New cyclobutane derivatives, useful as components of liquid crystal media for liquid crystal displays, reflective or trans-reflective displays and electro-optical displays

摘要

New cyclobutane derivatives with mesogenic groups attached to a cyclobutane ring with a carbonyl or optionally halogenated methylene group or two chlorine or fluorine atoms at position 2 and optionally an alkyl or methylene group at position 3. Cyclobutane derivatives of formula (I) are new. R1 = H, CN, F, OCHF2, OCF3, OCHFCF3, OCH2CF3, OCF2CF3 or 1-12C alkyl (optionally substituted with halogen or CN and optionally with one or more non-adjacent CH2 groups replaced by O, S, CO, cyclobutane-1,3-diyl, COO, OCO, OCOO or CH=CH groups); Q = C=O, CCl2, CF2 or C=CX1X2; X1, X2 = H, Cl or F; Y = CHR2 or (if Q = CCl2 or CF2) also C=CHR2; R2 = H or 1-12C alkyl (optionally with CH2 group(s) replaced as above); A, A1 = (a) trans-1,4-cyclohexylene, optionally with one or more non-adjacent CH2 groups replaced by O and/or S, (b) 1,4-phenylene, optionally with one or two CH groups replaced by N; (c) 1,4-bicyclo(2.2.2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl or its decahydro- or 1,2,3,4-tetrahydro derivatives, or (d) 1,4-cyclohexenylene, where groups (a), (b) and (d) may also be substituted with CN, Cl or F; Z1 = COO, OCO, CH2O, O, OCH2, CH2CH2, CH=CH, C equivalent to C or a single bond; and m = 1, 2 or 3. Independent claims are also included for: (a) liquid crystal (LC) media with at least two LC components, containing at least one compound (I); (b) LC display elements containing such media; and (c) reflective or trans-reflective LC display elements