Patents by Inventor Friedbert Wechs
Friedbert Wechs has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8727136Abstract: Method for producing this membrane from a casting solution comprising the hydrophobic first sulfone polymer and the hydrophilic second polymer in a solvent system, the method comprising the steps of pouring the casting solution, conditioned to a molding temperature, onto a carrier to form a film, which carrier has a temperature that is higher in comparison to the molding temperature, conveying the film through a climate-controlled zone, initiating the coagulation in a coagulation bath for the formation of a membrane structure, withdrawing the membrane structure from the carrier with a speed that is increased in comparison to the carrier speed, stabilizing, extracting, and subsequently drying the membrane.Type: GrantFiled: May 28, 2010Date of Patent: May 20, 2014Assignee: Membrana GmbHInventors: Wolfgang Ansorge, Oliver Schuster, Friedbert Wechs, Klaus Dombrowski
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Patent number: 8651284Abstract: A hydrophilic semipermeable hollow-fiber membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC?5·10?5·UFRAlb3?0.004·UFRAlb2+1.081·UFRAlb?0.25.Type: GrantFiled: December 14, 2009Date of Patent: February 18, 2014Assignee: Membrana GmbHInventors: Friedbert Wechs, Arne Gehlen, Bodo von Harten, Richard Kruger, Oliver Schuster
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Patent number: 8302781Abstract: A hydrophilic, semipermeable hollow-fiber membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possesses on its inner surface a porous separating layer and an open-pored supporting layer adjoining the separating layer, and has an ultrafiltration rate in albumin solution of 25 to 60 ml/(h·m2·mmHg). The hollow-fiber membrane is free from pore-stabilizing additives, and has a minimum sieving coefficient for cytochrome c of 0.8 and maximum sieving coefficient for albumin of 0.005.Type: GrantFiled: February 15, 2005Date of Patent: November 6, 2012Assignee: Membrana GmbHInventors: Friedbert Wechs, Arne Gehlen, Bodo Von Harten, Richard Kruger, Oliver Schuster
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Patent number: 7811507Abstract: A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possess on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to ?25 ml/(h·m2·mmHg). The hollow fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient of cytochrome c that satisfies the equation SCcc?5·10?5·UFRAlb3?0.004·UFRAlb2+0.1081·UFRAlb?0.25.Type: GrantFiled: February 15, 2005Date of Patent: October 12, 2010Assignee: Membrana GmbHInventors: Friedbert Wechs, Arne Gehlen, Bodo Von Harten, Richard Kruger, Oliver Schuster
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Publication number: 20100230843Abstract: Method for producing this membrane from a casting solution comprising the hydrophobic first sulfone polymer and the hydrophilic second polymer in a solvent system, the method comprising the steps of pouring the casting solution, conditioned to a molding temperature, onto a carrier to form a film, which carrier has a temperature that is higher in comparison to the molding temperature, conveying the film through a climate-controlled zone, initiating the coagulation in a coagulation bath for the formation of a membrane structure, withdrawing the membrane structure from the carrier with a speed that is increased in comparison to the carrier speed, stabilizing, extracting, and subsequently drying the membrane.Type: ApplicationFiled: May 28, 2010Publication date: September 16, 2010Inventors: Wolfgang Ansorge, Oliver Schuster, Friedbert Wechs, Klaus Dombrowski
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Publication number: 20100089820Abstract: A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilising additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC?5·10?5·UFRAlb3?0.004·UFRAlb2+1.081·UFRAlb?0.Type: ApplicationFiled: December 14, 2009Publication date: April 15, 2010Inventors: Friedbert Wechs, Arne Gehlen, Bodo von Harten, Richard Kruger, Oliver Schuster
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Patent number: 7429343Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure, using a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin is extruded to form a shaped object. The solvent used is one for which the demixing temperature of a solution of 25% by weight of the polyolefin in this solvent is 10 to 70° C. above the solidification temperature. After leaving the die, the shaped object is cooled using a liquid cooling medium that does not dissolve the polymer up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.Type: GrantFiled: January 8, 2003Date of Patent: September 30, 2008Assignee: Membrana GmbHInventors: Erich Kessler, Thomas Batzilla, Friedbert Wechs, Frank Wiese
