| 摘要 |
LCD based on the electrically controlled birefringence (ECB) principle has a cell made from 2 plane parallel plates with electrode layers and overlying orientation films on the inside. This is filled with a nematic liquid crystal (LC) mixt. with negative dielectric anisotropy and the surface tilt angle between the long axis of the mols. is ca. 85-95 deg.. The mixt. contains 1,4-di-substd.-2,30difluorobenzene cpd(s). of formula (I) and 1-(acylacetyl)-4-substd.-benzene cpd(s). of formula (II). R1-4 = 1-15C alkyl, in which 1 or more CH2 gps. may be replaced by -O-, -S-, -CO-, -CH(halogen)-, -CH(CN)-, -O-CO-, -O-COO-, -CO-O-, or -CH=CH- or a combination of 2 of these without directly linked hetero-atoms; A1-3 = 1,4-cyclohexylene (Cyc), opt. with halogen, Me and/or CN substit(s)., in which 1 or 2 non-adjacent CH2 gps. may be replaced by -O- and/or -S- or a -CH-CH2- gp. may be replaced by -C=N-; 1,4-phenylene (Phe), opt. with a halogen, Me and/or CN substit(s)., in which 1 or more CH gps. may be replaced by N; and one of A1-2 may = 2,6-naphthylene (Naph) or tetrahydro-2,6-naphthylene (4H-Naph), opt. substd. by halogen or CN; Z1-3 = -CO-O-, -O-CO-, -CH2CH2-, -OCH2-, -CH2O-, -C=C- or a single bond; m = 1 or 2; n = 0 or 1; o = 1, 2 or 3. The claims also cover the nematic LC mixt.. n = 0; R1-2 = 1-16C alk(en)yl, in which 1 or 2 CH2 gps. may be replaced by -O-, -S-; m = 1; A1 = Cyc, Phe, Cyc-Cyc or Phe-Phe; Z1 = -CH2O-, -CO-O-, -CH2CH2- or a single bond. The cpds. used are known cpds. or can be prepd. by methods analogous to those for known cpds.. Examples of (I) are described in WO8908637, DE3906019 and DE3906052 and examples of (II) in DE2918775. USE/ADVANTAGE - The cell is esp. suitable for shutter-type displays. These mixts. give a better combination of high negative dielectric anisotropy and long-term stability than known LC materials.
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| 申请人 |
MERCK PATENT GMBH, 64293 DARMSTADT, DE |
发明人 |
JUNGE, MICHAEL, DR., 6102 PFUNGSTADT, DE;REIFFENRATH, VOLKER, 6101 ROSSDORF, DE |
