Bayer Aktiengesellschaft

Heinrich Haupt

Hans-Josef Buysch

Josef Merten

Bert Brassat

Andreas Gittinger

Christian Lindner

Rudolf Binsack

Claus H Wulff

Karl H Hermann

Ludwig Trabert

Konrad Triebeneck

Dieter G&ouml;bbels

Hugo Vernaleken

Karsten-Josef Idel

Werner Nielinger

Leo Morbitzer

Dietrich Michael

Eckart Reese

Wolfgang Richter

Gunter B Weber

Heinz Bonten

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

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

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

This invention relates to high-impact mixtures of polyamides and polymers based on polyacrylates or polybutadienes having improved processing behaviour and improved technological properties and to the production of these polymers by a multistage process.

High-impact polyamide moulding compositions

Unfilled, unreinforced polyamide moulding compounds are disclosed which have high rigidity and notched impact strength and are highly fluid in the molten state, containing aliphatic polycarbonate polyurethanes which are substantially unbranched in the carbon chain, prepared from polyhexamethylene carbonate diols and/or mixtures thereof with oligo- or polyalkylene glycols having 4-100 carbon atoms and 1,6-diisocyanatohexane.

Polyamides having high notched impact strength and high fluidity in the

Thermoplastic moulding materials, with improved toughness at low temperatures, of polyamide and cross-linked graft rubbers from the diene rubber and acrylate rubber series, obtained by heating blends of the two components below the melting point of the polyamide.

Molding compounds of thermoplastic polyamide and graft rubber

Weather-resistant polyamides stabilized by a combination of special cyclic phosphorous acid esters and certain indole derivatives.

Weather-resistant polyamides

This invention relates to flame-proved polyamide moulding compositions containing a combination of from 10 to 18%, by weight melamine and from 1 to 7% by weight of a thermoplastic polyacetal, in each case based on the moulding composition.

Fire-resistant polyamide moulding compositions

Stabilized polyamides containing from 0.02 to 5%, by weight of a diphenylamine compound corresponding to the following general formula: ##STR1## wherein R.sup.1 and R.sup.3, which may be the same or different, represent hydrogen, a CH.sub.3 --, C.sub.2 H.sub.5 -- or isopropyl group and R.sup.3 is in the o-, m- or p-position to the N-atom substitution;

Stabilized polyamides

Extruded films having reduced proneness to stress-cracking, good resistance to casting resins of unsaturated polyesters and no blocking effect and produced from branched aromatic polycarbonates which are the reaction products of aromatic dihydroxy compounds and branching agents having more than three phenolic hydroxyl groups, with polycarbonate precursors. The films are useful as insulating films in the electrical industry.

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Krefeld, Germany

Heinrich Haupt