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Publication number: 20080197072Abstract: Integrally asymmetric flat membrane for microfiltration comprising at least 40 wt. % of a hydrophobic first sulfone polymer and a hydrophilic second polymer with a pore size distribution over the membrane wall, having a separating layer in the wall's interior, and also having, in the direction from this separating layer, pore sizes increasing towards the surfaces, the second surface having pores with a mean diameter of at least 1 ?m. The membrane comprises the hydrophilic second polymer in a concentration of 0.1-10 wt. %. The separating layer is located in an region facing the first surface, and the pore size passes through a maximum in the direction from the asymmetrical region towards the second surface.Type: ApplicationFiled: June 3, 2006Publication date: August 21, 2008Inventors: Wolfgang Ansorge, Oliver Schuster, Friedbert Wechs, Klaus Dombrowski
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Publication number: 20080000828Abstract: A hydrophilic, semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a porous separating layer and an open-pored supporting layer adjoining the separating layer, and has an ultrafiltration rate in albumin solution of 25 to 60 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilising additives, and has a minimum sieving coefficient for cytochrome c of 0.8 and maximum sieving coefficient for albumin of 0.005.Type: ApplicationFiled: February 15, 2005Publication date: January 3, 2008Inventors: Friedbert Wechs, Arne Gehlen, Bodo Harten, Richard Kruger, Oliver Schuster
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Publication number: 20070163950Abstract: A hydrophilic, semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a porous separating layer and an open-pored supporting layer adjoining the separating layer, and has an ultrafiltration rate in albumin solution of 25 to 60 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilising additives, and has a minimum sieving coefficient for cytochrome c of 0.8 and maximum sieving coefficient for albumin of 0.005.Type: ApplicationFiled: February 15, 2005Publication date: July 19, 2007Inventor: Friedbert Wechs
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Publication number: 20070163949Abstract: A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC?5·10?5·UFRAlb3?0.004·UFRAlb2+1.081·UFRAlb?0.Type: ApplicationFiled: February 15, 2005Publication date: July 19, 2007Inventors: Friedbert Wechs, Arne Gehlen, Bodo Harten, Kruger Richard, Schuster Oliver
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Patent number: 7201860Abstract: The invention relates to a method for producing a hydrolytically stable polyamide membrane having an open-pored, microporous and sponge-like support-layer structure, using a process involving thermally induced liquid-liquid phase separation. A solution of an aliphatic polyamide in a solvent system, comprising preferably a solvent and a non-solvent for the polyamide, is extruded to form a shaped object. After leaving the die, the shaped object is cooled by means of a cooling medium until phase separation occurs and the polymer-rich phase solidifies to form the membrane structure. The solution of the polyamide in the solvent system contains an antioxidant agent as a stabiliser for the polyamide which, together with the solvent system, is selected in a way that the antioxidant agent is essentially insoluble in the solvent system at the phase separation temperature.Type: GrantFiled: May 23, 2001Date of Patent: April 10, 2007Assignee: Membrana GmbHInventor: Friedbert Wechs
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Publication number: 20050145107Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure, using a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin is extruded to form a shaped object. The solvent used is one for which the demixing temperature of a solution of 25% by weight of the polyolefin in this solvent is 10 to 70° C. above the solidification temperature. After leaving the die, the shaped object is cooled using a liquid cooling medium that does not dissolve the polymer up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.Type: ApplicationFiled: January 8, 2003Publication date: July 7, 2005Inventors: Erich Kessler, Thomas Batzilla, Friedbert Wechs, Frank Wiese
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Patent number: 6632361Abstract: The invention describes hydrophilically acting shaped objects, in particular semipermeable membranes for pyrogen retention, comprising a synthetic polymer component and an additive made from a copolymer made from vinylpyrrolidone and a vinylimidazole compound, and furthermore processes for manufacturing the shaped objects. The shaped objects of the invention exhibit such a high pyrogen retention capacity that the pyrogen concentrations present in the filtrates are in part below the detection limit of the gel clot LAL test.Type: GrantFiled: December 22, 2000Date of Patent: October 14, 2003Assignee: Membrana GmbHInventors: Thorsten Niklas, Friedbert Wechs, Annekatrin Nothdurft
