Veb Werk Fur Fernsehelektronik Im Veb Kombinat Mikroelektronik

Veb Werk Fur Fernsehelektronik

Adalbert Wiegeleben

Dietrich Demus

Horst Zaschke

Horst Kresse

Wolfgang Weissflog

Reinhard Paschke

Hermann Schubert

Uta Bottger

Nematic liquid crystalline substances as additives in mixtures for electro-optical systems for the rendition of numbers, symbols and images. The additives provide new liquid crystalline substances of broad mesophase ranges which improve the chemical stability of the substance mixtures. It has been found that liquid crystalline 5-alkyl-pyridine-2-carboxylic acid esters of the general formula ##STR1## are suitable for utilization in mixtures for electro-optical displays for the rendition of numbers, symbols and images.

Liquid crystalline substances

The invention relates to the application of nematic liquid-crystalline substances in electro-optical device elements for the display of numbers, symbols and images. Such nematic liquid crystals having low melting points and extremely high temperatures of transparency. The nematic liquid-crystalline substances are 5-alkyl-2-[4-acyloxyphenyl]-pyrimidines having the general formula ##STR1## wherein ##STR2## R.sup.1 =C.sub.n H.sub.2n+1, C.sub.n H.sub.2n+1 O, C.sub.n H.sub.2n+1 OCOO, C.sub.n H.sub.2n+1 COO, C.sub.n H.sub.2n+1 S, F, Cl, Br, NO.sub.2, CN CF.sub.3

Liquid crystalline 5-alkyl-2 (4-acyloxy-phenyl)-pyrimidine

As the liquid crystal substance in electro-optical devices or as the stationary phase in gas chromatography is employed a compound of the formula ##STR1## in which R.sub.1 and R.sub.2 each is C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 COO-- or C.sub.n H.sub.2n+1 OCOO--, n being an integer of from 1 to 10, and R.sub.3 is Cl--, Br--, CH.sub.3 --, C.sub.2 H.sub.5 --, CH.sub.3 CO-- or CH.sub.3 OOC--.

Nematic liquid crystalline substances

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Halle, Germany

Adalbert Wiegeleben