Reactive additives in NMP system films

Abstract

The present disclosure provides a process for producing a modified microporous membrane, comprising: (i) providing a first solution comprising at least one first polymer and at least one epoxy-functional compound; (ii) providing a second solution comprising at least one diamine compound; and (iii) contacting the first solution with the second solution, thereby obtaining a modified microporous membrane comprising the at least one first polymer and a crosslinked reaction product of the at least one epoxy-functional compound and the at least one diamine compound, wherein the modified microporous membrane is a hollow fiber membrane, the first solution is a dope solution, the second solution is a bore solution, and the contacting of the first solution with the second solution occurs in a spinneret.

Description

Technical Field

[0001] The present disclosure relates to a process for producing a modified microporous membrane. Further, the present disclosure relates to a membrane obtained by such a process. The present disclosure further relates to the use of such a membrane for the filtration and purification of liquid media.

Background Art

[0002] Polymer membranes are used in a very wide range of different industrial, pharmaceutical, or medical applications for microfiltration. In these applications, the importance of membrane separation processes is increasing because these processes have the advantage that the substances to be separated are not thermally stressed or even damaged. Ultrafiltration membranes can be used for the removal or separation of macromolecules. Many more applications of membrane separation methods are known in the beverage industry, in biotechnology, in water treatment or sewage technology. Such membranes are generally classified according to their retention capacity, i.e., according to their capacity to retain particles or molecules of a specific size, or according to the size of the effective pores, i.e., the size of the pores that determine the separation behavior. Ultrafiltration membranes can thereby cover a pore size range that determines a separation behavior of approximately 0.01 to about 0.1 μm and can thus retain particles or molecules in a size range greater than 20,000 or greater than about 200,000 daltons.

[0003]

[0004] ​U.S. Patent No. 5,928,774 discloses asymmetric ultrafiltration membranes made from a sulfone polymer in the form of flat films. The membranes of U.S. Patent No. 5,928,774 exhibit significant asymmetry, with one surface having a separation layer in the form of a film and an adjacent support layer, and their pore structure does not have cavities also known as finger pores or macrovoids, and the pores gradually increase in size from the film toward the second surface. Due to their significant asymmetry, the membranes of U.S. Patent No. 5,928,774 are optimized for high intra- and trans-membrane flow and high contamination load capacity in their applications. Similar flat membranes with significant asymmetry made from polyethersulfone are further described in U.S. Patent No. 5,886,059.

[0005] The semipermeable membranes described in the above publication are made from hydrophobic sulfone polymers, and therefore the membranes have poor water-wetting properties, which severely limits their use for filtering aqueous media. Furthermore, hydrophobic membranes have a strong and nonspecific ability to adsorb, for example, proteins, and it is known that rapid coating of the membrane surface by mainly polymer components from the filtered liquid frequently occurs during use, resulting in reduced permeability. This phenomenon is commonly referred to as "membrane contamination." Various attempts have been made to make sulfone polymer membranes hydrophilic and simultaneously reduce their tendency to adsorb proteins in order to improve water-wetting properties and, consequently, permeability to aqueous media, and to prevent protein adhesion to the membrane surface. In one of these approaches, a hydrophilic polymer such as polyvinylpyrrolidone is mixed with the sulfone polymer during the manufacturing process.

[0006] European Patent No. 568045 relates to a hydrophilic polysulfone hollow fiber membrane having an asymmetric structure containing polyglycol and vinylpyrrolidone polymers to ensure hydrophilic properties. On the side facing the lumen, the hollow fiber membrane in European Patent No. 568045 has a separation layer 0.1 to 3 μm thick, which has slot-shaped pores 0.001 to 0.05 μm wide on its inner surface. This separation layer is joined by a support layer having a mesh-like or sponge-like structure and pores with an average size of 1 to 5 μm. The outer surface is a layer having a mesh-like or sponge-like structure that is denser than the support layer.

[0007] In European Patent No. 568045, the membrane separation section may be allocated to the ultrafiltration range, but the membrane is optimized for blood processing. In the examples described in European Patent No. 568045, a hollow fiber membrane is used, with a maximum of approximately 0.7 ml / cm³. 2 The permeability of water in minutes and bar is described. However, these membranes are relatively thin-walled, with a wall thickness of 40 μm, and therefore unsuitable for ultrafiltration applications due to their insufficient pressure and fracture stability.

