Poly(arylene ethersulfone) polymer film

Abstract

The present invention relates to a film comprising two different poly(arylene ethersulfone) polymers (P1) and (P2), a method for producing the same, and the use thereof.

Description

Technical Field

[0001] The present invention relates to a membrane comprising two different poly(arylene ether sulfone) polymers (P1) and (P2), to a process for producing the same, and to uses thereof.

[0002] Membrane technology has attracted significant attention over the past few decades. In several fields of application, membranes are used for energy-efficient separation of mixtures. In particular, membranes are widely used for water purification (J.-C. Schrotter, B. Bozkaya-Schrotter in "Membranes for Water Treatment", Ed. K.-V. Peinemann, S.Pereira Nunes, Wiley-VCH, Vol. 4, 2010). Another important field of application for certain membranes is purification of blood required for the treatment of people suffering from kidney diseases, in particular blood dialysis (hemodialysis) or hemodiafiltration therapy (C.R. Ronco, W.R. Clark, Nature Reviews Nephrology, 14, 2018, 394).

[0003] To be suitable for membrane applications, polymer materials must exhibit specific mechanical properties, thermal stability, and chemical resistance. One class of materials promising for membrane applications is polyarylene sulfone. It belongs to a group of high-performance polymers with high heat resistance, chemical resistance, excellent mechanical properties, and durability (EM Koch, H.-M. Walter, Kunststoffe 80 (1990) 1146; E. Doering, Kunststoffe 80, (1990) 1149, N. Inchaurondo-Nehm, Kunststoffe 98, (2008) 190). For example, it is generally suitable as a material for forming dialysis membranes and ultrafiltration (UF) membranes (NA Hoenich, KP Katapodis, Biomaterials 23 (2002) 3853; S. Savariar, GS Underwood, EM Dickinson, PJ Schielke, AS Hay, Desalination 144 (2002) 15). Membrane materials used for medical purposes must meet certain standards, and the quality standards for membranes used in medical applications are particularly high. For example, membranes often need to be sterilized, which usually means that the membrane is exposed to higher temperatures. Therefore, the membrane material needs to be heat resistant within the required temperature range.

[0004] One specific problem related to ultrafiltration membranes is membrane fouling, which leads to an undesirable decrease in membrane performance. A further challenge in membrane technology is the adjustment of appropriate pore size, especially for certain membranes such as dialysis membranes. Both problems have been addressed by using non-solvent-induced phase separation (NIPS) processes and by using hydrophilic pore-forming agents such as polyvinylpyrrolidone (PVP) in combination with the respective membrane-forming polymers. DE 19817364 describes a method for preparing a hydrophilic membrane with high porosity using a first hydrophobic polymer and a second hydrophilic polymer, for example, the first polymer being polysulfone and the hydrophilic polymer being polyvinylpyrrolidone. In particular, DE 19817364 uses two types of polyvinylpyrrolidone with different molecular weights to improve the membrane porosity. In EP 2113298, the same approach is used to prepare a polyethersulfone-based dialysis membrane.

[0005] An approach to producing ultrafiltration membranes without using pore-forming components via the NIPS process is described in EP0344581. In EP0344581, a doped solution containing polyarylate and polysulfone is used as the membrane polymer. However, one disadvantage of the method described in the example of EP0344581 is that the polyarylate polymer has been found to have limited solubility, and the components are unstable in solvents commonly used in membrane fabrication, such as N-methyl-2-pyrrolidone (NMP), resulting in turbidity of the solution. Furthermore, polyarylate is a polyester with limited stability for longer-term use in aqueous environments. Therefore, the applicability of this approach in ultrafiltration membrane technology is considerably limited.

[0006] There is a need for membranes, particularly ultrafiltration membranes, that exhibit excellent selectivity, high membrane productivity, and good mechanical properties, especially for medical applications such as dialysis. Specifically, ultrafiltration membranes are required that simultaneously possess a low molecular weight cutoff, high water permeability, and good aging stability. Furthermore, the polymer material needs to have good viscosity properties suitable for forming a stable membrane. The membrane material should also exhibit a certain degree of hydrophilicity so that the membrane can be wetted by the liquid that needs to pass through it. Pore size is also a critical parameter, as the pores need to be large enough to allow a high flow rate (PWP = pure water permeability) of the liquid being purified through the membrane while possessing selective capture properties. In particular, in the case of dialysis, the molecular weight cutoff is assumed to be less than 100 kD so that even proteins do not pass through. In addition, considering high permeation flux, the pores need to be connected. A further fundamental objective of the present invention was to provide a stable polymer solution that can be effectively used for the preparation of ultrafiltration membranes, particularly for use in the NIPS process, for membrane production.

[0007] These objectives are for the present invention's film (M) comprising poly(arylene ethersulfone) polymers (P1) and (P2), wherein (P1) and (P2) are units Ia to Is: [ka] [ka] [ka] [In the equation, x is between 0.05 and 1, and n is 1]; [ka] [In the equation, x is between 0.05 and 1, and n is 1]; [ka] [In the equation, x is between 0.05 and 1, and n is 1.] It includes at least one structural repeating unit selected from, At least one structural repeating unit of (P2) is different from at least one structural repeating unit of (P1), The membrane (M) handles the problem without issue.

[0008] The film according to the present invention exhibits excellent selectivity and efficiency, while simultaneously being remarkably stable, demonstrating excellent aging characteristics and remarkable maintenance of film performance over time.

[0009] In the context of this invention, the term “membrane” means a semipermeable structure that acts as a selective barrier, allowing some particles, substances, or chemicals to pass through while trapping others. Generally, membranes are applied in the separation of various liquids and gases. Membranes may have various geometric shapes, such as flat plates, spirals, pillows, tubular structures, single-bore hollow fibers, or multi-bore hollow fibers.

[0010] For example, the membrane (M) may be a nanofiltration (NF) membrane, a microfiltration (MF) membrane, or an ultrafiltration (UF) membrane. These membrane types are generally known in the art.

[0011] NF membranes are typically particularly well-suited for the removal of polyvalent and large monovalent ions. Typically, NF membranes function through mechanisms based on dissolution diffusion and / or filtration. NF membranes are commonly used in cross-flow filtration processes. Nanofiltration membranes often contain charged polymers with sulfonic acid groups, carboxylic acid groups, and / or ammonium groups.

[0012] MF membranes typically have an average pore size of 0.05 μm to 10 μm, preferably 1.0 μm to 5 μm, and are generally suitable for removing particles with a particle size of 0.1 μm or larger. While pressurized systems can be used in microfiltration, pressure is not required. MF membranes may be hollow fiber, capillary, plate, tubular, spiral, pillow, fine hollow fiber, or track etch. They are porous and contain water and monovalent species (Na). + Cl -It allows dissolved organic matter, small colloids, and viruses to pass through, but captures particles, sediment, algae, or larger bacteria.

[0013] UF films are typically suitable for removing suspended solid particles and high molecular weight solutes, such as those exceeding 100,000 Da. UF films may be particularly suitable for removing bacteria and viruses. Typically, UF films have an average pore size of 0.5 nm to 50 nm, preferably 1 to 40 nm, and more preferably 5 to 20 nm.

[0014] The film (M) of the present invention can be used in any process known to those skilled in the art in which the film is used.

[0015] Those skilled in the art are generally familiar with the preparation of membranes. During membrane preparation, solvent exchange is known to typically result in an asymmetric membrane structure.

