RU2198725C2 - From-melt formed polysulfone semipermeable membranes and method of preparation thereof - Google Patents

Abstract

FIELD: semipermeable membranes. SUBSTANCE: invention relates to technology of preparing polysulfone membranes that can be used to separate liquids, in particular for microfiltering, ultrafiltration, dialysis, and reverse osmosis. Membranes are prepared by stirring homogenous composition containing polysulfone compound, solvent such as sulfolane, antipyrin, deltavalerolactam, diethyl phthalate, and their mixtures, and nonsolvent such as polyethylene glycol, diethylene glycol, triethylene glycol, glycerol, and their mixtures. Composition is melted and subjected to from-melt formation of membranes. EFFECT: enabled convenient preparation of membranes with good physicochemical properties, biological compatibility, and resistance to bleaching agents, disinfecting substances, and salt solutions. 56 cl, 4 dwg, 7 ex

Description

FIELD OF THE INVENTION
The present invention relates to polysulfone semipermeable membranes and methods for their preparation. More specifically, the present invention relates to melt formed polysulfone semipermeable membranes.

BACKGROUND OF THE INVENTION
Modern semi-permeable membranes are available in various forms, such as sheets, tubes and hollow fibers. The term "hollow fibers" usually refers to hollow cylindrical structures in which the walls serve as permeable, impermeable or semi-permeable (ie selectively permeable) membranes, depending on the type of application. Typically, hollow fibers are used in the form of cylindrical membranes that allow selective exchange of materials through walls.

 Methods for separating liquids using selectively permeable membranes, such as methods including ultrafiltration, microfiltration, dialysis, reverse osmosis or the like, require a variety of materials adapted to various applications. For example, semi-permeable membranes are currently successfully used for extracorporeal treatment of blood, including hemodialysis, hemofiltration and hemodiafiltration. In such cases, membranes typically include hollow fibers that are bundled and enclosed in a housing so that blood can flow simultaneously in parallel through the lumens of the fibers, while the blood-purifying fluid passes through the housing at the same time so that it flushes the outer surfaces of the hollow fibers .

 Compounds used to prepare selectively permeable membranes include polymers such as cellulose, cellulose acetate, polyamide, polyacrylonitrile, polyvinyl alcohol, polymethyl methacrylate, polysulfone, polyolefin or the like, depending on the type of application of the membranes. Polysulfone compounds are of particular interest because, among other things, they have excellent physical and chemical properties, such as heat resistance, acid resistance, alkali resistance and oxidation resistance. It was found that polysulfone compounds are biocompatible, perfectly form pores and voids, and are chemically inert to compounds such as bleach, disinfectants, and salt solutions. Polysulfone compounds can be sterilized in various ways, such as ethylene oxide (EtO) treatment, gamma irradiation, steam autoclave treatment, and heated citric acid treatment. In addition, polysulfone compounds have sufficient strength and wear resistance to withstand reuse and sterilization cycles.

 Typically, polysulfone hollow fibers are prepared using solution spinning technology. Obtaining polysulfone hollow membranes by molding from a solution usually involves dissolving the polysulfone compounds in a relatively large amount of an aprotic solvent and a non-solvent, followed by extrusion of the solution through a multi-channel mouthpiece. For molding from a solution, a “solvent” is a compound in which the polysulfone compound practically dissolves at the molding temperature of the membrane (i.e., at ambient temperature). In the process of molding from a solution, a "non-solvent" is a compound in which the polysulfone compound is practically insoluble at the temperature of forming the membrane. For molding from a solution, solvents must be present in quantities sufficient to ensure that the polysulfone compound is practically dissolved and a homogeneous liquid is obtained at ambient temperature (membrane production temperature).

 With respect to solvents and non-solvents used for molding from a solution, it is required that the membranes can be leached and washed after they are formed, since even residual amounts of these substances in the membranes can cause unacceptable contamination of the liquids that are treated with the membranes. Avoiding such contamination is especially important for membranes used to treat blood during dialysis or desalination of water during reverse osmosis. In the manufacture of hollow fiber membranes by spinning from a solution, it is especially difficult to remove the core fluid used to make the fiber lumen. After removal of solvents, non-solvents and core fluid, a non-volatile water-soluble compound must be added in order to preserve the porous structure of the membranes before drying. Non-volatile material also serves as a surfactant in subsequent re-wetting of the membranes. Such a process is known as re-plasticization.

 Methods of molding from a solution require large amounts of solvents and non-solvents, many of which are toxic and it can be difficult to extract from the resulting polysulfone fiber. In addition, the large number of individual solvents and non-solvents removed from the fibers and their high level of toxicity can pose a problem for the disposal of hazardous waste.

 In addition, conventional molding techniques from a solution make it possible to obtain asymmetric polysulfone membranes (i.e., membranes with non-uniform porosity, which increases with increasing membrane thickness). That is, an inhomogeneous membrane has a dense shell or microporous barrier layer on one (or both) of the main surfaces of the membrane. A dense shell or microporous barrier layer forms a relatively small part of the membrane, but requires a disproportionately large control over the permeability of the membrane.

 Accordingly, there is a need for a polysulfone composition and a simple method for producing polysulfone semipermeable membranes, the composition and method having to minimize the occurrence of toxic by-products that go to waste.

 In addition, there is a need to develop a method for producing polysulfone semipermeable membranes, during which the solvents, non-solvents and auxiliary additives used in the manufacture of the membranes can be easily removed from the membranes after their manufacture and / or these substances will have relatively low toxicity. There is also a need for polysulfone semipermeable membranes having a more uniform structure over the entire thickness (i.e., homogeneous polysulfone membranes) so that the permeability of the membranes over the entire thickness can be easily controlled.

SUMMARY OF THE INVENTION
In General, the present invention provides, inter alia, a new method and polysulfone composition for producing homogeneous semi-permeable polysulfone membranes by the method of molding from the melt. The polysulfone composition comprises a liquid mixture of a polysulfone compound, a solvent and a non-solvent, which are relatively non-toxic and which preferably do not harm the environment.

 The solvent may be selected from the group consisting of tetramethylene sulfone (“sulfolane”); 3-methylsulfolane; benzophenone; N, N-dimethylacetamide; 2-pyrrolidone; 3-methylsulfolene; pyridine; thiophene; o-dichlorobenzene; 1-chloronaphthalene; methyl salicylate; anisole; o-nitroanisole; diphenyl ether; diphenoxymethane; acetophenone; p-methoxyphenyl-2-ethanol; 2-piperidine; antipyrine; diethyl phthalate; diphenylsulfone; diphenyl sulfoxide; phthalic acid dioctyl ester; phthalic acid dimethyl ester; phthalic acid diethyl ester; phthalic acid dibutyl ester; phthalic acid bis (2-ethylhexyl) ester; phthalic acid benzylbutyl ester; and phenyl sulfide. Especially good results were achieved when the solvent contained sulfolane, 2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (antipyrine), 2-piperidine, δ-valerolactam, diethyl phthalate, or mixtures thereof.

 The non-solvent can be selected from the group consisting of poly (ethylene glycol), di (ethylene glycol), three (ethylene glycol), glycerin, 1,1-diethylurea; 1,3-diethylurea; dinitrotoluene; 1,2-ethanediamine; diphenylamine; toluene diamine; o-toluic acid; m-toluic acid; toluene-3,4-diamine; dibutyl phthalate; piperidine; decalin; cyclohexane; cyclohexene; chlorocyclohexane; cellosolve solvent; N, N-dimethylbenzylamine; paraffin; mineral oil; mineral wax; talline amine; triethanolamine; lauryl methacrylate; stearic acid; ethylene glycol; tetra (ethylene glycol); diethyl adipate; d-sorbitol; chlorotriphenyl stannane; resorcinol; 2-methyl-8-quinolinol; quinaldine; 4-phenylpyridine; O, O-diethyl-o- (p-nitrophenyl) ester of thiophosphoric acid; N, N-dimethyl-p-phenylenediamine; 2,6-dimethoxyphenol; 4-allyl-2-methoxyphenol; phenanthridine; 2-naphthylamine; 1-naphthylamine; 1-naphthol; 2-naphthalentiol; 1-bromonaphthalene; levulinic acid; phenylpyrrol-2-ylketone; phenyl 4-pyridyl ketone; isothiocyanic acid m-nitrophenyl ester; 2-methyl-1H-indole; 4-methylimidazole; imidazole; 1,7-heptanediol; 9H-fluoren-9-one; ferrocene; 2.2 ', 2' '- nitrilotriethanol; 2,2'-iminodiethanol; dibenzofuran; cyclohexane acetic acid; cyanamide; coumarin; 2,2'-bipyridine; benzoic acid; benzene propionic acid; o-dinitrobenzene; 9-methyl-9-azabicyclo (3.3.1) nonan-3-one; chlorodiphenylarsine; antimony bromide; p-anisidine; o-anisaldehyde; adiponitrile; p-aminoacetophenone; monoacetin; diacetin; triacetin; pentoxane; 4-benzoyl biphenyl; methyl oleate; triethyl phosphate; butyrolactone; terphenyl; tetradecanol; polychlorinated biphenyl ("Aroclor 1242"); myristic acid; dodecyl ester of methacrylic acid; isocyanic acid methylenedi-p-phenylene ester; 2 - ((2-hexyloxy) ethoxy) ethanol; 4-nitrobiphenyl; benzyl ether; benzenesulfonyl chloride; 2,4-diisocyanato-1-1-methylbenzene; adipic acid diethyl ester; 2'-nitro-acetophenone; 1'-acetonaphton; tetradecanone; (dichlorophenyl) trichlorosilane; dichlorodiphenylsilane; thiophosphoric ester O, O-diethyl o- (p-nitrophenyl) ester; phosphoric acid tri-o-tolyl ester; phosphoric acid triphenyl ester; phosphoric acid tributyl ester; phenylphosphorous dichloride; p-nitrophenol; isocyanic acid methyl m-phenylene ester; 2,2'-iminodiethanol; N- (2-aminoethyl) -N '- (2 - ((2-aminoethyl) amino) ethyl) 1,2-ethanediamine; 2,6-di-tert-butyl p-cresol; chlorobiphenyl; 4-biphenylamine; benzyl ether; benzenesulfonyl chloride; 1,2- (methylenedioxy) -4-propenylbenzene; 2,4-diisocyanato-1-methylbenzene; chlorodinitrobenzene (mixture of isomers); hexahydro 2H-azepin-2-one; 4,4'-methylenedianiline; 1'-acetonaphton; mercaptoacetic acid and acetanilide. The best results were obtained when the non-solvent contained poly (ethylene glycol), di (ethylene glycol), three (ethylene glycol), glycerol, or mixtures thereof.

