Membranes containing blends of polyarylethersulfone and polyaryletherketone and methods for making same

Abstract

The present invention relates to a composition for producing a porous article, in particular a membrane, comprising a semi-crystalline polymer, an amorphous polymer, and at least one water-soluble salt. The present invention also relates to a method for producing said porous article and its use for purifying a fluid.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This application claims priority to U.S. Patent Application No. 62 / 880202, filed in the United States on July 30, 2019, and European Patent Application No. 19197984.8, filed in Europe on September 18, 2019, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to a composition for producing a porous article, in particular a membrane, comprising a semi-crystalline polymer, an amorphous polymer and at least one water-soluble salt. The present invention also relates to a method for producing said porous article and its use for purifying a fluid. [Background technology]

[0003] Porous membranes are discrete thin interfaces that moderate the permeation of chemical species in contact with them. An important property of porous membranes is their ability to control the rate of permeation of chemical species through the membrane itself. This feature is exploited in many different applications such as separation applications (water and gas) or drug delivery applications.

[0004] Aromatic polymers (such as polysulfones and polyethersulfones), partially fluorinated polymers (such as polyvinylidene fluoride), and polyamides are widely used in the preparation of microfiltration and ultrafiltration membranes due to their good mechanical strength and thermal stability.

[0005] Porous membranes prepared by processing poly(aryl ether ketone) (PAEK) polymers are known in the art, for example from U.S. Pat. No. 4,957,817 and U.S. Pat. No. 5,200,078 (both in the name of The Dow Chemical Company).

[0006] Porous membranes in both flat sheet and hollow fiber form have also been made starting from a blend of a PAEK polymer with one additional component and an optional solvent.

[0007] US Patent No. 5,205,968 (The Dow Chemical Company) discloses a method for preparing a microporous membrane from a non-sulfonated poly(ether ether ketone)-type polymer, which includes the steps of (A) forming a mixture containing a non-sulfonated poly(ether ether ketone)-type polymer, an amorphous polymer, and a plasticizer, (B) heating the resulting mixture to make the mixture fluid, (C) extruding or casting the fluid mixture into a membrane, (D) quenching or solidifying the membrane, and (E) leaching the membrane under conditions such that at least a portion of the plasticizer and / or the amorphous polymer is removed from the membrane. A long list of amorphous polymers is given in the general description of this patent. Among them, polysulfone (PS) and polyethersulfone are mentioned.

[0008] Ternary blends containing PEEK polymer for the production of membranes have also been described in the literature. In "Hollow Fiber Microfiltration Membranes from Poly(ether ether ketone) (PEEK)" (J.Appl. Pol.Sci., Vol.72, 175-181, 1999), Sonnenschein MF disclosed the preparation of hollow fiber membranes from a composition containing PEEK, polysulfone (PS), and a 75 / 25 wt.% mixture of diphenyl isophthalate (DPIP) and diphenyl terephthalate (DPTP). In "Micro- and Ultrafiltration Film Membranes from Poly(ether ether ketone) (PEEK)" (J.Appl. Pol.Sci., Vol.74, 1146-1155, 1999), Sonnenschein MF disclosed film membranes obtained by extruding a polymer blend of PEEK, PS, and a small molecule solvent mixture, followed by removal of PS and the solvent in a subsequent extraction step.

[0009] U.S. Pat. No. 4,755,540 (Raychem Limited) discloses porous membranes of aromatic polymers produced by solvent extraction of a polymer that is "partially incompatible" with the aromatic from a blend of the two.

[0010] WO 2018 / 065526 ​​(Solvay specialty Polymers USA, LLC) discloses a polymer composition for producing microporous membranes or hollow fibers. The composition described therein comprises: (I) poly(ether ether ketone) (PEEK) polymers or poly(phenylene sulfide) (PPS) polymers, and (II) at least 28% by weight, based on the total weight of the composition, of an additive which is a sulfonate or a carboxylate; Example compositions provided in the experimental section include binary blends of PEEK and sodium benzenesulfonate in a 60 / 40 ratio, and PPS and sodium benzenesulfonate in a 50 / 50 ratio.

[0011] U.S. Patent Application Publication No. 2019 / 0136057 (Solvay Specialty Polymers USA, LLC) discloses a polymer composition containing at least two different polymers independently selected from poly(aryl ether ketone) (PAEK), poly(aryl ether sulfone) (PAES), polyaryl sulfide (PAS), and polyetherimide (PEI), and about 0.05 to about 2 weight percent of at least one alkali metal carbonate.

[0012] Porous membranes and articles have also been disclosed in U.S. Pat. No. 3,965,020 (General Electric Company), U.S. Patent Application Publication No. 2003 / 0208014 (3M Innovative Properties Company), and by Swee Su Lim et al. in "Sulfonated poly(ether ether ketone) / poly(ether sulfone) composite membranes as an alternative proton exchange membrane in microbial fuel cells," International Journal of Hydrogen Energy, 37 (2012) 11409-11424. Summary of the Invention

[0013] The Applicant has recognised that there remains a need for porous membranes particularly suitable for use in water filtration which, in addition to water permeability, simultaneously exhibit exceptional mechanical properties, chemical resistance and thermal resistance, particularly at pressures above 1 bar.

[0014] The Applicant was faced with the problem of providing a porous membrane that can be produced in the form of flat sheets and tubular and hollow fibers, and that is characterized by excellent mechanical properties and high water permeability, and that is suitable for use in water filtration.

[0015] The Applicant has surprisingly found that the above problems can be solved by producing a membrane starting from a composition containing a ternary blend (i.e. three components) of at least one poly(aryl ether ketone) (PAEK) polymer, at least one poly(aryl ether sulfone) (PAES) polymer, and at least one sulfonate or carboxylate having a metal selected from the alkali metal or alkaline earth metal groups.