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Publication number: 20030159984Abstract: The invention relates to a method for producing a hydrolytically stable polyamide membrane having an open-pored, microporous and sponge-like support-layer structure, using a process involving thermally induced liquid-liquid phase separation. A solution of an aliphatic polyamide in a solvent system, comprising preferably a solvent and a non-solvent for the polyamide, is extruded to form a shaped object. After leaving the die, the shaped object is cooled by means of a cooling medium until phase separation occurs and the polymer-rich phase solidifies to form the membrane structure. The solution of the polyamide in the solvent system contains an antioxidant agent as a stabiliser for the polyamide which, together with the solvent system, is selected in a way that the antioxidant agent is essentially insoluble in the solvent system at the phase separation temperature.Type: ApplicationFiled: December 3, 2002Publication date: August 28, 2003Inventor: Friedbert Wechs
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Patent number: 6497752Abstract: Process for producing integrally asymmetrical hydrophobic polyolefinic membranes with a separation layer, in particular for gas exchange, via thermally induced liquid-liquid phase separation. A solution of at least one polyolefin in a solvent system containing a compound A and a compound B is extruded to form a shaped object. Compound A is a strong solvent and compound B a weak non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium, which does not dissolve the polymer and does not react chemically with it, until the phase separation and solidification of the high-polymer-content phase take place.Type: GrantFiled: August 24, 2001Date of Patent: December 24, 2002Assignee: Membrana GmbHInventors: Erich Kessler, Thomas Batzilla, Friedbert Wechs, Frank Wiese
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Patent number: 6375876Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure compared to the support structure, via a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin in a solvent system consisting of a compound A and a compound B is extruded to form a shaped object. Compound A is a weak solvent and compound B a non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium that does not dissolve or react chemically with the polymer at temperatures up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.Type: GrantFiled: September 4, 2001Date of Patent: April 23, 2002Assignee: Membrana GmbHInventors: Erich Kessler, Thomas Batzilla, Friedbert Wechs, Frank Wiese
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Publication number: 20010006160Abstract: The invention describes hydrophilically acting shaped objects, in particular semipermeable membranes for pyrogen retention, comprising a synthetic polymer component and an additive made from a copolymer made from vinylpyrrolidone and a vinylimidazole compound, and furthermore processes for manufacturing the shaped objects. The shaped objects of the invention exhibit such a high pyrogen retention capacity that the pyrogen concentrations present in the filtrates are in part below the detection limit of the gel clot LAL test.Type: ApplicationFiled: December 22, 2000Publication date: July 5, 2001Applicant: Membrana GmbHInventors: Thorsten Niklas, Friedbert Wechs, Annekatrin Nothdurft
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Patent number: 5919370Abstract: Membranes suitable for use in haemodialysis include a separating layer A with a cut-off between 500 and 5,000,000, a support layer B and a layer C which partly determines the hydraulic permeability. The cut-off and hydraulic permeability can be set independently of one another. The membranes are integral, multi-asymmetric, semi-permeable membranes made from .epsilon.-caprolactam-soluble polymers. The membranes may be in the form of flat, tubular or hollow fiber membranes.Type: GrantFiled: November 14, 1997Date of Patent: July 6, 1999Assignee: Akzo Nobel NVInventors: Henning Rottger, Friedbert Wechs
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Patent number: 5837234Abstract: A bioartificial organ for implanting to provide a therapeutic effect is prepared containing a core of living cells encapsulated in a foam-like membrane having three regions: a dense, fine-pored, permselective inner region, a middle region that lacks macrovoids and a fine-pored outer region. The membrane has a molecular weight cutoff that permits passage to nutrients to the cells but not passage of the cells. Preferably, the membrane is made of polyether sulfone, pores range in size between 0.02 .mu.m and 2.0 .mu.m and have polyhedrally symmetric boundaries and are arranged asymmetrically from one surface to the other. The membrane has an asymmetry factor AF relative to the maximum pore diameter of 0.01 to 2.0 and a ratio of the maximum mean free path length to the diameter of the largest pore of greater than 3. The membrane can be hydrophobic or hydrophilic. The bioartificial organ is formed by coextrusion or by stepwise assembly by forming the cell core and then applying the membrane.Type: GrantFiled: June 7, 1995Date of Patent: November 17, 1998Assignee: CytoTherapeutics, Inc.Inventors: Frank T. Gentile, Shelley R. Winn, Michael Lysaght, Ulrich Baurmeister, Friedbert Wechs, Henning Rottger