 The solvent and non-solvent are present in a ratio suitable for preparing a semipermeable polysulfone membrane suitable for carrying out liquid separation processes.

 In accordance with yet another aspect of the present invention, there is provided a “melt spinning” or “melt extrusion” process for producing semipermeable polysulfone membranes. The melt spinning process comprises the following steps: (1) a composition is prepared comprising a polysulfone compound, a solvent selected from the above group of possible solvents and preferably selected from the group consisting of tetramethylene sulfone, antipyrine, δ-valerolactam, diethyl phthalate, and mixtures thereof and optionally a non-solvent selected from the above group of possible non-solvents and preferably selected from the group consisting of poly (ethylene glycol), di (ethylene glycol), three (ethylene glycol), litserin or mixtures thereof; (2) heating the composition to a temperature at which the composition turns into a homogeneous liquid (i.e., to a temperature above ambient temperature); (3) extruding the composition through an extrusion die (such as an extrusion die with one or more holes for extruding a hollow fiber (the so-called "multi-channel mouthpiece")); and (4) passing the extruded product through a quench zone in which gelation and curing of the product takes place, whereby a membrane is formed.

 In accordance with another aspect of the present invention, melt-formed semipermeable polysulfone membranes are obtained having a uniform structure over the entire thickness of the membrane (i.e., a “homogeneous” membrane structure) suitable for liquid separation processes, such as, but not limited to, microfiltration, ultrafiltration, reverse osmosis and dialysis.

Brief Description of the Drawings
FIG. 1 illustrates a preferred embodiment of the method of the invention for producing uniform polysulfone hollow fibers (as members of a membrane configuration) of the present invention.

 FIG. 2. illustrates an alternative method for producing the homogeneous polysulfone hollow fibers of the present invention.

 In FIG. 3 is a three-dimensional diagram showing the proportions of a polysulfone compound, a solvent and a non-solvent, which are combined in representative compositions for melt molding of the present invention.

 In FIG. 4 is a photograph taken by a scanning electron microscope, which depicts the uniform polysulfone hollow fiber of the present invention.

 Figure 5 is a schematic illustration of a hemodialyzer comprising homogeneous hollow polysulfone fiber membranes of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The present invention covers, inter alia, compositions for melt forming polysulfone semipermeable membranes. Compositions include a polysulfone compound, a solvent, and optionally a non-solvent. In said composition, a solvent and an optional non-solvent are present in a ratio that is suitable for preparing a semipermeable membrane suitable for carrying out liquid separation processes. Membranes obtained by melt spinning using such a composition are uniform. That is, the melt-formed membranes are symmetrical, so that the membranes have almost the same structure throughout the thickness of the membranes, as shown by a photograph taken with an electron scanning microscope and shown in FIG. 4, and this structure is a hollow fiber obtained using the specified composition. As used herein, the term “homogeneous” polysulfone membrane refers to a membrane in which each part or section of the membrane provides a substantially proportional proportion of permeability to the total permeability of the membrane.

Polysulfone compounds and their synthesis are well known in the art. Preferred polysulfone compounds useful in the framework of the present invention satisfy the formula
R ₁ -SO ₂ -R ₂
where R ₁ and R ₂ (which may have the same or different meanings) are groups such as alkanes, alkenes, alkynes, aryls, alkyls, alkoxyls, aldehydes, anhydrides, esters, ethers, and mixtures thereof, each such group has fifty or fewer carbon atoms, and includes both unbranched and branched chain structures. Preferred polysulfone compounds useful in the framework of the present invention have a melt index in the range of about 1.7 dg / min to about 9.0 dg / min according to changes in accordance with the American Standard Test Method (ASTM) for changing the flow rate of thermoplastics when used extrusion plastometer (ASTM D 1238-94a). Good results were obtained when the polysulfone compounds had a melt index from about 2.0 dg / min to about 5.0 dg / min. Preferred polysulfone compounds useful in the framework of the present invention include, but are not limited to, polyaryl sulfones, for example, bisphenol A polysulfone, polyethersulfone, polyphenyl sulfone, and mixtures thereof. Particularly good results were obtained using bisphenol A polysulfone.

The term "solvent polysulfone compounds" in this text refers to a compound having the following characteristics: boiling point of at least about 150 ^o With solvating ability, allowing to dissolve from about 8 wt.% To about 80 wt.% Polysulfone compounds at temperatures in the range from from about 50 ^{° C.} to about 300 ^° C. The solvent can preferably dissolve from about 8 wt.% to about 80 wt.% polyaryl sulfone.

 Possible solvents useful in the framework of the present invention include, but are not limited to, tetramethylene sulfone; 3-methylsulfolane; benzophenone; N, N-dimethylacetamide; 2-pyrrolidone; 3-methylsulfolene; pyridine; thiophene; o-dichlorobenzene; 1-chloronaphthalene; methyl salicylate; anisole; o-nitroanisole; diphenyl ether; diphenoxymethane; acetophenone; p-methoxyphenyl-2-ethanol; 2-piperidine; antipyrine; diethyl phthalate; diphenylsulfone; diphenyl sulfoxide; phthalic acid dioctyl ester; phthalic acid dimethyl ester; phthalic acid diethyl ester; phthalic acid dibutyl ester; phthalic acid bis (2-ethylhexyl) ester; phthalic acid benzylbutyl ester; and phenyl sulfide. Most preferred solvents useful within the scope of the present invention include, but are not limited to, tetramethylene sulfone (“sulfolane”), antipyrine, δ-valerolactam, diethyl phthalate, and mixtures thereof. Especially good results were obtained when using tetramethylene sulfone as a solvent.

The term “polysulfone compound non-solvent” as used herein refers to a compound having the following characteristics: a boiling point of at least about 150 ^{° C.} and a solvation capacity low enough to dissolve less than about 5 wt.% Polysulfone compound at a temperature in the range of about 50 ^o C to about 300 ^o C.