[0008] hydrophilic There is still a need in the art for a process to produce polymer membranes, particularly PES membranes, that result in improved modified membranes, and ideally with reduced extract amounts without any degradation of filtration or flux / retention properties. [Overview of the project]

[0009] This disclosure relates to a process for producing a modified microporous membrane, (i) To provide a first solution comprising at least one first polymer and at least one epoxy-functional compound, (ii) To provide a second solution comprising at least one diamine compound, (iii) Contacting the first solution with the second solution to obtain a modified microporous film comprising at least one first polymer and a crosslinking reaction product of at least one epoxy-functional compound and at least one diamine compound, Modified microporous membranes are hollow fiber membranes. The first solution is a doping solution, the second solution is a bore solution, and the contact between the first and second solutions provides a process that occurs within the spinneret.

[0010] This disclosure further provides films obtained from the processes described herein.

[0011] Furthermore, this disclosure relates to specific uses of the membranes described herein in applications of filtration of aqueous media, particularly in viral filtration. [Modes for carrying out the invention]

[0012] Prior to describing any embodiment of this disclosure in detail, it should be understood that in its intended use, this disclosure is not limited to the structural details and configurations shown in the following description. Other embodiments of the invention are possible and can be practiced or implemented in various ways. As used herein, the terms “a,” “an,” and “the” are used interchangeably and mean one or more, and “and / or” is used to indicate that one or both of the described cases may occur, for example, A and / or B includes (A and B) and (A or B). Furthermore, as used herein, a range description by endpoints includes all numbers encompassed within that range (for example, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.). Furthermore, as used herein, a “at least one” description includes all numbers one or more (for example, at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.). Furthermore, it should be understood that the terminology and grammar used herein are for illustrative purposes only and should not be considered restrictive. Unlike the use of "consisting," which is intended to be restrictive, the use of "including," "containing," "comprising," or "having," and their variations, is intended to be non-restrictive and to encompass the items and additional items listed thereafter.

[0013] The amounts of components in a composition may be expressed in weight percent (or "%wt" or "wt-%") unless otherwise specified. The total amount of components is 100% by weight unless otherwise specified. When the amount of a component is specified in mole percent, the total amount of components is 100% by mole percent unless otherwise specified.

[0014] The parameters described herein may be determined as detailed in the experimental section.

[0015] Unless expressly indicated otherwise, all preferred scopes and embodiments may be freely combined.

[0016] This disclosure relates to a process for producing a modified microporous membrane, (i) To provide a first solution comprising at least one first polymer and at least one epoxy-functional compound, (ii) To provide a second solution comprising at least one diamine compound, (iii) Contacting the first solution with the second solution to obtain a modified microporous film comprising at least one first polymer and a crosslinking reaction product of at least one epoxy-functional compound and at least one diamine compound, Modified microporous membranes are hollow fiber membranes. The first solution is a doping solution, the second solution is a bore solution, and the contact between the first and second solutions provides a process that occurs within the spinneret.

[0017] This process provides a convenient, efficient, and reliable method for producing modified membranes, particularly hollow fiber membranes, thereby yielding microporous membranes modified with crosslinked epoxy compounds. This controlled incorporation of diamine crosslinked epoxy compounds is superior to that of unmodified membranes. hydrophilic This has the effect of providing a membrane with improved properties, thereby reducing extractables and simultaneously exhibiting good flux, filtration, and retention characteristics. The membrane obtained by the process described herein hydrophilic This improvement and enhancement may offer advantages such as improved membrane wettability, reduced "contamination" behavior, and improved filtration and / or retention properties.

