Abstract: Nematic liquid crystalline mixtures, which can be used in optoelectronic components. Compounds are provided which influence the characteristics of mixtures in the direction of high clarification temperatures at simultaneous favorable switching times. It has been found that compounds of the general formula ##STR1## wherein n, m=1 to 10 in nematic mixtures in quantities of 5 to 40% considerably increase the clarification points without significantly increasing the viscosity, so that favorable switching times are obtained. The new mixtures can be used for the production of optoelectronic components (displays) for watches, computers and other devices.

Abstract: What is described is an improved opto-electronic component and display which uses novel liquid crystal nematic substances for the control of the light transmission and for the display of numbers symbols and images. The novel nematic liquid crystal substances herein, which exhibit high clearing temperatures, low working temperatures and rapid switching times, are 7-alkyl-perhydrophenanthren-2-carboxylic acids and esters thereof.

Abstract: The invention relates to nematic liquid crystals, especially for electro-optical components for the modulation of transmitted or reflected light, as well as for the display of numbers, symbols and images, exhibiting favorable physical characteristics, as well as to a method for the production of the new substances.It has been found that new liquid crystal 2-substituted-1,3-dioxane-5-carboxylic acid esters of the general formula ##STR1## are suited for use in electro-optical components for the modulation of the light, as well as for the display of numbers, symbols and images, and can be used alone, in mixtures with each other and/or in mixtures with additional liquid crystal or non-liquid crystal substances.

Abstract: The invention relates to liquid crystal nematic substances based on new derivatives of 1,3-dioxanes in electro-optical components, which are used, for instance, as displays in electronic clocks and computer systems.The subject of the invention is nematic liquid crystal substances with favorable properties concerning melting and clear temperatures, stability against thermal stress and electrical fields, low viscosity and low threshold voltage.It was found that liquid crystal 2,5-di-substituted cyclohexyl derivatives of 1,3 dioxanes, having the general formula ##STR1## 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 COO; CN; NO.sub.2 ; F; Cl; Brand R.sup.2 =C.sub.n H.sub.2n+1 with n+1 to 9are suitable for use in electro-optical components.

Abstract: The invention relates to light emitting semi-conductor components, in which the individual chips are located at the cross-points between two mutually vertically oriented systems of parallel conducting paths, so that line- or matrix forms are created. Such components are used to produce electro-optical exhibits of numbers, letters or symbols, for instance, in the optical exhibit of recorded material.The invention employs only one supporting substrate with recesses for the semi-conductor light emitter chips and for the distribution of light as well, with at least one conducting path system, which is connected by means of conducting and non-conducting adhesives on the viewing side to a diffusion film, and on the backside to a flexible, conducting plate, which supports the semi-conductor chips.

Abstract: A nematic liquid crystal compound adapted for the modulation of the transmitted or incident light and reproduction in color of numerals, symbols and images by electro-optical devices, the said compound having the formula ##STR1## wherein R.sup.1 .dbd.Br--, Cl--, C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, n being 1 to 10,R.sup.2 .dbd.C.sub.n H.sub.2n+1 --, n being 2 to 10,R.sup.3 .dbd.C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, n being 1 to 10,R.sup.4 .dbd.C.sub.n H.sub.2n+1 --, C.sub.n H.sub.2n+1 O--, n being 1 to 10.

Abstract: Nematic liquid crystals are employed in electro-optical devices for the modulation of the transmittant or incident light and for the black and white or colored rendition of numerals, symbols and pictures.The object of the invention is the use of nematic liquid crystals having a high positive dielectric anisotropy, a low threshold and operating voltage and high clear points and a process for making these compounds.It was found that as liquid crystals for electro-optical devices mixtures are useful which, as an essential component, contain one or several compounds from the class of 5-cyano-2-[4-acyloxyphenyl]-pyrimidines of the formula ##STR1## wherein R.sup.1 is ##STR2## C.sub.5 H.sub.11 -- or C.sub.n H.sub.2n+1 O-- R.sup.2 is C.sub.n H.sub.2n+1 ; C.sub.n H.sub.2n+1 O; C.sub.n H.sub.2n+1 S; F; Cl; Br; CF.sub.3 ; C.sub.n H.sub.2n+1 COO; C.sub.n H.sub.2n+1 OCOO; CN; NO.sub.2 ; C.sub.n H.sub.2n+1 NH; or C.sub.n H.sub.2n+1 (CH.sub.3)N, n is 1 to 10, andR.sup.3 is C.sub.n H.sub.2n+1,n is 1 to 10.

Abstract: Liquid crystal substituted 1,3 dioxanes and mixtures containing the same.The invention relates to liquid crystalline substituted 1,3 dioxanes and substances containing the same, for electrooptical arrays for the modulation of incident or transmitted light as well as for the reproduction of figures, symbols and images.The objects of the invention are nematic crystal liquid substances with favorable properties with respect to melting and clear points; stability toward thermal stress, effect of light, chemicals and electric fields as well as loss of color; and processes for their production.The task is solved by the creation of new nematic liquid-crystal substances.As per invention, liquid crysalline 2,5-disubstituted derivatives of 1,3-dioxane of the general formula: ##STR1## are proposed, wherein: ##STR2## The new substances are used in mixtures containing at least one of the substances according to the invention.

Abstract: A nematic liquid crystal mixture for modulation of the transmitted or incident light and for rendition of colored numerals, symbols and images in electro-optical devices, the said mixture comprising(a) a nematic liquid crystal adapted for reorientation in an electrical field due to its dielectric anisotropy and(b) a dichroic dyestuff adapted for simultaneous orientation changes together with the said nematic liquid crystal between a light absorption and a light transmission position based on the guest-host effect, the said dyestuff being an s-tetrazine derivative having an elongate molecular structure and having the formula ##STR1## wherein X is ##STR2## R.sup.1 and Y is R.sup.2 -- or ##STR3## R.sup.1 being H--, F--, Cl--, Br--, J--, O.sub.2 N--, NC--, HO--, H.sub.2 N--, C.sub.n H.sub.2n+1 NH--, C.sub.n H.sub.2n+1 (CH.sub.3)N--, C.sub.n H.sub.2n+1" --, C.sub.n H.sub.2n+1 O--, C.sub.n H.sub.2n+1 S--, C.sub.n H.sub.2n+1 COS--, C.sub.n H.sub.2n+1 COO--, C.sub.n H.sub.2n+1 OOC--, C.sub.n H.sub.2n+1 CO-- or C.sub.

Abstract: 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.3R.sup.2 =C.sub.n H.sub.2n+1n denotes any of the numbers between 1 and 10.These substituted pyrimidines are used in electro-optical device elements singly or as mixtures of each other, as well as mixtures with other liquid-crystalline or non liquid-crystalline components.