 Possible non-solvents useful in the framework of the present invention include the following compounds: 1,1-diethylurea; 1,3-diethylurea; dinitrotoluene; 1,2-ethanediamine; diphenylamine; toluene diamine; o-toluic acid; m-toluic acid; toluene-3,4-diamine; dibutyl phthalate; piperidine; decalin; cyclohexane; cyclohexene; chlorocyclohexane; cellosolve solvent; N, N-dimethylbenzylamine; paraffin; mineral oil; mineral wax; talline amine; triethanolamine; lauryl methacrylate; stearic acid; di (ethylene glycol); three (ethylene glycol); ethylene glycol; poly (ethylene glycol); tetra (ethylene glycol); glycerol; diethyl adipate; d-sorbitol; chlorotriphenyl stannane; resorcinol; 2-methyl-8-quinolinol; quinaldine; 4-phenylpyridine; thiophosphoric ester O, O-diethyl o- (p-nitrophenyl) ester; N, N-dimethyl-p-phenylenediamine; 2,6-dimethoxyphenol; 4-allyl-2-methoxyphenol; phenanthridine; 2-naphthylamine; 1-naphthylamine; 1-naphthol; 2-naphthalentiol; 1-bromonaphthalene; levulinic acid; phenylpyrrol-2-ylketone; phenyl 4-pyridyl ketone; isothiocyanic acid m-nitrophenyl ester; 2-methyl-1H-indole; 4-methylimidazole; imidazole; 1,7-heptanediol; 9H-fluoren-9-one; ferrocene; 2.2 ', 2' '- nitrilotriethanol; 2,2'-iminodiethanol; dibenzofuran; cyclohexane acetic acid; cyanamide; coumarin; 2,2'-bipyridine; benzoic acid; benzene propionic acid; o-dinitrobenzene; 9-methyl-9-azabicyclo (3.3.1) nonan-3-one; chlorodiphenylarsine; antimony bromide; p-anisidine; o-anisaldehyde: adiponitrile; p-aminoacetophenone; monoacetin; diacetin; triacetin; pentoxane; 4-benzoyl biphenyl; methyl oleate; triethyl phosphate; butyrolactone; terphenyl; tetradecanol; polychlorinated biphenyl ("Aroclor 1242"); myristic acid; dodecyl ester of methacrylic acid; isocyanic acid methylenedi-p-phenylene ester; 2 - ((2-hexyloxy) ethoxy) ethanol; 4-nitrobiphenyl; benzyl ether; benzenesulfonyl chloride; 2,4-diisocyanato-1-1-methylbenzene; adipic acid, diethyl ether; 2'-nitro-acetophenone; 1-acetonaphton; tetradecanone; (dichlorophenyl) trichlorosilane; dichlorodiphenylsilane; O, O-diethyl o- (p-nitrophenyl) ester of phosphoric acid; phosphoric acid tri-o-tolyl ester; phosphoric acid triphenyl ester; phosphoric acid tributyl ester; phenylphosphorous dichloride; p-nitrophenol; isocyanic acid methyl m-phenylene ester; 2,2'-iminodiethanol; N- (2-aminoethyl) -N '- (2 - ((2-aminoethyl) amino) ethyl) 1,2-ethanediamine; 2,6-di-tert-butyl p-cresol; chlorobiphenyl; 4-biphenylamine; benzyl ether; benzenesulfonyl chloride; 1,2- (methylenedioxy) -4-propenylbenzene; 2,4-diisocyanato-1-methylbenzene; chlorodinitrobenzene (mixture of isomers); hexahydro 2H-azepin-2-one; 4,4'-methylenedianiline; 1'-acetonaphton; mercaptoacetic acid; and acetanilide.

 Most preferred non-solvents useful in the framework of the present invention include, but are not limited to, poly (ethylene glycol), di (ethylene glycol), tri (ethylene glycol), glycerol, and mixtures thereof.

 The concentrations of the components of the composition may vary and depend on a number of variable factors, many of which can be easily established in simple experiments. For example, the miscibility of a composition at a melt extrusion temperature is one of those factors that must be considered when determining the appropriate concentration of components. Miscibility of solutions of polysulfone compounds can be easily determined empirically by known methods (regardless of whether the miscibility of the components of the composition is fairly obvious). The final use of the membrane is another factor to consider when determining the appropriate mix composition, since the preferred pore size of the membrane and the rate at which liquids and solutions pass through the membrane are very dependent on the purpose of using the resulting fiber.

 When membranes are to be used for microfiltration of liquids, the concentration of the polysulfone compound is preferably at least about 8 wt.%, More preferably at least about 12 wt.%. The concentration of the solvent is preferably at least about 40 wt.%, More preferably at least about 60 wt. % The concentration of the non-solvent, if present, is preferably at least about 1 wt.%, And more preferably at least about 5 wt.%.

 When membranes are to be used for ultrafiltration or dialysis, the concentration of polysulfone compounds is preferably at least about 18 wt.%, More preferably at least about 25 wt.%. The concentration of the solvent is preferably at least about 40 wt.%, More preferably at least about 45 wt. % The concentration of the non-solvent, if present, is preferably at least about 1 wt.%, More preferably at least about 5 wt.%.

 The ratio of solvent to non-solvent (i.e., the ratio of solvent to non-solvent "sufficient to obtain a semipermeable membrane suitable for liquid separation") is preferably from about 0.95: 1 to about 80: 1, more preferably from about 2: 1 to about 10: 1. For example, as shown in FIG. 3, for a three-component composition (for melt spinning of polysulfone hollow fibers) comprising bisphenol A polysulfone, sulfolane (solvent) and poly (ethylene glycol) (non-solvent), acceptable amounts of the polysulfone compound, solvent and non-solvent are within the region limited to the final values of each component, forming zones A, B, C. Any specific composition consisting of such quantities of each of these three components that are in zones A, B, C of Fig. 3 are suitable for molding from a melt of hollow fiber membranes.

 When membranes are to be used for reverse osmosis, the polysulfone concentration is preferably at least about 30 wt.%, More preferably at least about 35 wt.%. The concentration of the solvent is preferably at least about 12 wt. %, more preferably at least about 20 wt.%. If a non-solvent is present, its concentration is preferably at least about 1 wt.%, More preferably at least about 5 wt.%.

 The compositions of the present invention can be used to make polysulfone semipermeable membranes suitable for “liquid separation processes”. For the purposes of this text, such processes include, but are not limited to, microfiltration, ultrafiltration, dialysis, and reverse osmosis. Figure 5 shows a representative device for the separation of liquids, suitable for use as a device for extracorporeal processing of blood, specifically for hemodialysis. The hemodialyzer 10 includes an outer casing 12, end caps 14, an inlet for dialysate 16, an outlet for dialysate 18, an inlet for blood 20, an outlet for blood 22, and a fiber bundle 24 sealed in the outer casing. The outer casing limits the dialysate chamber, and the lumens of the fibers form a blood chamber. As blood flows through the lumens of the fibers in parallel, the dialysate flows countercurrently through the dialysate chamber.

 The membranes of the present invention can be manufactured using alternative methods for implementing the methods, as shown in FIGS. 1 and 2. A number of schemes for implementing the method can be used to create polysulfone membranes with the desired properties.

 In one preferred method of the present invention, the polysulfone composition of the polysulfone compound, the solvent and the non-solvent are pre-mixed in a high shear mixer, melted, extruded (in the form of hollow fibers), cooled rapidly (FIG. 1), and then wound on cores or drums using one of a number of well-known winders, such as the Lesson winder. In this method, care must be taken to maintain a slight tension in the hollow fibers during winding. In another preferred method of the present invention, the polysulfone composition is pre-mixed in a high shear mixer, melted, extruded through a mouthpiece to make yarns (to obtain solid filaments), cooled, granulated, re-melted, extruded (to obtain hollow fibers), sharply cooled , then wound (figure 2). In another preferred method of the present invention, the polysulfone composition is pre-mixed, melted, extruded (to obtain hollow fibers), quenched, wound, kept dry for a certain period of time, soaked in a liquid that is a non-solvent of the polysulfone compound, and maintained in this liquid for up to 15 days (figure 1). In another preferred method of the present invention, the polysulfone composition is pre-mixed in a high shear mixer, melted, extruded (until hollow fibers), cooled rapidly, wound, soaked, leached, washed, re-plasticized, and then dried in an oven (preferably in a convection oven) (figure 1). In another preferred method of the present invention, the polysulfone composition is pre-mixed, melted, extruded (to obtain solid filaments), cooled, granulated, re-melted, extruded (to obtain hollow fibers), sharply cooled, wound, and then kept dry on air, after which it is soaked in a liquid that is non-solvent in relation to the polysulfone compound (figure 2). In another preferred method of the present invention, the polysulfone composition is pre-mixed, melted, extruded (to obtain solid filaments), cooled, granulated, re-melted, extruded (to obtain hollow fibers), sharply cooled, wound, soaked, leached, washed, re- plasticize and dry (figure 2).

 The components of the composition (i.e. polysulfone compound, solvent and non-solvent) to be extruded are combined and homogenized before extrusion by mixing in the usual way using conventional mixing equipment, for example a high shear mixer, such as a twin screw extruder mixer. The components of the extrusion composition can also be combined and homogenized directly in a melter equipped with an appropriate mixer for molten liquid. Alternatively, the polysulfone extrusion composition can be homogenized by extruding the molten composition through a filament head, cooling the extrudate in the form of round filaments, and grinding or granulating the extruded product to obtain particles of a certain size, ready to be fed into a heated single screw or twin screw extruder. Alternatively, other heating / homogenization methods that are known to those skilled in the art and which are used to produce a uniform molten extrusion fluid (referred to as "melt") may be used.

The melt is heated to a temperature that promotes the production of a homogeneous liquid, which has a viscosity suitable for extrusion. The temperature should not be too high so as not to cause decomposition of the polysulfone, solvent or non-solvent. The temperature should not be too low so that the liquid does not become too viscous for extrusion. For example, when the solution contains polysulfone bisphenol A, the extrusion temperature is preferably at least about 50 ^{° C.} , more preferably at least about 75 ^° C. The extrusion temperature is preferably about 300 ^{° C.} , more preferably lower than about 220 ^° C.