[0018] Epoxy-functional compounds are generally hydrocarbon compounds having at least one epoxy moiety suitable for crosslinking. More specifically, epoxy-functional compounds are oligomers, polymers, or copolymers comprising a constituent block containing at least one epoxy moiety. Preferably, the at least one epoxy-functional compound is a copolymer comprising a constituent block containing at least one epoxy moiety and at least one aliphatic or aromatic functional group. In this regard, it is preferable that the at least one epoxy-functional compound exhibits an aliphatic main chain; that is, the core carbon-carbon bonds between the various constituent blocks are preferably aliphatic. Furthermore, it is preferable that the constituent block containing at least one epoxy moiety is selected from aliphatic or aromatic ethers or esters. Preferably, the copolymer further comprises a constituent block containing a moiety selected from aliphatic, cyclic or aromatic esters, aliphatic, cyclic or aromatic amides, aliphatic, cyclic or aromatic ethers, aliphatic, cyclic or aromatic sulfones, aliphatic, cyclic or aromatic sulfides, aliphatic, cyclic or aromatic sulfonamides, and / or a metal chelating agent. This has the advantage that selected functional groups can be selectively incorporated into at least one epoxy-functional compound. This means that the membrane properties can be deliberately and intentionally modified. For example, hydrophobicity or hydrophilicity can be improved, charges can be introduced (e.g., via cations or anions), and protein injection sites, chelating agents, or even medical activators can be introduced and incorporated into the membrane. This can be advantageous for many applications in industry, or especially in the pharmaceutical or medical sector. Copolymers of epoxy-functional compounds described herein are more preferably further comprising a constituent block selected from constituent blocks comprising cyclic amides, cyclic or aliphatic esters, and / or aliphatic or cyclic silanes. Preferably, the further constituent block is selected from pyrrolidone, caprolactam, acetate, and / or formate.

[0019] Preferably, at least one epoxy-functional compound has formula (I). [ka] (where x, y, and z are evenly distributed). Preferably, when x + y + z are summed, it is at least 50, preferably at least 60, more preferably at least 70. In this regard, it is even more preferable that when x + y + z are summed, it is 140 or less, preferably 130 or less, more preferably 120 or less. Preferably, the sum of x + y + z is a number in the range of 50 to 140, preferably 60 to 130, more preferably 70 to 120. Epoxy-functional compounds having x, y, and z within these ranges in formula (I) are easily and surely crosslinked in the processes described herein, and it has been found that they produce a membrane with increased hydrophobicity and reduced extractables compared to membranes that do not contain these crosslinked compounds. The first solution used in the process according to the present disclosure contains at least one epoxy-functional compound in an amount in the range of 0.1 to 15% by weight, preferably in the range of 0.5 to 10% by weight, more preferably in the range of 1 to 7% by weight, based on the total weight of the first solution.

[0020] Generally, any diamine known to those skilled in the art for crosslinking epoxy-functional compounds can be used within the scope of the present disclosure as at least one diamine compound. To obtain reliable and optimal crosslinking results in the membranes obtained by the process according to the present disclosure, it is preferable that at least one diamine compound is selected from polyamines, polyetheramines, polyamidoamines, and any combinations and mixtures thereof. For example, a diamine compound suitable for use in the process according to the present disclosure is a polyetheramine commercially available under the trade name "Jeffamine", such as "Jeffamine ED-2003" from Huntsman Corp. The second solution used in the process according to the present disclosure contains at least one diamine in an amount in the range of 1 to 20% by weight, preferably 2 to 15%, more preferably 3 to 10% by weight, based on the total weight of the second solution.

[0021] In the process according to the present disclosure, the membrane is spun through a spinneret from a homogeneous first solution (i.e., the dope solution) and a second homogeneous solution (i.e., the bore solution) while the membrane is being spun. The first solution contains at least one first polymer and at least one first epoxy-functional compound in a solvent system. With respect to at least one first polymer used in the process described herein, basically, any polymer known in the art for manufacturing microporous membranes can be used. Preferably, at least one first polymer is selected from polyvinylidene fluoride, polyethylene, and / or polysulfone. These polymers produce stable microporous membranes, which exhibit good filtration properties, good flux, and good mechanical properties necessary for the industrial manufacture of membranes and for many uses of the membranes themselves in industrial and / or pharmaceutical or medical applications. In the process described herein, at least one first polymer is preferably selected from polysulfone, preferably polyethersulfone, polyphenylene sulfone, or polyarylether sulfone. Particularly, hydrophobic aromatic sulfone polymers are preferred.

[0022] Advantageous hydrophobic aromatic sulfone polymers used in the method according to the present invention are polysulfone, polyethersulfone, polyphenylene sulfone, or polyarylether sulfone. Preferably, the hydrophobic aromatic sulfone polymer is a polysulfone or polyethersulfone having repeating molecular units represented by the following formulas (II) and (III).

