Hoechst Aktiengesellschaft

Other

Peter Wegener

Wilhelm Riemenschneider

Norbert Rosch

Michael Feldhues

Takamasa Harada

Heinz Litterer

Rainer Wingen

Hans-Rolf Dubal

Steffen Dapperheld

Thomas Mecklenburg

Gunther Kampf

Dieter Ulmschneider

Frank P Sistig

Heinz Rieger

Alignment layers containing cyclic structural elements

Ferroelectric liquid-crystal display of high contrast and brightness. The use of alignment layers containing compounds having an amphiphilicity-providing effect increases the contrast and brightness of the image in FLC displays.

Ferroelectric liquid-crystal display of high contrast and brightness

A liquid crystal mixture composed of at least two components containing as one component a macrocyclic compound of the general formula (1) ##STR1## in which a, b, c, d, e, f, independently of one another, are an integer from zero to 4, a+b+c+d+e+f being greater than 7, and --A--, --B--, --C--, --D--, --E--, --F--, identical or different, are, for example, --CH.sub.2 --, --CH.dbd.CH--, --CO-- or --COO--, leads in FLC displays to the formation of a uniform alignment and avoids twist states, which is reflected in a significantly improved contrast.

Macrocyclic compounds as component for ferroelectric liquid crystal

Selectively dehalogenated thiophene derivatives are obtained from compounds of the formula II ##STR1## by an electrochemical reaction in a divided electrolysis cell in the presence of a suitable solvent, an onium compound or a compound which is converted into an onium compound in the electrolyte, and a conducting salt. Thiophene derivatives are important intermediates in the production of pharmaceuticals and plant protection agents.

Process for the preparation of thiophene derivatives

The invention relates to intrinsically electrically conductive polymers, preferably oligomers, which, in the oxidized form, are completely soluble in dipolar aprotic solvents at room temperature and which contain structural units which are derived from at least one monomer of the formula (I) ##STR1## in which R.sup.1 is a C.sub.1 -C.sub.2 -alkoxy group or --O(CH.sub.2 CH.sub.2 O).sub.n CH.sub.3 with n=1 to 4 and R.sup.2 is a hydrogen atom, a C.sub.1 -C.sub.12 -alkyl group, a C.sub.1 -C.sub.12 -alkoxy group or --O(CH.sub.2 CH.sub.2 O).sub.n CH.sub.3 with n=1 to 4, or R.sup.1 and R.sup.2 together are --O(CH.sub.2).sub.m --CH.sub.2 or --O(CH.sub.2).sub.m --O-- with m=1 to 12. The invention also relates to a process for the preparation of these polymers by electrochemical polymerization of at least one monomer of this formula (I) in the presence of a conductive salt, the anode having a specific surface area of at least 0.01 m.sup.2 /g and preferably a gauze, sponge, fabric or felt structure, the electrolyte solvent being dipolar and aprotic and the electrolyte system being moved only slightly or not at all relative to the anode. The polymers according to the invention can readily be used especially for coating purposes.

Soluble, electrically conductive polymers, process for preparing them,

Thiophene ethers having relatively large side chains can be easily obtained by reacting 2-, 3-, 2,3-, 2,4- or 3,4-C.sub.1 -C.sub.3 -alkoxythiophenes in the presence of an acid catalyst with a compound containing an OH group. The novel thiophene ethers are suitable as monomers for electrically conducting polymers.

Process for the preparation of thiophene ethers

The invention relates to a process for the production of chloroalkylsulfonyl isocyanates of the formula ##STR1## by a catalytically induced reaction of chlorosulfonyl isocyanate with one or more C.sub.2 -C.sub.4 -olefins. The reaction is carried out in a continuous manner in a tubular reactor.

Continuous process for the production of chloroalkyl-sulfonyl isocyanates

Cyanoformamide is prepared when cyanogen is contacted with a catalyst solution containing low molecular aliphatic carboxylic acids, from 0.025 to 1.0 mole/1 of copper-(II)-salts and up to 5% by weight of water. Hydrogen cyanide can be used instead of cyanogen, if the catalyst solution contains nitrate ions in addition.

Process for preparing cyanoformamide

Cyanogen is produced by catalytic oxidation of hydrogen cyanide with oxygen in the presence of a catalyst solution. The catalyst solution consists of aliphatic ethers or of nitriles and copper(II)nitrate and may further contain up to 20 % by weight of water.

Process for the manufacture of cyanogen

By contacting hydrogen cyanide with oxygen or air and a catalyst solution containing water, low molecular weight aliphatic carboxylic acids, copper ions and nitrate ions oxalic acid diamide is formed in high yields.

Growing community of inventors

Konigstein/Taunus, Germany

Peter Wegener