 The melt viscosity should not be so high that the melt becomes too viscous for extrusion at temperatures that do not adversely affect the polysulfone compound. However, the melt viscosity should not be so low that the extruded product cannot maintain its desired shape after exiting the extruder head. The melt can be extruded in various forms, for example, inter alia, in the form of hollow fibers, tubes, sheets, and also hollow fibers with ribs. You can help maintain the desired shape of the extruded product after extrusion by cooling it.

 To make hollow fiber membranes, the melt is extruded through the die to produce hollow fibers (multi-channel mouthpiece). A multi-channel mouthpiece typically has many openings and therefore allows a fiber bundle to be obtained. A multi-channel mouthpiece typically includes a means of supplying a stream (liquid or gas) to manufacture a core or “lumen” in the extruded article. The lumen flow is used to prevent the destruction of the hollow fibers when they exit the mouthpiece. The lumen flow may be a gas, such as nitrogen gas, air, carbon dioxide, or another inert gas, or a liquid that does not dissolve the polysulfone compound, such as, but not limited to water, poly (ethylene glycol), di (ethylene glycol) ), three (ethylene glycol), glycerin and mixtures thereof. Mixtures of solvents and non-solvents may be used if these mixtures are not solvents for the polysulfone compound. In an alternative embodiment, the melt is first extruded to obtain solid filaments, through a head with one or more holes, and the obtained solid filaments are cooled and granulated to obtain particles, the sizes of which allow them to be used for feeding into a single screw or twin screw extruder (figure 2). In this alternative production method, the particles are re-melted and then extruded through a mouthpiece with one or more holes to form hollow fibers, as described above.

 The extruded product exiting the extrusion enters one or more quench zones. The quench zone may be gas or liquid. In the quench zone, the extruded product is subjected to cooling sufficient to cause gelation and curing of the membrane. In one embodiment of the method of the present invention, the period of time starting after the extruded product leaves the mouthpiece and before the membrane is wound on a core or reel is an important factor in achieving the desired membrane permeability. During this period of time with respect to this composition, the permeability of the membrane depends largely on the cooling rate to which the extruded product is subjected. The permeability increases with sharper cooling of the extruded product compared with the permeability obtained with less severe cooling or slower gelation of the extruded product. The increased permeability of membranes as a result of sharper cooling usually affects the ability of membranes to transfer water or other fluids and compounds across the thickness of the membranes. Thus, the cooling rate of the extruded product (which is affected by the temperature and composition of the used cooling medium) can be varied in order to change the permeability of the resulting membrane.

In one method of the present invention, polysulfone hollow extruded fibers are quenched by air. In the cooling zone, the hollow fibers gel and harden. The temperature in the air cooling zone is preferably less than about 27 ^{° C.} , more preferably less than about 24 ^° C. The hollow fibers are held in the air cooling zone, preferably less than about 180 minutes, more preferably less than about 30 minutes.

In another preferred method of the present invention, the extruded hollow fibers are sharply cooled in a liquid that practically does not dissolve the polysulfone compound, such as water, poly (ethylene glycol), di (ethylene glycol), tri (ethylene glycol), glycerol, or a mixture thereof. Alternatively, a mixture of solvent (s) or non-solvent (s) can be used if this mixture does not substantially dissolve the polysulfone compound. If the quench liquid includes water and one or more components, the ratio of water to these other components is preferably from about 0.25: 1 to about 200: 1. The temperature in the area for quenching with liquid is preferably lower than about 50 ^{° C.} , more preferably lower than about 25 ^{° C.} , and even better lower than about 10 ^° C. The advantage of liquid cooling is that it provides less resistance to heat transfer from extruded product to the cooling medium than air cooling and, thus, it leads to faster heat removal from the extruded product as the membrane is formed. Rapid heat dissipation changes the permeability of the resulting membrane, and this can be used to adjust the permeability depending on the intended use of the membrane.

 Hollow fibers are optionally drawn using spinning discs or other conventional equipment to produce fibers of a specific diameter. More specifically, fiber drawing can be accomplished by passing a hollow fiber over a series of discs. The required degree of stretching can be obtained by controlling the rotation speed of the second disk or the second group of disks relative to the first disk onto which the fiber enters. Linear speeds are usually not very important and can vary over a wide range. Preferred linear velocities are at least about 10 feet (3.048 m) per minute and less than about 1000 feet (304.8 m) per minute.

 In another preferred method of the present invention, as shown in FIG. 2, after quenching, the membrane is passed through at least one leach bath containing a liquid that practically does not dissolve the polysulfone compound, such as water or a mixture of water and sulfolane and / or non-solvent (s), or a mixture of water and a solvent used in the melt composition. Good results were achieved when there was water in the leach bath. The membrane is leached to remove at least a portion of the solvent and non-solvent. In a leach bath, it is not necessary to remove all solvent and non-solvent from the membrane, which depends, at least in part, on the intended end use of the membrane.

The minimum temperature in the leach bath is such that the removal of solvent and non-solvent from the membrane occurs at a reasonable rate relative to the requirements of the manufacturing process. The minimum temperature in the leach bath is preferably at least about 20 ^{° C.} , more preferably at least about 40 ^° C. The maximum temperature in the leach bath is lower than the temperature at which the integrity of the membrane is compromised. Accordingly, the temperature in the leach bath is preferably less than about 95 ^° C.

 For example, the residence time of the hollow fiber membrane in the leach bath is preferably less than about 1200 seconds, more preferably less than about 300 seconds. The hollow fiber can optionally be pulled to the desired size before being placed in the leach bath, while it is in the leach bath, immediately after leaving the leach bath, or during several of these processes together.

 After being placed in the leach bath, the membrane can optionally be passed through a wash bath containing water. The washing bath allows you to remove residues from the leaching process from the membrane. The wash tub preferably has room temperature. For a hollow fiber, the residence time of the fiber in the wash bath is preferably less than about 1200 seconds, more preferably less than 300 seconds.

After leaching, the membrane can then be plasticized again. For hollow fiber membranes suitable for dialysis, a re-plasticization bath is used, which preferably contains less than about 50 wt.% Glycerol and more preferably less than about 45 wt. % glycerol, the rest is water. The minimum temperature in the bath for repeated plasticization is such that the repeated plasticization of the membrane occurs at a reasonable rate relative to the requirements of the production process. For example, the minimum temperature in the re-plasticization bath containing glycerin is preferably at least about 20 ^{° C.} , more preferably at least about 35 ^° C. The maximum temperature in the repeated plasticization bath is lower than the temperature at which the integrity of the membrane can be compromised. . Accordingly, the maximum temperature in the re-plasticization bath is preferably less than about 100 ^{° C.} , more preferably less than about 50 ^° C.

 After the membrane has been removed from the bathtub to re-plasticize, excess fluid adhering to the membrane is optionally removed, preferably using a conventional air scraper, operating under a pressure of from about 10 psi (68.9476 kPa) to about 60 psi ( 413.6856 kPa). For hollow fibers, good results were obtained when the air scraper had a pressure of about 30 psi (206.8428 kPa).

The resulting polysulfone membranes are optionally dried in an oven (preferably in a convection oven). The temperature in the furnace is maintained at a level of from about 20 ^{° C.} to about 200 ^° C. For hollow fibers, good results were obtained when the temperature in the furnace was about 70 ^° C. In a convection oven, the membranes are dried for about 5 seconds to about 1200 seconds. For hollow fibers, good results were obtained when the fiber was dried for at least about 140 seconds.

 Polysulfone semipermeable membranes obtained by the above methods can be used in liquid separation processes, such as, but not limited to, microfiltration, ultrafiltration, dialysis and reverse osmosis. A specific method for producing the membrane in the framework of the methods of the present invention is chosen so that the resulting membrane is consistent with the intended method of its application. Such an adaptation is easily achieved by a specialist based on the methods described here.

 The various examples below illustrate the present invention and do not limit its scope as defined by the appended claims.

 Example 1

A composition was obtained comprising 38 wt.% Udel P1835NT11 (bisphenol A polysulfone sold by Amoso Polymers, Inc. of Alfaretta, Georgia), about 44.3 wt.% Anhydrous sulfolane (manufactured by Phillips Chemical Company from g Borger, Texas) and about 17.7 wt.% Poly (ethylene glycol), the average molecular weight of which is about 1000 daltons (manufactured by the Dow Chemical Company from Midland, Michigan). The ratio of solvent to non-solvent was about 4.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 132 ^° C. The extruded composition was cooled, granulated using an RCP 2.0 pellet mill (manufactured by Randcastle Extrusion Systems, Inc. of Chedar Grove, NJ), and then re-melted and extruded through a multi-channel mouthpiece with 30 holes at a temperature of about 149 ^{° C.} using a single screw extruder. The obtained extruded hollow fibers were sharply cooled in air at a temperature of about 21 ^{° C.} for about 15 seconds, pulled from the first disk (rotating at a surface speed of 172 feet (52.4256 m) per minute) to the second disk (rotating at a surface speed of 182 feet (55.4736 m) per minute) in order to increase the fiber length by about 5.75%, wound around the core and soaked in a water bath at a temperature of about 25 ^o C for a period of about four hours.

