Hoechst Aktiengesellschaft

Carl Martin Bell

Reinhard Wagener

Karsten Blatter

Hermann Josef Gohl

Process for the preparation of polyether-amide solutions, steam-sterilizable dialysis membranes obtainable using the polyether-amide solutions, and a process for the production of these membranes. Polycondensation of one or more dicarboxylic acid derivatives of the formula I ##STR1## with one or more aromatic diamines of the formula II ##STR2## and, if appropriate, m-phenylenediamine, in aprotic polar solvents is known. As a result of passing ammonia, in an amount sufficient to neutralize the HCl formed, into the polymer solution obtained after the end of the polycondensation and filtering off the ammonium chloride formed, it is possible to prepare neutral, salt-free and particularly storage-stable polyether-amide solutions which can be further processed to membranes without isolation of the polymer. The resulting membranes are steam-sterilizable, chemically and thermally stable and show efficiency data in the region of that of good high-flux dialysis membranes. Flat and hollow fiber membranes for ultrafiltration.

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Hechingen, Germany

Carl Martin Bell