Chemical formula

Chemical formula

[0023] At least one polymer, such as at least one polysulfone polymer, may further contain additives such as antioxidants, nucleating agents, and ultraviolet absorbers to selectively modify the properties of the film. According to this disclosure, the concentration of at least one first polymer in the first solution is in the range of 10 to 40% by weight, preferably 12 to 35% by weight, and more preferably 15 to 30% by weight, based on the total weight of the first solution. Concentrations below 10% by weight may result in disadvantages, particularly with respect to the mechanical stability of the resulting hollow fiber film. On the other hand, films obtained from spinning solutions containing more than 40% by weight of the first polymer may exhibit an excessively dense structure and insufficient permeability.

[0024] In this regard, the first solution preferably further comprises at least one second polymer. This at least one second polymer is preferably a hydrophilic polymer or copolymer that is advantageously used in combination with a hydrophobic aromatic sulfone used as at least one first polymer in the first solution used in the process described herein. A long-chain polymer is advantageously used as at least one second polymer, i.e., at least one hydrophilic polymer having repeating polymer units that are hydrophilic on the one hand and exhibit compatibility with the hydrophobic aromatic sulfone polymer on the one hand. The average molecular weight M is greater than 10,000 daltons, preferably greater than 20,000 daltons, and more preferably greater than 30,000 daltons. W Hydrophilic polymers having the property of polyvinylpyrrolidone are preferably used. The hydrophilic polymers are preferably polysorbates such as polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polyglycol monoester, polyoxyethylene sorbitan monooleate, carboxymethylcellulose, or modified or copolymerized versions of these polymers, as well as any combinations and mixtures thereof. Polyvinylpyrrolidone and polyethylene glycol are particularly preferred. In certain preferred embodiments of this disclosure, at least one first polymer is selected from the polysulfones described herein, and at least one second polymer is selected from polyvinylpyrrolidone.

[0025] In the context of this disclosure, at least one hydrophilic polymer may further comprise a mixture of different hydrophilic polymers. The hydrophilic polymer may be, for example, a mixture of chemically different hydrophilic polymers or hydrophilic polymers having different molecular weights, such as a mixture of polymers with molecular weights differing by five times or more. Preferably, at least one hydrophilic polymer comprises a mixture of polyvinylpyrrolidone or polyethylene glycol and a hydrophilic modified aromatic sulfone polymer. The hydrophilic modified aromatic sulfone polymer may also preferably be a sulfonated aromatic sulfone polymer, in particular a sulfonated modified product of a hydrophobic aromatic sulfone polymer used in the films and methods of this disclosure. Mixtures of polyethersulfone, sulfonated polyethersulfone, and polyvinylpyrrolidone may be particularly advantageous. As a result of the presence of the hydrophilic modified aromatic sulfone polymer, a hollow fiber film with particularly stable hydrophilic properties in the application is obtained. Preferably, the first solution contains at least one second polymer in an amount ranging from 2 to 25% by weight, preferably 5 to 20% by weight, and more preferably 7.5% to 15% by weight, based on the total weight of the first solution.

[0026] The first solution, if present, comprises at least one solvent or solvent system compatible with at least one first polymer and at least one second polymer. For example, the solvent system used must be compatible with the hydrophobic aromatic sulfone polymer and at least one hydrophilic polymer used, thereby enabling the production of a homogeneous spinning solution. The solvent system preferably comprises a polar aprotic solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, or a mixture thereof, or a protic solvent such as ε-caprolactam. Furthermore, the solvent system may contain up to 80% by weight of a latent solvent, where, in the context of the present invention, the latent solvent is understood as a solvent that does not adequately dissolve the sulfone polymer or dissolves it only at high temperatures. When ε-caprolactam is used as a solvent, for example, γ-butyrolactone, propylene carbonate, or polyalkylene glycol can be used. In addition, the solvent system may contain a poor solvent (non-solvent) for film-forming polymers, such as water, glycerin, low molecular weight polyethylene glycol having an average molecular weight of less than 1000 daltons, or low molecular weight alcohols such as ethanol or isopropanol. In a preferred example of a solvent system according to this disclosure, the solvent system in the first solution comprises N-methylpyrrolidone and water. Preferably, the first solution contains N-methylpyrrolidone in an amount ranging from 40 to 80% by weight, preferably 50 to 75% by weight, and more preferably 55 to 70% by weight.

