Hoechst Aktiengesellschaft

Claus-Peter Krieg

Michael Haubs

Willi Kreuder

Detlef H Skaletz

Friedrich Herold

Juergen Wildhardt

Eberhard Ritter

Detlev Keil

Wildhardt Juergen

A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I: ##STR1## wherein E.sup.1 and E.sup.2 are identical or different and are selected from the groupings ##STR2## --AR.sup.1 --, and --AR.sup.1 --X--AR.sup.2, where AR.sup.1 and Ar.sup.2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C.sub.1 -C.sub.6)-alkyl, (C.sub.1 -C.sub.6)-alkoxy, --CF.sub.3 or halogen and X denotes

Semipermeable membrane made from a homogeneously miscible polymer blend

A process for the preparation of 4-halo-3-oxo-2-alkoxyiminobutyric esters. A process for the preparation of 4-halo-3-oxo-2-alkoxyiminobutyric esters by solvent-free halogenation of the liquid substrate of a 3-oxo-2-alkoxyaiminobutyric ester with elemental halogen.

Process for the preparation of 4-halo-3-oxo-2-alkoxyaminobutyric esters

A macrophorous, asymmetric, hydrophilic membrane containing polyaramid is described. The characterizing features are that it contains a copolyamide which has at least the following recurring structural units:

Macroporous, asymmetric, hydrophilic polyaramide membrane

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Claus-Peter Krieg