Filter membrane with improved hydrophilicity

Abstract

The present invention relates to a method for preparing a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), the membrane (M) obtained by the method of the present invention, a filtration (nanofiltration, ultrafiltration or microfiltration) system comprising the membrane (M), and the use of the membrane (M) in a filtration process.

Description

Technical Field

[0001] The present invention relates to a method for preparing a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), the membrane (M) obtained by the method of the present invention, a filtration (nanofiltration, ultrafiltration or microfiltration) system comprising the membrane (M), and the use of the membrane (M) in a filtration process.

[0002] Polyarylene sulfone polymers are high-performance thermoplastics characterized by high heat resistance, good mechanical properties and inherent flame retardancy (E.M. Koch, H.-M. Walter, Kunststoffe 80 (1990) 1146, E. Doering, Kunststoffe 80, (1990) 1149, N. Inchaurondo-Nehm, Kunststoffe 98, (2008) 190). Because they are highly biocompatible, they are used as materials for dialysis membranes (N.A. Hoenich, K.P. Katapodis, Biomaterials 23 (2002) 3853) and ultrafiltration (UF) membranes. Ultrafiltration membranes (UF) are said to have an active filtration layer with a molecular weight cut-off of 10 - 100 kDa corresponding to a pore size of 10 - 30 nm in order to efficiently remove yeast, bacteria, viruses and macromolecules from water. Since increasing the hydrophilicity of the membrane is considered to prevent performance loss due to the fouling effect (D. Rana et al. “Surface modifications for antifouling membranes”, Chemical Reviews, 2010, 110, 2448), sulfonated poly(arylene sulfone) polymers are also being considered for membrane applications.

[0003] In addition to their use as engineering plastics, polyarylene sulfone polymers are also used as membrane materials for water treatment.

[0004] The polyarylene sulfone polymer can be formed, in particular, either by the hydroxide method which initially forms a salt from a dihydroxy component and a hydroxide, or by the carbonate method.

[0005] General information regarding the formation of polyarylene sulfone polymers by the hydroxide method can be found, in particular, in R.N. Johnson et. al., J. Polym. Sci. A-1 5 (1967) 2375, and for the carbonate method, it is described in J.E. McGrath et. al., Polymer 25 (1984) 1827.

[0006] Methods for forming polyarylene sulfone polymers from aromatic bishalogen compounds and aromatic bisphenols or their salts in an aprotic solvent in the presence of one or more alkali metals or ammonium carbonate or ammonium bicarbonate are known to those skilled in the art and are described, for example, in European Patent Application Publication No. 297363 and European Patent Application Publication No. 135130.

[0007] International Publication No. 2019 / 016082 discloses a method for preparing a sulfonated polyarylene ether sulfone polymer (sP) by converting a reaction mixture (RG) containing at least one non-sulfonated aromatic dihalogen sulfone, at least one sulfonated aromatic dihalogen sulfone, at least one aromatic dihydroxy component containing trimethylhydroquinone, at least one carbonate component, and at least one aprotic polar solvent, and this sulfonated polyarylene ether sulfone polymer (sP) can be used for a membrane (M).

[0008] International Publication No. 2017 / 148850 discloses a method for preparing a membrane (M) comprising a porous organic polymer (PIM) and a sulfonated polyarylene sulfone polymer (sP).

[0009] International Publication No. 2019 / 016078 discloses a method for preparing a polyarylether sulfone - polyalkylene oxide block copolymer (PPC) comprising a step I) of converting a reaction mixture (RG) comprising, as components, (A1) at least one aromatic dihalogen sulfone, (B1) at least one aromatic dihydroxy component comprising trimethylhydroquinone, (B2) at least one polyalkylene oxide, (C) at least one carbonate component, and (D) at least one aprotic polar solvent, and this polyarylether sulfone - polyalkylene oxide block copolymer (PPC) can be used for membranes.

[0010] High - performance thermoplastic plastics such as polyarylene sulfone polymers are generally formed by polycondensation reactions carried out at high reaction temperatures in polar aprotic solvents such as DMF (dimethylformamide), DMAc (dimethylacetamide), sulfolane, DMSO (dimethyl sulfoxide), and NMP (N - methyl - pyrrolidone).

[0011] Sulfonated polyarylene sulfone polymers have been known for decades. Direct sulfonation of polyarylene sulfone polymers causes side reactions and can only limit the control of the sulfonation degree, but by using disulfonated aromatic dihalogen sulfones such as sulfonated dichlorodiphenyl sulfone (sDCDPS) as comonomers, the synthesis of well - defined sulfonated polyarylene sulfone polymers becomes possible.

[0012] Sulfonated polyarylene sulfone polymers exhibit some interesting properties, but it is still impossible to produce a nanofiltration membrane having both a low molecular weight cut - off and a high water permeability from a poly(arylene sulfone) polymer.

[0013] Accordingly, an object of the present invention is to provide a method for preparing a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), which has no or only reduced disadvantages of the prior art. This method is preferably easy to implement. The membrane (M) is preferably suitable for use in dialysis and ultrafiltration.

[0014] This object is achieved by a method for preparing a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), i) a reaction mixture (R G ), which comprises an aromatic dihalogen sulfone component (component (A)) comprising at least one sulfonated aromatic dihalogen sulfone (component (A1)) and at least one non-sulfonated aromatic dihalogen sulfone (component (A2)), at least one aromatic dihydroxy compound (component (B)), at least one carbonate compound (component (C)), and at least one aprotic polar solvent (component (D)) is converted to obtain a product mixture (P G ) comprising a sulfonated polyarylene sulfone polymer (sP), at least one aprotic polar solvent and at least one inorganic halide compound, G a step of obtaining; ii) separating at least one inorganic halide compound from the product mixture (P G ) to obtain a first solution (S1) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one aprotic polar solvent, iii) mixing at least one further polymer (fP) with the first solution (S1) to obtain a second solution (S2), iv) separating at least one aprotic polar solvent from the second solution (S2) to obtain a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP) is achieved by a method comprising:

[0015] This object is a method for preparing a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), i) a reaction mixture (R G ) which comprises an aromatic dihalogen sulfone component (component (A)) comprising at least one sulfonated aromatic dihalogen sulfone (component (A1)) and at least one non-sulfonated aromatic dihalogen sulfone (component (A2)), at least one aromatic dihydroxy compound (component (B)), at least one carbonate compound (component (C)), and at least one aprotic polar solvent (component (D)) is converted to give a product mixture (P G ) comprising a sulfonated polyarylene sulfone polymer (sP), at least one aprotic polar solvent and at least one inorganic halide compound, G a step of obtaining; ii) separating at least one inorganic halide compound from the product mixture (P G ) to obtain a first solution (S1) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one aprotic polar solvent, iii) mixing at least one further polymer (fP) with the first solution (S1) to obtain a second solution (S2), iv) separating at least one aprotic polar solvent from the second solution (S2) to obtain a membrane (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), comprising In step iii), further, at least one pore former (pA) is mixed with the first solution (S1) to obtain a second solution (S2), and at least one further polymer (fP) is at least one polyarylene sulfone polymer which may or may not be sulfonated, and the sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP) are different from each other, which is further achieved by the method.

[0016] Surprisingly, it has been found that by the method of the present invention, a membrane (M) showing improved hydrophilicity, improved pure water permeability (PWP) and improved molecular weight cut-off (MWCO) can be obtained. By the method of the present invention, the preparation time of the membrane (M) containing the sulfonated polyarylene sulfone polymer (sP) can be significantly shortened. The condensation according to step i) results in a polymer suspension containing the sulfonated polyarylene sulfone polymer (sP) and an inorganic halide salt. After separation of the salt, in the current state of the art, precipitation in isopropanol is usually carried out to isolate the sulfonated polyarylene sulfone polymer (sP), which results in a large amount of solvent mixture that requires reprocessing or disposal.

[0017] Furthermore, a part of the product does not completely precipitate, which may cause clogging of the filter during subsequent separation. Furthermore, it is necessary to redissolve the sulfonated copolymer to produce the membrane (M). The method of the present invention prevents the generation of a large amount of solvent mixture and avoids separation before membrane preparation.

[0018] Hereinafter, the present invention will be described in more detail.

[0019] Method The method of the present invention for preparing a membrane (M) containing a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP) includes steps i), ii), iii) and iv).