[0027] Preferably, after degassing and filtering to remove undissolved particles, a homogeneous first solution is extruded through the annular gap of a conventional hollow fiber die (i.e., spinneret) to produce a hollow fiber. A second solution (or bore solution), i.e., a coagulation medium containing at least one diamine compound and which may be a hydrophobic aromatic sulfone polymer, and which simultaneously provides an internal filler to stabilize the lumen of the hollow fiber, is extruded through a central nozzle opening coaxially positioned with the annular gap in the hollow fiber die / spinneret. In this disclosure, the terms “hollow fiber die” and “spinneret” may be used interchangeably. The second solution preferably contains at least one solvent selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone, and any combination and mixture thereof. Preferably, the second solution further comprises water, glycerin, low molecular weight polyethylene glycol having an average molecular weight of less than 1000 daltons, or a low molecular weight alcohol such as ethanol or isopropanol, and / or a non-solvent for the film-forming polymer such as a protic solvent such as caprolactam. For example, the second solution may contain water and glycerol, but may also contain additional components and / or a solvent.

[0028] The width of the annular gap and the inner diameter of the central nozzle opening can be selected according to the desired properties of the hollow fiber membrane, as is known in the art. That is, the spinneret may have an outer diameter for doping in the range of 1100 to 3000 μm, an outer diameter for doping in the range of 600 to 2000 μm, and an inner diameter for doping in the range of 400 to 1500 μm.

[0029] After leaving the hollow fiber die (i.e., spinneret), it is preferable that the hollow fiber passes through an environmental control zone having specified environmental conditions before entering the solidification medium. Therefore, the environmental control zone can take the form of, for example, a sealed chamber. For technical reasons, an air gap may be necessary between the hollow fiber die and the environmental control zone. However, this gap should be advantageously as small as possible, and the environmental control zone should preferably lead directly to the hollow fiber die.

[0030] In this regard, the hollow fibers have a holding time of 0.5 to 10 seconds in the environmental control zone, which contains air with a relative humidity of 40 to 95% and a temperature of 50 to 70°C. The air in the environmental control zone preferably has a relative humidity of 55 to 85%. It is also preferable that the holding time of the hollow fibers in the environmental control zone be 1 to 7 seconds. In order to establish stable conditions in the environmental control zone, the air flows through the environmental control zone at a speed of less than 0.5 m / s, and particularly preferably in the range of 0.15 to 0.35 m / s.

[0031] When hollow fibers are directed to pass through an environmentally controlled zone set to preferred environmental conditions in the method according to the present disclosure, the pre-solidification of the hollow fibers is induced by the absorption of moisture in the air, which acts as a non-solvent, on the outside of the hollow fibers.

[0032] After passing through the environmental control zone, the pre-solidified hollow fibers may be directed to pass through an aqueous solidification medium, preferably adjusted to 50-80°C, to complete the formation of the membrane structure and fix the membrane structure. The solidification medium is preferably adjusted to a temperature in the range of 60-75°C. Preferably, the solidification medium is water or a water bath.

[0033] In the solidification medium, the membrane structure is initially precipitated to the extent that it already possesses sufficient stability and can be bypassed, for example, by deflection rollers or similar means in the solidification medium. During further stages of the process, solidification is completed and the membrane structure stabilizes. Extraction of the solvent system and soluble substances is performed simultaneously here. Generally, most hydrophilic polymers, such as polyvinylpyrrolidone, are extracted from the membrane structure, and as a result, the solidification bath functions simultaneously as a washing or extraction bath. Water is preferably used as the solidification or washing medium in these solidification or washing baths.

