Liquid crystalline medium

Abstract

The present invention relates to a liquid-crystalline medium which comprises at least one compound of the formula I, in which R1 and R1* each, independently of one another, denote an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH2 groups in these radicals may each be replaced, independently of one another, by —C≡C—, —CF2O—, —OCF2—, —CH═CH—, —O—, —CO—O—, —O—CO— in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, L1 and L2 each, independently of one another, denote F, Cl, CF3 or CHF2, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PA-VA, SS-VA, SA-VA, PS-VA, PALC, IPS, PS-IPS, FFS or PS-FFS effect.

Description

technical field [0001] The invention relates to liquid-crystalline media comprising at least one compound of the formula I, [0002] [0003] in [0004] R 1 and R 1* Each independently of each other represents an alkyl or alkoxy group having 1-15 C atoms, wherein in addition, one or more CH in these groups 2 The groups can be each independently of each other by -C≡C-, -CF 2 O-, -OCF 2 -, -CH=CH-, -O-, -CO-O-, -O-CO- are replaced in such a way that the O atoms are not directly connected to each other, and wherein in addition, one or more H atoms may be replaced by halogen, [0005] L 1 and L 2 Each independently represents F, Cl, CF 3 or CHF 2 . [0006] Media of this type can be used, in particular, in electro-optic displays and IPS (In-Plane Switching) displays or FFS (Fringe Field Switching) displays with active-matrix addressing based on the ECB effect. Background technique [0007] In 1971, the principle of electric field controlled birefringence, namely...

AI Technical Summary

Problems solved by technology

However, properties such as low temperature stability must not be affected at the same time

Images