[0020] In the context of the present invention, the term "membrane (M)" means a semi-permeable structure capable of separating two fluids or separating molecular and / or ionic components or particles from a liquid. For this reason, the membrane acts as a selective barrier that allows certain particles, substances or chemical compounds to pass through while retaining others. The membrane (M) can have various shapes such as flat, spiral, pillow-shaped, tube-shaped, single-hole hollow fiber-shaped or porous hollow fiber-shaped, etc.

[0021] The membrane (M) can be used as a nanofiltration membrane.

[0022] Therefore, a further object of the present invention is also to use the membrane (M) as a nanofiltration membrane.

[0023] Step i) In step i) according to the present invention, a reaction mixture (R G ) containing an aromatic dihalogen sulfone component, at least one aromatic dihydroxy compound, at least one carbonate compound and at least one aprotic polar solvent is converted to obtain a product mixture (P G ) containing a sulfonated polyarylene sulfone polymer (sP), at least one aprotic polar solvent and at least one inorganic halide compound.

[0024] The aromatic dihalogen sulfone component is also referred to as component (A). The terms aromatic dihalogen sulfone component and component (A) in the present invention are used synonymously and thus have the same meaning.

[0025] At least one aromatic dihydroxy compound is also referred to as component (B). The terms at least one aromatic dihydroxy compound and component (B) in the present invention are used synonymously and thus have the same meaning.

[0026] At least one carbonate compound is also referred to as component (C). The terms at least one carbonate compound and component (C) in the present invention are used synonymously and thus have the same meaning.

[0027] At least one aprotic polar solvent is also referred to as component (D). The terms at least one aprotic polar solvent and component (D) in the present invention are used synonymously and thus have the same meaning.

[0028] Reaction mixture (R G ) is the mixture prepared in step i) to form the sulfonated polyarylene sulfone polymer (sP) contained in the product mixture (P G ). For this reason, all components in this specification regarding the reaction mixture (R G ) relate to the mixture existing prior to the conversion by step i), i.e., the polycondensation.

[0029] The polycondensation is carried out to convert the reaction mixture (R G ) into a product mixture (P G ) containing the sulfonated polyarylene sulfone polymer (sP) by the polycondensation of components (A) and (B).

[0030] In step i), components (A) and (B) enter into the polycondensation reaction. Component (C) acts as a base that deprotonates the hydroxyl group of component (B). Component (D) acts as a solvent.

[0031] The product mixture (P G ) obtained after the polycondensation by step i) contains the sulfonated polyarylene sulfone polymer (sP). The product mixture (P G ) further contains at least one inorganic halide compound and at least one aprotic polar solvent (component (D)). The at least one inorganic halide compound is formed during the conversion of the reaction mixture (R G ). In the conversion, component (C) reacts with component (B) to deprotonate component (B). Then, the deprotonated component (B) reacts with component (A) to form at least one inorganic halide compound. This process is known to those skilled in the art.

[0032] The components of the reaction mixture (R G ) are preferably reacted simultaneously. The individual components may be mixed in an upstream process and subsequently reacted. It is also possible to supply the individual components to a reactor, mix them there, and then react them.

[0033] In step i) of the process of the present invention, the individual components of the reaction mixture (R G ) are preferably reacted simultaneously. This reaction is preferably carried out in one step. That is, the deprotonation of component (B) and further the condensation reaction between components (A) and (B) are preferably carried out in a single reaction step without isolating the deprotonated species of the intermediate product, for example, component (B).

[0034] It is more preferable that the reaction mixture (R G ) prepared in step i) does not contain toluene or monochlorobenzene. It is particularly preferable that the reaction mixture (R G ) does not contain any substance that forms an azeotrope with water. Preferably, the same also applies to the product mixture (P G ).

[0035] The ratio of component (A) to component (B) in step i) is in principle derived from the stoichiometry of the polycondensation reaction that proceeds the theoretical elimination of hydrogen halide, preferably hydrogen chloride, and is established by methods known to those skilled in the art.

[0036] Preferably, in step i), the ratio of the halogen terminal group derived from component (A) to the phenol terminal group derived from component (B) is adjusted by the controlled establishment of an excess of component (A) relative to component (B) as the starting compound.

[0037] More preferably, in step i), the molar ratio of component (A) to component (B) is 0.95 to 1.08, particularly 0.98 to 1.06, and most preferably 0.985 to 1.05.

[0038] Preferably, the conversion rate in the polycondensation reaction of step i) is at least 0.9.

[0039] The polycondensation reaction in step i) is generally carried out at a temperature in the range of 80 to 250 °C, preferably in the range of 100 to 220 °C. The upper limit of the temperature is preferably determined by the boiling point of at least one aprotic polar solvent (component (D)) at standard pressure (1013.25 mbar). The reaction is generally carried out at standard pressure. The reaction is preferably carried out over a period in the range of 0.5 to 14 hours, particularly 1 to 12 hours.

[0040] In a preferred embodiment, in step i), the reaction mixture (R G ) which is X mol of an aromatic dihalogen sulfone component (component A)), based on the total molar amount of the aromatic dihalogen sulfone component (component A)) in the reaction mixture (R G ), X 1 mol% of at least one sulfonated aromatic dihalogen sulfone (component (A1)) and X 2 mol% of at least one non-sulfonated aromatic dihalogen sulfone (component (A2)) containing, X 1 is in the range of 2 to 70, X 2 is in the range of 30 to 98, X mol of an aromatic dihalogen sulfone component (component A)), Y mol of at least one aromatic dihydroxy compound (component (B)), Z mol of at least one carbonate compound (component (C)) containing reaction mixture (R G ) is converted, the ratio of X to Y is in the range of 0.95 to 1.08, Z is in the range of P to Q, P is calculated according to the following formula: P = Y × (1.05 + X 1 / 100 × 1.05) and Q is calculated according to the following formula: Q = Y × (1.05 + X 1 / 100 × 1.4) It is calculated according to

[0041] In a preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) obtained in step i) is not separated from the product mixture (P G ).

[0042] In one embodiment, no further process steps are performed between step i) and step ii). In a further preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) in the product mixture (P G ) obtained in step i) remains in a dissolved form before performing step ii).

[0043] Hereinafter, the components used in step i) will be described in more detail.

[0044] Component (A) Component (A), also referred to as an aromatic dihalogen sulfone component, contains at least one sulfonated aromatic dihalogen sulfone and at least one non-sulfonated aromatic dihalogen sulfone.

[0045] At least one sulfonated aromatic dihalogen sulfone is also referred to as component (A1). The terms at least one sulfonated aromatic dihalogen sulfone and component (A1) in the present invention are used synonymously and thus have the same meaning.

[0046] At least one non-sulfonated aromatic dihalogen sulfone is also referred to as component (A2). The terms at least one non-sulfonated aromatic dihalogen sulfone and component (A2) in the present invention are used synonymously and thus have the same meaning.

[0047] As used herein, "at least one sulfonated aromatic dihalogen sulfone" means exactly one sulfonated aromatic dihalogen sulfone, or further a mixture of two or more sulfonated aromatic dihalogen sulfones. Preferably, exactly one sulfonated aromatic dihalogen sulfone is used.

[0048] As used herein, the term "at least one non-sulfonated aromatic dihalogen sulfone" means exactly one non-sulfonated aromatic dihalogen sulfone or, alternatively, a mixture of two or more non-sulfonated aromatic dihalogen sulfones. Preferably, exactly one non-sulfonated aromatic dihalogen sulfone is used.

[0049] In the above preferred embodiment, "X" preferably means the molar amount of component (A) in reaction mixture (R G ). "X" as used herein preferably means the total molar amount of the aromatic dihalogen sulfone component (component (A)) in reaction mixture (R G ). In other words, "X" preferably means the sum of the molar amounts of component (A1) and component (A2) contained in component (A), preferably contained in reaction mixture (R G ). "X 1 " as used herein means the molar amount in mol% of component (A1) based on the total molar amount of component (A) in reaction mixture (R G ), and "X 2 " as used herein means the molar amount in mol% of component (A2).

[0050] X 1 In any case, it may range from 2 to 70 mol%, preferably from 5 to 65 mol%, more preferably from 7.5 to 60 mol%, and most preferably from 10 to 57.5 mol% based on the total molar amount of the aromatic dihalogen sulfone component (component (A)) in reaction mixture (R G ).

