Abstract: The invention discloses methods of improving blocking resistant properties and reducing the coefficient of friction of a multilayer film comprising providing at least one layer of an ethylene-propylene impact copolymer having from about 3% to about 30% by weight ethylene, wherein said copolymer has no more than two peaks in the melting curve within the range from about 110° C. to about 165° C., and wherein said layer is non-heat sealable, to a multilayer film having a core layer comprising polypropylene, high density polyethylene (HDPE) or linear low density polyethylene (LLDPE), whereby anti-blocking and coefficient of friction characteristics of said film is improved without necessity of adding an antiblock or slip agent.

Abstract: Selective, water-permeable membranes for reverse osmosis and nanofiltration are prepared by interfacially polymerizing on a microporous support an essentially monomeric bipiperidine reactant, and an essentially monomeric amine-reactive polyfunctional aromatic or cycloaliphatic acyl halide having on the average at least about 2 acyl halide groups per reactant molecule. The polymerization is optionally carried out in the presence of a monomeric amine salt, which can increase the flux rate of the resulting membrane.

Abstract: A method for producing porous structures in which a liquid or pasty mixture of substances is brought at least partially to solidification and subsequently freeze-dried.

Abstract: In a process for drying microporous, fluid-containing particles, the heat required for increasing the temperature is supplied by convection by reducing the interfacial tension of the fluid, preferably to 0 to 1/10, in particular to 0 to 1/20, of the interfacial tension of the fluid at room temperature, by appropriately increasing the temperature at from close to the critical pressure to supercritical pressure of the fluid. Furthermore, microporous, three-dimensionally networked particles are prepared by a process in which the drying process is used. In addition, an apparatus is used for carrying out the drying process, the apparatus comprising a pressure container having an inner container and pressure-withstanding outer container and suitable measuring and control apparatuses and pump apparatuses and heat exchangers, the inner container being provided for holding the particles to be dried and a gap being provided between the inner container and the outer container.

Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.

Abstract: An at least two zone, unsupported, continuous microporous membrane is disclosed. The at least two zone, unsupported, continuous microporous membrane may include at least two different membrane pore size zones or the pore sizes may have about the same pore size. Apparatus and processes for fabricating at least a two zone unsupported, continuous, microporous membrane are also disclosed.

Abstract: A method for preventing activation of the contact phase of blood or plasma which comes into contact with a semi-permeable membrane based on polyacrylonitrile bearing fixed negative charges, which is fitted in apparatus for the treatment of blood or plasma, by extra-corporal circulation, said method comprising contacting blood or plasma with said semi-permeable membrane, wherein: a neutral or cationic polymer is combined with said semi-permeable membrane before or after formation of the membrane, and before sterilization of the membrane; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is negative; the overall ionic capacity of the semi-permeable membrane, based on polyacrylonitrile bearing fixed negative charges and containing a neutral or cationic polymer, is, as an absolute value, not more than 10% less than the overall ionic capacity of the same semi-permeable membrane without a neutral or cati

Abstract: A novel method of producing a porous product is provided, including the steps of: preparing a molded product by subjecting a molding material comprising a polymer component and a pore-forming agent dispersed in the polymer component, the pore-forming agent assuming a solid state at a room temperature, to molding at a temperature which causes the pore-forming agent to melt; and soaking the molded product with a solvent which dissolves the pore-forming agent but fails to dissolve the polymer component, to form pores.

Abstract: Disclosed are methods of manufacturing electronic devices, particularly integrated circuits. Such methods include the use of low dielectric constant material prepared by using a removable porogen material.

Abstract: A method of producing artificial fossil coral which is an artistic replica of a natural coral reef formed from a slurry of cement, sand, ground PVC chips, colorant and water admixed with artistic rigid lightweight sponge or Styrofoam. Fiber glass strands are used to provide a plant like look to the artificial fossil coral and coloring of the artificial fossil coral duplicates the colors found in natural coral reefs.

Abstract: A silicone rubber is produced by curing a silicone rubber composition which includes (A) a curable organopolysiloxane composition and (B) at least one hollow organic resin filler whereby the filler forms cells in an open-cell state. The open-cell state gives the silicone rubber good cushioning property and a low compression set.