After soaking in water, the hollow fiber was unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through a water bath at 37 ^° C for about 40 seconds. Then the fiber was immersed at room temperature in a washing bath for washing with water for 139 seconds. After the wash bath, the fiber was re-plasticized by immersing for 140 seconds in a bath with repeated plasticization containing a 40% aqueous glycerol solution at a temperature of about 37 ^° C. After removing the fiber from the bath with an aqueous glycerol solution, the excess liquid was removed from the fiber using an air cutting tool operating under a pressure of 30 psi (206.8428 kPa). Then the obtained fiber was dried in a convection oven at a temperature of about 70 ^o C for 155 seconds.

где К_b представляет собой сопротивление массопередаче в жидкости, присутствующей в просвете полого волокна, а Р_m представляет собой проницаемость мембраны. Невозможно было определить проницаемость мембраны Р_m саму по себе, используя оборудование для тестирования, поскольку поток раствора через отдельное волокно невозможно было сделать достаточно большим, чтобы сделать К_b незначительным.The resulting hollow fiber had an average lumen diameter of 160 μm and an average wall thickness of 18 μm. A dialysis device containing 150 fibers was made from a hollow fiber. The in vitro water flow in this device was 102.5 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 1.92 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber. The indicator K _{ov was} determined by the following equation:

where K _b represents the resistance to mass transfer in the fluid present in the lumen of the hollow fiber, and P _m represents the permeability of the membrane. It was not possible to determine the permeability of the membrane P _m alone using testing equipment, since the flow of the solution through a single fiber could not be made large enough to make K _b insignificant.

 A device that can be used as an ultrafiltration cell to remove contaminants from water or aqueous solutions can be made from this hollow fiber membrane.

 Example 2

A composition was prepared comprising 36 wt.% Uriel P1835NT11 (Amoco Polymers, Inc.), about 45.7 wt.% Anhydrous sulfolane (Phillips Chemical Company) and about 18.3 wt.% Poly (ethylene glycol), average whose molecular weight is about 1000 daltons (Dow Chemical Company), obtaining a ratio of solvent to non-solvent of about 2.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 173 ^° C. The extruded composition was granulated, re-melted and extruded through a multi-channel mouthpiece with 30 holes at a temperature of about 178 ^{° C.} using a single-screw extruder. The obtained extruded hollow fibers were sharply cooled in air at a temperature of about 22 ^o C for about 7-8 seconds. The resulting hollow fiber membrane was wound around the core at a speed of about 110 feet (33.528 m) per minute and kept dry for about one hour. Then the hollow fiber was placed in a water bath, the temperature of which was about 25 ^o C, for a period of about 12-15 hours.

Then the hollow fiber was unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through the bath for leaching with water at a temperature of 36 ^o C for about 40 seconds. Then the fiber at room temperature for 139 seconds was immersed in a wash bath for washing with water. After the wash bath, the fiber was plasticized again by immersion for 140 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 37 ^° C. After removing the fiber from the bath with an aqueous glycerol solution, excess liquid was removed from the fiber using an air scraper operating under 30 pounds per square inch (206.8428 kPa) pressure. Then the obtained fiber was dried in a convection oven at a temperature of about 70 ^o C for 155 seconds.

The resulting hollow fiber had an average project diameter of 142 microns and an average wall thickness of 31 microns. A dialysis device containing 150 fibers was made from a hollow fiber. The in vitro water flow in this device was 68.0 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 2.28 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber. A device that can be used as an ultrafiltration cell to remove contaminants from water or aqueous solutions can be made from this hollow fiber membrane.

 Example 3

A composition was obtained comprising 38 wt.% Udel P1835NT11 (Amoso Polymers, Inc.), about 44.3 wt.% Anhydrous sulfolane (Phillips Chemical) and about 17.7 wt.% Poly (ethylene glycol), average molecular weight whose weight is about 1000 daltons (Dow Chemical), obtaining a solvent to non-solvent ratio of about 4.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 99 ^{° C.} and extruded directly through a multi-channel mouthpiece with 30 holes. The obtained extruded hollow fibers were rapidly cooled in air at a temperature of about 26 ^{° C.} for about 6 seconds. The resulting hollow fiber membrane was wound around the core at a speed of about 160 feet (48.768 m) per minute and immediately placed in a water bath for a period of about 12-15 hours.

Then, the hollow fiber was unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through the bath for leaching with water at a temperature of 37 ^{° C.} for about 40 seconds. Then the fiber was immersed at room temperature in a wash bath for washing with water for 140 seconds. After the wash bath, the fiber was plasticized again by immersion for 140 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 38 ^° C. After removing the fiber from the bath with an aqueous glycerol solution, the excess liquid was removed from the fiber using an air scraper operating at a pressure of 30 psi (206.8428 kPa). Then the obtained fiber was dried in a convection oven at a temperature of about 70 ^o C for 155 seconds.

The resulting hollow fiber had an average lumen diameter of 237 μm and an average wall thickness of 35 μm. A dialysis device containing 150 fibers was made from a hollow fiber. The in vitro water flow in this device was 143.5 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 0.88 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber. A device that can be used as an ultrafiltration cell to remove contaminants from water or aqueous solutions can be made from this hollow fiber membrane.

 Example 4

A composition was prepared comprising 36 wt.% Udel P1835NT11 (Amoco Polymers, Inc.), about 45.7 wt.% Anhydrous sulfolane (Phillips Chemical), and about 18.3 wt.% Poly (ethylene glycol), average molecular weight whose weight is about 1000 daltons (Dow Chemical), obtaining a ratio of solvent to non-solvent of about 2.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 143 ^{° C.} and extruded directly through a multi-channel mouthpiece with 30 holes. The obtained extruded hollow fibers were sharply cooled in air at a temperature of about 25 ^{° C.} for about 0.08 minutes, wound around the core at a speed of about 203 feet (61.8744 m) per minute, and kept dry for thirty minutes, after which placed in a water bath with a temperature of 25 ^o With for a period of about three days.

Then, the hollow fiber was unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through the bath for leaching with water at a temperature of 38 ^{° C.} for about thirty seconds. Then the fiber was immersed at room temperature in a washing bath for washing with water for 148 seconds. After the wash bath, the fiber was plasticized again by immersion for 149 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 38 ^° C. After removing the fiber from the bath with an aqueous glycerol solution, excess liquid was removed from the fiber using an air scraper operating under a pressure of about thirty pounds per square meter. inch (206.8428 kPa). Then the obtained fiber was dried in a convection oven at a temperature of about 70 ^o C for 147 seconds.

The resulting hollow fiber had an average lumen diameter of 192 μm and an average wall thickness of 29.5 μm. A dialysis device containing 150 fibers was made from a hollow fiber. The in vitro water flow in this device was 141.2 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 1.20 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber. A device that can be used as an ultrafiltration cell to remove contaminants from water or aqueous solutions can be made from this hollow fiber membrane.

 Example 5

A composition was obtained comprising 34 wt.% Udel P1835NT11 (Amoco Polymers, Inc.), about 54 wt.% Anhydrous sulfolane (Phillips Chemical), about 11 wt. % poly (ethylene glycol), the average molecular weight of which is about 1000 daltons (Dow Chemical) and about 1 wt.% glycerol (VanWaters & Rogers, Inc., Seattle, WA), obtaining a solvent to non-solvent ratio of about 4.5 :1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 144 ^° C. The obtained extruded product was then cooled, granulated, re-melted and extruded through a multi-channel mouthpiece with 30 holes at a temperature of about 134 ^{° C.} using a single-screw extruder. The resulting extruded product was sharply cooled in air at a temperature of about 20 ^o C for about 0.08 minutes, wound on the core at a speed of about 200 feet (60.96 m) per minute. The entire core was immediately placed in a water bath at a temperature of 25 ^o C for a period of about 15-20 hours.

The hollow fiber was then unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through the bath to leach water at room temperature for 97 seconds. Then the fiber was subjected to repeated plasticization by immersing for 145 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 38 ^° C. After removing the fiber from the bath with an aqueous glycerol solution, excess liquid was removed from the fiber using an air scraper operating under a pressure of about 30 pounds per square inch (206.8428 kPa). Then, the obtained fiber was dried in a convection oven at a temperature of about 62 ^{° C.} for 151 seconds.

The resulting hollow fiber had an average lumen diameter of 165 μm and an average wall thickness of 18 μm. Research devices containing 150 fibers each were made from hollow fiber. The in vitro water flow in this device was 67.2 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 2.19 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber.