[0051] X 2 In any case, it may range from 30 to 98 mol%, preferably from 35 to 95 mol%, more preferably from 40 to 92.5 mol%, and most preferably from 42.5 to 90 mol% based on the total molar amount of the aromatic dihalogen sulfone component (component (A)) in reaction mixture (R G ).

[0052] X1 and X 2 The amounts of and X generally total 100 mol%.

[0053] In a preferred embodiment, component (A) contains 2 to 70 mol% of component (A1) and 30 to 98 mol% of component (A2) based on the total molar amount of component (A) in the reaction mixture (R G ).

[0054] In a more preferred embodiment, component (A) contains 5 to 65 mol% of component (A1) and 35 to 95 mol% of component (A2) based on the total molar amount of component (A) in the reaction mixture (R G ).

[0055] In an even more preferred embodiment, component (A) contains 7.5 to 60 mol% of component (A1) and 40 to 92.5 mol% of component (A2) based on the total molar amount of component (A) in the reaction mixture (R G ).

[0056] In a particularly preferred embodiment, component (A) contains 10 to 57.5 mol% of component (A1) and 42.5 to 90 mol% of component (A2) based on the total molar amount of component (A) in the reaction mixture (R G ).

[0057] Component (A1) Component (A1), also referred to as a sulfonated aromatic dihalogen sulfone, preferably contains at least one -SO3X 3 group.

[0058] Component (A1) preferably contains at least one -SO3X 3 group. As used herein, the term "at least one -SO3X 3 group" means that component (A1) may contain exactly one -SO3X 3 group, or further, two or more -SO3X 3 groups. Component (A1) more preferably contains two -SO3X 3 groups.

[0059] General formula -SO3X 3 includes a sulfonic acid functional group, and further derivatives of the sulfonic acid functional group such as sulfonate. -SO3X 3 In the group, X 3 can be hydrogen and / or one cation equivalent.

[0060] In the context of the present invention, "one cation equivalent" means one cation with a single positive charge or one charge equivalent of a cation having two or more positive charges, such as Li, Na, K, Mg, Ca, NH4, preferably Na, K. Na or K is particularly preferred.

[0061] Component (A1) is preferably selected from the group consisting of 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid and 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid, and derivatives thereof.

[0062] In the context of the present invention, the terms "sulfonic acid" and "-SO3X 3 group" are used synonymously and have the same meaning. Therefore, the term "sulfonic acid" in 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid and 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid means "-SO3X 3 group", where X 3 is hydrogen or a cation equivalent.

[0063] In one embodiment, component (A1) preferably has -SO3X with a cation equivalent 3It contains a base. Particularly preferably, component (A1) is selected from the group consisting of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, dipotassium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, 4,4'-difluorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate, and dipotassium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate.

[0064] Accordingly, another object of the present invention is a method in which component (A1) contains at least one compound selected from the group consisting of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, dipotassium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, 4,4'-difluorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate, and dipotassium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate.

[0065] In one embodiment, component (A1) is at least one -SO3X 3 group-containing at least one aromatic dihalogen sulfone component selected from the group consisting of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, dipotassium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate, 4,4'-difluorodiphenyl sulfone-3,3'-disulfonic acid, disodium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate, and dipotassium 4,4'-difluorodiphenyl sulfone-3,3'-disulfonate is contained in an amount of 70 wt% or more, preferably 90 wt% or more, more preferably 98 wt% or more based on the total weight of component (A1) in the reaction mixture (R G ).

[0066] In a further particularly preferred embodiment, component (A1) is at least one -SO3X selected from the group consisting of 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid, disodium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate, dipotassium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate, 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid, disodium 4,4'-difluorodiphenylsulfone-3,3'-disulfonate and dipotassium 4,4'-difluorodiphenylsulfone-3,3'-disulfonate. 3 It consists of at least one aromatic dihalogen sulfone containing a -SO3X group.

[0067] In these embodiments, dipotassium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate and disodium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate are particularly preferred for use as component (A1).

[0068] In a further particularly preferred embodiment, component (A1) consists of dipotassium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate or disodium 4,4'-dichlorodiphenylsulfone-3,3'-disulfonate, and mixtures thereof.

[0069] Component (A2) Component (A2), also referred to as a non-sulfonated aromatic dihalogen sulfone component, preferably does not contain a -SO3X 3 group.

[0070] Preferably, component (A2) is at least one aromatic dihalogen sulfone selected from the group consisting of 4,4'-dichlorodiphenylsulfone and 4,4'-difluorodiphenylsulfone in the reaction mixture (R GIt contains 80 wt% or more, preferably 90 wt% or more, more preferably 98 wt% or more, based on the total weight of component (A2). The weight percentage here for component (A2) further relates to the sum of 4,4'-dichlorodiphenyl sulfone used and 4,4'-difluorodiphenyl sulfone used.

[0071] Therefore, another object of the present invention is that component (A2) is at least one aromatic dihalogen sulfone selected from the group consisting of 4,4'-dichlorodiphenyl sulfone and 4,4'-difluorodiphenyl sulfone in reaction mixture (R G ) and contains 80 wt% or more based on the total weight of component (A2).

[0072] In a further particularly preferred embodiment, component (A2) consists of at least one aromatic dihalogen sulfone selected from the group consisting of 4,4'-dichlorodiphenyl sulfone and 4,4'-difluorodiphenyl sulfone.

[0073] In these embodiments, 4,4'-dichlorodiphenyl sulfone is particularly preferred for use as component (A2).

[0074] In a further particularly preferred embodiment, component (A2) consists of 4,4'-dichlorodiphenyl sulfone.

[0075] Preferably, component (A2) is selected from the group consisting of 4,4'-dichlorodiphenyl sulfone and 4,4'-difluorodiphenyl sulfone.

[0076] Component (B) Component (B), also referred to as an aromatic dihydroxy compound, generally contains two hydroxy groups.

[0077] In the present specification, the "at least one aromatic dihydroxy compound" means exactly one aromatic dihydroxy compound, and further means a mixture of two or more aromatic dihydroxy compounds. Preferably, exactly one aromatic dihydroxy compound is used.

[0078] In the above preferred embodiment, "Y" preferably means the molar amount of component (B) in the reaction mixture (R G ) herein. "Y" in the present specification preferably means the total molar amount of the aromatic dihydroxy compound (component (B)) in the reaction mixture (R G ).

[0079] Preferably, component (B) is selected from the group consisting of 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), 4,4'-dihydroxybenzophenone, hydroquinone and hydroquinone derivatives. Among the above-mentioned aromatic dihydroxy components, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone and bisphenol A are preferred, and 4,4'-dihydroxybiphenyl is particularly preferred.

[0080] Therefore, the present invention also provides a method in which component (B) is selected from the group consisting of 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, bisphenol A, 4,4'-dihydroxybenzophenone and hydroquinone.

[0081] Preferably, component (B) contains 80 wt% or more, preferably 90 wt% or more, more preferably 98 wt% or more of 4,4'-dihydroxybiphenyl based on the total weight of component (B) in the reaction mixture (R G ).

[0082] Therefore, another object of the present invention is that component (B) is in the reaction mixture (R G)A method comprising 80 wt% or more of 4,4'-dihydroxybiphenyl based on the total weight of component (B).

[0083] The weight percentage here for component (B) further relates to the sum of 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl sulfone, bisphenol A (2,2-bis-(4-hydroxyphenyl)propane), 4,4'-dihydroxybenzophenone and hydroquinone used.

[0084] In a further particularly preferred embodiment, component (B) consists of at least one aromatic dihydroxy component selected from the group consisting of 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl sulfone, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), 4,4'-dihydroxybenzophenone and hydroquinone.

[0085] In these embodiments, 4,4'-dihydroxybiphenyl, bisphenol A and 4,4'-dihydroxydiphenyl sulfone are particularly preferred for use as component (B), and 4,4'-dihydroxybiphenyl is most preferred.

[0086] Component (C) Reaction mixture (R G ) contains at least one carbonate compound as component (C). The term "at least one carbonate compound" is understood in this case to mean exactly one carbonate compound, or further a mixture of two or more carbonate compounds. The at least one carbonate compound is preferably at least one metal carbonate. The metal carbonate is preferably anhydrous. In this case, the terms "at least one carbonate compound" and "component (C)" are used synonymously and thus have the same meaning.