[0016] The membrane (M) may be a porous membrane. Porous membranes typically have pores, the pores having diameters in the range of 1 nm to 10,000 nm, preferably 2 to 500 nm, and particularly preferably 5 to 250 nm, determined by filtration experiments using solutions containing different PEGs with molecular weights ranging from 300 to 1,000,000 g / mol. The capture rate of the membrane for each molecular weight can be determined by comparing the GPC traces of the feed solution and the filtrate. The molecular weight at which the membrane exhibits a 90% capture rate is considered the molecular weight cutoff (MWCO) of this membrane under given conditions. The average pore size of the membrane can be determined using a known correlation between the Stokes diameter of PEG and its molecular weight. Details of this method are described in the literature (Chung, J. Membr. Sci. 531 (2017) 27-37). Porous membranes can typically be obtained when the membrane is prepared via a phase inversion process.

[0017] Dense films are typically substantially pore-free. Dense films can typically be obtained by a solution casting process, in which the solvent contained in the cast solution is evaporated. Usually, the separation layer is cast onto a support, which may be polysulfone or another polymer such as cellulose acetate. Sometimes, a layer of polydimethylsiloxane is applied on top of the separation layer.

[0018] In one embodiment of the present invention, the membrane (M) is a dense membrane. In particular, when the membrane is a dense membrane, it is especially suitable for gas separation.

[0019] The film (M) of the present invention may have any thickness. For example, the film thickness may be in the range of 2 to 350 μm, preferably in the range of 3 to 200 μm, and most preferably in the range of 5 to 100 μm.

[0020] According to one embodiment of the present invention, the membrane (M) is an asymmetric membrane. In a further embodiment, the membrane is porous.

[0021] The membrane (M) of the present invention is particularly suitable for nanofiltration, microfiltration and / or ultrafiltration, especially when the membrane is a porous membrane.

[0022] Accordingly, according to one embodiment of the present invention, the membrane (M) is a nanofiltration, ultrafiltration (UF), and / or microfiltration membrane. Typical nanofiltration, ultrafiltration, and microfiltration processes are known to those skilled in the art.

[0023] According to one particular embodiment, the membrane of the present invention is an ultrafiltration membrane.

[0024] In further specific embodiments, the membrane (M) of the present invention is a UF membrane that is a spiral membrane, a pillow membrane, or a plate membrane. In another embodiment, the membrane (M) of the present invention is a UF membrane that is a tubular membrane.

[0025] In yet another embodiment, the membrane (M) is a hollow fiber membrane, which may be a single-bore hollow fiber membrane or a multi-bore hollow fiber membrane. In the hollow fiber membrane, the semipermeable barrier is in the form of hollow fibers.

[0026] A multi-channel membrane (also called a multi-bore membrane) has more than one longitudinal channel (also called a "channel" or "bore").

[0027] The number of channels is typically 2 to 19. In one embodiment, the multi-bore hollow fiber membrane has 2 or 3 channels. In another embodiment, the multi-bore hollow fiber membrane has 5 to 9 channels. In one particular embodiment, the multi-bore hollow fiber membrane has 7 channels. In yet another embodiment, the multi-bore hollow fiber membrane has 20 to 100 channels.

[0028] The shape of one or more bores may vary. Typically, the film according to the present invention has a diameter that is essentially circular, elliptical, or rectangular. Preferably, the film according to the present invention is essentially circular, i.e., the bore has a diameter that is essentially circular.

[0029] In another embodiment, such a bore has an essentially elliptical diameter. In yet another embodiment, the channel has an essentially rectangular diameter. In some cases, the actual shape of such a channel may deviate from the ideal circular, elliptical, or rectangular shape.

[0030] Typically, such channels have an outer diameter of 0.05 mm to 3 mm, preferably 0.5 mm to 2 mm, more preferably 0.9 mm to 1.5 mm (for essentially circular diameters), a smaller outer diameter (for essentially elliptical diameters), or a smaller outer feed size (for essentially rectangular diameters). In another preferred embodiment, such channels have an outer diameter in the range of 0.2 mm to 0.9 mm (for essentially circular diameters), a smaller outer diameter (for essentially elliptical diameters), or a smaller outer feed size (for essentially rectangular diameters).

[0031] According to the present invention, in one preferred embodiment, the hollow fiber membrane has an outer diameter of 2 to 10 mm, preferably 3 to 8 mm, more preferably 4 to 6 mm (for essentially circular diameters), a smaller outer diameter (for essentially elliptical diameters), or a smaller outer feed size (for essentially rectangular diameters).

[0032] In another preferred embodiment of the present invention, the hollow fiber membrane has an outer diameter of 2 to 4 mm (for an essentially circular diameter), a smaller outer diameter (for an essentially elliptical diameter), or a smaller outer feed size (for an essentially rectangular diameter).

[0033] The hollow fiber membrane may have any thickness. For example, the membrane thickness is in the range of 20 to 150 μm, preferably in the range of 20 to 100 μm, and most preferably in the range of 30 to 60 μm. This may be particularly suitable for dialysis membranes.

[0034] If the multi-bore hollow fiber membrane contains channels that are essentially rectangular in shape, these channels may be arranged in a single row. If the channels of the multi-bore hollow fiber membrane are essentially circular in shape, these channels are preferably arranged such that the central channel is surrounded by the other channels. In one preferred embodiment, the membrane comprises one central channel and, for example, four, six, or eighteen further channels arranged in a ring around the central channel. The wall thickness of such a multi-channel membrane is typically 0.02 to 1 mm at its thinnest point, preferably 30 to 500 μm, and more preferably 100 to 300 μm.

[0035] According to one embodiment, in the film (M) of the present invention, at least one repeating structural unit of (P1) and (P2) is preferably selected from units Ia to Io and Is, respectively.

[0036] In a further embodiment, in the film (M) of the present invention, at least one repeating structural unit of (P1) and (P2) is preferably selected from units Ia to Io.

[0037] In yet another embodiment, in the film (M) of the present invention, at least one repeating structural unit of (P1) and (P2) is preferably selected from units Ia, Ig, Ik, Ip, and Is, and more specifically, selected from units Ia, Ig, Ik, and Is.

[0038] In yet another embodiment of the film (M) of the present invention, at least one repeating structural unit of (P1) and (P2) is preferably selected from units Ia, Ig, and Ik, respectively.

[0039] Poly(arylene ethersulfone) containing the structural repeating unit of formula Ia is also called polysulfone (PSU).

[0040] Poly(arylene ether sulfone) containing the structural repeating unit of formula Ig is also called polyphenylene sulfone (PPSU).

[0041] Poly(arylene ethersulfone) containing the structural repeating unit of formula Ik is also called polyethersulfone (PESU or PES).

[0042] In this disclosure, abbreviations such as PSU, PPSU, and PESU (PES) are used in accordance with DIN EN ISO 1043-1:2001.

[0043] According to one particular embodiment, (P1) includes unit Ia as a structural repeating unit, and (P2) includes unit Ig.

[0044] According to a further specific embodiment, (P1) includes unit Ia as a structural repeating unit, and (P2) includes unit Ik.

[0045] In yet another specific embodiment, (P1) includes the unit Ig as a structural repeating unit, and (P2) includes the unit Ik.

[0046] According to a further specific embodiment of the present invention, (P1) includes unit Ia as a structural repeating unit, and (P2) includes unit Ip.

[0047] In yet another specific embodiment, (P1) includes the unit Ig as a structural repeating unit, and (P2) includes the unit Ip.

[0048] In yet another specific embodiment, (P1) includes the unit Ik as a structural repeating unit, and (P2) includes the unit Ip.

[0049] According to a further specific embodiment of the present invention, (P1) includes unit Ia as a structural repeating unit, and (P2) includes unit Is.

