Abstract: In a micromembrane pump with pump housing top and bottom parts and a membrane structure disposed between the housing top and bottom parts such that pump chambers, valves, flow channels and a cavity system are formed between the membrane structure and the housing parts, heating means are disposed on the membrane structure in the area of the pump housing for operating said pump and the cavity system is filled with a cement for joining the membrane and the housing parts.

Abstract: 2,6-dimethylphenylmaleimide is used as a comonomer for the preparation of styrene copolymers and vinyl chloride copolymers having an increased glass transition temperature and low intrinsic coloration compared with the prior art.

Abstract: A process for the dissolution of chemical compounds by use of ureas in which at least one of the urea's two nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom as a chemical solvent, and a method of producing tri- or tetraalkylated ureas or bis ureas wherein at least one of the urea's nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom by means of dialkylating the --NH.sub.2 group of a urea with an alkene or alkene arylene alkene dihalogenide, disulphonate or dihydrogen sulphonate in the presence of a solid base and a phase-transfer catalyst.

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds, and a process for the preparation of N-mono- or N,N-disubstituted ureas by reaction of ammonium isocyanates with a primary or secondary amine in a diluent.

Abstract: A process for the dissolution of chemical compounds by use of ureas in which at least one of the urea's two nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom as a chemical solvent, and a method of producing tri- or tetraalkylated ureas or bis ureas wherein at least one of the urea's nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom by means of dialkylating the --NH.sub.2 group of a urea with an alkene or alkene arylene alkene dihalogenide, disulphonate or dihydrogen sulphonate in the presence of a solid base and a phase-transfer catalyst.

Abstract: A process for the preparation of isocyanic acid, characterized in that N,N-disubstituted ureas are decomposed at elevated temperature to a secondary amine of lower volatility and to isocyanic acid, which is drawn off at the top.

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds, and a process for the preparation of N-mono- or N,N-disubstituted ureas by reaction of ammonium isocyanate with a primary or secondary amine in a diluent.

Abstract: Process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia by introducing a tertiary amine or ether at 250.degree. to 600.degree. C. The gaseous reaction mixture is passed into an inert diluent and cooled, to condense an adduct of isocyanic acid and tertiary amine or ether, and the ammonia being removed as a gas.

Abstract: Process for the preparation of asymmetrically substituted ureas, carbamates, thiocarbamates or substituted isocyanates by reaction of an adduct of isocyanic acid and a tertiary amine with a primary and secondary amine, an alcohol, a thiol or a compound having one or two non-cumulated olefinic double bonds.

Abstract: Process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia by introducing a tertiary amine or ether at 250.degree. to 600.degree. C. The gaseous reaction mixture is passed into an inert diluent and cooled, to condense an adduct of isocyanic acid and tertiary amine or ether, and the ammonia being removed as a gas.

Abstract: Process for the preparation of asymmetrically substituted ureas by reaction of a gaseous mixture of isocyanic acid and ammonia having a temperature of 260.degree. to 600.degree. C. with a primary or secondary amine.

Abstract: A method of producing thin sheets that are stretched over a frame and have planar and smooth surfaces with a low density of defects, and to the use of such sheets for the production of X-ray masks, wherein the sheet material is applied to a substrate through the intermediary of a release layer, whereupon the sheet is connected with the frame and separated from the substrate. During application of the release layer to the substrate, an area along the entire edge of the substrate is left free of the release layer material but is convered by the subsequently applied sheet material. Thereafter the sheet is connected with the frame in a region overlying the release layer and is severed around the periphery of the frame. Finally, the sheet and frame are released from the substrate and any release layer material remaining on the sheet is removed. The resulting sheet and frame arrangement may then be used to form an X-ray mask by applying desired X-ray absorber structures to the surface of the sheet.

Abstract: Process for selective removal and destruction of hydrogen cyanide contained in nitrous gases, in which the nitrous-containing gases are washed with nitric acid in counter-current in an absorption column and the nitric acid charged with hydrogen cyanide is regenerated at elevated temperature, with simultaneous hydrolysis and oxidation of the hydrogen cyanide.

Abstract: Acetonitrile and molten sodium are reacted at a temperature of 96.degree.-140.degree. C. in the presence of an organic solvent which is inert to sodium, to give the sodium salt of diacetonitrile, the salt is hydrolyzed with water, the aqueous and the solvent phases are separated off, and very pure diacetonitrile crystallizes out in cold water.

Abstract: A polyacrylonitrile fiber which has flame-retardant properties, is produced by dry spinning, has an acrylonitrile content of at least 85% by weight in the parent polymer and contains as flame retarder 15 to 40% by weight of tris-2,3-dibromopropyl isocyanurate, based on the polymer. The flame-retardant effect can be further increased by a content of up to 10% by weight of one or more synergistic compounds.

Abstract: Process for the preparation of monomeric methylolmelamine which is partially etherified with methanol or ethanol and which contains at least 4 moles of formaldehyde per mole of melamine, by reacting melamine, paraformaldehyde and methanol or ethanol in a single stage reaction, the molar ratio of melamine to formaldehyde to alcohol being 1:5 to 10:6 to 20, in a virtually anhydrous medium, under a nitrogen atmosphere, at a pH of 7 to 8 and a temperature from 50.degree. to 90.degree. C. and with a reaction time of from 3 to 30 hours.

Abstract: A filler for paper, card or board which has a good retention and consists of an inert core material and a hydrophilic coating, which consists of polyacrylamide having a molecular weight of 10.sup.5 to 10.sup.7 or of a mixture of this polyacrylamide with a urea-formaldehyde condensation resin. The filler is prepared by suspending the inert core material in an aqueous solution of a polyacrylamide having a molecular weight of 10.sup.5 to 10.sup.7 or in an aqueous solution of such a polyacrylamide and a urea-formaldehyde condensation resin, and drying this suspension by spray drying or in a stream of hot air. This crosslinks the initially water-soluble polymer and forms a coating, adhering to the core, which is insoluble in water but is hydrophilic and swells, and becomes tacky, in the presence of water.

Abstract: A storage-stable lacquer resin which can be baked without yellowing at a low baking temperature, and is based on an alkyd resin, acrylic resin or epoxy resin, is obtained by reacting the resin with a bis- or tris-alkoxyalkylamino-s-triazine which has been obtained by heating a triazine derivative of the general formula: ##STR1## wherein X is an alkyl group having 1 to 4 carbon atoms, a phenyl group or the group ##STR2## and each of R and R' is an alkyl group radical having up to six carbon atoms, at 100.degree. to 200.degree. C. up to a weight loss of 3 to 25%, preferably 5 to 15%.

Abstract: Foamed plastics with improved combustion characteristics are produced by condensing an aqueous solution of formaldehyde-urea and/or melamine precondensates with polyisocyanates and optionally a polyol in the presence of an acid catalyst, being present in an amount of 1 part by weight per at least 20 parts by weight of precondensate, whereby this catalyst is added to the isocyanate before mixing with the precondensate or to the mixture of isocyanate and precondensate, but separately from the precondensate.

Abstract: The resistance of plants to environmental factors such drought is increased by treating the plants themselves, their seeds before sowing or the surrounding soil, before or after emergence of the plants, with compositions containing aliphatic epoxymonocarboxylic acids containing one to three epoxy groups and 6 to 22 carbon atoms or the salts, lower alkyl esters, lower polyhydroxyalkyl esters, amides, monoalkylamides and dialkylamides thereof as active ingredient.