Wacker-chemie Gmbh

Hoechst Aktiengesellschaft

Ernst Selbertinger

Ludwig Schmidhammer

Gunter Roscher

Rudolf Strasser

Gerhard Dummer

Dominik Dempf

Karl-Heinz Schmidt

The invention relates to a process for the manufacture of unsaturated carboxylic acid esters by the reaction of olefins or cyclo-olefins with oxygen and carboxylic acids in the gaseous phase, in the presence of a catalyst which contains elements of the subsidiary group VIII of the periodic system and/or compounds thereof, and an alkali metal acetate, at temperatures of from 100.degree. to 250.degree. C. and pressures of from 0.5 to 21 bar absolute, wherein from 1 to 8000 parts per million (by weight), calculated on the carboxylic acid used, of organic chlorine compounds are added to the reaction mixture.

Process for the manufacture of unsaturated carboxylic acid esters

In the chlorination of ethylene in the liquid phase, an excess stoichiometric amount of chlorine is normally used in order to achieve as complete as possible a conversion of the ethylene. Part of the excess chlorine reacts by substitution and thereby reduces the yield of desired 1,2-dichloroethane. The unreacted excess chlorine therefore has laboriously to be removed in subsequent reaction steps. As a result of the method according to the invention to limit the chlorine excess to less than 600 ppm by weight in the reaction cycle, these disadvantages can be obviated. The constant compliance with such a low chlorine excess without fluctuations is rendered possible in industrial operation by the arrangement according to the invention for the continuous recording of the chlorine concentration, even in the presence of catalysts.

Process for the continuous chlorination of olefins in the liquid phase

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Marktl, Germany

Ernst Selbertinger