[0034] After extraction, the hollow fiber membrane thus obtained can be dried, and then the dried membrane can be rolled. During the extraction and drying of the membrane, slight drawing may be advantageous to selectively set specific membrane properties such as surface porosity and separation characteristics. The hollow fiber membrane according to this disclosure may then be textured (if necessary) to improve the exchange properties of the hollow fiber membranes in the bundle. Finally, the hollow fiber membrane can be processed using conventional methods, for example, by being wound on a coil or directly formed into a bundle having a suitable number and length of fibers. Before the production of the bundle, auxiliary threads, for example, in the form of multifilament threads, can be added to the hollow fiber membrane to ensure spacing between the hollow fiber membranes and better flow around the individual hollow fiber membranes in the bundle.

[0035] By the method described herein, a film according to this disclosure having the advantageous structure and properties described herein can be obtained.

[0036] By a unique combination of properties of the hollow fiber membranes described herein, obtained from the methods described herein, this disclosure further provides the use of the membranes described herein for microfiltration, nanofiltration, or ultrafiltration. “Microfiltration,” “nanofiltration,” and “ultrafiltration” have general meanings in the art. Preferably, the uses described herein involve water filtration or filtration of aqueous media. In this regard, the uses according to this disclosure include the pharmaceutical industry, the biopharmaceutical industry, medical applications, residential water treatment, and food and beverage filtration.

[0037] This disclosure can be further illustrated by the following exemplary and preferred items.

[0038] Item 1: A process for manufacturing a modified microporous membrane, (i) To provide a first solution comprising at least one first polymer and at least one epoxy-functional compound, (ii) To provide a second solution comprising at least one diamine compound, (iii) Contacting the first solution with the second solution to obtain a modified microporous film comprising at least one first polymer and a crosslinking reaction product of at least one epoxy-functional compound and at least one diamine compound, Modified microporous membranes are hollow fiber membranes. The first solution is the doping solution, and the second solution is the bore solution. The contact between the first and second solutions is a process that occurs within the spinneret.

[0039] Item 2: The process according to Item 1, wherein at least one epoxy-functional compound is a copolymer comprising a structural block comprising at least one epoxy moiety and at least one aliphatic or aromatic alkoxy functional group.

[0040] Item 3: The process described in Item 2, wherein a constituent block comprising at least one epoxy moiety is selected from an aliphatic or aromatic glycidyl ether.

[0041] Item 4: The process according to Item 2 or 3, wherein the copolymer further comprises a constituent block having a portion selected from aliphatic, cyclic or aromatic esters, aliphatic, cyclic or aromatic amides, aliphatic, cyclic or aromatic ethers, aliphatic, cyclic or aromatic sulfones, aliphatic, cyclic or aromatic sulfides, aliphatic, cyclic or aromatic sulfonamides, and / or a metal chelating agent.

[0042] Item 5: The process according to Item 4, wherein further constituent blocks are selected from constituent blocks comprising cyclic amides, cyclic or aliphatic esters, and / or aliphatic or cyclic silanes.

[0043] Item 6: The process described in Item 4 or 5, wherein a further constituent block is selected from constituent blocks comprising pyrrolidone, caprolactam, acetate, and / or formate.

[0044] Item 7: At least one epoxy-functional compound is of formula (I) [ka] A process described in any one of items 1 to 6, having the following equation (wherein x, y, and z are evenly distributed).

[0045] Item 8: The process described in Item 7, where x + y + z = 100.

[0046] Item 9: The process according to any one of items 1 to 8, wherein at least one diamine compound is selected from polyamines, polyetheramines, polyamidoamines, and any combinations and mixtures thereof.

[0047] Item 10: The process according to any one of items 1 to 9, wherein at least one first polymer is selected from polyvinylidene fluoride, polyethylene, and / or polysulfone.

[0048] Item 11: The process according to Item 10, wherein at least one first polymer is selected from polysulfone, preferably polyethersulfone, polyphenylenesulfone, or polyarylethersulfone.

[0049] Item 12: The process according to any one of items 1 to 11, wherein the first solution comprises at least one second polymer.

[0050] Item 13: The process according to Item 12, wherein at least one second polymer is a hydrophilic polymer or copolymer.

[0051] Item 14: The process according to item 11 or item 12, wherein at least one first polymer is selected from polysulfone and at least one second polymer is selected from polyvinylpyrrolidone.

[0052] Item 15: The process described in any one of items 1 to 11, wherein the first solution comprises at least one solvent.

[0053] Item 16: The process according to Item 15, wherein at least one solvent is selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone, and any combination or mixture thereof.