[0016] Thus, in a first aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: (a) at least one poly(aryl ether ketone) (PAEK) polymer; (b) at least one poly(aryl ether sulfone) (PAES) polymer, and (c) at least one compound comprising a sulfonate or a carboxylate of a metal selected from the group consisting of alkali metals, alkaline earth metals, aluminum, iron, zinc, nickel, copper, palladium, and silver [compound (S)]; The present invention relates to a composition [composition (C)] comprising, or preferably consisting of, the following:

[0017] According to a preferred embodiment, said composition (C) comprises at least one PAEK polymer in an amount of 25% to 65% by weight, based on the total weight of said composition (C).

[0018] According to a preferred embodiment, said composition (C) comprises said at least one PAES polymer in an amount of 10% by weight to 45% by weight, based on the total weight of said composition (C).

[0019] According to a preferred embodiment, the composition (C) contains at least one compound (S) in an amount of 10% by weight to 50% by weight, more preferably 10% by weight to 45% by weight, and even more preferably 15% by weight to 40% by weight, based on the total weight of the composition (C).

[0020] The Applicant has surprisingly found that the composition (C) defined above can be advantageously processed by a melt extrusion process.

[0021] Thus, in a second aspect, the present invention provides a porous layer comprising at least one porous layer [layer L Q A method for producing a membrane [membrane (Q)] comprising the steps of: Q )], (I) preparing a composition as defined above [composition (C)]; (II) treating said composition (C) to obtain pellets; (III) The pellets obtained in step (II) are melt-extruded to form a precursor layer [layer (L P )]; (IV-a) The layer (L) obtained in step (III) P ) with at least one organic solvent to form an intermediate porous layer [layer (L -iQa )]; (IV-b1) The layer (L P ) with water to form a first intermediate porous layer [layer (L -iQb )], and (IV-b2) obtaining the layer (L -iQb ) with at least one organic solvent to form a second intermediate porous layer [layer (L -iQb2 )]; (V) The layer (L -iQa ) or the layer (L -iQb2 ) was contacted with water to form a porous layer [layer (L Q )]; Methods including the method (Method (M Q )].

[0022] In a third aspect, the present invention provides a method for producing a gypsum lamination comprising the steps of:Q Advantageously, said at least one layer (L Q ) is the above method (M Q ) is obtained.

[0023] The Applicant has surprisingly found that the membrane (Q) according to the invention is characterized by very good mechanical properties.

[0024] The applicant has surprisingly found that the membranes (Q) according to the invention are characterized by high water permeability. Indeed, when used in high pressure filtration processes (e.g. at pressures above 1 bar), the membranes of the invention do not undergo compression and can withstand high pressures without exhibiting compression or significant flux reduction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] For the purposes of this description, - the use of parentheses around symbols or numbers identifying compounds, chemical formulae or parts of formulae has the sole purpose of better distinguishing those symbols or numbers from the rest of the text, and therefore said parentheses may also be omitted; - the term "membrane" is intended to denote a discrete, generally thin, interface that is moderately permeable to chemical species in contact with it, said membrane containing pores of finite dimensions; - the membrane of the present invention has as its only layer a porous layer (L Q ), the term "membrane (Q)" refers to the layer (L) as if the two were the same. Q ) is used to indicate; - the term "weight porosity" is intended to mean the fraction of voids over the total volume of a porous membrane; - The term "solvent" is used herein in its ordinary sense, i.e. it denotes a substance capable of dissolving another substance (solute) to form a mixture uniformly dispersed at the molecular level. In the case of polymer solutes, it is common practice to refer to a solution of polymer in a solvent when the resulting mixture is transparent and no phase separation is observed in the system. Phase separation is taken to be the point at which the solution becomes turbid or cloudy due to the formation of polymer aggregates, often referred to as the "cloud point". - "melting temperature (Tm)" or "Tm" or "melting point" is intended to indicate the melting temperature measured by differential scanning calorimetry (DSC) at 20°C / min according to ASTM D3418, as detailed in the examples; - the term "halogen", unless otherwise specified, includes fluorine, chlorine, bromine and iodine; - the adjective "aromatic" means any mononuclear or polynuclear cyclic group (or moiety) having a number of pi electrons equal to 4n+2, where n is 1 or any positive integer, and aromatic groups (or moieties) can be aryl and arylene groups (or moieties).

[0026] Membranes that contain pores uniformly distributed throughout their thickness are generally known as symmetric (or isotropic) membranes; membranes that contain pores that are non-uniformly distributed throughout their thickness are generally known as asymmetric (or anisotropic) membranes.

[0027] The membrane (Q) may be either a symmetric or an asymmetric membrane.

[0028] The asymmetric porous membrane (Q) typically comprises an outer layer containing pores having an average pore size smaller than the average pore size of the pores in one or more inner layers. Each of said layers is a layer (L) as defined above. Q ) may be.

[0029] Preferably, said membrane (Q) has an average pore size, measured by ASTM F316, of 0.040 μm to 0.100 μm, a bubble point (i.e. largest pore) of 0.300 μm to 0.400 μm, and a smallest pore of 0.020 μm to 0.220 μm.

[0030] Suitable techniques for measuring the average pore size in the porous membrane of the present invention are described, for example, in Handbook of Industrial Membrane Technology. Edited by PORTER, Mark C. Noyes Publications, 1990. p. 70-78. The pore size of the membrane can be estimated by several techniques, including scanning electron microscopy (SEM) and / or bubble point, gas flux, water flux, and molecular weight cutoff measurements.

[0031] The membrane (Q) typically has a weight porosity of 5% to 90% by volume, preferably 10% to 85% by volume, and more preferably 30% to 75% by volume, based on the total volume of the membrane. Good results were obtained with a weight porosity of 50% to 75% by volume.

[0032] A suitable technique for measuring the weight porosity in a membrane (Q) is described, for example, in SMOLDERS, K. ​​et al., Terminology for membrane distillation. Desalination. 1989, vol. 72, p. 249-262.

[0033] The film (Q) is the only layer of the layer (L Q ) or said layer (L) preferably supported on a substrate. Q ) or a multilayer film including the same.

[0034] The base layer is the layer (L Q ) may be partially or completely interpenetrated with

[0035] The substrate is preferably made of a material that minimally affects the selectivity of the porous membrane. The substrate layer is preferably made of non-woven materials, glass fibers, and / or polymeric materials such as polypropylene, polyethylene, and polyethylene terephthalate.