[0087] Alkali metal carbonates and / or alkaline earth metal carbonates are preferred as the metal carbonate. At least one metal carbonate selected from the group consisting of sodium carbonate, potassium carbonate, and calcium carbonate is particularly preferred as the metal carbonate. Potassium carbonate is most preferred.

[0088] For example, component (C) is present in the reaction mixture (R G ) in an amount of 50 wt% or more, more preferably 70 wt% or more by weight, and most preferably 90 wt% or more of potassium carbonate, based on the total weight of at least one carbonate component in the reaction mixture (R

[0089] Therefore, another object of the present invention is a method in which component (C) contains 50 wt% or more of potassium carbonate based on the total weight of component (C) in the reaction mixture (R G ).

[0090] In a preferred embodiment, component (C) consists of potassium carbonate. As the potassium carbonate, potassium carbonate having a volume-weighted average particle size of less than 200 μm, more preferably less than 100 μm, even more preferably less than 70 μm, and most preferably less than 50 μm is preferred. The volume-weighted average particle size of potassium carbonate is determined using a particle size analyzer in a suspension of potassium carbonate in a chlorobenzene / sulfolane mixture (60 / 40 by weight).

[0091] In the above preferred embodiment, "Z" preferably means the molar amount of component (C) in the reaction mixture (R G ) in step i). "Z" in this specification preferably means the total molar amount of at least one carbonate component (component (C)) in the reaction mixture (R G ).

[0092] Z is in the range of P to Q.

[0093] "P" is calculated according to the following formula: P = Y × (1.05 + X 1 / 100 × 1.05) and "Q" is calculated according to the following formula: Q = Y × (1.05 + X 1 / 100 × 1.4) is calculated according to

[0094] In this formula, Y is the value of the molar amount of component (B) in the reaction mixture (R G ), and X 1 is likewise the value of the mol% of component (A1) in the reaction mixture (R G ).

[0095] Component (D) The reaction mixture (R G ) preferably contains at least one aprotic polar solvent as component (D). According to the present invention, "at least one aprotic polar solvent" is understood to mean exactly one aprotic polar solvent, or furthermore a mixture of two or more aprotic polar solvents. In this case, the terms "at least one aprotic polar solvent" and "component (D)" are used synonymously and thus have the same meaning.

[0096] Suitable aprotic polar solvents are selected from the group consisting of, for example, anisole, dimethylformamide, dimethyl sulfoxide, sulfolane, N-methylpyrrolidone, N-ethylpyrrolidone and N-dimethylacetamide.

[0097] Preferably, component (D) is selected from the group consisting of N-methylpyrrolidone, N-dimethylacetamide, dimethyl sulfoxide and dimethylformamide. N-methylpyrrolidone is particularly preferred as component (D).

[0098] It is preferred that component (D) contains at least one solvent selected from the group consisting of N-methylpyrrolidone, N-dimethylacetamide, dimethyl sulfoxide and dimethylformamide in an amount of 50 wt% or more, preferably 70 wt% or more, more preferably 90 wt% or more, based on the total weight of component (D) in the reaction mixture (R G ). N-methylpyrrolidone is particularly preferred as component (D).

[0099] Accordingly, another object of the present invention is that component (D) is at least one solvent selected from the group consisting of N-methylpyrrolidone, N-dimethylacetamide, dimethyl sulfoxide and dimethylformamide, based on the total weight of component (D) in the reaction mixture (R G ) and contains 50 wt% or more.

[0100] In a preferred embodiment, component (D) consists of N-methylpyrrolidone. N-methylpyrrolidone is also referred to as NMP or N-methyl-2-pyrrolidone.

[0101] Hereinafter, the sulfonated polyarylene sulfone polymer (sP) obtained in step i) will be described in more detail.

[0102] The sulfonated polyarylene sulfone polymer (sP) obtained in step i) The sulfonated polyarylene sulfone polymer (sP) obtained in step i) of the method of the present invention preferably has the general formula I:

Chemical formula

[0103] Accordingly, another object of the present invention is a method in which the sulfonated polyarylene sulfone polymer (sP) obtained in step i) contains repeating units of general formula (I) as defined above.

[0104] In a preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) obtained in step i) contains at least 80 mol% of repeating units of general formula (I) based on the total molar amount of the sulfonated polyarylene sulfone polymer (sP) obtained in step i).

[0105] When Q 1 , T or Y 1 is a chemical bond, this means that the adjacent group on the left and the adjacent group on the right are directly bonded to each other by a chemical bond.

[0106] R a and R b are each independently hydrogen or C1-C 12 alkyl.

[0107] Preferred C1-C 12Examples of the alkyl group include linear and branched saturated alkyl groups having 1 to 12 carbon atoms. The following moieties are particularly preferred: C1-C6 alkyl, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, 2-methylpentyl or 3-methylpentyl, or relatively long-chain moieties, such as unbranched heptyl, octyl, nonyl, decyl, undecyl, lauryl and their branched analogs.

[0108] The C1-C 12 Examples of the alkyl moiety of the alkoxy group include the alkyl groups defined above having 1 to 12 carbon atoms. The cycloalkyl moieties preferably used include, in particular, C3-C 12 cycloalkyl moieties, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopropylmethyl, cyclopropylethyl, cyclopropylpropyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylethyl, -propyl, -butyl, -pentyl, -hexyl, -cyclohexylmethyl, -dimethyl, -trimethyl.

[0109] Ar and Ar 1 are each independently C6-C 18 aryl. Hereinafter, preferably, Ar is preferably selected from the group consisting of sulfonated or non-sulfonated hydroquinone, resorcinol, dihydroxynaphthalene, particularly 2,7-dihydroxynaphthalene, which is an aromatic substance rich in electrons and very susceptible to electrophilic attack, starting from the starting material. Ar 1 is preferably an unsubstituted C6 or C 12 arylene group.

[0110] In a preferred embodiment of formula (I), Ar and Ar 1 are preferably each independently selected from sulfonated or non-sulfonated 1,4-phenylene, 1,3-phenylene, naphthylene, particularly 2,7-dihydroxynaphthalene and 4,4'-bisphenylene.

[0111] The following structural units (Ia) to (Io):

Chemical formula

Chemical formula

Chemical formula

[0112] "One cation equivalent" in the context of the present invention means a single cation with a single positive charge or one charge equivalent of a cation having two or more positive charges, such as Li, Na, K, Mg, Ca, NH4, preferably Na, K.

[0113] In addition to the preferred structural units (Ia) to (Io), structural units in which one or more sulfonated or non-sulfonated 1,4-dihydroxyphenyl units are replaced by resorcinol or dihydroxynaphthalene are also preferred.

[0114] A more preferred sulfonated polyarylene sulfone polymer (sP) contains, as repeating structural units, at least 80 mol%, particularly preferably at least 90 mol%, particularly preferably at least 98 mol% of one or more units Ia to Io, based on the total molar amount of the sulfonated polyarylene sulfone polymer (sP) obtained in step i).

[0115] Particularly preferred sulfonated polyarylene sulfone polymers (sP) contain, as repeating structural units, at least 80 mol%, particularly preferably at least 90 mol%, and particularly preferably at least 98 mol% of one or more units Ia, Ig and / or Ik, based on the total molar amount of the sulfonated polyarylene sulfone polymer (sP) obtained in step i).

[0116] Particularly preferred sulfonated polyarylene sulfone polymers (sP) are at least one polymer selected from sulfonated polyphenylene sulfone (sPPSU), sulfonated polyether sulfone (sPESU) and sulfonated polysulfone (sPSU), with sulfonated polyphenylene sulfone (sPPSU) being particularly preferred.

[0117] Sulfonated polyphenylene sulfone (sPPSU) is formed from the formula Ig of the repeating units described above. Sulfonated polysulfone (sPSU) is formed from the repeating unit Ia described above. Sulfonated polyether sulfone (sPESU) is formed from the formula Ik of the repeating units described above.

[0118] Copolymers composed of combinations of various structural units or composed of sulfonated and non-sulfonated structural units can also be used.

[0119] The structural units (Ia), (Ib), (Ig) and (Ik) or their copolymers are particularly preferably used as repeating units of the general formula (I).