[0050] In yet another specific embodiment, (P1) includes the unit Ig as a structural repeating unit, and (P2) includes the unit Is.

[0051] In yet another specific embodiment, (P1) includes the unit Ik as a structural repeating unit, and (P2) includes the unit Is.

[0052] In addition to at least one unit selected from units Ia to Is present in (P1) or (P2), each other repeating unit is obtained by replacing one or more 1,4-phenylene units derived from hydroquinone with 1,3-phenylene units derived from resorcinol or naphthylene units derived from dihydroxynaphthalene.

[0053] Weight-average molar mass M of poly(arylene ethersulfone) polymers (P1) and (P2) w Each of these values ​​is determined by gel permeation chromatography in dimethylacetamide as a solvent against a narrowly distributed polymethyl methacrylate as a standard, preferably in the range of 10,000 to 180,000 g / mol, more preferably in the range of 15,000 to 150,000 g / mol, and particularly preferably in the range of 20,000 to 125,000 g / mol. More specifically, Mw The g / mol concentration is 10,000 to 100,000 g / mol, more specifically 10,000 to 95,000 g / mol, particularly 12,000 to 93,000 g / mol, and especially preferably 14,000 to 90,000 g / mol, determined by gel permeation chromatography in dimethylacetamide as a solvent against a narrowly distributed polymethyl methacrylate as a standard.

[0054] The viscosity numbers (VN) of the poly(arylene ethersulfone) polymers (P1) and (P2) are determined as a 1% solution in N-methylpyrrolidone at 25°C. The viscosity number (VN) is preferably in the range of 60 to 120 ml / g.

[0055] According to one embodiment, it is preferable that the poly(arylene ethersulfone) polymers (P1) and / or (P2) used in the film (M) of the present invention have high purity, particularly with respect to the cyclic oligomer content. "Cyclic dimers" are undesirable by-products that may be formed during polycondensation when preparing the polymer. This impurity can be measured by the turbidity of the polymer product in solution using DMF, DMAc, or NMP as the solvent. Methods for measuring turbidity are well known to those skilled in the art.

[0056] The production processes leading to the aforementioned poly(arylene ethersulfone) polymers are known to those skilled in the art, and are described, for example, in Herman F. Mark, "Encyclopedia of Polymer Science and Technology," third edition, volume 4, 2003, chapter "Polsulfones," pages 2 to 8, and in Hans R. Kricheldorf, "Aromatic Polyethers," in: Handbook of Polymer Synthesis, second edition, 2005, pages 427 to 443.

[0057] The synthesis of poly(arylene ethersulfone) polymers can generally be carried out by polycondensation of suitable monomers in a dipolar aprotic solvent at elevated temperatures.

[0058] Outline of the preparation of poly(arylene ethersulfone) polymers using the hydroxide and carbonate methods is described, for example, in RN Johnson et.al., J. Polym. Sci. A-1 5 (1967) 2375 and JE McGrath et.al., Polymer 25 (1984) 1827. Furthermore, the production of polyaryl ethersulfone polymers is described in patent applications US4870153, EP113112, EP297363 and EP135130, which are incorporated herein by reference. In these patent applications, suitable reactants, catalysts, solvents, and ratios of components used, as well as reaction times and reaction temperatures, can be found.

[0059] In the carbonate process, aromatic dihydroxyl compounds and aromatic dihalogen compounds are reacted with each other in the presence of a carbonate, preferably potassium carbonate. Generally, N,N-dimethylacetamide, DMF, N-ethylpyrrolidone, or NMP are preferably used as solvents, and toluene or chlorobenzene is added as an azeotrope to remove water. Processes that do not use an azeotrope are preferred.

[0060] Compared to the hydroxide method, the carbonate method has the advantage of being able to vary the potassium carbonate excess over a relatively wide range of regimes without reducing the molecular weight of the resulting polymer. Thus, reaction control is simplified compared to the hydroxide method. According to the present invention, poly(arylene ethersulfone) polymers produced by any process can be used.

[0061] In an aprotic polar solvent, a reaction between at least one aromatic compound having two halogen substituents and at least one aromatic compound having two functional groups reactive to the aforementioned halogen substituents is particularly preferred in the presence of an anhydrous alkali metal carbonate, particularly sodium carbonate, potassium carbonate, calcium carbonate, or a mixture thereof, most preferably potassium carbonate. One particularly suitable combination is N-methyl-2-pyrrolidone as the solvent and potassium carbonate as the base.

[0062] The poly(arylene ether sulfone) polymer (P1) and / or (P2) preferably have a halogen-terminated group, particularly a chlorine-terminated group, or an etherifying-terminated group, particularly an alkyl ether-terminated group, which can be obtained by the reaction of an OH or phenolate-terminated group with a suitable etherifying agent. Examples of suitable etherifying agents are monofunctional alkyl or aryl halides, such as C1-C6 alkyl chlorides, C1-C6 alkyl bromides, or C1-C6 alkyl iodides, preferably methyl chloride, or benzyl chloride, benzyl bromide, or benzyl iodide, or mixtures thereof. In the polyarylene (ether) sulfone of component A), preferred terminological groups are halogens, particularly chlorine, alkoxys, particularly methoxy, aryloxys, particularly phenoxy, or benzyloxy.

[0063] The total weight percent of poly(arylene ethersulfone) polymers (P1) and (P2) contained in the film (M) of the present invention is preferably at least 50% by weight, more preferably at least 70% by weight, and most preferably at least 90% by weight, based on the total weight of the film (M). In a further preferred embodiment, the film (M) is essentially composed of poly(arylene ethersulfone) polymers (P1) and (P2). "Essentially composed of" means that the film (M) contains more than 95% by weight, preferably more than 97.5% by weight, and most preferably more than 98% by weight of poly(arylene ethersulfone) polymers (P1) and (P2) as the total weight percent of (P1) and (P2), based on the total weight of the film.

[0064] According to one embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) in the film (M) of the present invention, as defined herein and as preferred herein, is 40 to 98% by weight, more specifically 45 to 97% by weight, even more specifically 50 to 96% by weight, and even more specifically 60 to 95% by weight, based on the total weight of the film (M).

[0065] The ratio of poly(arylene ethersulfone) polymer (P1) to (P2) in the film (M) of the present invention may be any possible weight ratio, for example, 1:10 to 10:1, particularly 1:9 to 9:1, especially 1:8 to 8:1, and even more particularly 1:7 to 7:1. According to a particular embodiment, the ratio may be 1:6 to 6:1 or 1:5 to 5:1, particularly 1:4 to 4:1, especially 1:3 to 3:1, and even more particularly 1:2 to 2:1. According to one very particular embodiment of the present invention, (P1) and (P2) may be present in equal or nearly equal amounts (1:1). “Nearly equal amounts” in this context means that the difference in amounts between (P1) and (P2) is only negligible.

[0066] The film of the present invention may also contain at least one hydrophilic polymer additive (A). In particular, the at least one additive (A) is selected from poly(alkylene oxide), polyvinylpyrrolidone (PVP), and sulfonated poly(arylene ethersulfone) polymer (SP).

[0067] According to one particular embodiment, the membrane (M) does not contain any additives (A).