[0036] Depending on the final application, the membrane (Q) may be flat, where flat membranes are required, or may be in tubular shape, where tubular or hollow fiber membranes are required.

[0037] In applications where a compact module with a large surface area is required, hollow fiber membranes are particularly advantageous, whereas flat membranes are generally preferred where high flux is required.

[0038] When the membrane (Q) is flat, its thickness is advantageously from about 10 to about 800 microns, more preferably from about 25 to about 600 microns.

[0039] If the membrane (Q) is tubular, its outer diameter can be up to 15 mm. If the outer diameter of the membrane (Q) is included between 0.5 mm and 3 mm, it is called a hollow fiber membrane. If the diameter of the membrane (Q) is less than 0.5 mm, it is called a capillary membrane.

[0040] As used herein, "poly(aryl ether ketone) (PAEK)" refers to a poly(aryl ether ketone) having an Ar'-C(=O)-A r* Groups (wherein Ar′ and Ar * are equal to or different from each other and are aromatic groups) PAEK ) means any polymer that contains more than 50 mole %.

[0041] Repeating unit (R PAEK ) are units of the following formulae (JA) to (JD): [ka] and wherein: - each R' is equal to or different from one another and is selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium; j' is zero or an integer ranging from 1 to 4.

[0042] Repeating unit (R PAEK ), each phenylene moiety is independently a repeat unit (R PAEK ) may have 1,2-, 1,4-, or 1,3-linkages to other moieties different from R'. Preferably, the phenylene moiety has 1,3- or 1,4-linkages, more preferably 1,4-linkages.

[0043] Repeating unit (R PAEK In each occurrence, j' is preferably zero such that the phenylene moiety has no other substituents other than those connecting the main chain of the polymer.

[0044] Advantageously, said PAEK polymer is chosen in the group comprising, and preferably consisting of, poly(ether ether ketone) (PEEK), poly(ether ketone ketone) (PEKK), poly(ether ketone) (PEK) and copolymers of PEEK and poly(diphenyl ether ketone) (PEEK-PEDEK copolymers).

[0045] Preferably, the poly(ether ether ketone) (PEEK) comprises more than 50 mol % of the formula (J'-A): [ka] Repeating units (R PAEK ) is meant any polymer containing

[0046] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units (R PAEK ) is the repeating unit (J'-A).

[0047] Preferably, the poly(ether ketone ketone) (PEKK) comprises more than 50 mol % of formula (J'-B) and formula (J"-B): [ka] Repeating units (R PAEK ) is meant any polymer containing

[0048] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units (R PAEK ) is a combination of repeating units (J'-B) and (J"-B).

[0049] Preferably, the poly(ether ketone) (PEK) comprises more than 50 mol % of the formula (J'-C): [ka] Repeating units (R PAEK ) is meant any polymer containing

[0050] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units (R PAEK ) is the repeating unit (J'-C).

[0051] Preferably, the PEEK-PEDEK copolymer comprises more than 50 mol % of the repeat units of formula (J'-A) (PEEK repeat units) and the repeat units of formula (J'-D) (poly(diphenyl ether ketone) (PEDEK) repeat units). [ka] Repeating units (R PAEK) is meant any polymer containing

[0052] The PEEK-PEDEK copolymer may include repeat units (J'-A) and (J'-D) (PEEK / PEDEK) in a relative molar ratio ranging from 95 / 5 to 60 / 40. Preferably, the sum of repeat units (J'-A) and (J'-D) accounts for 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol% or more of the repeat units in the PAEK. In some embodiments, repeat units (J'-A) and (J'-D) account for all of the repeat units in the PAEK.

[0053] Most preferably, the PAEK is PEEK or PEEK-PEDEK.

[0054] Very good results were obtained when the PAEK polymer used to make the porous membrane was PEEK. KETASPIRE® PEEK is commercially available from Solvay Specialty Polymers USA, LLC.

[0055] For purposes of the present invention, poly(aryl ether sulfone) (PAES) is a polyaryl ether sulfone having a repeating unit (R PAES ) means any polymer that contains at least 50 mol % of: [ka] (In the formula, each R is equal to or different from one another and is selected from halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium; each h is the same or different and is an integer ranging from 0 to 4; T is a bond, a sulfone group [-S(=O)2], and a group -C(R j )(R k )-(where R jand R k are equal to or different from each other and are selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine, and quaternary ammonium. j and R k is preferably a methyl group.

[0056] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units in the PAES are repeat units (R PAES ).

[0057] Advantageously, said PAES polymer is chosen in the group comprising, and preferably consisting of, polyphenylsulfone (PPSU), polyethersulfone (PES) and polysulfone (PSU).

[0058] Preferably, the polyphenylsulfone (PPSU) has the formula (K'-A): [ka] By this is meant any polymer that contains more than 50 mole % of repeat units of the formula:

[0059] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units in the PPSU are repeat units of formula (K'-A).

[0060] PPSU can be prepared by known methods and is available as RADEL® PPSU from Solvay Specialty Polymers USA, LLC, among others.

[0061] Preferably, the polyethersulfone (PES) has the formula (K'-B): [ka] By this is meant any polymer that contains at least 50 mole % of repeat units of the formula:

[0062] Preferably, at least 60 mol %, 70 mol %, 80 mol %, 90 mol %, 95 mol %, 99 mol %, and most preferably all of the repeat units in the PES are repeat units of formula (K'-B).

[0063] PES can be prepared by known methods and is available, inter alia, as VERADEL® PESU from Solvay Specialty Polymers USA, LLC.

[0064] Preferably, the polysulfone (PSU) has the formula (K'-C): [ka] By this is meant any polymer that contains at least 50 mole % of repeat units of the formula:

[0065] Preferably, at least 60 mol%, 70 mol%, 80 mol%, 90 mol%, 95 mol%, 99 mol%, and most preferably all of the repeat units in the PSU are repeat units of formula (K'-C).

[0066] PSU can be prepared by known methods and is available as UDEL® PSU from Solvay Specialty Polymers USA, LLC.

[0067] Very good results were obtained when the PEAS polymer used to prepare the porous membrane was PSU.