 Example 6

A composition was obtained comprising 34 wt.% Udel P1835NT11 (Amoco Polymers, Inc.), about 54 wt.% Anhydrous sulfolane (Phillips Chemical), about 6 wt.% Poly (ethylene glycol), the average molecular weight of which is about 1000 dalton (Dow Chemical) and about 6 wt.% three (ethylene glycol) (Aldrich Chemical Company, Inc., Milwaukee, Wisconsin) to obtain a solvent to non-solvent ratio of about 4.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 153 ^° C. The obtained extruded product was then cooled, granulated, re-melted and extruded through a multi-channel mouthpiece with 30 holes at a temperature of about 137 ^{° C.} using a single-screw extruder. The resulting extruded product was sharply cooled in air at a temperature of about 20 ^o C for about 0.08 minutes, wound on the core at a speed of about 200 feet (60.96 m) per minute. The entire core was immediately placed in a water bath at a temperature of 25 ^o C for a period of about 15-20 hours.

The hollow fiber was then unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through a water leach bath at room temperature for 95 seconds. Then the fiber was immersed in a wash bath for washing with water at room temperature for 134 seconds. Then the hollow fiber was subjected to repeated plasticization by immersion for 146 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 38 ^o C. After removing the fiber from the bath with an aqueous glycerol solution, the excess liquid was removed from the fiber using an air scraper operating under pressure about 30 pounds per square inch (206.8428 kPa). Then the obtained fiber was dried in a convection oven at a temperature of about 70 ^o C for 150 seconds.

The resulting hollow fiber had an average lumen diameter of 180 μm and an average wall thickness of about 20 μm. Research devices containing 150 fibers each were made from hollow fiber. The in vitro water flow in this device was 60.0 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 2.17 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber.

 Example 7

A composition was obtained including 32 wt.% Udel P1835NT11 (Amoso Polymers, Inc.), about 53 wt.% Anhydrous sulfolane (Phillips Chemical) and about 15 wt.% Poly (ethylene glycol), the average molecular weight of which is about 1000 Dalton (Dow Chemical), obtaining a solvent to non-solvent ratio of about 2.5: 1. The composition was mixed in a co-rotating twin-screw extruder at a temperature of about 131 ^{° C.} and extruded directly through a multi-channel mouthpiece with 30 holes. The resulting extruded product was rapidly cooled in water at a temperature of about 7 ^{° C.} for about 6 seconds. The resulting hollow fiber membranes were wound around the core at a speed of about 244 feet (74.3712 m) per minute. The entire core was immediately placed in a water bath at a temperature of 25 ^o C for a period of about 15-20 hours.

The hollow fiber was then unwound from the core at a speed of about 30 ft / min (9.144 m / min) and the fiber was passed through a water leach bath at room temperature for 97 seconds. Then the fiber was immersed in a wash bath for washing with water at room temperature for 135 seconds. Then the hollow fiber was subjected to repeated plasticization by immersion for 146 seconds in a bath containing approximately 40% aqueous glycerol solution at a temperature of about 38 ^o C. After removing the fiber from the bath with an aqueous glycerol solution, the excess liquid was removed from the fiber using an air scraper operating under pressure about 30 pounds per square inch (206.8428 kPa). Then, the obtained fiber was dried in a convection oven at a temperature of about 45 ^{° C.} for 152 seconds.

The resulting hollow fiber had an average lumen diameter of 203 μm and an average wall thickness of about 37 μm. Research devices containing 150 fibers each were made from hollow fiber. The in vitro water flow in this device was 9.1 ml (h • mm Hg • m ² ), and the average K _ov for sodium chloride was 1.76 • 10 ^-2 centimeters per minute at a solution flow rate through the lumen fibers of about 0.02 milliliters per minute per fiber.

 The principles of the present invention are disclosed and illustrated by several preferred options for its implementation and numerous examples, however, specialists should be clear that within the framework of these principles there may be changes and specification. All these changes are included in the scope of the present invention, limited by the claims.

Claims (56)