Abstract: 3-D biodegradable porous, polymer (natural or synthetic) scaffolds with well-controlled, interconnected pores, and method for forming the porous materials. Hydrophilic and/or hydrophobic porogen materials were fabricated into 3-D negative replicas of the desired macroporous architectures. Biodegradable polymers (PLLA and PLGA) were dissolved in a solvent and cast onto the negative replica. After dissolving/leaching out the porogen materials, a porous polymer scaffold was formed. The skeletal structure of PLLA foams consisted of small platelets or nano-fibers, while PLGA foams had homogeneous skeletal structure. To improve the cell seeding, distribution, mass transport, and new tissue organization and vascularization, 3-D macroporous architectures are built in the nano-fibrous matrices. The method tailors polymer scaffolds for a variety of potential tissue engineering applications due to the well-controlled architecture, inter-pore connectivity, and mechanical properties.

Abstract: A composite membrane and method for making the same, comprising a porous support and a crosslinked polyamide surface. The subject membrane provides improved flux and/or rejection rates. The subject membrane is further capable of operating at lower operating pressures. The subject method includes reacting a polyfunctional amine with a polyfunctional acyl halide to form a polyamide. The method includes the step of contacting a phosphorous containing compound with the polyfunctional acyl halide prior to and/or during the reaction between the polyfunctional acyl halide and a polyfunctional amine. The subject process is easily adapted to commercial scale manufacturing processes and is particularly suited for making nanofiltration and reverse osmosis composite membranes.

Abstract: This invention discloses a system for cold bond processing of combustion ash which enhances various characteristics of the resulting cured consolidated combustion ash materials. Specifically, the invention relates to processing techniques which enhances both density and strength of the of the consolidated combustion ash materials. The invention also relates to processing techniques which control various chemical reactions which assure that certain types of minerals are formed in the proper amounts which results in a cured consolidated combustion ash material which has greater dimensional stability and enhanced resistance to degradation. Embodiments for both normal weight and light weight combustion ash aggregates are disclosed which meet various ASTM and AASHTO specifications.

Abstract: A composite membrane and method for making the same, comprising a porous support and a polyamide surface. The subject membrane provides improved flux and/or rejection rates. The subject membrane is further capable of operating at lower operating pressures. The subject method includes reacting a polyfunctional amine with a polyfunctional acyl halide to form a polyamide. The method includes the step of contacting a complexing agent with the polyfunctional acyl halide prior substantial reaction between the polyfunctional acyl halide and a polyfunctional amine. The subject process is easily adapted to commercial scale manufacturing processes and is particularly suited for making nanofiltration and reverse osmosis composite membranes.

Abstract: A porous material is disclosed, made of a semi IPN type polymer alloy of a crosslinked polymer (A) obtained by the crosslinking polymerization of a crosslinking-polymerizable vinyl monomer and/or oligomer (a) with a non-crosslinked polymer (D) which is soluble in a solvent (B) capable of dissolving said monomer and/or oligomer (a) therein and subjecting said crosslinked polymer (A) to gelation but is insoluble in a coagulating solution (C) which is compatible with said solvent (B) but doesn't subject said crosslinked polymer (D) to gelation. A porous material excellent in mechanical strength as well as in heat resistance can be prepared. Various functional groups can be introduced into the surface of the porous material. Further, the pore diameter can be easily controlled.

Abstract: To pot membranes in a header, a dense, viscous liquid, suspension or, preferably, a thixotropic, water soluble gel, is placed in a header pan in space reserved for a permeate channel. A plurality of hollow fiber membranes are collected together and their open ends are inserted into the gel. A fixing liquid, typically a resin, is placed over the gel. The fixing liquid surrounds each membrane and then solidifies, simultaneously sealing the outer surfaces of the membranes and forming a plug in the opening of the header to complete the permeate channel. After the fixing liquid has solidified, the gel is removed by various means. The space initially occupied by the gel becomes part of the permeate channel after the gel is removed. In one embodiment, membranes are grouped by a cushioning adhesive which later surrounds the membranes where they exit the completed header.