[0068] Preferably, said compound (S) conforms to the following formula (I): (R)a -Ar-(T) b (I) (In the formula, - Ar is an aromatic moiety selected from the group consisting of substituted or unsubstituted aromatic monocyclic or polycyclic groups having 5 to 18 carbon atoms; - a is zero or an integer ranging from 1 to 5, preferably a is 7 zero or 1; When a is an integer of 1 to 5, each R is the same or different and is a halogen atom, —OH, —NH, C1 to C 18 Aliphatic group, C1~C 18 Alicyclic groups and C1-C 18 selected from the group consisting of aromatic groups; - b is an integer ranging from 1 to 4, preferably b is 1 or 2; - T are the same or different from each other, (SO3 - )(M p+ ) 1 / p Or (COO - )(M p+ ) 1 / p And M p+ is a p-valent metal cation selected from the group consisting of alkali metals, alkaline earth metals, aluminum, iron, zinc, nickel, copper, palladium, and silver).

[0069] As shown in formula (I) above, compound (S) may contain 1 to 4 groups T, which may be the same or different from each other, as defined above.

[0070] Preferably, each R is the same or different from one another and is selected from the group consisting of a halogen atom, -OH, -NH2, and a C1-C3 aliphatic group (such as methyl, ethyl, or propyl).

[0071] Preferably, M p+ is selected from alkali metals (Group IA of the Periodic Table) or alkaline earth metals (Group IIA of the Periodic Table).

[0072] In a preferred embodiment, M p+is sodium or potassium, such that T is a sodium and / or potassium salt of a sulfonic acid and / or a carboxylic acid.

[0073] Preferably, the aromatic moiety in formula (I) is selected from the group consisting of: [ka] (In these formulas, Z is a divalent moiety selected from the group consisting of -SO2-, -CO-, and alkylene of 1 to 6 carbon atoms.

[0074] Preferably, Z is -C(CH)- or -C(CH)-, where n is an integer from 1 to 6. n H 2n -, for example -CH2- or -CH2-CH2-.

[0075] Preferably, the aromatic moieties of formulae (Ar-A) to (Ar-D) contain 1, 2 or 3 groups T, which may be the same or different from one another, and X is as defined above.

[0076] More preferably, the aromatic moieties of formulae (Ar-A) to (Ar-D) contain one or two groups T as defined above. More preferably, the aromatic moiety in formula (I) conforms to the following formula (Ar-A-II): [ka] (In the formula, a, R, b, and T are as defined above).

[0077] Preferably, in the above formulas (I) and (II), a is 0, 1, or 2.

[0078] According to one embodiment, a is zero, so that the phenylene moiety has no substituents other than the sulfonate or carboxylate functional group.

[0079] According to another embodiment, a is 1 and R is -NH2.

[0080] Advantageously, compound (S) is essentially water-soluble.

[0081] As will be appreciated by those skilled in the art, said compound (S) may also be referred to as extractable, as defined below.

[0082] Preferably, compound (S) is selected from the group comprising, more preferably consisting of, benzoate, methylbenzoate, ethylbenzoate, propylbenzoate, benzenesulfonate, benzenedisulfonate, p-toluenesulfonate, xylenesulfonate, cumenesulfonate, p-cymenesulfonate and dodecylbenzenesulfonic acid.

[0083] According to a preferred embodiment of the present invention, the compound (S) is selected from the group consisting of sodium or potassium benzoate, sodium or potassium methyl benzoate, sodium or potassium ethyl benzoate, sodium or potassium butyl benzoate, sodium or potassium benzenesulfonate, sodium or potassium benzene-1,3-disulfonate, sodium or potassium p-toluenesulfonate, sodium or potassium xylenesulfonate, sodium or potassium cumenesulfonate, sodium or potassium para-cymenesulfonate, sodium or potassium n-butylbenzenesulfonate, sodium or potassium iso-butylbenzenesulfonate, sodium or potassium tert-butylbenzene(benezene)sulfonate and sodium or potassium dodecylbenzenesulfonate.

[0084] According to another preferred embodiment, compound (S) further comprises at least one amino group. In this embodiment, a suitable example of compound (S) is a para-aminobenzoate containing an alkali metal or an alkaline earth metal.

[0085] In a further preferred embodiment, the composition (C) comprises - said PAEK polymer in an amount of from 30% to less than 55% by weight, more preferably from 35% to less than 50% by weight; - more than 20% to 40% by weight, more preferably 25% to 35% by weight, of said PAES polymer; and said compound (S) in an amount of from 10% to less than 45% by weight, more preferably from 15 to 40% by weight; Contains These amounts are based on the total weight of said composition (C).

[0086] In a further preferred embodiment, said at least one PAEK polymer is a PEEK polymer as defined above and said at least one PAES polymer is a PSU polymer as defined above.

[0087] Optional components may be added to the composition (C) according to the invention, said optional components may be selected by the person skilled in the art based on the intended end use of the membrane.

[0088] When present, said optional ingredients are in a combined amount of less than 10 wt.%, preferably less than 5 wt.%, and more preferably less than 3 wt.%, based on the total weight of said composition (C).

[0089] Suitable optional ingredients are inorganic fillers such as (nano)silica, TiO2, ZnO, ZrO, sulfates, NaCl, carbonates; diphenic acid, N,N-diphenylformamide, benzil, anthracene, i-phenylnaphthalene, 4-bromobiphenyl, 4-bromodiphenylether, benzophenone, 1-benzyl-2-pyrrolidinone, o,o'-biphenol, phenanthrene, triphenylmethanol, triphenylmethane, triphenylene, 1,2,3-triphenylbenzene, diphenylsulfone, 2,5-diphenyloxazole, 2-biphenylcarboxylic acid, 4-biphenylcarboxylic acid, m-terphenyl, 4-benzoylbiphenyl, 2-benzoylnaphthalene, 3-phenoxybenzyl alcohol, fluoranthene, 2,5-diphenyl1-1,3,4-oxadiazole, 9-fluorenone, 1,2,dibenzoylbenzene, dibenzoylmethane, p-terpheny a plasticizer comprising at least one solvent selected from the group consisting of terphenyls, 4-phenylphenol, 4,4'-bromobiphenyl, diphenylphthalate, 2,6-diphenylphenol, phenothiazine, 4,4'-dimethoxybenzophenone, 9,10-diphenylanthracene, pentachlorophenol, pyrene, 9,9'-bifluorene, terphenyl mixtures, mixtures of partially hydrogenated terphenyls, mixtures of terphenyls and quaterphenyls, 1-phenyl-2-pyrrolidinone, 4,4'-isopropylidenediphenol, 4,4'-dihydroxybenzophenone, quaterphenyl, diphenyl terephthalate, 4,4'-dimethyldiphenyl sulfone, 3,3',4,4'-tetramethyldiphenyl sulfone, and mixtures thereof;