 1. A method of producing a polysulfone semipermeable membrane by melt spinning, the method comprising the following steps: (a) a composition comprising a polysulfone compound, a polysulfone compound solvent and a polysulfone compound non-solvent, the solvent and non-solvent being present in the composition in a ratio sufficient to obtaining a semi-permeable membrane suitable for the process of separation of liquids; (b) heating the composition to a temperature at which the composition is a homogeneous liquid; (c) extruding a homogeneous liquid to obtain an extruded product; (d) thermally sharply cool the extruded product to separate phases and form a semipermeable membrane as a result.  2. The method according to claim 1, in which the solvent is selected from the group consisting of tetramethylene sulfone, 3-methylsulfolane, benzophenone, N, N-dimethylacetamide, 2-pyrrolidone, 3-methylsulfolene, pyridine, thiophene, o-dichlorobenzene, 1- chloronaphthalene, methyl salicylate, anisole, o-nitroanisole, diphenyl ether, diphenoxymethane, acetophenone, p-methoxyphenyl-2-ethanol, 2-piperidine, antipyrine, δ-valerolactam, diethyl phthalate, diphenyl sulfate, diphenyl sulfoxide, diphenyl sulfoxide, phthalic acid ester, phth diethyl ester acid, phthalic acid dibutyl ester, phthalic acid bis (2-ethylhexyl) ester, phthalic acid benzylbutyl ester, phenyl sulfide and mixtures thereof.  3. The method according to claim 1, in which the polysulfone compound is a polyaryl sulfonic compound.  4. The method according to claim 1, wherein the polysulfone compound is selected from the group consisting of bisphenol A polysulfone, simple polyether polysulfone, polyphenyl polysulfone, and mixtures thereof.  5. The method according to claim 1, wherein the non-solvent is selected from the group consisting of poly (ethylene glycol), di (ethylene glycol) tri (ethylene glycol) glycerol, and mixtures thereof.  6. The method according to claim 1, wherein the step of quenching the extruded product comprises passing the extruded product through the quench zone, wherein the quench zone comprises a fluid selected from the group consisting of air, water, glycerin, tetramethylene sulfone, and mixtures thereof.  7. The method according to claim 1, which further includes the step of drawing a semi-permeable membrane.  8. The method according to claim 1, which further includes the step of keeping the semipermeable membrane in liquid for from about 4 hours to about 15 days.  9. The method of claim 8, which further includes the step of passing a semipermeable membrane through a leach bath.  10. The method of claim 8, in which the leach bath contains a polysulfone compound nonsolvent.  11. The method of claim 8, in which the leach bath contains water.  12. The method according to claim 9, which further includes the step of passing a semipermeable membrane through the wash bath.  13. The method according to item 12, in which the wash bath contains water.  14. The method according to item 12, which further includes the step of passing a semi-permeable membrane through the bath for re-plasticization.  15. The method according to 14, in which the bath for re-plasticization contains an aqueous solution of glycerol.  16. The method according to clause 15, in which an aqueous solution of glycerol contains less than about 50 wt.% Glycerol.  17. The method according to 14, which further includes the step of drying a semipermeable membrane.  18. The method according to 17, in which the semi-permeable membrane is dried in an oven.  19. A method of producing a meshed molding of a polysulfone semipermeable membrane suitable for a liquid membrane separation process, said method comprising the steps of: (a) preparing a composition comprising a polysulfone compound, a polysulfone compound solvent and a polysulfone compound nonsolvent, with a solvent and a non-solvent in a composition in a ratio sufficient to produce a semipermeable membrane suitable for a liquid separation process; (b) heating the composition to a temperature at which the composition is a homogeneous liquid; (c) squeezing a homogeneous liquid through the head to obtain filaments to obtain solid filaments; (d) thermally sharply cool a homogeneous liquid to obtain filaments; (e) granulate the filaments to obtain particles of such sizes that they can be easily fed into the extruder; (e) re-melting the particles to form a liquid; (g) extruding a liquid to form an extruded product and thermally cooling the extruded product sharply to separate phases and form a semipermeable membrane as a result.  20. The method according to claim 19, in which the solvent is selected from the group consisting of tetramethylene sulfone, 3-methylsulfolane, benzophenone, N, N-dimethylacetamide, 2-pyrrolidone, 3-methylsulfolene, pyridine, thiophene, o-dichlorobenzene, 1- chloronaphthalene, methyl salicylate, anisole, o-nitroanisole, diphenyl ether, diphenoxymethane, acetophenone, p-methoxyphenyl-2-ethanol, 2-piperidine, antipyrine, δ-valerolactam, diethyl phthalate, diphenyl sulfate, diphenyl sulfoxide, diphenyl sulfoxide, phthalic acid ester, diethyl ether ft Left acid ester, dibutyl ester, phthalic acid ester, bis (2-ethylhexyl) ester, phthalic acid, benzyl butyl ester of phthalic acid, δ-valerolactam, diethyl phthalate, phenyl sulfide, and mixtures thereof.  21. The method according to claim 19, in which the non-solvent is selected from the group consisting of 1,1-diethylurea, 1,3-diethylurea, dinitrotoluene, 1,2-ethanediamine, diphenylamine, toluene diamine, o-toluic acid, m-toluic acid, toluene-3,4-diamine, dibutyl phthalate, piperidine, decalin, cyclohexane, cyclohexene, chlorocyclohexane, solvent cellosolve, N, N-dimethylbenzylamine, paraffin, mineral oil, mineral wax, tallin amine, triethanolamine, lauryl methacrylate, stearyl acid di (ethylene glycol), three (ethylene glycol), ethylene glycol, poly (ethyl nglycol), tetra (ethylene glycol), glycerol, diethyl adipate, d-sorbitol, chlorotriphenylstannan, resorcinol, 2-methyl-8-quinolinol, quinaldine, 4-phenylpyridine, o, o-diethyl o- (p-nitrophenyl) ether phosphoric acid, N, N-dimethyl-p-phenylenediamine, 2,6-dimethoxyphenol, 4-allyl-2-methoxyphenol, phenanthridine, 2-naphthylamine, 1-naphthylamine, 1-naphthol, 2-naphthalentiol, 1-bromonaphthalene, levulinic acid, phenylpyrrole -2-ylketone, phenyl 4-pyridyl ketone, isothiocyanic acid m-nitrophenyl ester, 2-methyl-1H-indole, 4-methylimidazole, imidazole, 1,7-heptanediol, 9H-fluoren-9-one, ferroce , 2,2 ', 2' '- nitrilotriethanol, 2,2'-iminodiethanol, dibenzofuran, cyclohexane acetic acid, cyanamide, coumarin, 2,2'-bipyridine, benzoic acid, benzene propionic acid, o-dinitrobenzene, 9-methyl-9 -azabicyclo (3.3.1) nonan-3-one, chlorodiphenylarsine, antimony bromide, p-anisidine, o-anisaldehyde, adiponitrile, p-aminoacetophenone, monoacetin, diacetin, triacetin, pentoxane, 4-benzoylbiphenylthenolate, methyl terphenyl, tetradecanol, polychlorinated biphenyl, myristic acid, dodecyl ester of methacrylic acid, me isocyanic acid ilendi-p-phenylene ester, 2 - ((2-hexyloxy) ethoxy) ethanol, 4-nitrobiphenyl, benzyl ether, benzenesulfonyl chloride, 2,4-diisocyanato-1-1-methylbenzene, adipic acid diethyl ester, 2 '-nitro-acetophenone, 1'-acetonaphton, tetradecanone, (dichlorophenyl) trichlorosilane, dichlorodiphenylsilane, o, o-diethyl-o- (p-nitrophenyl) phosphoric acid ester, phosphoric acid tri-o-tolyl ester, triphenyl ester phosphoric acid, tributyl ester of phosphoric acid, phenylphosphoric acid dichloride, p-nitrophenol, isocyanic acid methyl m-phenylene ester, 2,2'-iminodiethanol, N- (2-aminoethyl) -N '- (2 - ((2-aminoethyl) amino) ethyl) 1,2-ethanediamine , 2,6-di-tert-butyl-p-cresol, chlorobiphenyl, 4-biphenylamine, benzyl ether, benzenesulfonyl chloride, 1,2- (methylenedioxy) -4-propenylbenzene, 2,4-diisocyanato-1-methylbenzene, chlorodinitrobenzene (mixture of isomers), hexahydro-2H-azepin-2-one, 4,4'-methylenedianiline, 1'-acetonaphton, mercaptoacetic acid, acetanilide, glycerin, and mixtures thereof.  22. The method according to claim 19, in which the polysulfone compound is a polyaryl sulfonic compound.  23. The method according to p. 19, further comprising the step of quenching the extruded product by passing the extruded product through the quench zone, the quench zone containing a fluid selected from the group consisting of air, water, glycerin, tetramethylene sulfone, and mixtures.  24. The method according to claim 19, further comprising the step of drawing a semi-permeable membrane.  25. The method according to claim 19, further comprising the step of keeping the semipermeable membrane in liquid for from about 4 hours to about 15 days.  26. The method according to claim 19, further comprising the step of passing a semi-permeable membrane through a leach bath.  27. The method according to p, in which the leach bath contains a non-solvent polysulfone compounds.  28. The method according to p, in which the leach bath contains water.  29. The method according to claim 19, further comprising the step of passing a semipermeable membrane through the wash bath.  30. The method according to clause 29, in which the wash bath contains water.  31. The method according to claim 19, further comprising the step of passing a semi-permeable membrane through the bath for re-plasticization.  32. The method according to p, in which the bath for re-plasticization contains an aqueous solution of glycerol.  33. The method according to p, in which the aqueous solution of glycerol contains less than about 50 wt.% Glycerol.  34. The method according to claim 19, further comprising the step of drying the semipermeable membrane.  35. The method according to clause 34, in which the semi-permeable membrane is dried in an oven.  36. The method according to any one of claims 1 or 19, where the resulting polysulfone semipermeable membrane is intended for microfiltration of a liquid, characterized in that the composition contains at least 8 wt.% Polysulfone compounds, at least 40 wt.% Solvent polysulfone compounds and not less than 1 wt.% Non-solvent polysulfone compounds, and the ratio of solvent to non-solvent is from about 0.95: 1 to about 80: 1.  37. The method according to any one of claim 1 or 19, where the resulting polysulfone semipermeable membrane is designed for ultrafiltration or dialysis, characterized in that the composition contains at least 18 wt.