Huels Aktiengesellschaft

Degussa-huels Aktiengesellschaft

Bertram Trautvetter

Burkhard Standke

Jaroslaw Monkiewicz

Michael Horn

Albert-Johannes Frings

Hans-Guenther Srebny

Peter Jenker

Peter Jenkner

Claus-Dietrich Seiler

An apparatus for the purification of crude N,N&prime;-diphenyl-p-phenylenediamine (DPPD) in which there is an extraction unit containing a liquid permeable container and an adsorption layer downstream of the container, a solvent evaporator downstream of the adsorption layer, a filter unit, a line for returning the filtrate to the solvent evaporator, and a condenser for returning solvent to the extraction unit.

Apparatus for the purification of commercially available diphenyl-p-phenylenediamine (DPPD)

Acetoxysilanes are prepared by a process comprising:

Process for preparing acetoxysilanes

A process for the purification of crude N,N'-diphenyl-p-phenylenediamine (DPPD), which comprises extracting crude DPPD with a hydrocarbon or hydrocarbon mixtures thereby forming an extract solution containing DPPD, passing the extract solution over an adsorption layer, and recovering purified DPPD from the solution.

Process and apparatus for the purification of commercially available

A process for the stabilizing of an organosilane with an effective, stabilizing amount of purified N,N'-diphenyl-p-phenylenediamine (DPPD). The purification of crude DPPD involves extracting crude DPPD with hexane thereby forming an extract solution containing DPPD, passing the extract solution over an adsorption layer comprising silica gel as the adsorbent to form a solution containing purified DPPD and recovering the purified DPPD from the solution.

Process for the stabilizing of an organosilane

Organocarbonoyloxysilanes are prepared by reacting an organochlorosilane with a carboxylic acid in a first step which liberates HCl, removing the HCl which is formed, reacting the reaction mixture from the first step with a carboxylic acid anhydride in a second reaction step, the first and/or second reaction steps being conducted in the presence of a catalyst, and isolating the resulting organocarbonoyloxysilane product from the reaction mixture.

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Rheinfelden, Germany

Bertram Trautvetter