[0090] In a preferred embodiment, the method of the present invention (M Q The composition (C) used in step (a) contains only the PAEK polymer, the PAES polymer, and the compound (S).

[0091] The composition (C) defined above can be prepared by methods well known to those skilled in the art.

[0092] For example, such methods include, but are not limited to, melt mixing processes. Melt mixing processes are typically carried out by heating a thermoplastic polymer above its melting temperature, thereby forming a melt of the thermoplastic polymer. Such processes can be carried out by heating the polymer above the melting temperature (Tm) of the PAEK polymer and / or above the glass transition temperature (Tg) of the PAES polymer to form a melt of the polymer.

[0093] In some embodiments, the treatment temperature is in the range of about 180 to 450°C, preferably about 220 to 440°C, about 260 to 430°C, or about 280 to 420°C.

[0094] Preferably, the processing temperature is at least 15° C., preferably at least 30° C., at least 50° C., at least 80° C., or at least 100° C. higher than the melting temperature (Tg) of the PAEK polymer.

[0095] Preferably, the processing temperature is at least 15° C., preferably at least 30° C., or at least 50° C., higher than the glass transition temperature (Tg) of the PAES polymer.

[0096] When a blend of PAEK and PAES polymers is provided, the melt mixing process is carried out at the highest of the Tm or Tg temperatures.

[0097] The method of the present invention (M Q Step (I) and step (II) of the above process can be carried out as follows.

[0098] Step (I) can be carried out in a melt mixing device, for which any melt mixing device known to those skilled in the art for preparing polymer compositions by melt mixing can be used. Suitable melt mixing devices are, for example, kneaders, Banbury mixers, single screw extruders and twin screw extruders. Preferably, extruders are used that are equipped with means for introducing all the desired components into the extruder, either at the extruder feed throat or in the melt. In the process for preparing the polymer composition, the components for forming the composition are fed into a melt mixing device, where they are melt mixed. The components can be fed simultaneously as a powder mixture, also known as a dry blend, or as a granular mixer, or fed separately.

[0099] In step (II) of the process of the present invention, composition (C) is advantageously provided in the form of pellets which are then processed by a melt extrusion process under step (III).

[0100] The order of combining the polymers during melt mixing is not particularly limited. In a preferred embodiment, a first step of melt extruding the PAEK polymer and the compound (S) is carried out, resulting in a first composition in the form of pellets, followed by a second step of melt extruding the pellets obtained with the PAES, resulting in a second composition in the form of pellets. The second composition is then used in step (III) of the method of the present invention.

[0101] The process for producing the polymer composition (C) may, if necessary, comprise several successive steps of melt mixing or extrusion under different conditions.

[0102] The method itself, or each step of the method, where relevant, may also further comprise a step consisting of cooling the molten mixture.

[0103] In step (III), the layer (L P ) is produced from the polymer composition (C) using a melt extrusion process.

[0104] Preferably, the layer (L P ) is used as it is in step (IV-a) or step (IV-b1).

[0105] In step (IV-a), at least a part of the PAES polymer is extracted with at least one solvent (S) to form a layer (L P ) and the resulting layer (L -iQa ) is obtained.

[0106] The step (IV-a) preferably comprises the step of: introducing the at least one layer (L) into a first bath (also called a "leaching bath" or "solvent extraction bath") containing at least one solvent (S). P ) is inserted.

[0107] Suitable solvents (S) are selected from polar aprotic solvents, preferably dimethylacetamide (DMAC), N-methyl-2-pyrrolidone (NMP), dimethylsulfoxide (DMSO), dimethylformamide (DMF), methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (available from Solvay under the trade name Rhodiasolv® PolarClean), tetrahydrofuran (THF), dichloromethane, sulfolane, dihydrolevoglucosenone (available from Circa Group under the trade name Cyrene®), diphenylsulfone, ε-caprolactam,

[0108] Advantageously, said step (IV-a) is carried out at a temperature between 5° C. and the boiling point of the solvent.

[0109] Preferably, the residence time in the bath is such that at least a portion of the PAES polymer is removed. The time required to dissolve at least a portion of the PAES polymer varies. Preferably, the time can vary between 30 minutes and 10 hours.

[0110] In step (IV-b1), at least a part of the compound (S) is extracted with water to the layer (L P ) and the resulting layer (L -iQb Then, a step (IV-b2) of extraction with at least one solvent (S) is carried out, in which at least a portion of the PAES polymer is separated into a layer (L -iQb ) and the resulting layer (L -iQ2 ) is obtained.

[0111] The step (IV-b1) is a step of forming the at least one layer (L P ) in a water bath.

[0112] The step (IV-b2) is a step of forming the at least one layer (L -iQb ) into a second bath (also called "leaching bath" or "solvent extraction bath") containing at least one solvent (S). The preferred solvents (S), temperatures and times are as described above for step (IV-a).

[0113] In step (V), an extraction with water is carried out to remove both the solvent (S) used in the previous step and at least a portion of the optional compound (S), resulting in a layer (L Q ) is obtained.

[0114] In the step (V), the layer (L -iQa ) or the layer (L -iQb2 ) in a water bath.

[0115] Optionally, a step of chemical treatment with an acid, more preferably sulfuric acid (H2SO4), can be carried out before or after each of steps (IV-a), (IV-b1), (IV-b2), and (V).