[0120] In a particularly preferred embodiment, Ar is 1,4-phenylene, t is 1, T is a chemical bond, Y 1 is -SO2-, q is 0, p is 0, m is 0, n is 1, and k is 1. The sulfonated polyphenylene sulfone composed of the repeating structural units described herein is denoted as sPPSU.

[0121] In a particularly preferred embodiment, Ar is 1,4-phenylene, t is 0, Y is -SO2-, q is 0, n is 0, and k is 0. The polyarylene sulfone composed of the repeating units of this description is represented as sulfonated polyether ether sulfone (sPEES).

[0122] In an advantageous embodiment, the sulfonated polyarylene sulfone polymer (sP) obtained in step i) The non-sulfonated repeating unit of formula (1)

Chemical formula

Chemical formula

[0123] In particular, the sulfonated polyarylene sulfone polymer (sP) obtained in step i) consists only of the non-sulfonated repeating unit of formula (1) and the sulfonated repeating unit of formula (2).

[0124]

Chemical formula

[0125] The sulfonated polyarylene sulfone polymer (sP) obtained in step i) according to the present invention preferably has an intrinsic viscosity of 20 ml / g to 250 ml / g, preferably 50 ml / g to 200 ml / g. This intrinsic viscosity is quantified in accordance with DIN EN ISO 1628-1 at 25 °C in a 1% solution of N-methylpyrrolidone (NMP). The measurement can also be performed at a lower polymer concentration, for example 0.5%.

[0126] The weight average molecular weight (M W) is generally in the range of 10,000 to 250,000 g / mol, preferably in the range of 15,000 to 200,000 g / mol, more preferably in the range of 18,000 to 150,000 g / mol. The weight average molecular weight (M W ) is measured using gel permeation chromatography (GPC). Dimethylacetamide (DMAc) is used as the solvent, and narrow-disperse polymethylmethacrylate is used as the standard for measurement.

[0127] Step ii) In step ii), the inorganic halide compound formed during the condensation reaction in step i) is removed from the product mixture (P G ). A first solution (S1) containing the sulfonated polyarylene sulfone polymer (sP) and component (D) is obtained.

[0128] The inorganic halide compound can be removed by means generally known in the art such as filtration, centrifugation, decantation, etc.

[0129] Therefore, the present invention provides ii) a step of filtering, centrifuging and / or decanting the product mixture (P G ) obtained in step i) to obtain a first solution (S1) also provides a method comprising.

[0130] In a preferred embodiment, the first solution (S1) obtained in step ii) does not contain solid inorganic halide compounds. In a further preferred embodiment, the first solution (S1) obtained in step ii) contains less than 3 wt%, more preferably less than 1.5 wt%, particularly preferably less than 0.5 wt% of inorganic halide components based on the total weight of the first solution (S1) obtained in step ii).

[0131] In a more preferred embodiment, the first solution (S1) obtained in step ii) does not contain solid inorganic compounds.

[0132] In a further preferred embodiment, the first solution (S1) obtained in step ii) contains less than 0.4 wt%, more preferably less than 0.3 wt%, and particularly preferably less than 0.2 wt% of inorganic components based on the total weight of the first solution (S1) obtained in step ii).

[0133] In a preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) in step ii) is not separated from the first solution (S1).

[0134] In one embodiment, no further method step is performed between step ii) and step iii).

[0135] In a further preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) in the first solution (S1) of step ii) remains in a dissolved form before performing step iii).

[0136] Step iii In step iii), at least one further polymer (fP) is mixed with the first solution (S1) to obtain a second solution (S2). In a preferred embodiment, in step iii), at least one further pore-forming agent (pA) is further mixed with the first solution (S1) to obtain a second solution (S2).

[0137] In a preferred embodiment, in step iii), at least one further polymer (fP) and at least one pore-forming agent (pA) are mixed with the first solution (S1) to obtain a second solution (S2).

[0138] As used herein, "at least one further polymer (fP)" means exactly one further polymer (fP), or a mixture of two or more further polymers (fP). As used herein, "at least one pore-forming agent (pA)" means exactly one pore-forming agent (pA), or a mixture of two or more pore-forming agents (pA).

[0139] At least one further polymer (fP) is preferably at least one polyarylene sulfone polymer, which may or may not be sulfonated. The sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP) are different from each other. Preferably, at least one further polymer (fP) is at least one non-sulfonated polyarylene sulfone polymer.

[0140] Preferred further polymers (fP) are those containing at least one of the following units IIa to IIo as repeating structural units:

Chemical formula

Chemical formula

[0141] More preferred further polymers (fP) are those containing, as repeating structural units, one or more of the units IIa to IIo in an amount of at least 80 mol%, particularly preferably at least 90 mol%, and particularly preferably at least 98 mol% based on the total molar amount of the further polymer (fP).

[0142] Particularly preferred as the further polymer (fP) are those containing, as repeating structural units, one or more of the units IIa, IIg and / or IIk in an amount of at least 80 mol%, particularly preferably at least 90 mol%, and particularly preferably at least 98 mol% based on the total molar amount of the further polymer (fP).

[0143] Particularly preferred further polymers (fP) are at least one polymer selected from polyphenylene sulfone (PPSU), polyether sulfone (PESU) and polysulfone (PSU), with polyether sulfone (PESU) being particularly preferred.

[0144] Polyphenylene sulfone (PPSU) is formed from the formula IIg of the repeating unit described above. Polysulfone (PSU) is formed from the repeating unit IIa described above. Polyethersulfone (PESU) is formed from the formula IIk of the repeating unit described above.

[0145] Abbreviations such as PPSU, PESU, and PSU in the context of the present invention comply with DIN EN ISO 1043-1 (Plastics - Symbols and Abbreviations - Part 1: Basic Polymers and Their Characteristics (ISO 1043-1:2001); German version EN ISO 1043-1:2002).

[0146] Preferred pore-forming agents (pA) are selected from the group consisting of, for example, polyvinylpyrrolidone (PVP), polyethylene oxide, polypropylene oxide, and polyethylene oxide - polypropylene oxide copolymers.

[0147] In step iv), the pore-forming agent (pA), if present, is at least partially removed from the precipitation film, leaving pores in the membrane (M).

[0148] In a particularly preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) in the method of the present invention remains dissolved until step iv) is carried out.

[0149] In a further particularly preferred embodiment, the sulfonated polyarylene sulfone polymer (sP) is not separated before step iv) is carried out. In other words, the method of the present invention preferably includes only one separation step (step iv) of the sulfonated polyarylene sulfone polymer (sP), during which the membrane (M) is formed.

[0150] Step iv) In step iv), at least one aprotic polar solvent is separated from the second solution (S2) to obtain the membrane (M). In a preferred embodiment, the second solution (S2) is degassed before step iv) is carried out.

[0151] In step iv), when the pore-forming agent (pA) is added in step iii), it is at least partially removed from the second solution (S2). "At least partially removed" in the context of the present invention means that at least 50% of the total amount of the pore-forming agent (pA) added in step iii) is removed from the second solution (S2).

[0152] Separation of at least one aprotic polar solvent from the second solution (S2) in step iv), and separation of the pore-forming agent (pA) if present, can be carried out by any method known to those skilled in the art suitable for separating the aprotic solvent and the pore-forming agent from the polymer.

[0153] Preferably, separation of at least one aprotic polar solvent from the second solution (S2) in step iv), and separation of the pore-forming agent (pA) if present, is carried out by a phase inversion process.

[0154] The phase inversion process in the context of the present invention means the process by which the dissolved sulfonated polyarylene sulfone polymer (sP) is converted into a solid phase. Thus, the phase inversion process can also be referred to as a precipitation process. According to step iv), the conversion is preferably carried out by separation of at least one aprotic polar solvent from the sulfonated polyarylene sulfone polymer (sP), and separation of the pore-forming agent (pA) if present. Suitable phase inversion processes are known to those skilled in the art.

[0155] The phase inversion process can preferably be carried out by bringing the second solution (S2) into contact with a protic polar liquid that is a non-solvent for the sulfonated polyarylene sulfone polymer (sP) and in which the pore-forming agent (pA) is soluble. Then, the sulfonated polyarylene sulfone polymer (sP) precipitates. Suitable protic polar solvents that are non-solvents for the sulfonated polyarylene sulfone polymer (sP) are, for example, the protic polar solvents in the liquid state described below. Another phase inversion process preferred in the context of the present invention is phase inversion by immersing the second solution (S2) in at least one protic polar solvent.

