Degussa Aktiengesellschaft

Evonik Degussa Gmbh

Huels Aktiengesellschaft

Norbert Wilczok

Martin Roos

Georg Oenbrink

Thomas Schiffer

Juergen Herwig

Franz-Erich Baumann

Dirk Kuppert

Jürgen Herwig

Bernd Guenzel

Johann Gaube

Wilhelm Brügging

Peter Wiedenbusch

Anita Völkel

Anita Voelkel

Rudolf Burghardt

Manfred Thiery

Matthias May

The present invention relates to the preparation of trimethylcyclododecatriene in a continuous or batchwise process by trimerizing isoprene in the presence of a catalyst system and of a solvent. It is possible to isolate the resulting crude trimethylcyclododecatriene by means of distillation. The dimethylcyclooctadiene formed as a by-product may likewise be isolated from the crude product.

Method for producing trimethylcyclododecatriene

Preparation of cyclododecatriene in a continuous or discontinuous process by trimerization of butadiene in the presence of a catalyst system and a solvent, the crude cyclododecatriene obtained being able to be isolated by means of distillation. The cyclooctadiene formed as by-product can likewise be isolated from the crude product.

Process for preparing cyclododecatriene

A process for preparing cyclododecene by selective gas-phase hydrogenation of at least one starting material selected from cyclododecatriene, cyclododecadiene and mixtures thereof, wherein the starting material present in the gas phase is hydrogenated in the presence of a catalyst in a fixed-bed reactor and the Bodenstein number for the process is greater than 100.

Selective hydrogenation of cyclododecatriene to cyclododecene

A process for the isolation of high-boiling monomers from distillation residue formed in the cyclodimerization and/or cyclotrimerization of 1,3-butadiene after target products of cyclooctadiene, vinylcyclohexene and/or cyclododecatriene have been separated off, comprising extracting the distillation residue with a nonpolar or slightly polar solvent, separating off insoluble oligomers and polymers that have at least partly crystallized by mechanical separation, removing the extractant, and isolating the high-boiling monomers.

Process for the isolation of high boilers from the cyclooligomerization of 1,3-butadiene

Cyclododecatrienes may be prepared in a continuous process by reacting 1,3-butadiene in the presence of a catalyst system and cyclooctadiene and/or cyclododecatriene. The resulting crude cyclododecatriene product may be separated from this mixture by distillation, and 50 to 100% of the catalyst system may be recycled back into the process.

Process for preparing cyclododecatrienes with recycling of the catalyst

Certain applications require polyamide powders of narrow particle size distribution and low porosity. The precipitation process of the invention incorporating a prior nucleation phase provides the desired products.

Preparation of precipitated polyamide powders of narrow particle size

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Muelheim, Germany

Norbert Wilczok