[0054] Item 17: The process according to item 15 or 16, wherein the first solvent preferably further comprises at least one protic solvent selected from ε-caprolactam, water, γ-butyrolactone, propylene carbonate, and polyalkylene glycol, and any combination or mixture thereof.

[0055] Item 18: The process described in Item 17, wherein the first solution comprises water and / or N-methylpyrrolidone.

[0056] Item 19: The process according to any one of items 1 to 18, wherein the second solution comprises dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone, and at least one solvent selected from any combination or mixture thereof.

[0057] Item 20: The process according to item 19, wherein the second solution preferably further comprises at least one protic solvent selected from ε-caprolactam, water, γ-butyrolactone, propylene carbonate, and polyalkylene glycol, and any combination or mixture thereof.

[0058] Item 21: The process described in Item 19 or Item 20, wherein the second liquid comprises water and / or N-methylpyrrolidone.

[0059] Item 22: A modified film obtained by the process described in any one of items 1 through 21.

[0060] Item 23: Use of the membranes described in Item 22 for microfiltration, nanofiltration, or ultrafiltration.

[0061] Item 24: Use as described in Item 23, including water filtration or filtration of an aqueous medium.

[0062] Item 25: Uses described in Item 23 or Item 25, including the pharmaceutical industry, the biopharmaceutical industry, medical applications, residential water treatment, and food and beverage filtration.

[0063] Item 26: Uses described in any one of items 23-25, including virus filtration. [Examples]

[0064] Further explanation of this disclosure is provided, but it is not intended to limit this disclosure to these examples. The following examples are presented to illustrate specific embodiments, but are not intended to limit them in any way. Before that, some test methods used to characterize the materials and their properties are described. All parts and percentages are based on weight unless otherwise indicated.

[0065] Test method Measurement of the nitrogen content of the membrane The nitrogen content of the membrane is measured according to the Kjehldahl procedure in the corresponding instrument. Approximately 1 g of dry membrane sample is carefully weighed into a glass vial in 0.1 mg increments. To this sample, Spezial-Kjeltab Cu / 3.5 tablets and 16 mL of concentrated sulfonic acid are carefully added. Triple measurements are performed. For blank value measurements, three samples containing only Spezial-Kjeltab Cu / 3.5 tablets and 16 mL of concentrated sulfonic acid are prepared. The vials are placed in the corresponding holders of the Kjehldahl instrument and the procedure is performed at 400°C under vacuum. This procedure is considered complete when a clear blue solution forms in the glass vial. The NH3 content in the vial is then measured by titration with HCl, and the corresponding nitrogen content is calculated.

[0066] Measurement of residual extracts by UV spectroscopy Approximately 1.5 g of the membrane sample was weighed into an Erlenmeyer flask to the nearest 0.1 mg. 150 mL of ultrapure water, pre-boiled and cooled to room temperature, was added. The closed flask was then shaken at 70°C for 1 hour, and then cooled to room temperature. Next, the eluent was subjected to UV spectroscopy at 10 nm intervals in the wavelength range of 350 nm to 250 nm. The highest absorbance in this wavelength range was used as the measured value.

[0067] Example 1: Modified hollow fiber membrane Doped solutions having the compositions listed in Table 1 were prepared. The VP / VA / GMA copolymers used in Table 1 are copolymers obtained from Ashland having the following general formula 1, where x, y, and z are randomly distributed and x+y+z=100. [ka]

[0068] Hollow fiber membranes were spun through a spindle at a temperature of 50°C and a spinning rate of 40 m / min using a bore solution containing diamine (Jeffamine ED-2003) according to the composition shown in Table 1. Spinning was performed at a coagulation bath temperature of 65°C and a spinning rate of 40 m / min. The temperature of the bore solution was 35°C. The residence time of the reaction between the two components at the interface between the bore solution and the polymer dope was estimated to be 38 seconds. The spindle temperature was 50°C. The counterpart to the epoxy-functional compound (i.e., diamine) according to Formula 1 above was added to the bore solution (5% in an NMP / water mixture). Crosslinking between the epoxide (VP / VA / GMA) and the diamine (Jeffamine ED-2003) began immediately after the spindle exit when the dope solution and the bore solution came into contact.