[0156] Thus, in one embodiment, in step iv), by immersing the second solution (S2) in at least one protic polar solvent, at least one aprotic polar solvent contained in the second solution (S2) is separated from the sulfonated polyarylene sulfone polymer (sP) contained in the second solution (S2).

[0157] That is, the membrane (M) in step iv) is formed by immersing the second solution (S2) in at least one protic polar solvent.

[0158] Suitable at least one protic polar solvent is known to those skilled in the art. Preferred at least one protic polar solvent is water, methanol, ethanol, n-propanol, isopropanol, glycerol, ethylene glycol, and mixtures thereof.

[0159] Thus, in a preferred embodiment, step iv) comprises iv-1) casting the second solution (S2) obtained in step iii) to obtain a film of the second solution (S2), iv-2) separating at least one aprotic polar solvent from the film of the solution (S) obtained in step iii-1) to obtain a membrane (M) in the form of a film and includes.

[0160] The separation in step iv-2) can be carried out as described above. Preferably, the separation in step iv-2) is carried out by immersing the film of the second solution (S2) in at least one protic polar solvent.

[0161] Thus, in a particularly preferred embodiment, step iv) comprises iv-1) casting the second solution (S2) obtained in step iii) to obtain a film of the second solution (S2), Step iv-2): Immersing the film of the second solution (S2) obtained in step iv-1) in at least one protic polar solvent to obtain a film (M) in the form of a film is included.

[0162] In step iv-1), the second solution (S2) can be cast by any method known to those skilled in the art. Usually, the second solution (S2) is preferably heated to a temperature in the range of 20 to 150 °C, preferably in the range of 40 to 100 °C, more preferably in the range of 60 to 85 °C and cast using a casting knife, a coma bar, a meyer bar, a slot die or a reverse roll.

[0163] In step iv-1), the second solution (S2) is usually cast on a substrate (carrier material) that does not react with the sulfonated polyarylene sulfone polymer (sP) and / or at least one solvent contained in the second solution (S2).

[0164] Suitable substrates (carrier materials) are, for example, steel belts, drying cylinders or polymer films. The substrate (carrier material) is generally not part of the finished film (M) and is used only for processing purposes.

[0165] It is also possible to cast the second solution (S2) on a porous support layer that will form part of the film (M).

[0166] To produce single-hole hollow fibers or porous hollow fibers, step iv) can be carried out by extruding a second solution (S2) through an extrusion nozzle equipped with the required number of hollow needles. Subsequently, a coagulation liquid (at least one protic solvent) is injected into the second solution (S2) extruded through the hollow needles, thereby forming parallel continuous channels extending in the extrusion direction in the extruded second solution (S2). Preferably, the pore size of the outer surface of the extruded membrane (M) is controlled by contacting the outer surface after exiting the extrusion nozzle with a weak coagulant so that the shape is fixed without an active layer on the outer surface, and then contacting the membrane with a strong coagulant, or vice versa.

[0167] Membrane (M) Generally, the membrane (M) is, based on the total weight of the membrane (M), 1 to 99.5 wt% of a sulfonated polyarylene sulfone polymer (sP) and 0.5 to 99 wt% of at least one further polymer (fP) is included.

[0168] Preferably, the membrane (M) is, based on the total weight of the membrane (M), 2 to 97.5 wt% of a sulfonated polyarylene sulfone polymer (sP) and 2.5 to 98 wt% of at least one further polymer (fP) is included.

[0169] More preferably, the membrane (M) is, based on the total weight of the membrane (M), 2.5 to 95 wt% of a sulfonated polyarylene sulfone polymer (sP) and 5 to 97.5 wt% of at least one further polymer (fP) is included.

[0170] Even more preferably, the membrane (M) is, based on the total weight of the membrane (M), 3.5 to 90 wt% of a sulfonated polyarylene sulfone polymer (sP) and 10 to 96.5 wt% of at least one further polymer (fP) comprises

[0171] Particularly preferably, the membrane (M) is, based on the total weight of the membrane (M), 5 to 90% by weight of a sulfonated polyarylene sulfone polymer (sP) and 10 to 95% by weight of at least one further polymer (fP) comprises

[0172] When a pore-forming agent is present, the membrane (M) generally is, based on the total weight of the membrane (M), 1 to 99.45% by weight of a sulfonated polyarylene sulfone polymer (sP), 0.5 to 98.95% by weight of at least one further polymer (fP), and 0.05 to 10% by weight of a pore-forming agent (pA) comprises

[0173] Preferably, the membrane (M) is, based on the total weight of the membrane (M), 2 to 97.4% by weight of a sulfonated polyarylene sulfone polymer (sP), 2.5 to 97.9% by weight of at least one further polymer (fP), and 0.1 to 5% by weight of a pore-forming agent (pA) comprises

[0174] More preferably, the membrane (M) is, based on the total weight of the membrane (M), 2.5 to 94.85% by weight of a sulfonated polyarylene sulfone polymer (sP), 5 to 97.35% by weight of at least one further polymer (fP), and 0.15 to 4% by weight of a pore-forming agent (pA) comprises

[0175] Even more preferably, the membrane (M) is, based on the total weight of the membrane (M), 3.5 to 89.8% by weight of a sulfonated polyarylene sulfone polymer (sP), 10 to 96.3% by weight of at least one further polymer (fP), and 0.2 to 4 wt% of a pore former (pA) is included.

[0176] In particular, the membrane (M) is, based on the total weight of the membrane (M), 5 to 89.8 wt% of a sulfonated polyarylene sulfone polymer (sP), 10 to 94.8 wt% of at least one further polymer (fP), and 0.2 to 3 wt% of a pore former (pA) is included.

[0177] The membrane (M) preferably has a pure water permeability of more than 25 kg / (h·m 2 ·bar) determined at 23 °C and a water pressure of 1 bar using ultrapure water (salt-free water, filtered by a Millipore UF system) with a pressure cell having a diameter of 74 mm. The pure water permeability (PWP) is given by the following (Equation (1)): PWP = m / (A × P × t) (1) PWP: pure water permeability [kg / bar·h·m 2 m: mass of the permeated water [kg] A: membrane area [m 2 P: pressure [bar] t: time of the permeation experiment [h] and is calculated as such.

[0178] The membrane (M) preferably has a surface area of more than 1 m 2 / g determined by gas adsorption - desorption (GAD) experiments with nitrogen using the Brunauer - Emmett - Teller (BET) surface model.

[0179] In a preferred embodiment, the membrane has a contact angle of 30 to 70°.

[0180] The contact angle is determined by time - resolved automatic image analysis by dropping approximately 2 μL of deionized water 8 to 10 drops onto the sample at 23 °C using a Kruess DSA100 (A. KRUESS Optronic GmbH, Hamburg, Germany). ​​

[0181] An apparatus comprising a membrane (M) Another object of the present invention is an apparatus comprising a membrane (M) obtained by the method of the present invention. The apparatus is preferably an ultrafiltration apparatus.

[0182] Preferred ultrafiltration apparatuses are selected from dialysis apparatuses and pure water production apparatuses.

[0183] For the use of the membrane (M) obtained by the method of the present invention, in a preferred embodiment, the membrane (M) is activated. The activation can be carried out by bringing the membrane (M) into contact with an acidic aqueous solution such as an aqueous solution of an inorganic acid. Preferably, an aqueous solution of sulfuric acid (H2SO4) is used for the activation. The concentration of the acidic aqueous solution is preferably in the range of 0.1 to 4.0 M. After bringing the membrane (M) into contact with an acidic aqueous solution such as an aqueous solution of sulfuric acid, the membrane can be brought into contact with water, preferably DI water. After activation, the membrane (M) is usually obtained in the H + form.

[0184] In other words, after activation, the sulfonated polyarylene sulfone polymer (sP) contained in the membrane (M) contains at least 70 mol%, more preferably at least 80 mol%, particularly preferably at least 90 mol% of -SO3H groups based on the total molar amount of the -SO3X 3 groups contained in the sulfonated polyarylene sulfone polymer (sP).

[0185] The present invention will be described more specifically by the following examples, but the present invention is not limited thereto.

