Bayer Aktiengesellschaft

Andreas Gittinger

Heinrich Haupt

Karsten-Josef Idel

Edgar Ostlinning

Konrad Triebeneck

Dieter G&ouml;bbels

Friedrich-Karl Bruder

Claus H Wulff

Werner Nielinger

Detlev Joachimi

Aziz El-Sayed

Helmut Schulte

Ralf Lange

Heinrich Morhenn

Cliff Scherer

Hans-J&uuml;rgen Dietrich

A process for using low-molecular weight compounds that are water-extracted from (co)polyamides in the production of polyamide is disclosed. The process entails reacting these compounds with 10 to 15 wt. % water for a period of 3.5 to 6 hours at a temperature of 220&deg; C. to 270&deg; C., and polymerizing the resulting product along with caprolactam.

Process for the production of polyamide

The invention relates to thermally stable, weather-resistant polyamide moulding compositions containing as stabiliser, a mixture of a copper halide, one or more halogen compounds and hypophosphorous acid or an alkali metal or alkaline earth metal salt of this acid, wherein the individual components of the stabiliser mixture are added in an amount such that the molar amount of halogen contained in the moulding composition is greater than or equal to six times the molar amount of and less than or equal to fifteen times the molar amount of copper contained in the moulding composition and the molar amount of phosphorus is greater than or equal to the molar amount of and less than or equal to ten times the molar amount of copper contained in the moulding composition.

Thermally stable, weather-resistant polyamide moulding compositions

A process for removing low molecular weight constituents from polyamide 6 or from copolyamides based on caprolactam (herein (co)polyamide) is disclosed. The process comprise subjecting the (co)polyamide to liquid-extraction at a temperature which is above the boiling point of the liquid at atmospheric pressure said liquid containing water in an amount of at least 80 percent relative to its weight.

Process and device for extracting polyamide

A process for the production of polyamides is disclosed. In a first reaction step, suitable monomers such as caprolactam or an aliphatic aminocarboxylic acid are reacted with polyfunctional amines, which contain at least one secondary amino group, and/or with salts containing such amines and dicarboxylic acids. The reaction product is in a further process step undergoes solid phase post-condensation.

Method of producing branched polyamides

The invention relates to a method for recycling (reprocessing) aqueous extract solutions obtained in the production of polyamides. The method for reprocessing the aqueous extract solutions obtained consists in that the aqueous extract solution is concentrated and polymerised, adding small amounts of dicarboxylic acid or polycarboxylic acid to the extract solution.

Method for reprocessing aqueous extract solutions obtained in the

The invention relates to a process for the production of high molecular weight polyamide 6 (polycaprolactam).

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Krefeld, Germany

Andreas Gittinger