Abstract: The present invention relates to hydrophilic membranes containing blends of polysulfone polymers and sulfonated polymers or copolymers, where the sulfonated polymers or copolymers are sulfonated before blending with the polysulfone polymer. The invention also relates to methods of preparing the hydrophilic membranes. In one aspect of the invention, the membranes are formed by casting a mixed polymer solution comprising a sulfone polymer and a copolymer of a sulfonated polymer and a sulfone polymer and quenching the film in an aqueous bath to produce a coagulated membrane. The membranes can be ultrafiltration or microfiltration membranes, symmetric or asymmetric.

Abstract: Lyocell fibres contain elongated domains of polyester, polyamide or an olefin copolymer, the domains having an aspect ratio at least 1.5 and being aligned substantially parallel to the axis of the fibre. A process for the preparation of lyocell fibre or film by extruding a solution of cellulose in amine oxide through a spinneret or film die at elevated temperature via an air gap into an aqueous precipitation bath is characterised in that 0.1 to 60 wt % based on cellulose of a thermoplastic low-melting polymer is incorporated into the cellulose solution. A process for the preparation of a bicomponent fibre by extruding two polymers through a spinneret in side-by-side relationship at elevated temperature is characterised in that one of the polymers is a solution of cellulose in amine oxide and the other polymer is a molten thermoplastic polymer having a melting point above 25° C. but below the extrusion temperature.

Abstract: There is provided a leukocyte eliminating filter capable of exhibiting an excellent performance of eliminating leukocyte and platelet, which can be obtained through a simple process comprising the steps of coating a substrate constituting the filter with a polymer having a chemical structure represented by any one of the following formulas (I) and (II), and heat-drying the coated polymer: wherein R1, R3, R4, R5R6 and R7 may be the same or different and are individually hydrogen atom or an alkyl group having 1 to 4 carbon atoms; R2 is CONH2 or COOH; R8 is an alkyl group having 1 to 12 carbon atoms; and x is an integer of 3 or 4.

Abstract: The present invention relates to produce a polysulfone based hollow fiber membrane, having high water permeable coefficient and excellent permeability with no deterioration of separation capability, characterized by using an internal coagulating liquid and/or an external coagulating liquid containing diethylene glycol(DEG) and/or salt which can form a hydrate in the process of producing the polysulfone based hollow fiber membrane by following steps: (a) Extrude a spinning dope comprising polysulfones resin, organic solvent and polyvinyl pyrrolydone(PVP) into air through a biannular spinning nozzle to obtain an extrudate in the form of a hollow fiber, (b) Simultaneously inject an internal coagulating liquid into the biannular spinning nozzle at inside bore thereof, and (c) Subsequently introduce said extrudate to an external coagulating liquid.

Abstract: A material is disclosed which produced by a process in which a mold is filled of deformable shaped bodies, after which the mold is filled with a base material. The bodies are removed and the solidified base material forms a material of shell-like structures and an interconnecting pore system between the skeleton structures. The material produced by the process can be used as bone replacement materials, implants, filters and drug delivery systems.

Abstract: A non-cracking hydrophilic polyether sulfone membrane is prepared by (a) directly coating the entire surface of a hydrophobic polyethersulfone membrane with an aqueous solution of a polyalkylene oxide polymer and at least one polyfunctional monomer, and (b) polymerizing the monomer over the entire surface of the membrane under conditions which cause the resulting polymer to attach to the polyethersulfone membrane and the polyethylene oxide to form a non-extractable surface which does not crack when the membrane is folded to form a pleated cartridge.

Abstract: A device useful for localized delivery of a therapeutic material is provided. The device includes a structure including a porous material; and a water-insoluble salt of a therapeutic material dispersed in the porous material. The water-insoluble salt is formed by contacting an aqueous solution of a therapeutic salt with a heavy metal water-soluble salt dispersed throughout a substantial portion of the porous material. The porous material can be made of a polymer other than fibrin with fibrin incorporated into the pores, which can be the only layer of polymeric material on the medical device (e.g., stent). A new method for preparing a porous polymer material on a medical device.

Abstract: Improved asymmetric hyperfiltration membranes and their method of preparation and use are disclosed. The membranes are fashioned from polyimides and conditioned with a lubricating oil. Permselective separation of aromatic hydrocarbons from non-aromatic hydrocarbons in a feed stream may be accomplished using the membranes under hyperfiltration conditions.