[0186] Components used : DCDPS 4,4'-Dichlorodiphenyl sulfone sDCDPS Sodium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonate BP 4,4'-Dihydroxybiphenyl K2CO3: Potassium carbonate, anhydrous, average particle size 32.6 μm NMP: N-Methylpyrrolidone, anhydrous PVP: Polyvinylpyrrolidone (Luvitec® K40); pore former (pA) PESU: Polyethersulfone (Ultrason® E 6020P); further polymer (fP)

[0187] The viscosity number VN of the sulfonated polyarylene sulfone polymer (sP) was measured in a 1 wt% NMP solution in accordance with DIN ISO 1628-1.

[0188] The incorporation ratio (incorporation rate) of sDCDPS was determined by 1 1H-NMR in CDCl3. Furthermore, the polymer content of the polymer solution after filtration was also quantified by 1 1H-NMR in CDCl3.

[0189] The isolation of the sulfonated polyarylene sulfone polymer (sP) is carried out by dropping a NMP solution of the sulfonated polyarylene sulfone polymer (sP) into isopropanol at room temperature, unless otherwise instructed. The dropping height is 0.5 m. The throughput is about 2.5 l per hour. The resulting precipitate is subsequently extracted with water (water throughput 160 l / h) at 85 °C for 20 hours. Then, the precipitate is dried at a temperature below the glass transition temperature T g to make the residual moisture content less than 0.5 wt%.

[0190] Filtration of the product mixture was carried out with a heated metal pressure filter using a filter with a pore size of 5 μm and an N2 pressure of 3 bar. The filter was heated to 60 °C to reduce the viscosity of the reaction mixture.

[0191] The yield of the polymer after precipitation was determined by gravimetry.

[0192] Comparative Example 1; C1p and C1sol : In a 4-liter glass reactor equipped with a thermometer, a gas inlet tube, and a Dean-Stark trap, 470.942 g (1.64 mol) of DCDPS, 196.50 g (0.4 mol) of sDCDPS, 372.42 g (2.00 mol) of BP, and 304.052 g (2.20 mol) of potassium carbonate with a volume average particle size of 32.6 μm were suspended in 1250 ml of NMP under a nitrogen atmosphere.

[0193] The mixture was heated to 190 °C within 1 hour. Hereinafter, the reaction time is understood to be the time during which the reaction mixture was maintained at 190 °C. The water generated during the reaction was continuously removed by distillation.

[0194] After a reaction time of 16 hours, 1750 ml of NMP was added, and the reaction was stopped by cooling to room temperature (within 1 hour). The potassium chloride generated during the reaction was removed by filtration. Subsequently, the obtained polymer solution was separated into two parts. One part was precipitated in isopropanol, and after separating the resulting polymer precipitate, it was extracted with hot water (85 °C) for 20 hours. Then, the precipitated substance was dried under reduced pressure (less than 100 mbar) at 120 °C for 24 hours. The precipitated sulfonated polyarylene sulfone polymer (sP) is hereinafter referred to as (C1p).

[0195] The filtrate is hereinafter referred to as (C1sol). The filtrate was 1 Characterized by 1H-NMR (content of sDCDPS-based units, polymer content).

[0196] Comparative Example 2; C2p and C2sol : In a 4-liter glass reactor equipped with a thermometer, a gas inlet tube, and a Dean-Stark trap, 470.942 g (1.64 mol) of DCDPS, 196.50 g (0.4 mol) of sDCDPS, 372.42 g (2.00 mol) of BP, and 331.704 g (2.40 mol) of potassium carbonate with a volume average particle size of 32.6 μm were suspended in 1250 ml of NMP under a nitrogen atmosphere.

[0197] The mixture was heated to 190 °C within 1 hour. Hereinafter, the reaction time is understood to be the time during which the reaction mixture was maintained at 190 °C. The water generated during the reaction was continuously removed by distillation.

[0198] After a reaction time of 16 hours, 1750 ml of NMP was added and the reaction was stopped by cooling to room temperature (within 1 hour). The potassium chloride formed during the reaction was removed by filtration. The resulting polymer solution was then separated into two parts. One part was precipitated in isopropanol, separated and then extracted with hot water (85 °C) for 20 hours. The precipitated substance was then dried under reduced pressure (less than 100 mbar) at 120 °C for 24 hours. The precipitated sulfonated polyarylene sulfone polymer (sP) is hereinafter referred to as (Cp).

[0199] The filtrate is hereinafter referred to as (C2sol). The filtrate was 1 Characterized by 1H-NMR (content of sDCDPS-based units, polymer content).

[0200] Example 3 : In a 4-liter glass reactor equipped with a thermometer, a gas inlet tube and a Dean-Stark trap, 470.942 g (1.64 mol) of DCDPS, 196.50 g (0.4 mol) of sDCDPS, 372.42 g (2.00 mol) of BP and 359.35 g (2.60 mol) of potassium carbonate with a volume-average particle size of 32.6 μm were suspended in 1250 ml of NMP under a nitrogen atmosphere.

[0201] The mixture was heated to 190 °C within 1 hour. Hereinafter, the reaction time is understood to be the time during which the reaction mixture was maintained at 190 °C. The water generated during the reaction was continuously removed by distillation.

[0202] After a reaction time of 7 hours, 1750 ml of NMP was added and the reaction was stopped by cooling to room temperature (within 1 hour). Potassium chloride formed during the reaction was removed by filtration. The resulting polymer solution was then separated into two parts. One part was precipitated in isopropanol (3p), separated, and then extracted with hot water (85 °C) for 20 hours. The precipitated substance was then dried under reduced pressure (less than 100 mbar) at 120 °C for 24 hours. The precipitated sulfonated polyarylene sulfone polymer (sP) is hereinafter referred to as (C1p).

[0203] The filtrate is hereinafter referred to as (C1sol). The filtrate was 1 characterized by 1H-NMR (content of sDCDPS-based units, polymer content).

[0204] Comparative Example 4 : In a 4-liter glass reactor equipped with a thermometer, a gas inlet tube, and a Dean-Stark trap, 442.226 g (1.54 mol) of DCDPS, 245.625 g (0.50 mol) of sDCDPS, 372.42 g (2.00 mol) of BP, and 317.88 g (2.30 mol) of potassium carbonate with a volume average particle diameter of 32.6 μm were suspended in 1250 ml of NMP under a nitrogen atmosphere.

[0205] The mixture was heated to 190 °C within 1 hour. Hereinafter, the reaction time is understood to be the time during which the reaction mixture was maintained at 190 °C. Water formed during the reaction was continuously removed by distillation.

[0206] After a reaction time of 16 hours, 2312 ml of NMP was added and the reaction was stopped by cooling to room temperature (within 1 hour). Potassium chloride formed during the reaction was removed by filtration. The resulting polymer solution was then precipitated in isopropanol, the resulting polymer beads were separated, and then extracted with hot water (85 °C) for 20 hours. The precipitate was then dried under reduced pressure (less than 100 mbar) at 120 °C for 24 hours. The precipitated sulfonated polyarylene sulfone polymer (sP) is hereinafter referred to as (C4p).

[0207] Example 5 : In a 4-liter glass reactor equipped with a thermometer, a gas inlet tube, and a Dean-Stark trap, 442.226 g (1.54 mol) of DCDPS, 245.625 g (0.50 mol) of sDCDPS, 372.42 g (2.00 mol) of BP, and 373.17 g (2.70 mol) of potassium carbonate with a volume average particle size of 32.6 μm were suspended in 1250 ml of NMP under a nitrogen atmosphere.

[0208] The mixture was heated to 190 °C within 1 hour. Hereinafter, the reaction time is understood to be the time during which the reaction mixture was maintained at 190 °C. The water generated during the reaction was continuously removed by distillation.

[0209] After a reaction time of 7.5 hours, 2312 ml of NMP was added, and the reaction was stopped by cooling to room temperature (within 1 hour). The potassium chloride generated during the reaction was removed by filtration. Subsequently, the obtained polymer solution was separated into two parts. One part was precipitated in isopropanol, separated, and then extracted with hot water (85 °C) for 20 hours. Then, the precipitated substance was dried under reduced pressure (less than 100 mbar) at 120 °C for 24 hours. The precipitated sulfonated polyarylene sulfone polymer (sP) is hereinafter referred to as (5p).

[0210] The filtrate is hereinafter referred to as (5sol). The filtrate was 1 Characteristically evaluated by 1H-NMR (content of sDCDPS-based units, polymer content).