[0068] Polyvinylpyrrolidone is commercially available (for example, Luvitec (registered trademark) manufactured by BASF SE). According to one embodiment, PVP has a solution viscosity characterized by a K-value of at least 12 (PVP K12), at least 30 (PVP K30) or at least 85 (PVP K85). It will be preferred if PVP has a solution viscosity characterized by a K-value of at least 80 (PVP K80), such as for example Luvitec (registered trademark) K80. In a further preferred embodiment, PVP has a solution viscosity characterized by a K-value of at least 85 (PVP K85), such as for example Luvitec (registered trademark) K85. It will also be preferred if PVP has a solution viscosity characterized by a K-value of at least 90 (PVP K90), such as for example Luvitec (registered trademark) K90.

[0069] The solution viscosity is determined according to the method of Fikentscher (Fikentscher, Cellulosechemie 13, 1932 (58)).

[0070] The sulfonated poly(arylene ether sulfone) polymer preferably comprises units of formula (I). Chemical formula wherein the symbols t, q, Q, T, Y, Ar and Ar 1 are defined as follows: t and q are each independently 0, 1, 2 or 3; Q, T and Y are each independently a chemical bond or a group selected from -O-, -S-, -SO₂-, S=O, C=O, -N=N- and -CR a R b -, wherein in the formula, R a and R b are each independently a hydrogen atom, (C₁~C 12 ) alkyl, (C₁~C 12 ) alkoxy, (C₃~C 12 ) cycloalkyl or (C₆~C 18) an aryl group, having at least one of Q, T, and Y, and being -SO2-; and Ar and Ar 1 They are independent of each other (C6~C 18 ) are allirenes; Here, At least one unit (I) contains an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + [is]

[0071] If Q, T, or Y is a chemical bond as described above, this is understood to mean that the group adjacent to the left and the group adjacent to the right are directly bonded to each other via a chemical bond. It will be easily understood that if at least one of the group consisting of Q, T, and Y is -SO2-, then at least one of the groups in equation (I) is -SO2-. Thus, when q=0, at least one of T and Y is -SO2-; for example, when t=0, at least one of Q and Y is -SO2-, and when q=0 and t=0, Y is SO2.

[0072] According to one preferred embodiment, t and q are independently 0 or 1.

[0073] According to one preferred embodiment, Q, T, and Y in formula II are chemical bonds, -O-, -SO2-, and -CR, provided that at least one of Q, T, and Y is present and -SO2-. a R b - is selected independently of R. a and R b However, it would be preferable that each element be hydrogen or (C1-C4) alkyl, independently of the others.

[0074] -CR a R b -Medium, R a and R b Preferably, hydrogen, (C1~C 12 ) Alkyl, (C1~C 12 )alkoxy and (C6~C 18 ) Selected independently of the arrow.

[0075] (C1~C 12 Alkyl refers to a linear or branched saturated hydrocarbon group having 1 to 12 carbon atoms. The following parts are particularly included: (C1-C6) alkyl, e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, 2- or 3-methylpentyl, and (C7-C 12 Alkyl groups, such as unbranched heptyl, octyl, nonyl, decyl, undecyl, lauryl, and their monobranched or multibranched analogues.

[0076] "C1~C 12 The term "alkoxy" refers to linear or branched alkyl groups having 1 to 12 carbon atoms bonded via oxygen at any position of the alkyl group, such as methoxy, ethoxy, n-propoxy, 1-methylethoxy, butoxy, 1-methyl-propoxy, 2-methylpropoxy, or 1,1-dimethylethoxy.

[0077] (C3~C 12 Cycloalkyl refers to a monocyclic saturated hydrocarbon group having 3 to 12 carbon ring members, and in particular includes (C3-C8) cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopropylmethyl, cyclopropylethyl, cyclopropylpropyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylethyl, -propyl, -butyl, -pentyl, -hexyl, cyclohexylmethyl, -dimethyl, and -trimethyl.

[0078] Ar and Ar 1They are independent of each other (C6~C 18 ) is an arylene group. According to a particular embodiment, Ar 1 is non-substituted (C6~C 12 ) It is sometimes preferable that the group be an arylene group.

[0079] Ar and Ar 1 However, it is sometimes preferable to independently select from phenylene, bisphenylene and naphthylene groups, as well as from anthracene, phenanthrene, or arylene groups derived from naphthacene. For example, Ar and Ar 1 The is independently selected from 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,6-naphthylene, 1,7-naphthylene, 2,6-naphthylene and 2,7-naphthylene, 2,7-dihydroxynaphthylene and 4,4'-bisphenylene.

[0080] In particular, Ar and Ar 1 However, it is preferable to be independently selected from phenylene and naphthylene groups, such as being independently selected from 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,6-naphthylene, 1,7-naphthylene, 2,6-naphthylene and 2,7-naphthylene, or more specifically, independently selected from 1,4-phenylene, 1,3-phenylene and naphthylene. Furthermore, according to another embodiment of the present invention, Ar and Ar 1 The group is independently selected from an arylene group derived from anthracene, phenanthrene, or naphthacene. According to yet another embodiment, Ar and Ar 1 The compound is independently selected from 2,7-dihydroxynaphthylene and 4,4'-bisphenylene.

[0081] A preferred sulfonated poly(arylene ethersulfone) polymer is one which comprises at least one unit Ia to Io as a defined, preferably as defined herein, repeating structural unit, where at least one unit Ia to Io comprises an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + That is the case.

[0082] According to one embodiment, a sulfonated poly(arylene ethersulfone) polymer comprises at least one unit selected from units Ia, Ig, and Ik as a repeating structural unit, at least one of which comprises an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + That is the case.

[0083] According to one embodiment, a sulfonated poly(arylene ethersulfone) polymer comprises a repeating structural unit of formula Ia, also known as a sulfonated polysulfone (sPSU), where unit Ia comprises an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + That is the case.

[0084] According to further embodiments, the sulfonated poly(arylene ether sulfone) polymer comprises a repeating structural unit of formula Ig and is also called sulfonated polyphenylene sulfone (sPPSU). Therein, unit Ig comprises an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + That is the case.

[0085] In yet another embodiment, the sulfonated poly(arylene ethersulfone) polymer comprises a repeating structural unit of formula Ik and is also called sulfonated polyethersulfone (sPESU or sPES). Therein, the unit Ik comprises an arylene group substituted with at least one -SO2X group, where X is Cl and O in combination with one countercation. - A selection is made from the group consisting of H, and the counter cation is H + Li + na + , K + Mg 2+ Ca 2+ or NH4 + That is the case.

[0086] Sulfonated poly(arylene ethersulfone) polymers have been known for several decades (A. Noshay, LM Robeson, J. Appl. Polym. Sci. 20 (1976) 1885). Direct sulfonation of poly(arylene ethersulfone) polymers leads to side reactions and offers limited control over the degree of sulfonation, but the use of disulfonated dichlorodiphenyl sulfone (sDCDPS) as a comonomer enables the synthesis of clearly defined sulfonated poly(arylene ethersulfone) polymers (Ueda et.al., J. Polym. Sci. A, Polym. Chem. 31 (1993) 853; JE McGrath et.al., Macromol. Symp. 175 (2001) 387). Further details regarding the synthesis of high molecular weight sulfonated poly(arylene ethersulfone) polymers can be found in PCT / EP2023 / 064280.

[0087] According to one embodiment, additive (A) preferably comprises polyvinylpyrrolidone (PVP).

[0088] More preferably, the hydrophilic polymer additive (A) comprises at least 50% by weight, preferably at least 60% by weight, and particularly at least 70% by weight of PVP relative to the amount of additive (A) in the film. In a preferred embodiment, the hydrophilic polymer additive (A) comprises polyvinylpyrrolidone as defined herein and as preferred herein. In one embodiment, the film (M) comprises PVP as defined herein and as preferred herein.