[0069] All the obtained membranes had a wall thickness of approximately 49 μm, and their lumen was 300–370 μm. [Table 1]

[0070] Comparative Example 1 As a comparative example, Example 1 was repeated using compositions that did not contain VP / VA / GMA in the doping solution and diamine in the bore solution.

[0071] The nitrogen content of the membranes prepared in Example 1 and Comparative Example 1 was measured. Then, the membranes from Example 1 and Comparative Example 1 were treated in a Soxhlet apparatus for 7 days, and the nitrogen content was measured again after this extraction procedure. The results are summarized in Table 2. [Table 2]

[0072] The nitrogen content of the film in Example 1 is clearly much higher than the corresponding value in Comparative Example 1, indicating that nitrogen is incorporated into the film. This is evidence of crosslinking between the epoxy functional groups in the VP / VA / GMA units and the diamine in the film structure.

[0073] Similarly, residual extracts from these membranes were measured by UV spectroscopy. The results are summarized in Table 3. [Table 3]

[0074] Table 3 shows that less VP / VA / GMA is washed away from the membrane than with normal PVP. This is a clear indicator of cross-linked VP / VA / GMA and stable, hydrophilic membranes with less extract.

[0075] Finally, the film according to Example 1 yielded a retention rate of 100% for 15 nm gold particles, compared to the 57% retention rate for 15 nm gold particles obtained by the film according to Comparative Example 1. This disclosure includes the following embodiments of the invention: <Aspect 1> A process for manufacturing modified microporous membranes, (i) To provide a first solution comprising at least one first polymer and at least one epoxy-functional compound, (ii) To provide a second solution comprising at least one diamine compound, (iii) Contacting the first solution with the second solution to obtain a modified microporous membrane comprising at least one first polymer and a crosslinking reaction product between the at least one epoxy-functional compound and the at least one diamine compound, The modified microporous membrane is a hollow fiber membrane. The first solution is a doping solution, the second solution is a bore solution, and the contact between the first solution and the second solution occurs within the spinneret. <Aspect 2> The process according to embodiment 1, wherein the at least one epoxy-functional compound is a copolymer comprising a structural block containing at least one epoxy moiety and at least one aliphatic or aromatic alkoxy functional group. <Aspect 3> The process according to embodiment 3, wherein the constituent block comprising at least one epoxy moiety is selected from an aliphatic or aromatic glycidyl ether. <Aspect 4> The process according to embodiment 2 or 3, wherein the copolymer further comprises a constituent block comprising a portion selected from aliphatic, cyclic or aromatic esters, aliphatic, cyclic or aromatic amides, aliphatic, cyclic or aromatic ethers, aliphatic, cyclic or aromatic sulfones, aliphatic, cyclic or aromatic sulfides, aliphatic, cyclic or aromatic sulfonamides, and / or a metal chelating agent. <Aspect 5> The at least one epoxy-functional compound is

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Claims

1. A process for manufacturing modified microporous membranes, (i) To provide a first solution comprising at least one first polymer, at least one second polymer, and at least one epoxy-functional compound, (ii) To provide a second solution containing at least one diamine compound, (iii) Contacting the first solution with the second solution to obtain a modified microporous film comprising at least one first polymer and a crosslinking reaction product between the at least one epoxy-functional compound and the at least one diamine compound, The modified microporous membrane is a hollow fiber membrane. The first solution is a doping solution, the second solution is a bore solution, and the contact between the first solution and the second solution occurs within the spinneret. The first polymer is a polyethersulfone, The second polymer is polyvinylpyrrolidone, The diamine compound is a polyetheramine, and The epoxy-functional compound is defined by the following formula: 【Chemistry 1】 A process having the following equation (wherein x, y, and z are evenly distributed and x + y + z = 100).

2. Use of a membrane obtained by the process according to claim 1 for microfiltration, nanofiltration, or ultrafiltration of water or an aqueous medium.

3. The process according to claim 1, wherein the first solution comprises at least one solvent.

4. The process according to claim 3, wherein the at least one solvent is selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and N-methylpyrrolidone, and any combination or mixture thereof.

5. The use according to claim 2, wherein the microfiltration, nanofiltration, or ultrafiltration includes viral filtration.

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