Gambro Lundia Ab

Gambro Dialysatoren Gmbh & Co Kg

Gambro Dialysatoren Kg

Hoechst Aktiengesellschaft

Gambro, Inc.

Gambro Dialysatoren Gmbh & Co.

Hermann Josef Gohl

Reinhold J Buck

Carl-Martin Bell

Bernd Krause

Markus Hornung

Carina Zweigart

Claes-Ake Gullberg

Markus Storr

Reinhold Deppisch

Karsten Blatter

Reinhard Wagener

Manfred Pirner

Carl Martin Bell

Gunther F Geiling

Georg B Mayer

Erich H Harttig

Peter Konstatin

Maria T Ohmayer

Richard M McDonogh

Barbara Thome

The present invention concerns a semipermeable hollow fiber membrane having an outer wall surface, an inner wall surface and an interior lumen extending along the length thereof and having the selective layer on the outer wall surface with a surface roughness below 10 nm. According to the invention the membrane has the smallest pore size on the outer wall surface, and has an outer wall surface which is smooth, continuous and homogeneous in a nanoscopic scale and four to five distinct layers of different pore size and density. Further the present invention concerns a process for manufacturing thereof and the use thereof.

Hollow fiber membrane and method for manufacturing thereof

A method for preparing by solvent phase inversion spinning a hollow fiber membrane suitable for dialysis. The membrane includes at least one hydrophobic polymer and at least one hydrophilic polymer. An outer surface of the membrane is characterized by pores having sizes in the range of 0.5-3 &#x3bc;m, with the density of the pores on the outer surface of the membrane being in the range of 10,000 to 150,000 pores per mm. The method includes dissolving the at least one hydrophobic polymer and the at least one hydrophilic polymer in at least one solvent to form a polymer solution, extruding the thus-formed polymer solution through an outer ring slit of a nozzle with two concentric openings, extruding a center fluid through the inner opening of the nozzle, and wishing said membrane. The polymer solution coming out through the outer slit opening on the outside of the precipitating fiber is exposed to a humid steam/air mixture including a solvent content of between 0.5 and 10% by weight related to the water content.

Permselective membrane and process for manufacturing thereof

Heat-sterilizable membranes are disclosed comprising at least two hydrophobic polymers which are normally immiscible with each other, and in which at least one of the hydrophobic polymers is normally unstable under sterilization conditions while at least one of the other hydrophobic polymers is normally stable at sterilization conditions, and in which the at least two hydrophobic polymers are compatibilized with each other so that the membrane formed therefrom is stable at such sterilization conditions.

Heat-sterilizable membrane

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.

Process for the preparation of polyether amide solutions,

A process for the production of hydrophilic membranes using at least one hydrophobic polymer and polyvinyl pyrrolidone as a hydrophilic polymer, membrane-forming shaping of the polymers and immobilization of the polyvinyl pyrrolidone is characterized in that the polyvinyl pyrrolidone is immobilized on and/or in the membrane by treatment with an aqueous solution of peroxodisulphate in a hot condition. The solution of peroxodisulphate is kept substantially free of oxygen during immobilization by degassing the solution. The membranes are used for hemodialysis, hemodiafiltration and hemofiltration of blood.

Process for the production of hydrophilic membranes

Membranes composed of sulphonated polyaryl ether sulphones are disclosed in which the repetitive polymer units have the formula ##STR1## in which the aryl radicals are substituted by SO.sub.3 X where X is hydrogen or an alkali metal and the polymer includes from about 0.3 to 0.6 SO.sub.3 X radicals per unit. Processes for producing these membranes are also disclosed.

Membrane and process for the production thereof

A method for drying porous ultrafiltration membranes by the use of heat and possibly also at reduced pressure is characterized in that prior to the application of heat the pores of the membranes are at least partially filled with a solution of a water-soluble organic solid which swells the membranes and which has a melting point above 35.degree. C. in an organic solvent which is completely miscible with water and which does not change the membrane structure.

Method for drying porous ultrafiltration membranes

A membrane for hemodialysis is prepared by casting, extruding or spinning a solution of a polyether-polycarbonate block copolymer and a swelling agent having a molecular weight of about 1,000 to about 20,000 Daltons, then partially evaporating the solvent, gelling and washing. The membrane has a top cut-off value less than about 68,000 Daltons, and hence is substantially impermeable to albumin, but nonetheless provides high permeability to water and to other small molecules.

Membrane and process for producing the membrane

Processes for producing semipermeable membranes in the form of hollow fibers are disclosed including extruding a solution of a block copolymer including at least one hydrophilic polymer and at least one hydrophobic polymer while simultaneously injecting a gaseous or vaporous center medium into the center bore of the hollow fiber extrudate, including coagulating the extrudate so formed therefrom. The preferred process includes using air or the components of air as the center medium and employing a polyethyleneoxide-polycarbonate block copolymer to form the hollow fiber membranes.

Process for producing hollow fiber semi-permeable membranes

A filtration membrane is disclosed which has an ultrafiltration rate of between 200.times.10.sup.-4 and 500.times.10.sup.-4 ml/sec..times.cm.sup.2 .times.bar at 20.degree. C. and which is substantially impermeable to albumin of a molecular weight of about 44,000 or greater. A process for producing a filtration membrane is also disclosed in which a polymer solution is extruded with a center liquid under conditions such that the ratio of the volume of polymer solution to the volume of center liquid is within the range of from about 2:1 to about 4:1 to form a membrane extrudate.

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Bisingen, Germany

Hermann Josef Gohl