Liquid crystalline medium with a nematic phase and a negative dielectric anisotropy, useful in electro-optical displays or components, comprises a substituted cyclic compound and a compound comprising substituted piperidine structural unit

摘要

Liquid crystalline medium with a nematic phase and a negative dielectric anisotropy, comprises: (a) at least one substituted cyclic compound (I); and (b) at least one compound comprising at least one substituted piperidine structural unit (IIa) (upto 1 wt.%). Liquid crystalline medium with a nematic phase and a negative dielectric anisotropy, comprises: (a) at least one substituted cyclic compound of formula (I); and (b) at least one compound comprising at least one substituted piperidine structural unit of partial formula (IIa) (upto 1 wt.%). R 11, R 12upto 15C alkyl or upto 15C alkenyl (both unsubstituted) (where at least one CH 2group may be replaced by -O-, cyclobutane-1,3-diyl, -CC-, -CF 2-O-, -O-CF 2-, -CO-O- or -O-CO-, in which O atoms are not directly linked with each other, and at least one H may be replaced by halo); A 11-A 13substituted cyclohexane-1,4-diyl moiety of formula (Ia) or (Ib), cyclohexane-1,4-diyl, 2-fluoro-cyclohexene-1,4-diyl, cyclohexene-1,4-diyl, cyclohexene-3,6-diyl, [1,3]dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, benzene-1,4-diyl, 2-fluoro-benzene-1,4-diyl or 2,3-difluoro-benzene-1,4-diyl (where A 11, A 12and A 13are not equal); Y 1halo; Z 11, Z 12-CH 2-CH 2-, -CH 2-CF 2-, -CF 2-CH 2-, -CF 2-CF 2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -CC-, -CH 2-O-, -O-CH 2-, -O-, -CH 2-, -CO-O-, -O-CO-, -CF 2-O-, -O-CF 2- or single bond; n : 0 or 1; and R 21-R 25upto 15C alkyl or upto 15C alkenyl (both unsubstituted) (where at least one CH 2group may be replaced by -O-, -S-, cyclobutane-1,3-diyl, -CC-, -CF 2-O-, -O-CF 2-, -CO-O- or -O-CO-, in which O atoms are not directly linked with each other) or H. Independent claims are also included for: (1) an electro-optical display or an electro-optical component comprising the above liquid crystalline medium; (2) producing the liquid crystalline medium, comprising mixing at least one compound (I) with at least one compound (II); and (3) stabilizing the liquid crystalline medium, which comprises at least one compound (I), comprising adding at least one compound comprising 2,2,6,6-tetramethyl-piperidine derivative of formulae (II-1)-(II-7) into the medium. [Image] [Image] [Image] [Image] [Image].