% Polysulfone compounds, at least 40 wt.% Solvent polysulfone compounds and not less than 1 wt.% non-solvent polysulfone compounds, and the ratio of solvent to non-solvent is about 0.95: 1 - 80: 1.  38. The method according to any one of claim 1 or 19, where the resulting polysulfone semipermeable membrane is intended for reverse osmosis, characterized in that the composition contains at least 30 wt.% Polysulfone compounds, at least 12 wt.% Solvent polysulfone compounds and not less than 1 wt.% Non-solvent polysulfone compounds.  39. A polysulfone semipermeable membrane comprising a mixture of a polysulfone compound and a solvent of a polysulfone compound and having a homogeneous structure such that said polysulfone semipermeable membrane has a substantially uniform structure.  40. The polysulfone semipermeable membrane of claim 39, wherein the polysulfone compound is a polyaryl sulfone compound.  41. The polysulfone semipermeable membrane of claim 39, wherein the polysulfone compound is selected from the group consisting of bisphenol A polysulfone, polyether polysulfone, polyphenyl polysulfone, and mixtures thereof.  42. The polysulfone semipermeable membrane of claim 39, wherein the solvent is selected from the group consisting of tetramethylene sulfone, antipyrine, δ-valerolactam, diethyl phthalate, and mixtures thereof.  43. A polysulfone semipermeable membrane characterized by a composition comprising a mixture of a polysulfone compound, a solvent of a polysulfone compound and a non-solvent of a polysulfone compound, said polysulfone semipermeable membrane having a homogeneous structure such that said polysulfone semipermeable membrane has a substantially uniform structure.  44. The polysulfone semipermeable membrane of claim 43, wherein the non-solvent is selected from the group consisting of 1,1-diethylurea, 1,3-diethylurea, dinitrotoluene, 1,2-ethanediamine, diphenylamine, toluene diamine, o-toluic acid, m- toluic acid, toluene-3,4-diamine, dibutyl phthalate, piperidine, decalin, cyclohexane, cyclohexene, chlorocyclohexane, solvent cellosolve, N, N-dimethylbenzylamine, paraffin, mineral oil, mineral wax, tallic amine, triethanolamine, lauryl mercari , di (ethylene glycol), three (ethylene glycol ol), ethylene glycol, poly (ethylene glycol), tetra (ethylene glycol), glycerol, diethyl adipate, d-sorbitol, chlorotriphenylstannan, resorcinol, 2-methyl-8-quinolinol, quinaldine, 4-phenylpyridine, complex o, o-diethyl-o- (p-nitrophenyl) phosphoric acid ester, N, N-dimethyl-p-phenylenediamine, 2,6-dimethoxyphenol, 4-allyl-2-methoxyphenol, phenanthridine, 2-naphthylamine, 1-naphthylamine, 1-naphthol, 2-naphthalentiol, 1-bromonaphthalene, levulinic acid, phenylpyrrol-2-yl-ketone, phenyl-4-pyridylketone, isothiocyanic acid m-nitrophenyl ester, 2-methyl-1H-indole, 4-methylimidazole, imidazole, 1,7-hep tandiol, 9H-fluoren-9-one, ferrocene, 2.2 ', 2' '- nitrilotriethanol, 2,2'-iminodiethanol, dibenzofuran, cyclohexanoacetic acid, cyanamide, coumarin, 2,2'-bipyridine, benzoic acid, benzenepropionic acid, o-dinitrobenzene, 9-methyl-9-azabicyclo (3.3.1) nonan-3-one, chlorodiphenylarsine, antimony bromide, p-anisidine, o-anisaldehyde, adiponitrile, p-aminoacetophenone, monoacetin, diacetin, triacetin, , 4-benzoyldiphenyl, methyl oleate, triethyl phosphate, butyrolactone, terphenyl, tetradecanol, polychlorinated diphenyl, myristic acid, dodecyl ester me tacrylic acid, isocyanic acid methylene di-p-phenylene ester, 2 - ((2-hexyloxy) ethoxy) ethanol, 4-nitrodiphenyl, benzyl ether, benzenesulfonyl chloride, 2,4-diisocyanato-1-1-methylbenzene, adipic acid diethyl ester, 2'-nitroacetophenone, 1'-acetonaphton, tetradecanone, (dichlorophenyl) trichlorosilane, dichlorodiphenylsilane, complex o, o-diethyl-o- (p-nitrophenyl) phosphoric acid ester, tri-o-tolyl ester phosphoric acid phosphoric acid triphenyl ester, phosphoric acid tributyl ester, fe phosphoric acid dichloride, p-nitrophenol, isocyanic acid methyl m-phenylene ester, 2,2'-iminodiethanol, N- (2-aminoethyl-N '- (2 - ((2-aminoethyl) amino) ethyl) - 1,2-ethanediamine, 2,6-di-tert-butyl-p-cresol, chlorodiphenyl, 4-diphenylamine, benzyl ether, benzenesulfonyl chloride, 1,2- (methylenedioxy) -4-propenylbenzene, 2-4-diisocyanato- 1-methylbenzene, chlorodinitrobenzene (a mixture of isomers), hexahydro-2H-azepin-2-one, 4,4'-methylenedianiline, 1'-acetonaphton, mercaptoacetic acid, acetanilide, glycerol and mixtures thereof.  45. The polysulfone semipermeable membrane of claim 43, wherein the polysulfone compound is a polyaryl sulfone compound.  46. The polysulfone semipermeable membrane of claim 43, wherein the polysulfone compound is selected from the group consisting of bisphenol A polysulfone, polyether polysulfone, polyphenyl polysulfone, and mixtures thereof.  47. The polysulfone semipermeable membrane of claim 43, wherein the polysulfone compound comprises bisphenol A polysulfone.  48. The polysulfone semipermeable membrane of claim 43, comprising about 8 to 80% by weight of the polysulfone compound.  49. Polysulfone semipermeable membrane according to item 43, comprising at least about 25 wt.% Polysulfone compounds.  50. The polysulfone semipermeable membrane of claim 43, wherein the solvent is selected from the group consisting of tetramethylene sulfone, 3-methylsulfolane, benzophenone, N, N-dimethylacetamide, 2-pyrrolidone, 3-methylsulfolene, pyridine, thiophene, o-dichlorobenzene, 1 -chloronaphthalene, methyl salicylate, anisole, o-nitroanisole, diphenyl ether, diphenoxymethane, acetophenone, p-methoxyphenyl-2-ethanol, 2-piperidine, antipyrine, δ-valerolactam, diethyl phthalate, diphenyl sulfoxide, diphenyl sulfoxide phthalic acid dimethyl ether you, phthalic acid diethyl ester, phthalic acid dibutyl ester, phthalic acid bis (2-ethylhexyl) ester, phthalic acid benzylbutyl ester, phenyl sulfide and mixtures thereof.  51. The polysulfone semipermeable membrane of claim 43, wherein the solvent is selected from the group consisting of tetramethylene sulfone, antipyrine, δ-valerolactam, diethyl phthalate, and mixtures thereof.  52. The polysulfone semipermeable membrane of claim 43, wherein the solvent comprises tetramethylene sulfone.  53. The polysulfone semipermeable membrane of claim 43, wherein the solvent and non-solvent are present in a ratio of about 2: 1 to 10: 1.  54. A polysulfone semipermeable membrane having an almost uniform structure across the thickness of the membrane, said polysulfone semipermeable membrane being made from a mixture of a polysulfone compound selected from the group consisting of a polyarylsulfonic compound, bisphenol A polysulfone, simple polyether polysulfone, polyphenyl polysulfone and solvent mixtures thereof, and a compound selected from the group consisting of tetramethylene sulfone, 3-methylsulfolane, benzophenone, N, N-dimethylacetamide, 2-pyrrolide n, 3-methylsulfolene, pyridine, thiophene, o-dichlorobenzene, 1-chloronaphthalene, methylsalicylate, anisole, o-nitroanisole, diphenyl ether, diphenoxymethane, acetophenone, p-methoxyphenyl-2-ethanol, 2-piperidine, antipyrine, δ valerolactam, diethyl phthalate, diphenyl sulfone, diphenyl sulfoxide, phthalic acid dioctyl ester, phthalic acid dimethyl ester, phthalic acid diethyl ester, phthalic acid dibutyl ester, phthalic acid bis (2-ethylhexyl) phthalic ester, phthalic acid ilsulfid and mixtures thereof.  55. The polysulfone semipermeable membrane of Claim 54, wherein the mixture comprises a non-solvent of a polysulfone compound.  56. The polysulfone semipermeable membrane of Claim 54, wherein the non-solvent is selected from the group consisting of 1,1-diethylurea, 1,3-diethylurea, dinitrotoluene, 1,2-ethanediamine, diphenylamine, toluene diamine, o-toluic acid, m- toluic acid, toluene-3,4-diamine, dibutyl phthalate, piperidine, decalin, cyclohexane, cyclohexene, chlorocyclohexane, solvent cellosolve, N, N-dimethylbenzylamine, paraffin, mineral oil, mineral wax, tallic amine, triethanolamine, lauryl mercari , di (ethylene glycol), three (ethylene glycol ol), ethylene glycol, poly (ethylene glycol), tetra (ethylene glycol), glycerol, diethyl adipate, d-sorbitol, chlorotriphenylstannan, resorcinol, 2-methyl-8-quinolinol, quinaldine, 4-phenylpyridine, complex o, o-diethyl-o- (p-nitrophenyl) phosphoric acid ester, N, N-dimethyl-p-phenylenediamine, 2,6-dimethoxyphenol, 4-allyl-2-methoxyphenol, phenanthridine, 2-naphthylamine, 1-naphthylamine, 1-naphthol, 2-naphthalentiol, 1-bromonaphthalene, levulinic acid, phenylpyrrol-2-yl-ketone, phenyl-4-pyridylketone, isothiocyanic acid m-nitrophenyl ester, 2-methyl-1H-indole, 4-methylmidazole, imidazole, 1,7-hept andiol, 9H-fluoren-9-one, ferrocene, 2.2 ', 2' '- nitrilotriethanol, 2,2'-iminodiethanol, dibenzofuran, cyclohexanoacetic acid, cyanamide, coumarin, 2,2'-bipyridine, benzoic acid, benzenepropionic acid, o-dinitrobenzene, 9-methyl-9-azabicyclo (3.3.1) nonan-3-one, chlorodiphenylarsine, antimony bromide, p-anisidine, o-anisaldehyde, adiponitrile, p-aminoacetophenone, monoacetin, diacetin, triacetin, , 4-benzoyldiphenyl, methyl oleate, triethyl phosphate, butyrolactone, terphenyl, tetradecanol, polychlorinated diphenyl, myristic acid, meth dodecyl ester acrylic acid, isocyanic acid methylene di-p-phenylene ester, 2 - ((2-hexyloxy) ethoxy) ethanol, 4-nitrodiphenyl, benzyl ether, benzenesulfonyl chloride, 2,4-diisocyanato-1-1-methylbenzene, adipic acid diethyl ester, 2'-nitroacetophenone, 1'-acetonaphton, tetradecanone, (dichlorophenyl) trichlorosilane, dichlorodiphenylsilane, o, o-diethyl-o- (p-nitrophenyl) phosphoric acid ester, tri-o-tolyl ester phosphorosulfonate phosphoric acid triphenyl ester, phosphoric acid tributyl ester, hair dryer lphosphoric acid dichloride, p-nitrophenol, isocyanic acid methyl m-phenylene ester, 2,2'-iminodiethanol, N- (2-aminoethyl) -N '- (2 - ((2-aminoethyl) amino) ethyl 1,2-ethanediamine, 2,6-di-tert-butyl-p-cresol, chlorodiphenyl, 4-diphenylamine, benzyl ether, benzenesulfonyl chloride, 1,2- (methylenedioxy) -4-propenylbenzene, 2,4-diisocyanato- 1-methylbenzene, chlorodinitrobenzene (a mixture of isomers), hexahydro-2H-azepin-2-one, 4,4'-methylenedianiline, 1'-acetonaphton, mercaptoacetic acid, acetanilide, glycerol and mixtures thereof.

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