[0089] If present, the amount of PVP in the membrane (M) of the present invention, as defined herein and as preferred herein, is preferably 0.1 to 5% by weight, more specifically 0.2 to 3% by weight, and even more specifically 0.3 to 2% by weight, based on the total weight of the membrane. In further embodiments, the amount of PVP in the membrane of the present invention is 0.4 to 1.5% by weight, more specifically 0.5 to 1.3% by weight, and even more specifically 0.6 to 1.2% by weight. In yet another embodiment, the amount of PVP is 0.7 to 1.1% by weight. In particular, PVP may be present in an amount of 0.1 to 1% by weight, more specifically 0.3 to 1% by weight.

[0090] According to one particular embodiment of the present invention, the membrane (M) of the present invention is essentially PVP-free. “Essentially PVP-free” within the context of the present invention means that the membrane contains at most 0.05% by weight, preferably at most 0.04% by weight, particularly preferably at most 0.03% by weight, and more specifically at most 0.01% by weight, based on the total weight of the membrane. According to one very particular embodiment, the membrane (M) of the present invention is PVP-free.

[0091] In yet another embodiment, additive (A) preferably comprises a sulfonated poly(arylene ethersulfone) polymer (SP). Preferably, the hydrophilic polymer additive (A) comprises at least 50% by weight, preferably at least 60% by weight, and particularly at least 70% by weight of sulfonated poly(arylene ethersulfone) polymer (SP) relative to the amount of additive (A) in the film. In a preferred embodiment, the hydrophilic polymer additive (A) consists of at least one sulfonated poly(arylene ethersulfone) polymer (SP) as defined herein and as preferred herein. In one embodiment, the film (M) comprises at least one sulfonated poly(arylene ethersulfone) polymer (SP) as defined herein and as preferred herein.

[0092] If present, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) in the film (M) of the present invention is preferably 0.1 to 5% by weight, more specifically 0.2 to 3% by weight, and even more specifically 0.3 to 2% by weight, based on the total weight of the film. In further embodiments, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) in the film of the present invention is 0.4 to 1.5% by weight, more specifically 0.5 to 1.3% by weight, and even more specifically 0.6 to 1.2% by weight. In yet another embodiment, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) is 0.7 to 1.1% by weight. In particular, the sulfonated poly(arylene ethersulfone) polymer (SP) may be present in an amount of 0.1 to 1% by weight, more specifically 0.3 to 1% by weight.

[0093] According to one particular embodiment of the present invention, the film (M) of the present invention is essentially free of sulfonated poly(arylene ethersulfone) polymer (SP). Within the scope of the present invention, "essentially free" means that the film contains at most 0.05% by weight, preferably at most 0.04% by weight, particularly preferably at most 0.03% by weight, and more specifically at most 0.01% by weight of sulfonated poly(arylene ethersulfone) polymer (SP) based on the total weight of the film. According to one very particular embodiment, the film (M) of the present invention is free of any sulfonated poly(arylene ethersulfone) polymer (SP).

[0094] According to a further embodiment of the present invention, the membrane (M) comprises polyvinylpyrrolidone (PVP) as defined above and as preferred above, and a sulfonated poly(arylene ethersulfone) polymer (SP) as defined above and as preferred above.

[0095] In yet another embodiment, at least one additive (A) includes poly(alkylene oxide), particularly poly(ethylene oxide), poly(propylene oxide), and poly(ethylene oxide)-poly(propylene oxide) copolymers.

[0096] According to a further embodiment of the present invention, the membrane (M) comprises a poly(alkylene oxide) selected from poly(ethylene oxide), poly(propylene oxide), and poly(ethylene oxide)-poly(propylene oxide) copolymer.

[0097] If present, the amount of poly(alkylene oxide) in the film (M) of the present invention is preferably 0.1 to 5% by weight, more specifically 0.2 to 3% by weight, and even more specifically 0.3 to 2% by weight, based on the total weight of the film. In further embodiments, the amount of poly(alkylene oxide) in the film of the present invention is 0.4 to 1.5% by weight, more specifically 0.5 to 1.3% by weight, and even more specifically 0.6 to 1.2% by weight. In yet another embodiment, the amount of poly(alkylene oxide) is 0.7 to 1.1% by weight. In particular, poly(alkylene oxide) may be present in an amount of 0.1 to 1% by weight, more specifically 0.3 to 1% by weight.

[0098] As will be obvious to those skilled in the art, all components of the film (M) together make up a maximum of 100% by weight.

[0099] The membrane (M) can be prepared by any method for preparing membranes. A further object of the present invention is a method for preparing membrane (M), a) a step of preparing a composition (C) comprising poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein, and at least one solvent (D); b) The step of separating at least one solvent (D) from composition (C) to obtain a film (M) This method includes [something].

[0100] The composition (C) of step a) comprises (P1) and (P2) as defined herein and as preferred herein. Preferably, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 10% by weight or more based on the total weight of composition (C). According to a further embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 11% by weight or more, more specifically 12% by weight or more based on the total weight of composition (C). According to a particular embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 13% by weight or more based on the total weight of composition (C).

[0101] In certain embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 14% by weight or more based on the total weight of composition (C). According to further embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 15% by weight or more, more specifically 16% by weight or more based on the total weight of composition (C). According to further specific embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 17% by weight or more based on the total weight of composition (C).

[0102] Furthermore, according to the present invention, it is preferable that the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 18% by weight or more based on the total weight of composition (C). According to yet another embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 19% by weight or more, more specifically 20% by weight or more based on the total weight of composition (C). According to yet another specific embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 21% by weight or more based on the total weight of composition (C). According to one embodiment, it would be even more preferable that the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 22% by weight or more, more specifically 23% by weight or more, even more specifically 24% by weight or more, and even more specifically 25% by weight or more, based on the total weight of composition (C).

[0103] According to one embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 10 to 30% by weight, more specifically 13 to 25% by weight, and even more specifically 15 to 23% by weight or more, based on the total weight of composition (C).

[0104] The ratio of poly(arylene ethersulfone) polymers (P1) to (P2) as defined herein and preferred herein in composition (C) may be any possible weight ratio, for example, 1:10 to 10:1, particularly 1:9 to 9:1, especially 1:8 to 8:1, and even more particularly 1:7 to 7:1. According to certain embodiments, the ratio may be 1:6 to 6:1 or 1:5 to 5:1, particularly 1:4 to 4:1, especially 1:3 to 3:1, and even more particularly 1:2 to 2:1. According to one very specific embodiment of the present invention, (P1) and (P2) may be present in composition (C) in equal or nearly equal amounts (1:1). “Nearly equal amounts” in this context means that the difference in amounts between (P1) and (P2) is only negligible.

[0105] Within the scope of the present invention, "at least one solvent" means exactly one solvent, as well as a mixture of two or more solvents.

[0106] Preferably, at least one solvent (D) is an aprotic polar solvent. In particular, at least one solvent (D) is soluble in water.

[0107] According to one embodiment, at least one solvent (D) is preferably selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone and N-tert.-butyl-2-pyrrolidone, 2-pyrrolidone, N-dimethylacetamide, dimethyl sulfoxide, dimethylformamide, N,N-dimethyl-2-hydroxypropanamide, N,N-diethyl-2-hydroxypropanamide, γ-valerolactone, dihydrolevoglucocenone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate and sulfolane. N-alkyl-2-pyrrolidone, γ-valerolactone and N,N-dimethyl-2-hydroxypropanamide are particularly preferred. N-methylpyrrolidone is most preferred as at least one solvent (D).

[0108] According to one embodiment, composition (C) contains solvent (D) in such an amount that the total amount of all components in the composition is a maximum of 100% by weight.