Abstract: In a method of making solvent and acid resistant membrane on the basis of polyacrylnitrile (PAN) and a comonomer copolymerized therewith wherein the membrane is formed from a solution by phase inversion, glycidylmethacrylate is used as the comonomer and the membrane formed thereby is then subjected to ammonia.

Abstract: Process for the partial modification of porous, hydrophilitic filter membranes, of filter membranes treated in such manner and filter modules equipped with such filter membranes. When hydrophilic filter membranes are embedded in hydrophobic securing components of filter modules, the membrane filters are hydrophobized beyond the embedding area in an edge region, so that this edge region, that can no longer be wetted by water, forms an air by-pass when the filter modules are tested, rendering thus impossible that the filter modules can be tested. The novel process is intended to modify the edge regions in such a manner that, even after partial areas have been embedded in a hydrophobic polymer material, they remain porous and hydrophilic over the whole of their effective area.

Abstract: The present invention provides a process for producing alveolar cellulosic products (sponges, sponge-cloths, etc.) from a cellulosic raw material, the process comprising:at least partially dissolving a cellulosic raw material in an intrinsic solvent for cellulose;incorporating an effective quantity of at least one pore-forming agent into the resulting mixture, with mixing; said pore-forming agent(s), being compatible with the cellulosic mixture, being capable of generating macro- and micro-pores when it/they is/are actuated;gelling the homogeneous dough thus obtained;treating said gelled dough under conditions in which the cellulose precipitates out and the pore-forming agent(s) present are actuated.The process is an advantageous alternative to the viscose process which is a polluting process. The properties of the products obtained are completely similar to those of products obtained using the viscose process. The (novel) products form part of the invention.

Abstract: A polysulfone membrane for purifying blood having excellent compatibility with blood and the process producing the membrane are disclosed. The membrane comprises a mixed polymer phase of a graft copolymer and/or block copolymer having a molecular weight of 3.times.10.sup.5 daltons or more and comprising (A) a hydrophilic segment and (B) a hydrophobic segment (exclusive of polysulfone) in a total amount of from 0.5 to 30 parts by weight per 100 parts by weight of polysulfone, with the monomer unit ratio (A/B) between the segments A and B being from 0.5 to 5. The copolymer is preferably a graft copolymer where the hydrophilic segment is a polyvinylpyrrolidone segment and the hydrophobic segment is a polystyrene segment. The membrane can be prepared by applying a wet film formation process to a dope containing an appropriate solvent of the mixed polymer, such as N,N-dimethylacetamide.

Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.

Abstract: Respective hollow fiber membranes suitable for use in removing undesired contaminants from blood, in particular in an artificial kidney, have:(1) per membrane area of 1.8 m.sup.2, in vitro clearances for urea and phosphorus respectively of .gtoreq.195, and .gtoreq.180, ml/min, a .beta..sub.2 -microglobulin clearance .gtoreq.44 ml/min and an albumin permeability .ltoreq.0.5%;(2) an albumin permeability .ltoreq.1.5% and an overall mass transfer coefficient Ko .gtoreq.0.0012 cm/min; and(3) a vitamin B.sub.12 dialyzance of .gtoreq.135 ml/min and an albumin permeability .ltoreq.3%. The membranes can be prepared by spinning hollow fibers from a spinning solution comprising a polysulfone, a hydrophilic polymer, a solvent and water, the spinning solution having a viscosity x at 30.degree. C. of 25-130 poise and a quantity y % of water given by:-0.01x+1.45.ltoreq.y.ltoreq.-0.01x+2.

Abstract: A pollutant-reducing catalytic converter for an internal combustion engine. The catalytic converter is of ceramic and operates at higher temperatures for increased efficiency. A ceramic foam is used as the substrate for the catalyst. The foam is an open-celled foam and the substrate is deposited on the walls of the cells. Thus, there is a maximum area of catalyst with a minimum amount of catalyst required. The catalytic converter can be placed in the engine compartment adjacent the engine for maximum efficiency without causing temperature problems within the engine compartment.

Abstract: A process for rendering hydrophilic a separation membrane having a hydrophobic matrix polymer comprises doping the membrane solvent system with a cyclic ester additive which is compatible with the matrix polymer and adding a wetting agnet additive, such that the resulting membrane is instantaneously wetted. The invention further relates to the membrne formed in accord with this process.