[0211] The characteristic evaluations of the precipitated sulfonated polyarylene sulfone polymer (sP) and the obtained solution are shown in Table 1:

Table 1

[0212] By using an excessive amount of potassium carbonate in the present invention, a high molecular weight copolymer in which a large amount of sDCDPs is incorporated can be prepared.

[0213] Preparation of Membrane For the preparation of the membrane, various solutions containing sulfonated polyarylene sulfone polymer (sP), NMP, PVP, and PESU were prepared. In the examples of the present invention, the obtained solution of sulfonated polyarylene sulfone polymer (sP) was used, and in the comparative examples, the precipitate of sulfonated polyarylene sulfone polymer (sP) was used.

[0214] The amounts of the components (sulfonated polyarylene sulfone polymer (sP), NMP, PVP, and PESU) used in the preparation of the membrane-forming solution are shown in Table 2.

[0215] The components were placed in a three-necked flask equipped with a magnetic stirrer. The mixture was heated at 60 °C with gentle stirring until a homogeneous, transparent, viscous solution was obtained. The solution was degassed at room temperature overnight. Then, the membrane solution was reheated at 60 °C for 2 hours and cast onto a glass plate with a casting knife (300 microns) at 60 °C using an Erichsen coating machine operating at a speed of 5 mm / min. The membrane film was allowed to stand for 30 seconds and then immersed in a water bath at 25 °C for 10 minutes.

[0216] After peeling the membrane from the glass plate, the membrane was carefully transferred to the water bath and left for 12 hours. Then, the membrane was transferred to a bath containing 2000 ppm of NaOCl and left at 50 °C for 4.5 hours to remove PVP. After that process, the membrane was washed with water at 60 °C and once with a 0.5 wt% solution of NaBisulfite to remove active chlorine. After several washing steps with water, the membrane was stored in a wet state until the property evaluation was started.

[0217] A flat continuous film having the microstructure characteristics of a UF membrane with a size of at least 10 × 15 cm is obtained. The membrane exhibits a thin skin layer (1 - 10 microns) on the top and a porous layer (thickness: 100 - 150 microns) below it. The results are shown in Table 2.

[0218] Property Evaluation of Membrane A pressure cell with a diameter of 60 mm was used to test the pure water permeability (PWP) of the membrane using ultrapure water (salt-free water, filtered by a Millipore UF system). In subsequent tests, various PEG standard solutions were filtered at a pressure of 0.15 bar. The molecular weight cut-off was determined by GPC measurement of the feed and permeate.

[0219] The contact angle (CA) with respect to water was measured as described above.

[0220] The molecular weight cut-off (MWCO) was determined as described above.

[0221]

Table 2

[0222] The membrane obtained by the method of the present invention exhibits higher water permeability than the reference membrane with equivalent separation performance, and further shows a lower CA, that is, the hydrophilicity is improved.

Claims

1. A method for preparing a film (M) comprising a sulfonated polyarylene sulfone polymer (sP) and at least one further polymer (fP), i) Reaction mixture (R Ｇ ) and An aromatic dihalogen sulfone component (component (A)) comprising at least one sulfonated aromatic dihalogen sulfone (component (A1)) and at least one non-sulfonated aromatic dihalogen sulfone (component (A2)), At least one aromatic dihydroxy compound (component (B)), At least one carbonate compound (component (C)), At least one aprotic polar solvent (component (D)) and Reaction mixture containing (R Ｇ ) is converted to produce a product mixture (P) comprising the sulfonated polyarylene sulfone polymer (sP), the at least one aprotic polar solvent, and at least one inorganic halogen compound. Ｇ The process of obtaining ) ii) said product mixture (P Ｇ A step of separating at least one inorganic halogen compound from the above to obtain a first solution (S1) containing the sulfonated polyarylene sulfone polymer (sP) and at least one aprotic polar solvent, iii) A step of mixing at least one further polymer (fP) with the first solution (S1) to obtain a second solution (S2), iv) A step of separating the at least one aprotic polar solvent from the second solution (S2) to obtain the film (M) comprising the sulfonated polyarylene sulfone polymer (sP) and the at least one further polymer (fP). Includes, In step iii), at least one pore-forming agent (pA) is further mixed with the first solution (S1) to obtain the second solution (S2), wherein the at least one further polymer (fP) is at least one polyarylene sulfone polymer which may or may not be sulfonated, and the sulfonated polyarylene sulfone polymer (sP) and the at least one further polymer (fP) are different from each other. Component (A1) comprises at least one compound selected from the group consisting of 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid, 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid disodium salt, 4,4'-dichlorodiphenylsulfone-3,3'-disulfonic acid dipotassium salt, 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid, 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid disodium salt, and 4,4'-difluorodiphenylsulfone-3,3'-disulfonic acid dipotassium salt, Component (A2) is a reaction mixture (R) containing at least one aromatic dihalogen sulfone selected from the group consisting of 4,4'-dichlorodiphenyl sulfone and 4,4'-difluorodiphenyl sulfone. Ｇ ) Contains 80 wt% or more based on the total weight of component (A2) in the container. Component (B) is selected from the group consisting of 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylsulfone, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), 4,4'-dihydroxybenzophenone, hydroquinone, and hydroquinone derivatives. In step i), the reaction mixture (R Ｇ ) and X mol of aromatic dihalogen sulfone component (component (A)), wherein the reaction mixture (R Ｇ Based on the total molar amount of the aromatic dihalogen sulfone component (component (A)) in ), X １ mol% of at least one sulfonated aromatic dihalogen sulfone (component (A1)) and X ２ at least one non-sulfonated aromatic dihalogen sulfone (component (A2)) in mol% Including, X １ The range is 2 to 70. X ２ The range is 30 to 98. Xmol aromatic dihalogen sulfone component (component (A)), Ymol has at least one aromatic dihydroxy compound (component (B)), At least one carbonate compound of Zmol (component (C)) Reaction mixture containing (R Ｇ Convert ) and The ratio of X to Y is in the range of 0.95 to 1.

08. Z is in the range of P to Q, P is given by the following formula: P=Y×(1.05+X １ / 100×1.05) It is calculated according to the following: Q is expressed by the following formula: Q=Y×(1.05+X １ / 100×1.4) It is calculated according to the formula, and component (A) is the reaction mixture (R) Ｇ The mixture contains 2 to 70 mol% of component (A1) and 30 to 98 mol% of component (A2) based on the total molar amount of component (A) in the mixture, and in step i), the molar ratio of component (A) to component (B) is 0.95 to 1.

08. In step ii), the sulfonated polyarylene sulfone polymer (sP) in the first solution (S1) remains in the dissolved form it was in before step iii). method.

2. Component (B) reacts with the mixture (R Ｇ The method according to claim 1, comprising 80 wt% or more of 4,4'-dihydroxybiphenyl based on the total weight of component (B) in ).

3. Component (C) is the reaction mixture (R Ｇ The method according to claim 1, comprising 50 wt% or more of potassium carbonate based on the total weight of component (C) in ).

4. Component (D) is at least one solvent selected from the group consisting of N-methylpyrrolidone, N-dimethylacetamide, dimethyl sulfoxide, and dimethylformamide, and the reaction mixture (R) Ｇ The method according to claim 1, comprising 50 wt% or more of component (D) based on the total weight of the component (D) in the following:

5. Process iv) is, iv-1) A step of casting the second solution (S2) obtained in step iii) to obtain a film of the second solution (S2), iii-2) A step of separating the at least one aprotic polar solvent from the film of the second solution (S2) obtained in step iv-1) to obtain the film (M) in the form of a film. The method according to claim 1, including the method described in claim 1.

6. Process iv) is, iv-1) A step of casting the second solution (S2) obtained in step iii) to obtain a film of the second solution (S2), iii-2) A step of immersing the film of the second solution (S2) obtained in step iv-1) in at least one protic solvent to obtain the film (M) in the form of a film. The method according to claim 1, including the method described in claim 1.

7. A membrane (M) for ultrafiltration obtained by the method according to any one of claims 1 to 6, wherein in each case, the membrane (M) comprises 1 to 99.5% by weight of the sulfonated polyarylene sulfone polymer (sP) and 0.5 to 99% by weight of the at least one further polymer (fP), based on the total weight of the membrane (M).

8. An ultrafiltration apparatus comprising the membrane (M) according to claim 7.