[0109] Composition (C) preferably comprises at least one solvent (D) in the range of 50 to 85% by weight, preferably at least one solvent (D) in the range of 55 to 84% by weight, more preferably at least one solvent (D) in the range of 60 to 83% by weight, and even more preferably at least one solvent (D) in the range of 67 to 82% by weight, based on the total weight of composition (C). According to a particular embodiment, composition (C) preferably comprises at least one solvent (D) in the range of 68 to 75% by weight, and also preferably at least one solvent (D) in the range of 70 to 75% by weight.

[0110] Furthermore, composition (C) may also contain a hydrophilic polymer additive (A) defined above for the film (M) and defined above as preferred. According to one particular embodiment, composition (C) does not contain any additive (A).

[0111] According to a preferred embodiment, composition (C) comprises polyvinylpyrrolidone (PVP) as defined herein and as preferred herein.

[0112] If present, the amount of PVP in composition (C) as defined herein and as preferred herein is preferably 0.1 to 8% by weight, more specifically 0.2 to 6% by weight, and even more specifically 0.3 to 5% by weight, based on the total weight of composition (C). In further embodiments, the amount of PVP in composition (C) is 0.4 to 3% by weight, more specifically 0.5 to 2.5% by weight, and even more specifically 0.6 to 2.0% by weight. In yet another embodiment, the amount of PVP is 0.7 to 1.8% by weight. In particular, PVP may be present in an amount of 0.1 to 1.7% by weight, more specifically 0.3 to 1.5% by weight.

[0113] According to one particular embodiment of the present invention, composition (C) is essentially PVP-free. “Essentially PVP-free” within the context of the present invention means that composition (C) contains at most 0.05% by weight, preferably at most 0.04% by weight, particularly preferably at most 0.03% by weight, and more specifically at most 0.01% by weight of PVP based on the total weight of composition (C). According to one very particular embodiment, composition (C) contains no PVP at all.

[0114] In further embodiments, composition (C) preferably comprises a sulfonated poly(arylene ethersulfone) polymer (SP) defined above for the film (M) and as preferred above.

[0115] If present, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) in composition (C) as defined herein and as preferred herein is preferably 0.1 to 5% by weight, more specifically 0.2 to 3% by weight, and even more specifically 0.3 to 2% by weight, based on the total weight of composition (C). In further embodiments, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) in composition (C) is 0.4 to 1.5% by weight, more specifically 0.5 to 1.3% by weight, and even more specifically 0.6 to 1.2% by weight. In yet another embodiment, the amount of sulfonated poly(arylene ethersulfone) polymer (SP) is 0.7 to 1.1% by weight. In particular, the sulfonated poly(arylene ethersulfone) polymer (SP) may be present in an amount of 0.1 to 1% by weight, more specifically 0.3 to 1% by weight.

[0116] According to one particular embodiment of the present invention, composition (C) is essentially free of sulfonated poly(arylene ethersulfone) polymer (SP). “Essentially free” within the context of the present invention means that composition (C) contains at most 0.05% by weight, preferably at most 0.04% by weight, particularly preferably at most 0.03% by weight, and more specifically at most 0.01% by weight of sulfonated poly(arylene ethersulfone) polymer (SP) based on the total weight of composition (C). According to one very particular embodiment, composition (C) is free of any sulfonated poly(arylene ethersulfone) polymer (SP).

[0117] According to a further embodiment of the present invention, composition (C) comprises a poly(alkylene oxide) selected from poly(ethylene oxide), poly(propylene oxide), and poly(ethylene oxide)-poly(propylene oxide) copolymer.

[0118] If present, the amount of poly(alkylene oxide) in composition (C) is preferably 0.1 to 5% by weight, more specifically 0.2 to 3% by weight, and even more specifically 0.3 to 2% by weight, based on the total weight of composition (C). In further embodiments, the amount of poly(alkylene oxide) in composition (C) is 0.4 to 1.5% by weight, more specifically 0.5 to 1.3% by weight, and even more specifically 0.6 to 1.2% by weight. In yet another embodiment, the amount of poly(alkylene oxide) is 0.7 to 1.1% by weight. In particular, poly(alkylene oxide) may be present in an amount of 0.1 to 1% by weight, more specifically 0.3 to 1% by weight.

[0119] The composition (C) of step a) is preferably a solution and can be prepared by any method known to those skilled in the art, for example, in a conventional container which may be equipped with a stirring device and preferably a temperature control device. Preferably, the composition (C) or the solution is prepared by dissolving (P1) and (P2) in at least one solvent (D), preferably under stirring.

[0120] Step a) is preferably carried out at a raised temperature, particularly in the range of 20 to 120°C, more preferably in the range of 40 to 100°C. Those skilled in the art will choose the temperature according to at least one solvent.

[0121] Each composition (C) or solution preferably comprises polymers (P1) and (P2) completely dissolved in at least one solvent (D). This means that composition (C) preferably does not contain solid particles of polymers (P1) and (P2), and that polymers (P1) and (P2) preferably cannot be separated from at least one solvent (D) by filtration.

[0122] The duration of step a) may vary within a wide range. Preferably, the duration of step a) is in the range of 10 minutes to 48 hours, particularly in the range of 10 minutes to 24 hours, and more preferably in the range of 15 minutes to 12 hours. Those skilled in the art will preferably choose the duration of step a) to obtain a homogeneous solution.

[0123] In step b) of the method of the present invention, at least one solvent (D) is separated from each of the composition (C) or solution to obtain a membrane (M). To obtain a filtered solution, each of the composition (C) or solution prepared in step a) can be filtered before at least one solvent (D) is separated.

[0124] Furthermore, in order to obtain a degassed solution, it is possible to degas each of the composition (C) or the solution before at least one solvent (D) is separated in step b). This embodiment is preferred. The following embodiments and preferences for separating at least one solvent (D) from each of the composition (C) or the solution are similarly applicable when separating at least one solvent (D) from a degassed solution. Degassing in step a) can be carried out by any method known to those skilled in the art, for example, by vacuum, or by allowing each of the composition (C) or the solution to stand.

[0125] The following embodiments and preferred forms for separating at least one solvent (D) from each of the composition (C) or solutions are also applicable to separating at least one solvent from the filtered solution used in this embodiment of the present invention. The separation of at least one solvent can be carried out by any method known to those skilled in the art that is suitable for separating solvents from polymers. Preferably, the separation is carried out via a phase inversion process.

[0126] Within the scope of the present invention, a phase inversion process means a process that transforms dissolved polymers (P1) and (P2) into a solid phase. Therefore, a phase inversion process may also be referred to as a precipitation process. Suitable phase inversion processes are known to those skilled in the art.

[0127] The phase inversion process can be carried out, for example, by cooling the solution, in which case the polymers (P1) and (P2) contained in the solution will precipitate. Another possible means of carrying out the phase inversion process is to bring the composition into contact with a gaseous liquid that is a nonsolvent of the polymers (P1) and (P2). In this case, the polymers (P1) and (P2) will precipitate in the same manner. Suitable gaseous liquids that are nonsolvents of the polymers (P1) and (P2) are, for example, protic polar solvents in a gaseous state as described below.

[0128] Another preferred phase inversion process within the context of the present invention is phase inversion by immersion of the solution in at least one protic polar solvent. Thus, in one embodiment of the present invention, in step b), at least one solvent (D) contained in composition (C) is separated from polymers (P1) and (P2) by immersion of the solution in at least one protic polar solvent. This leads to the formation of a film. Suitable at least one protic polar solvents are known to those skilled in the art. The at least one protic polar solvent is preferably a non-solvent of polymers (P1) and (P2). Preferred at least one protic polar solvents are water, methanol, ethanol, n-propanol, isopropyl alcohol, glycerol, ethylene glycol, and mixtures thereof.