[0116] According to a preferred embodiment, said step of chemical treatment is carried out before said step (IV-a) or (IV-b1) or (V).

[0117] Optionally, one or more optional steps can be carried out after step (V).

[0118] Preferably, the layer (L obtained after step (V) Q ) can be contacted with at least one oxidizing agent. Suitable oxidizing agents are selected from the group including, for example, potassium permanganate; ammonium persulfate; sodium hypochlorite; hydrogen peroxide; ozone; dichromate; and combinations thereof.

[0119] Preferably, an iron salt can be used as a catalyst together with said at least oxidizing agent.

[0120] For example, the layer (L Q ) can be dried and / or stretched (this process is also called "stretching") and / or contacted with an alkali, preferably in the form of a liquid solution of, for example, 4-aminobutyric acid, 6-aminocaproic acid, 8-aminocaprylic acid, 3-amino-1-propanesulfonic acid, and the like.

[0121] According to one embodiment, prior to drying, the solvent (S) remaining in the film can be exchanged with a more volatile non-polar drying agent [solvent (D)] that has a low surface tension compared to the solvent (S).

[0122] Advantageously, said solvent (D) is a solvent for the solvent (S) used in step (IV) and a non-solvent for the PAEK polymer, so that the possibility of pore collapse during drying is reduced.Preferably, solvent (D) is chosen from isopropanol or isooctane.

[0123] The exchange from the solvent (S) to the solvent (D) can be carried out at a temperature that does not adversely affect the membrane, preferably at about 0°C to about 100°C.

[0124] Drying can be carried out by working under vacuum.

[0125] The membrane (Q) is preferably dried by appropriately selecting the temperature so that the membrane (Q) is not adversely affected.

[0126] Advantageously, drying is carried out at a temperature between 0°C and 200°C, more preferably between 40°C and 100°C.

[0127] At the end of step (V), - the above-mentioned (L Q ), - Said layer (L Q The substrate as defined above, A membrane (Q) comprising:

[0128] Preferably, the membrane (Q) has a glass transition temperature (T g ) and below the crystalline melting point of the PAEK polymer.

[0129] According to another embodiment, a step of annealing the film (Q), or in other words a step of exposing the film (Q) to high temperature, can be optionally carried out after step (III) and before step (IV-a) or (IV-b1).

[0130] Preferably, the annealing step is performed at or above the glass transition temperature (T g ) and about 10° C. below the melting point of the PAEK polymer.

[0131] Preferably, the annealing step is carried out for about 30 seconds to about 24 hours.

[0132] Preferably, the membrane (Q) according to the invention is used to filter biological solutions (e.g., bioburden, viruses, other large molecules) and / or buffer solutions (e.g., solutions that may contain small amounts of solvents such as DMSO or other polar aprotic solvents).

[0133] Preferably, the membrane (Q) according to the invention is used to filter oil / water emulsions, in particular fracking water and so-called "produced water", or in other words water from oil wells, water with a high solids content, wastewater, etc.

[0134] Therefore, in a further aspect, the present invention relates to the use of a membrane (Q) as defined above for filtering at least one fluid selected from the group comprising, and preferably consisting of, biological solutions, buffer solutions, oil / water emulsions, product water.

[0135] According to another aspect, the present invention relates to a method for filtering at least one fluid, comprising contacting said fluid with at least one membrane (Q) as defined above.

[0136] Advantageously, said fluid is a liquid phase selected from the group including, and more preferably consisting of, biological solutions (e.g. bioburden, viruses, other large molecules); and / or buffer solutions (e.g. solutions which may contain small amounts of solvents such as DMSO or other polar aprotic solvents); and / or oil / water emulsions, especially fracking water and so-called "produced waters", or in other words water from oil wells, water with high solids content, wastewater, etc.

[0137] In addition to the above, the membrane (Q) according to the present invention can also be used in reverse osmosis, ultrafiltration and gas separation processes, as well as liquid to liquid gas transfer applications.

[0138] Examples of gas separation applications include the production of nitrogen from air, hydrogen recovery in refineries and petrochemical plants, gas dehydration, and the removal of acid gases from natural gas.

[0139] To the extent that the disclosures of any patents, patent applications, and publications incorporated herein by reference conflict with the statements of this application to the extent that a term may be unclear, this statement shall control.

[0140] The invention will now be illustrated in more detail in the following sections by means of non-limiting examples. EXAMPLES

[0141] material The following were obtained from Solvay Specialty Polymers USA, LLC.: - Ketaspire® KT-820 NL PEEK polymer (MFR=3g / 10min measured at 400°C, 2.16Kg); - Udel® P1700 PSU polymer (MFR=6.5g / 10min measured at 343°C / 2.16Kg); - Udel® P3703 PSU polymer (MFR=17g / 10min measured at 343°C / 2.16Kg); Dimethylacetamide (DMAC) and isopropyl alcohol (IPA) were obtained from Sigma Aldrich®. Micronized sodium benzoate was obtained commercially from Fluid Energy, Telford, PA.

[0142] Example 1 Preblends of PEEK polymer and sodium benzoate or sodium benzenesulfonate were obtained by blending these components in the ratios detailed in Table 1 using a ZSK-26 twin-screw extruder (Coperion GmbH, Stuttgart, Germany) equipped with 12 barrel zones and a heated exit die operating at a maximum of 450°C.

[0143] The barrel profile was as follows:

[0144] [Table 1]

[0145] [Table 2]

[0146] To obtain the proper mass ratio of the components, each preblend was fed into the feeding section of the extruder using a K-Tron T-35 gravimetric feeder (from Coperion GmbH, Stuttgart, Germany). The components were melted and mixed in a screw designed to obtain a homogeneous molten composition. The actual melt temperature at the exit die was measured with a small instrument and found to be between 390 and 400 °C.

[0147] The melt stream was air-cooled and fed into a Maag Primo 60E pelletizer (from Maag Automatik GmbH, Stuttgart, Germany). Typical production rates were 10-20 kg per hour. Pellets from each preblend were collected and used to produce compounds with the compositions detailed in Table 2.

