Loading patent…
AssigneeHoechst Aktiengesellschaft
InventorsKarsten Blatter, Reinhard Wagener, Carl Martin Bell, Hermann Josef Gohl
Estimating the term…
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.
A process for the preparation of a polyether-amide solution in which one or more dicarboxylic acid derivatives of the formula I ##STR12## in which Ar is a divalent, aromatic or heteroaromatic radical, the two carbonyl groups being on non-adjacent ring carbon atoms and the Ar radical selected is optionally substituted by one or two branched or unbranched radicals from the group consisting of C.sub.1 -C.sub.3 -alkyl, C.sub.1 -C.sub.3 -alkoxy, aryl, aryloxy, C.sub.1 -C.sub.6 -perfluoroalkyl and C.sub.1 -C.sub.6 -perfluoroalkoxy radicals, fluorine, chlorine, bromine and/or iodine, are subjected to a polycondensation reaction with one or more aromatic diamines of the formula II ##STR13## in which X is a group --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2, --CO--, --SO--, --SO.sub.2 --, --CH.sub.2 --, --S--, or --O-- or a direct bond, and optionally up to 50 mol % of the diamines II are replaced by m-phenylenediamine, in aprotic polar solvents, which comprises 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 salt formed.
A semipermeable, porous, asymmetric membrane comprising a polyaramid containing, as structural repeating units, one or more structural units of the formula I' ##STR14## in which Ar is a divalent, aromatic or heteroaromatic radical, the two carbonyl groups being on non-adjacent ring carbon atoms and the Ar radical is optionally substituted by one or two branched or unbranched radicals selected from the group consisting of C.sub.1 -C.sub.3 -alkyl , C.sub.1 -C.sub.3 -alkoxy, aryl, aryloxy, C.sub.1 -C.sub.6 -perfluoroalkyl and C.sub.1 -C.sub.6 -perfluoroalkoxy radicals, fluorine, chlorine, bromine and/or iodine, and, based on the sum of (II') and (III'), to the extent of 50 to 100 mol %, structural units of the formula (II') ##STR15## in which X is a group --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2, --CO--, --SO--, --SO.sub.2 --, --CH.sub.2 --, --S--, or --O-- or a direct bond, and, based on the sum of (II') and (III') 0 to 50 mol %, structural units of the formula (III') ##STR16## the membrane being obtained by the phase inversion process, in which a homogeneous polymer solution is brought into contact with a precipitating bath containing a precipitating liquid, the precipitating liquid being miscible with the solvent of the polymer solution and the polymers dissolved in the polymer solution being precipitated as a membrane, wherein the polymer solution has a chloride content of less than 0.1% by weight, based on the total weight of the polymer solution.
Dependencies are inferred from the claim text.