Abstract: The present invention is a method for producing a nonwoven fabric from a water modifiable polyolefin-containing film. In order to produce the fabric where polyethylene is the minority constituent, a polymer blend is formed with the polyethylene as the dispersed phase and polyethylene oxide as the continuous phase. In another embodiment wherein the polyethylene is the majority constituent and the polyethylene oxide is the minority constituent of the film, a reactive blend created during processing exhibits an inverse phase morphology so that the polyethylene oxide becomes the continuous phase and the polyethylene becomes the dispersed phase. In either embodiment, the film is then treated with an aqueous solvent to remove the polyethylene oxide to produce the nonwoven, porous fabric. The resulting nonwoven, porous fabric has a silk-like hand and shine ideal for disposable personal hygiene articles, and is flushable through waste water disposal systems.

Abstract: A method of producing a membrane comprises providing a solution containing a plurality of polymers in a non-aqueous liquid solvent, at least one of the polymers (hereinafter referred to as the "first polymer") having been prepared by polymerizing at least one vinyl or acrylic monomer, at least one other of the polymers being a membrane-forming hydrophobic polymer (hereinafter referred to as the "second polymer"), the first polymer and the second polymer being mutually incompatible in said solution, and contacting the solution with an aqueous medium thereby to precipitate the polymers from the solution to form the membrane.

Abstract: The present invention relates to cationically charge-modified membranes and methods of preparing such membranes. In one major aspect of the invention, the membranes are hydrophobic membranes that are treated with one or more polymeric wetting agents to render the membranes substantially hydrophilic, followed by treatment with one or more charge-modifying agents, the agents causing the membranes to possess a fixed formal positive charge. In another major aspect of the invention, a cationic membrane is formed from casting in a film a mixed polymer solution comprising a sulfone polymer and a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, and quenching the film in an aqueous bath to produce a coagulated membrane. The membrane can be further cationically charge-modified with one or more charge-modifying agents.

Abstract: The invention relates to a material of a three-dimensional framework of supporting, trabecular structures encompassing cavities which are connected with one another and which can be predeterminedly adjusted. The material is obtainable by forming the framework around the shaped bodies serving as space retainers for the cavities and subsequently removing the shaped bodies. The material according to the invention can be used for example as a implant or as a filter.

Abstract: The present invention is embodied in a ceramic foam made by mixing a liquid pre-ceramic resin and a liquid phenolic resin, allowing the resultant mixture to chemically foam, curing the mixture for a time and at a temperature sufficiently to convert the mixture to a polymeric foam, and then heating the resultant polymeric foam for a time and at a temperature sufficient to break-down polymers of the polymeric foam and convert the polymeric foam to a ceramic foam. The ceramic foam of the present invention contains residual decomposed components of the liquid phenolic resin and/or liquid pre-ceramic resin.

Abstract: Porous inking members for impact printers and methods of making the same which control the ink transfer flow rate from the porous inking members to dot matrix or other impact print heads. One preferred embodiment of the porous inking members for impact printers and methods of making the same uses peptizer and liquid nitrile rubber as ingredients in the manufacturing process to produce porous inking members.

Abstract: A process is disclosed for producing a positive-material with a skeleton made of shell-like structures and an interconnecting pore system designed between the skeleton structures. Also disclosed is a process for producing a negative-material made of shaped bodies interconnected by bridges a process for producing a positive/negative-material, materials produced by this process and their use as bone replacement materials, implants, filters and drug delivery systems. According to this process deformable shaped bodies in bulk are poured into a mold that forms a negative model of the material.

Abstract: The present invention relates to membranes useful in the separation of water from a solution containing volatile organic compounds and water. The membranes may be used in dehydrating an organic/water mixture to purify an organic when an organic is of interest or, alternatively, producing pure water from an organic/water mixture when clean water is of interest. The membranes include a hydrophilic base polymer, an optional pore-forming polymer and a surface modifying macromolecule (SMM) which imparts surface hydrophobicity to the membrane.

Abstract: Microporous ultrafiltration membranes containing polymeric material having oxyalkylene tentacles dangling from a carbon backbone can be improved for separation of micromaterials such as salts, unicellular pathogens and the like by separating said tentacles further part on the carbon backbone.