[0129] In step b), composition (C) is typically handled to form a shape corresponding to a desired shape of the film. Therefore, in one embodiment of the present invention, step b) includes the step of casting the composition to obtain a film of the composition, or the step of passing the solution through at least one spinneret to obtain at least one hollow fiber of each of the composition or solution. Therefore, in one preferred embodiment of the present invention, step b) is b-1) A step of casting each of the compositions (C) or solutions prepared in step a) to obtain a film of the composition, b-2) A step of evaporating at least one solvent from the film of the composition obtained in step b-1) to obtain a film in the form of a membrane. Includes.

[0130] This means that a film is formed by evaporating at least one solvent from the film of the composition. In step b-1), the composition can be cast by any method known to those skilled in the art. Typically, the composition is cast using a casting knife heated to a temperature in the range of 20 to 150°C, preferably in the range of 40 to 100°C. The composition is typically cast onto a substrate that does not react with the polymer (P1) and (P2) or at least one solvent (D) contained in the solution. Suitable substrates are known to those skilled in the art and are selected from polymer fabrics such as glass plates and nonwoven materials. To obtain a dense film, the separation in step b) is typically carried out by evaporation of at least one solvent (D) contained in the composition.

[0131] During film formation, the poly(arylene ethersulfone) polymers (P1) and (P2) are separated from at least one solvent (D). Therefore, the resulting film (M) of the present invention is essentially free of at least one solvent (D). Within the scope of the present invention, "essentially free" means that the film contains at most 1% by weight, preferably at most 0.5% by weight, and particularly preferably at most 0.1% by weight, of the total weight of the film, of at least one solvent.

[0132] A further object of the present invention is the membrane (M) that can be obtained by the method of the present invention described above.

[0133] A further object of the present invention is a separation element, membrane module, membrane cartridge, or separation system comprising the membrane (M) of the present invention as described herein and as preferred herein.

[0134] A further object of the present invention is the use of the membrane (M) of the present invention, as described herein and as preferred herein, in an ultrafiltration process.

[0135] The present invention also relates to the use of membranes (M) as described herein and as preferred herein, or to the use of separation elements, membrane modules, membrane cartridges, or separation systems comprising membranes (M) of the present invention, for water treatment applications, treatment of industrial or municipal wastewater, desalination of seawater or brackish water, dialysis, plasmolysis, and / or food processing.

[0136] In particular, the present invention also relates to the use of the membrane (M) described herein and as preferred herein for dialysis, in particular hemodialysis, or to the use of separation elements, membrane modules, membrane cartridges, or separation systems comprising the membrane (M) of the present invention. According to certain embodiments, the membrane (M) of the present invention is used as a dialysis membrane in a dialysis process.

[0137] Furthermore, the present invention relates to a dialysis apparatus comprising the membrane (M) of the present invention as described herein or as preferred herein, or to a separation element, membrane module, membrane cartridge, or separation system comprising the membrane (M) of the present invention.

[0138] A further object of the present invention is a composition (C) comprising poly(arylene ethersulfone) polymers (P1) and (P2) and at least one solvent (D), wherein (P1) and (P2) each comprise at least one of units Ia to Is as repeating structural units as defined herein and preferred herein, and at least one unit of (P2) is different from at least one unit of (P1).

[0139] The polymers (P1) and (P2), as well as the solvent (D), and, if present, the additive (A), are defined above and are defined as preferred above, and the embodiments and preferences are independently and appropriately applied to compositions (C) of the present invention.

[0140] According to one embodiment of composition (C) of the present invention, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) in composition (C) is 10% by weight or more based on the total weight of composition (C).

[0141] It is preferable that the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 11% by weight or more based on the total weight of composition (C). According to a further embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 12% by weight or more, more specifically 13% by weight or more based on the total weight of composition (C). According to a particular embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 14% by weight or more based on the total weight of composition (C).

[0142] In certain embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 15% by weight or more based on the total weight of composition (C). According to further embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 16% by weight or more, more specifically 17% by weight or more based on the total weight of composition (C). According to further specific embodiments, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 18% by weight or more based on the total weight of composition (C).

[0143] Furthermore, according to the present invention, it would be preferable that the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 19% by weight or more based on the total weight of composition (C). According to yet another embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 20% by weight or more, more specifically 21% by weight or more based on the total weight of composition (C). According to yet another specific embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 22% by weight or more based on the total weight of composition (C). According to one embodiment, it would be even more preferable that the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 23% by weight or more, more specifically 24% by weight or more, and even more specifically 25% by weight or more based on the total weight of composition (C).

[0144] According to one embodiment, the total amount of poly(arylene ethersulfone) polymers (P1) and (P2) as defined herein and as preferred herein is 10 to 30% by weight, more specifically 13 to 25% by weight, and even more specifically 15 to 23% by weight or more, based on the total weight of composition (C).

[0145] The ratio of poly(arylene ethersulfone) polymers (P1) to (P2) defined, preferably as defined herein, in composition (C) of the present invention may be any possible weight ratio, for example, 1:10 to 10:1, particularly 1:9 to 9:1, especially 1:8 to 8:1, and even more particularly 1:7 to 7:1. According to a particular embodiment, the ratio may be 1:6 to 6:1 or 5:1 to 1:5, particularly 1:4 to 4:1, especially 1:3 to 3:1, and even more particularly 1:2 to 2:1. According to one very particular embodiment of composition (C) of the present invention, (P1) and (P2) may be present in equal or nearly equal amounts in composition (C). “Nearly equal amounts” in this context means that the difference in amounts between (P1) and (P2) is only negligible.

[0146] According to one embodiment, composition (C) comprises a solvent (D) as defined herein and as preferred herein, in an amount such that the total amount of all components in the composition is at most 100% by weight.

[0147] Surprisingly, within the scope of the present invention, composition (C) was found to be remarkably stable even with high polymer-content poly(arylene ethersulfone) polymers (P1) and (P2). Composition (C) is very suitable for the preparation of membranes, particularly ultrafiltration membranes, especially in preparations in non-solvent-induced phase separation processes (NIPS).

[0148] Therefore, a further object of the present invention is the use of composition (C) of the present invention for the production of membranes.

[0149] Remarkably, specific combinations of polymers (P1) and (P2) according to the present invention enable the selective and efficient preparation of membranes with good mechanical properties. According to the present invention, it is possible to adjust the pore size and hydrophilicity of the membrane while avoiding known membrane drawbacks. The membrane-forming compositions of the present invention allow for high polymer content and exhibit favorable viscosity, both of which are critical to successful membrane formation. The membranes of the present invention are particularly suitable for medical purposes where high quality standards exist, and possess low molecular weight cutoff, high water permeability, and good aging stability.

