which additionally contain an optically active compound as a dopant in the case of ferroelectric behaviour are based on at least 2 components of the general formula (I) and at least one carboxylic ester of the general formula (XI) or (XII) in which x is an integer of from 2 to 14 and n is an integer of from 6 to 14 in which a and b independently of one another may denote an integer of from 2 to 14 and -X- may denote an or an -O- group; in which A denotes, for example, pyrimidine-2,5-diyl, -Y- denotes, for example, -O- or -S-, -M- denotes, for example, -O- or -CH2-, -R denotes, for example, CH3 and c, d and e denote, for example, integers such as 2, 3 or 4. The mixtures, which may also contain further components, have advantageous properties for use in electrooptical display elements, such as low melting points and low crystallisation temperatures.

    FERROELECTRIC LIQUID CRYSTAL COMPONENTS HAVING HIGH SPONTANEOUS POLARIZATION AND LOW HELICAL PITCH
    68.
    发明专利
    FERROELECTRIC LIQUID CRYSTAL COMPONENTS HAVING HIGH SPONTANEOUS POLARIZATION AND LOW HELICAL PITCH 未知

    公开(公告)号：CA2019652A1

    公开(公告)日：1990-12-23

    申请号：CA2019652

    申请日：1990-06-22

    Applicant: HOECHST AG

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

    IPC: G02F1/1337 ,  C09K19/02 ,  C09K19/34 ,  C09K19/58 ,  G02F1/137 ,  G02F1/141 ,  G02F1/13

    Abstract: HOE 89/F 197 Ferroelectric liquid crystal components having a high spontaneous polarization and a small helical pitch Liquid crystal materials are becoming increasingly important in electro-optical switching and display devices. During recent times, ferroelectric liquid crystal mixtures have also been investigated to a particularly great extent and used in displays. A physical quantity which is particularly important for the purpose of describing FLC mixtures is the spontaneous polarization (Ps). On the one hand, a high spontaneous polarization leads to short switching times, while on the other hand in the case of high Ps values an optical hysteresis occurs, which leads, inter alia, to so-called "ghost images". In spite of high spontaneous polarization, the problem of the optical hysteresis may be overcome by the use of FLC mixtures having a high spontaneous polarization (Ps 20 nC/cm2) and a natural helical pitch of less than one half of the layer thickness in an SSFLC display with a layer thickness of 1 to 10 .mu.m. FLC mixtures with Ps > 40 nC/cm2 can also be switched under these conditions.

    69.
    发明专利
    未知

    公开(公告)号：DE3907601A1

    公开(公告)日：1990-09-13

    申请号：DE3907601

    申请日：1989-03-09

    Applicant: HOECHST AG

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

    IPC: G02F1/13 ,  C07D317/30 ,  C07D317/72 ,  C07D405/12 ,  C07D409/12 ,  C09K19/06 ,  C09K19/34 ,  C09K19/58

    Abstract: Optically active 1,3 dioxolane derivatives containing a mesogenic residue, of the general formula (I), are suitable as doping agents especially in ferro-electrical liquid crystal mixtures. The meanings of the symbols in the general formula are: R is constructed similarly to the part of the general formula to the right of X or an alkyl or alkylene residue which may be substituted; R , R , R = H or alkyl (R may also be alkenyl) which may also be substituted [R , R together with the C(2) of the dioxolane ring may be a cycloaliphate or a keto group]; j, l, n = zero, 1 or 2 and k, m = zero or 1 provided that if k = zero, n = zero also, if n = zero, m = zero also and l , -A , -A = aromatic, heterocyclic or aliphatic ring system; -M ,- M = -CO-O, -O-CO, -CH2CH2, -CH=CH, -CH2O, -OCH2, -C=C and X = CH=CH, CH2-CH2. The special advantage of the compounds with the general formula (I) is that they can induce a high twisting capacity in a cholesteric phase without substantially affecting in the smectic C* phase the value of the spontaneous polarisation already in the mixture. They are therefore suitable for pitch compensation, especially for ferro-electrical liquid crystal mixtures.

Patent Agency Ranking