Abstract: A microporous film can be made by adding a foaming agent to the components of a film material to create bubbles in the film. The microporous film can also be made by adding filaments to the components of the film material and dissolving the filaments to create the pores. In either process, the size of the pores can be controlled to be no greater than 0.027 .mu.m.

Abstract: A process for treatment of zeolite membranes to improve performance which comprises contacting the membrane with a silicic acid or a mixture of silicic acids.

Abstract: A filtration membrane for micro- or ultra-filtration is formed from a complex of PVDF and calcined .alpha.-alumina (".alpha.-Al") particles, in which complex the particles are reacted and dispersed. The suspended complex is then mixed with a hydrophilic polymer such as polyvinyl alcohol (40%-90% hydrolyzed) referred to herein as HPVA, which reacts with the complex imparting hydrophilicity to the polymer. The novel membrane provides about 50% higher specific flux than a membrane made with the same polymer but without the .alpha.-Al particles. Unexpectedly, the net flux is improved by treating the membrane with a solution of sodium hypochlorite which fails to remove the HPVA from the novel membrane but does remove it from the prior art membrane which does not contain the .alpha.-Al. The preferred membrane comprises a macroporous support coated on its outer surface with a thin tubular asymmetric semipermeable film of polymer containing less than about 50% by is weight of .alpha.-A1 particles.

Abstract: A sponge cloth of decrystallized cellulose modified by the acetyl group content, where the average degree of substitution is 0.2 to 1.5. The cloth does not contain any organic or inorganic sulfur compounds. The sponge cloth is produced by treating wood pulp with sodium hydroxide solution, then treating it with acetylating substances, drying and dissolving in an organic solvent with the addition of a pore-forming salt, fibers and optionally pigment dyes and foaming agents, spreading the mixture on a web and boiling in water with subsequent drying to form a finished cloth.

Abstract: The present invention relates to the field synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a sulfone polymer membrane with high surface porosity (high pore density) and distinctive asymmetry that can separate solids (i.e., blood cells) from a liquid (i.e., plasma) without the need for centrifugation. The membrane is further rendered hydrophilic through co-casting the sulfone polymer (which is a hydrophobic polymer) with a hydrophilic polymer, such as polyvinylpyrrolidone. Because of these properties and the fact that it requires only a small amount of the solid containing liquid (i.e., whole blood) to be applied to the larger pore surface, the membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications (i.e., the detection of physiological conditions (i.e.

Abstract: A sponge of decrystallized cellulose modified by an acetyl group content, where the average degree of substitution is 0.2 to 1.5. No organic or inorganic sulfur compounds are present in the sponge. The sponge is produced by treating pulp with sodium hydroxide solution, then treating it with acetylating substances, drying and dissolving in an organic solvent with the addition of a pore-forming salt, fibers and optionally pigment dyes, pressing the mixture into a perforated mold whose receiving volume corresponds to the dimensions of the sponge to be produced, then placing the mold with its contents in boiling water, and removing the sponge thus formed in the mold.

Abstract: A process is provided for the production of a porous retainer for use in a rolling bearing for holding rolling elements. The process comprises the following steps:(1) blending a polyimide resin, which serves as a porous matrix material for the porous retainer, with another heat-resistant resin which has a forming temperature range close to the polyimide resin and, when treated with a solvent in the presence of the polyimide resin, is solely dissolved out;(2) forming the resulting resin blend into a retainer of a desired shape; and(3) treating the thus-formed retainer with the solvent, whereby the another heat-resistant resin is solely dissolved out.

Abstract: A synthetic membrane consisting of a mixture of polysulfone and sulfonated polysulfone and not more than 20 wt. % of other polymers, characterized in that the mixture contains 0.5 to 8 wt. % sulfonated polysulfone, possibly as the salt of sulfonic acid, and a method for manufacturing this synthetic membrane, characterized in that one or more solvents are added to a mixture composed of 0.5 to 8 wt. % sulfonated polysulfone, possibly as the salt of sulfonic acid, polysulfone and not more than 20 wt. % of other polymers, the mixture is dissolved to form a polymer solution, the latter is shaped, and precipitated to form a membrane in a precipitating bath by means of one or more precipitating agents.