Basf Aktiengesellschaft

Ralf Mohrschladt

Volker Hildebrandt

Dieter Krauss

Gunter Pipper

Eberhard Fuchs

Alfons Ludwig

Martin Weber

Wolfgang Harder

Volker Warzelhan

Motonori Yamamoto

Robert Weiss

Helmut Winterling

Martin Leemann

Dieter Keller

Method for the production of polyamides

Described is the use of metal oxides as heterogeneous catalysts in a process for producing polyamides by polymerization of lactams and optionally further polyamide-forming monomers wherein the metal oxides are used in a form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture during or after the polymerization, to reduce the extractables content of the polyamide obtained.

Use of heterogeneous catalysts in methods for the production of polyamides

In a process for producing polyamides, a mixture comprising hexamethylenediamine and aminocapronitrile and obtained from the hydrogenation of adiponitrile is reacted with water and a dicarboxylic acid.

A process for producing polyamides by reacting at least one lactam and optionally further polyamide-forming monomers with aqueous monomer and oligomer extracts obtained during the extraction with water of the polymer product obtained in the production of polyamides, the water content of the reaction mixture being in the range from 0.5 to 13% by weight comprises conducting the reaction in the presence of metal oxides, beta-zeolites, sheet-silicates or silica gels, which may be doped, as heterogeneous catalysts, the heterogeneous catalysts being used in the form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of the polymerization or after it has ended.

Method for preparing polyamides from lactams and polyamide extracts

Disclosed are the use of lactams, aminocarboxylic acids or mixtures thereof as acceleratant or cocatalyst in the production of polyamides from aminonitriles and water, and a suitable process therefor.

Accelerator for the production of polyamides from aminonitriles

Method for producing polyamide 6 of a low extract content, high viscosity stability and low remonomerization rate

Method for producing polyamides from amino carboxylic acid compounds

Aqueous monomer and oligomer extracts obtained from polyamide production by extraction of the polymer with water are used for producing polyamides by direct reaction with aminonitriles.

Method for producing polyamides from aminonitriles

Method for producing polymer mixtures comprised of amino nitriles and thermoplastic polymers

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

Polyamide particles, or polymer particles comprising polyamides, are extracted with aqueous solutions of aminonitiles and optionally further polyamide-forming monomers, polyamide-forming oligomers or mixtures thereof.

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Schwetzingen, Germany

Ralf Mohrschladt