Bayer Aktiengesellschaft

Jurgen Lahrs

Wulf Von Bonin

Klaus Schubert

Harald Gleinig

Erhard Schellmann

Eberhard Born

Dietrich Liebsch

Dorde Jovcic

Werner Schulte-Huermann

Claus Gosling

Hans-Joachim Hennig

Reiner Skerhut

Organic mono- or poly-isocyanates are produced on a continuous basis by phosgenating the corresponding amines. A solution of the amine to be phosgenated is continuously sprayed through a smooth-jet nozzle into a solution of phosgene continuously flowing through a mixing chamber. The mixing chamber is maintained at a temperature of 120.degree.to 300.degree. C. and a pressure of from 10 to 1000 bars. The molar ratio of phosgene to primary amino groups is generally from 2:1 to 30:1.

Continuous process for the production of organic isocyanates

Pulverulent preparations with a low dust content, in particular dyestuff powders, are obtained when the customary dustproofing agents are not added before the drying process and also are not sprayed directly onto the product to be dustproofed, but are allowed to act on the pulverulent product in the form of an aerosol. The average particle size of the aerosol is less than 10.mu..

Process for the manufacture of preparations with a low dust content

A modular block for osmotic methods of separation under pressure can be folded open and the filtration unit can easily be removed and introduced in the process. The filtration unit consists of a base plate with a membrane filter candle, and the filter candle consists of a stack of membrane filter plates. Spacers are placed between the filter plates and deflecting plates are provided to ensure zigzag penetration. The permeate transportation is displaced to the edge of the plates. The permeate issues laterally at the flange.

Modular block for osmotic methods of separation

In a process for the continuous preparation of chloroformic acid methyl ester by contacting phosgene with methanol at a temperature of up to 50.degree. C. in a reactor which contains chloroformic acid methyl ester as the solvent and in which phosgene is dispersed, the improvement wherein gaseous phosgene is dispersed by already formed and circulated chloroformic acid methyl ester into the reaction chamber by means of a dispersing device, and at the same time methanol is introduced into the homogeneous gas-in-liquid dispersion.

Process for the preparation of chloroformic acid methyl ester

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Cologne, Germany

Jurgen Lahrs