[0148] [Table 3]

[0149] The pellets were collected and stored in a sealed plastic bucket until used in melt film extrusion.

[0150] The pellets were dried overnight at 130° C. and then fed into a single screw extruder and extruded into a film using a film die at a profile temperature of 360-390° C. The film was wound onto a cooled godet roll operating at a speed of 0.5-2 m / min and a temperature of 90-170° C.

[0151] The precursor layer obtained from the above step was leached in DMAC overnight, decanted, added clean DMAC with stirring for 2 hours, decanted, added clean DMAC with stirring for 2 hours at room temperature, and then transferred to water for three water washes with stirring for 1 hour each.

[0152] Final compositions were prepared according to the methods disclosed in Example 1 and as described in the following examples.

[0153] Example 2 A compound of 45.5 wt.% KetaSpire® KT-820P, 30 wt.% Udel® P-1700, and 24.5 wt.% sodium benzoate was prepared by combining 70% Preblend B with 30% Udel® P1700.

[0154] Example 3 A compound of 40.7 wt.% KetaSpire® KT-820, 26 wt.% Udel® P-1700, and 33.3 wt.% sodium benzoate was prepared by combining 74% Preblend D with 26% Udel® P1700.

[0155] Example 4 A compound of 40.6 wt.% KetaSpire® KT-820, 30 wt.% Udel® P-1700, and 29.4 wt.% sodium benzoate was prepared by combining 70% Preblend C with 30% Udel® P1700.

[0156] Example 5 A compound of 45.5 wt.% KetaSpire® KT-820, wt.% Udel® P-3703, and 24.5 wt.% sodium benzoate was prepared by combining 70% Preblend B with 30% Udel® P3703.

[0157] Example 6 A compound of 49 wt% KetaSpire® KT-820, 30 wt% Udel® P-3703, and 21 wt% sodium benzoate was prepared by combining 70% Preblend A with 30% Udel® P3703.

[0158] Example 7 (Comparative Example): A compound of 55 wt% KetaSpire® KT-820 and 45 wt% Udel® P-3703 was prepared by blending the ingredients in a Coperion ZSK-26 twin screw extruder (Coperion GmbH, Stuttgart, Germany). The ingredients were melted and mixed with a screw designed to obtain a homogenous molten composition. The melt stream was cooled in a water bath and fed into a Maag Primo 60E pelletizer (Maag Automatik GmbH, Stuttgart, Germany). The pellets were collected and stored in sealed plastic buckets until used for melt film extrusion.

[0159] The pellets were then processed into a precursor bed following the same procedure as described above in Example 1. The precursor bed was then leached in DMAC overnight, decanted, and clean DMAC was added with stirring for 2 hours, decanted, and clean DMAC was added with stirring for 2 hours at room temperature.

[0160] method water flux transmittance The water flux (J) through each membrane at a given pressure was defined as the volume permeated per unit area and unit time. L / (h×m 2 ) is calculated by the following formula:

number

[0161] Weight porosity The weight porosity of the membrane was defined as the volume of pores divided by the total volume of the membrane. The porosity (ε) of the membrane was determined according to the gravimetric method detailed below. A completely dry piece of membrane was weighed and soaked in isopropyl alcohol (IPA) for 24 hours. After this time, the excess liquid was removed with tissue paper and the membrane weight was measured again. The porosity was measured using IPA (isopropyl alcohol) as the wetting fluid according to the procedure described in Appendix of Desalination, 72 (1989) 249-262.

number

[0162] Bubble point and pore size determination The membrane bubble point (i.e., measurement of the largest pore), minimum pore size, and average pore size were determined using a Porolux™ 1000 capillary flow porometer (Porometer-Belgium) according to ASTM F316 method. For each test, the membrane sample was first thoroughly wetted with Fluorinert C 43 (a fluorinated fluid with a surface tension of 16 dyn / cm). Nitrogen (an inert gas) was used.

[0163] Thickness measurement The thickness values ​​were measured on dry films using a Mitutoyo Digimatic Indicator (Model ID-H0530). At least five measurements were taken and the average values ​​were calculated. They are reported in the table below.

[0164] Tensile measurements Tensile measurements were made according to ASTM D638 Type V. Each sample was tested five times. Values ​​reported in the table below include modulus, stress at break, and strain at break.

[0165] Preparation of membranes Membranes were prepared using the compositions detailed in Table 1. Compounding, membrane extrusion, and membrane extraction procedures were performed as detailed in Example 1 above.

[0166] Membrane 4 was prepared by performing an annealing step (heat treatment at 250° C. for 1 hour) after membrane extrusion and before membrane extraction.

[0167] [Table 4]

[0168] [Table 5]

[0169] [Table 6]

[0170] The above results showed that the membranes made according to the invention retained better flux at each pressure step, especially above 1 bar, and that the proportional relationship between flux and pressure was maintained as the pressure was increased, whereas the flux measured for the comparative membrane was strongly affected by pressure compression as the pressure was increased.

Claims

1. (a) at least one poly(aryl ether ketone) (PAEK) polymer; (b) at least one poly(aryl ether sulfone) (PAES) polymer, and (c) at least one compound containing a sulfonate or a carboxylate of a metal selected from the group consisting of alkali metals, alkaline earth metals, aluminum, iron, zinc, nickel, copper, palladium, and silver [compound (S)]; A composition [composition (C)] comprising: - said at least one PAEK polymer in an amount ranging from 25 to 65% by weight; said at least one PAES polymer in an amount ranging from 10 to 45% by weight; said at least one compound (S) in an amount ranging from 10 to 50% by weight; and these amounts are based on the total weight of the composition (C).

2. - said at least one PAEK polymer in an amount of from 30% to less than 55% by weight; - said PAES polymer in an amount of from greater than 20% to 40% by weight; and - from 10% to less than 45% by weight of said compound (S); The composition (C) of claim 1, wherein these amounts are based on the total weight of the composition (C).

