Basf Aktiengesellschaft

Gunter Pipper

Eckhard M Koch

Martin Weber

Herbert Fisch

Axel Gottschalk

Christoph Plachetta

Walter Goetz

Horst Reimann

Alfons Ludwig

Hans-Peter Weiss

Volker Warzelhan

Gerd Blinne

Peter Hildenbrand

Gerhard Heinz

Peter Bauer

Claus Cordes

Franz Schmidt

Walter Betz

Josef G Floss

Motonori Yamamoto

Ursula Seeliger

Rainer Theysohn

Ralf Mohrschladt

Martin Laun

Wolfgang F Mueller

Stefan Grutke

Franz Zahradnik

Peter Steiert

Dieter Bernhard Beimborn

Udo Pagga

Siegfried Riegger

Bernd Bruchmann

Wolfgang Harder

Graham E McKee

Peter Ittemann

Eberhard Fuchs

Bernd Hisgen

Brigitte Gareiss

Thomas Heitz

Volker Hildebrandt

Axel Wilms

Robert Weiss

Josef Wunsch

Georg N Simon

Karl Schlichting

Hermann Fischer

Jens Rieger

Peter Wolf

Andreas Kleinke

Karlheinz Ulmerich

Paul Matthies

Rainer Neuberg

Eduard Heil

Richard Thoma

Thomas Sauer

J&ouml;rg Erbes

Dieter Krauss

Gisbert Schleier

Uwe Faller

James Hurley

Alexander Gluck

Walter G&ouml;tz

Reinhard Lang

Klaus Muhlbach

Wilfried Vogel

Heiner Gorrissen

Harald Dauns

Guenter Mattern

Dieter Keller

Ragnhild Pille

Christoph Kowitz

J&uuml;rgen Deininger

Hans-Harald H&uuml;nger

An apparatus ( ) is proposed for drying and heat-treating pellets with a stream of inert gas, wherein the apparatus has a cuboid base unit ( ) with a feed ( ) for the pellets in its upper part and an outlet ( ) in its lower part, with a feed ( ) on one lateral surface and with an exhaust base ( ) on the opposite lateral surface of the cuboid base unit ( ) for the stream of inert gas, and also with distribution and retention equipment ( ) in the region of the feed ( ) and, respectively, of the exhaust ( ) for the stream of inert gas, where each of these extends essentially over the entire vertical cross section of the cuboid base unit ( ).

Device for drying and thermally treating granulates with an inert gas stream

Method for the continuous production of copolyamides based on a lactam (I), a diamine (II) and a dicarboxylic acid (III)

The disclosure is a process for preparing polyamides by concentrating the wash water extract from the extraction of polyamide to an extractables content of not more than 85% by weight, adding fresh lactam down to a water content of from 0.5 to 13% by weight, and effecting at least one adiabatic expansion during the polymerization.

Preparation of polyamides

In a process for producing polyamides by polymerization of lactams in the presence of metal oxides as heterogeneous catalysts, the metal oxides are used in a form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of or on completion of the polymerization.

Method for producing polyamides

A process for continuous extraction of polyamide particles using a recirculating extractant in a vertical extraction column that is divided into two zones comprises treating the polyamide with an aqueous extractant comprising from 40 to 95% by weight of &egr;-caprolactam in a first zone at from 100 to 140&deg; C., and then effecting an aftertreatment with water in a second zone. The caprolactam can then be extracted in a conventional manner. The process provides for economical production of polyamide having a low dimer content.

Continuous polyamide extraction process

A process for continuous extraction of polyamide particles in an essentially vertical extraction column using an aqueous extractant comprises using an extraction column that is divided into two zones and performing an extraction with a recirculating 15-40% strength by weight aqueous &egr;-caprolactam solution in the first zone and then with countercurrent water at a from 5 to 40&deg; C. lower temperature in the second zone. The process provides for economical extraction of polyamides with a low level of monomers and oligomers.

Molding compositions comprising random copolyamides, their use, and process for their preparation

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Bad Durkheim, Germany

Gunter Pipper