[0150] The present invention will be further illustrated by the following examples, without limitation. [Examples]

[0151] Ingredients and abbreviations used: PESU-1: Polyethersulfone, VN = 81 ml / g (1 wt% NMP, 25℃) PPSU: Polyphenylene sulfone, VN = 66 ml / g (1 wt% NMP, 25℃) sPPSU-1: Polyphenylene sulfone containing 4.7 mol% units based on sDCDPS and biphenol, VN = 66.7 ml / g (1 wt% NMP, 25℃) sPPSU-2: Polyphenylene sulfone containing 19.4 mol% units based on sDCDPS and biphenol, VN = 67.8 ml / g (1 wt% NMP, 25℃) PSU: Polysulfone, VN = 80 ml / g (1 wt% NMP, 25℃) PAR: Polyarylate, U-100, Unitika Ltd.; VN = 47.5 ml / g (1 wt% NMP, 25℃) PVP: Polyvinylpyrrolidone, e.g., K85 (BASF, SE) NMP: N-methylpyrrolidone, anhydrous NTU (Nutrient Unit) Polyvinylpyrrolidone with a solution viscosity characterized by a K value of 85, determined according to Fikentscher's method (Fikentscher, Cellulosechemie 13, 1932 (58)). MWCO Molecular Weight Cutoff PWP pure water permeability

[0152] The viscosity number (VN) of poly(arylene ethersulfone) polymers and polyarylates was measured in a 1 wt% NMP solution according to DIN ISO 1628-1.

[0153] The turbidity of the polymer solution was measured at 60°C using a turbidimeter 2100AN (Hach Lange GmbH, Düsseldorf, Germany) with an 860 nm filter, and expressed in turbidimetric turbidity units (NTU). An NTU value of less than 1 is preferred.

[0154] Membrane preparation, general procedure The components listed in Table 1 were added to a three-necked flask equipped with a magnetic stirrer. The mixture was heated to 60°C with gentle stirring until a homogeneous, clear, viscous solution was obtained. The solution was degassed overnight at room temperature. The film solution was then reheated to 60°C for 2 hours and cast onto a glass plate at 60°C using a casting knife (300 microns) with an Erichsen coating machine operating at a speed of 5 mm / min. After allowing the film to stand for 30 seconds, it was immersed in a water / NMP 50 / 50 (by weight) bath at 25°C for 10 minutes.

[0155] After the film peeled off the glass plate, it was carefully transferred to a water bath for 12 hours. The film was then washed three times with VE water at 75°C for 2.5 hours each time, with the water changed after each wash. The film was then stored in a wet state until characterization was initiated.

[0156] A portion of the polymer solution was used for turbidity measurement (see above). A continuous flat film with the microstructural characteristics of a UF film and dimensions of at least 10 × 15 cm was obtained. The film showed a thin skin layer on top (1-10 microns) and a porous layer below (thickness: 100-150 microns).

[0157] Membrane characterization: The membrane's permeability to pure water was tested using ultrapure water (salt-free water filtered by a Millipore UF system) in a pressure cell with a diameter of 60 mm. In subsequent tests, solutions of different PEG standards were filtered at a pressure of 0.15 bar. The molecular weight cutoff was determined by GPC measurements of the feed solution and permeate.

[0158] The thermal stability of the film was tested by storing circular film pieces in a pressure cooker at 100°C for 60 hours. The film was then re-tested for its performance. In some cases, the film became too brittle to be tested after this treatment.

[0159] [Table 1]

[0160] Membranes based on the new composition exhibit higher water permeability and significantly better aging stability than the reference membrane, while maintaining comparable separation performance. M1C, M2C, and M3C are comparative samples, while M4-M9 are representative of the present invention.

Claims

1. A film (M) comprising a poly(arylene ethersulfone) polymer (P1) and a poly(arylene ethersulfone) polymer (P2), wherein (P1) and (P2) are composed of the following units Ia to Is: 【Chemistry 1-1】 【Chemistry 1-2】 [In the formula, x is between 0.05 and 1, and n is 1]; 【Chemistry 2】 [In the formula, x is between 0.05 and 1, and n is 1]; 【Transformation 3】 [In the formula, x is between 0.05 and 1, and n is 1.] It includes at least one structural repeating unit selected from, The at least one repeating structural unit of (P2) is different from the at least one repeating structural unit of (P1), Membrane (M).

2. The film according to claim 1, wherein the at least one structural repeating unit of (P1) and (P2) is selected from the units Ia, Ig, and Ik, and the at least one structural repeating unit of (P2) is different from the at least one structural repeating unit of (P1).

3. The film according to claim 1 or 2, wherein the at least one structural repeating unit of (P1) is Ik(PESU), and the at least one structural repeating unit of (P2) is PSU or PPSU containing the structural repeating unit Ia or Ig, respectively.

4. The film according to any one of claims 1 to 3, wherein the ratio of poly(arylene ethersulfone) polymer (P1) to poly(arylene ethersulfone) polymer (P2) is 1:10 to 10:

1.

5. The film according to any one of claims 1 to 4, further comprising a sulfonated poly(arylene ethersulfone) polymer (SP).

6. A film according to any one of claims 1 to 4, further comprising polyvinylpyrrolidone (PVP).

7. The membrane according to any one of claims 1 to 6, which is a nanofiltration (NF) membrane, a microfiltration (MF) membrane, or an ultrafiltration (UF) membrane.

8. The membrane according to any one of claims 1 to 7, wherein the membrane is a flat plate or a hollow fiber membrane.

9. A dialysis membrane, as described in any one of claims 1 to 8.

10. A method for preparing a membrane (M), a) the step of preparing a composition (C) comprising a poly(arylene ethersulfone) polymer (P1) and a poly(arylene ethersulfone) polymer (P2) according to any one of claims 1 to 4, and at least one solvent (D); b) The step of separating the at least one solvent (D) from the composition (C) to obtain the film (M) Methods that include...

11. The method according to claim 10, wherein the total amount of poly(arylene ethersulfone) polymer (P1) and poly(arylene ethersulfone) polymer (P2) in composition (C) is 10% by weight or more based on the total weight of composition (C).

12. The method according to claim 10 or 11, wherein the ratio of poly(arylene ethersulfone) polymer (P1) to poly(arylene ethersulfone) polymer (P2) in the composition (C) is 1:10 to 10:

1.

13. The method according to any one of claims 10 to 12, wherein the at least one solvent (D) is selected from the group consisting of N-alkyl-2-pyrrolidone, preferably N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-butyl-2-pyrrolidone and N-tert-butyl-2-pyrrolidone, 2-pyrrolidone, N-dimethylacetamide, dimethyl sulfoxide, dimethylformamide, N,N-dimethyl-2-hydroxypropanamide, N,N-diethyl-2-hydroxypropanamide, γ-valerolactone, dihydrolevoglucocenone, methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate, and sulfolane.

14. The method according to any one of claims 10 to 13, wherein the composition (C) also includes a water-soluble polymer additive (A) containing polyvinylpyrrolidone (PVP).

15. A film that can be obtained by the method described in any one of claims 10 to 14.

16. A separation element, membrane module, membrane cartridge, or separation system comprising a membrane according to any one of claims 1 to 9 or claim 15.

17. Use of a membrane according to any one of claims 1 to 9 or claim 15 in an ultrafiltration process.

18. Use of a membrane according to any one of claims 1 to 9 or claim 15, or use of a separation element, membrane module, membrane cartridge or separation system according to claim 16, for water treatment applications, treatment of industrial or municipal wastewater, desalination of seawater or brackish water, dialysis, plasmolysis and / or food processing.

19. A dialysis apparatus comprising a membrane according to any one of claims 1 to 9 or claim 15.

20. A composition (C) comprising a poly(arylene ethersulfone) polymer (P1) and a poly(arylene ethersulfone) polymer (P2) and at least one solvent (D), wherein (P1) and (P2) each comprise at least one of the structural repeating units Ia to Is described in any one of claims 1 to 4, and at least one unit of (P2) is different from at least one unit of (P1).

21. Use of composition (C) according to claim 20 for the production of membranes, particularly in a non-solvent-induced phase separation process.

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