3. The PAEK polymer is Ar′-C(=O)-Ar ＊ Groups (wherein Ar′ and Ar ＊ are equal to or different from each other and are aromatic groups) ＰＡＥＫ ) in an amount of more than 50 mol %; ＰＡＥＫ 3. The composition (C) according to claim 1 or 2, wherein the unit (J-A) is selected from the group consisting of units of the following formulae (J-A) to (J-D): 【Chemistry 1】 (In the formula, each R' is equal to or different from one another and is selected from the group consisting of halogen, alkyl, alkenyl, alkynyl, aryl, carboxylic acid, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amino group, quaternary ammonium, and a group containing an ether, a thioether, an ester amide or an imide; -j' is zero or an integer ranging from 1 to 4.

4. The PAEK polymer - Formula (J'-A); 【Chemistry 2】 Repeating units (R ＰＡＥＫ %, Formula (J'-B) and Formula (J"-B): 【Chemistry 3】 Repeating units (R ＰＡＥＫ %, - Formula (J'-C): 【Chemistry 4】 Repeating units (R ＰＡＥＫ %, Formula (J'-A) (PEEK repeat unit) and Formula (J'-D) (Poly(diphenyl ether ketone) (PEDEK) repeat unit) 【Chemistry 5】 Repeating units (R ＰＡＥＫ %, a copolymer of PEEK and poly(diphenyl ether ketone) containing more than 50 mol % of PEEK (PEEK-PEDEK copolymer); The composition (C) according to claim 3, selected from the group comprising:

5. The PAES polymer has a repeating unit of formula (K) (R ＰＡＥＳ The composition (C) according to claim 1 or 2, comprising at least 50 mol% of 【Chemistry 6】 (In the formula, each R is equal to or different from one another and is selected from halogen, alkyl, alkenyl, alkynyl, aryl, carboxylic acid, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amino group, quaternary ammonium, and a group containing an ether, thioether, ester, amide, or imide; Each h is the same or different and is an integer ranging from 0 to 4; T is a bond, a sulfone group [-S(=O) ２ -], and the group -C(R ｊ ) (R ｋ ) - (where R ｊ and R ｋ are equal or different and are selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, carboxylic acid, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amino group, quaternary ammonium, and groups containing ether, thioether, ester, amide or imide.

6. The PAES polymer is - Formula (K'-A): 【Chemistry 7】 A polyphenylsulfone (PPSU) polymer containing more than 50 mol % of repeat units of - Formula (K'-B): 【Chemistry 8】 A polyethersulfone (PES) polymer containing at least 50 mol % of repeat units of and - Formula (K'-C): 【Chemistry 9】 A polysulfone (PSU) polymer containing at least 50 mol % of repeat units of The composition (C) according to claim 5, selected from the group comprising:

7. Composition (C) according to claim 1 or 2, wherein the compound (S) is according to the following formula (I): (R) ａ -Ar-(T) ｂ (I) (In the formula, Ar is an aromatic moiety selected from the group consisting of substituted or unsubstituted aromatic monocyclic or polycyclic groups having 5 to 18 carbon atoms; a is zero or an integer ranging from 1 to 5; When a is an integer from 1 to 5, each R is the same or different from the others and is a halogen atom, —OH, —NH ２ , C １ ~C １８ aliphatic group, C １ ~C １８ Alicyclic groups, and C １ ~C １８ selected from the group consisting of aromatic groups; - b is an integer ranging from 1 to 4; Each of T is the same or different from each other, (SO ３ － ) (M ｐ＋ ) １／ｐ Or (COO － ) (M ｐ＋ ) １／ｐ And M ｐ＋ is a p-valent metal cation selected from the group consisting of alkali metals, alkaline earth metals, aluminum, iron, zinc, nickel, copper, palladium, and silver).

8. At least one porous layer [layer L Ｑ ))] for producing a membrane [membrane (Q)] [Membrane (M Ｑ ) ] (I) The composition according to any one of claims 1 to 7. (a) at least one poly(aryl ether ketone) (PAEK) polymer; (b) at least one poly(aryl ether sulfone) (PAES) polymer, and (c) providing at least one compound [compound (S)]; (II) (a) at least one poly(aryl ether ketone) (PAEK) polymer; (b) at least one poly(aryl ether sulfone) (PAES) polymer, and (c) treating at least one compound [compound (S)] to obtain pellets; (III) The pellets obtained in step (II) are melt-extruded to form a precursor layer [layer (L Ｐ ) to obtain (IV-a) The layer (L) obtained in step (III) Ｐ ) with at least one organic solvent to form an intermediate porous layer [layer (L －ｉＱａ (IV-b1) obtaining the layer (L ) obtained in step (III); Ｐ ) with water to form a first intermediate porous layer [layer (L －ｉＱｂ (IV-b2) obtaining the layer (L －ｉＱｂ ) with at least one organic solvent to form a second intermediate porous layer [layer (L －ｉＱｂ２ ) to obtain (V) The layer (L) obtained in step (IV-a) －ｉＱａ ) or the layer (L －ｉＱｂ２ ) was contacted with water to form a porous layer [layer (L Ｑ ) to obtain A method comprising the steps of: Ｑ ) .

9. The step (II): a first step of melt extruding said PAEK polymer and said compound (S) to obtain a first composition in the form of pellets; a second step of melt extruding the pellets with the PAES polymer to obtain a second composition in the form of pellets; The method according to claim 8, comprising Ｑ ).

10. - said step (IV-a) comprises the step of depositing said at least one layer (L) in a first bath containing at least one organic solvent [solvent (S)] Ｐ ) and / or - said step (IV-b1) is carried out by forming said at least one layer (L －ｉＱｂ In order to obtain at least one layer (L Ｐ ), and said step (IV-b2) is carried out by placing said at least one layer (L) in a second bath containing at least one organic solvent [solvent (S)]. －ｉＱｂ ) into the The method according to claim 8 (M Ｑ ).

11. The method according to claim 10, wherein the at least one solvent (S) is selected from polar aprotic solvents (M Ｑ ).

12. After the step (V), the layer (L Ｑ 12. The method according to claim 8, wherein M is dried and / or stretched and / or contacted with an alkali. Ｑ ).

13. A process for the filtration of at least one fluid, comprising contacting said fluid with at least one membrane (Q) obtainable by the process according to any one of claims 8 to 12.

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