Microporous articles and corresponding methods of formation

Abstract

The present invention relates to certain microporous articles comprising certain PEDEK-PEEK copolymers, methods for making said microporous articles, and in particular to methods for making microporous articles from blends comprising said PEDEK-PEEK copolymers and at least one additional polymer, the methods comprising processing said blend into a film and treating the film with a solvent to obtain a microporous article.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 109,648, filed November 4, 2020, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to certain microporous articles comprising certain PEDEK-PEEK copolymers, methods for making said microporous articles, and in particular to methods for making microporous articles from blends comprising said PEDEK-PEEK copolymers and at least one additional polymer, the methods comprising processing said blend into a film and treating the film with a solvent to obtain a microporous article. [Background technology]

[0003] Poly(ether ether ketone), or poly(aryl ether ketone) (PAEK), such as PEEK, among others, exhibits advantageous chemical and physical properties for many applications: high melting points, high glass transition temperatures, low solubility, and high chemical resistance make PAEKs the preferred material for separation applications for harsh environments.

[0004] PAEKs are known to be unaffected by common organic solvents at room temperature. They are also generally resistant to acids and bases, with the exception of strong acids at high concentrations. While the general insolubility of PAEKs is a useful and advantageous attribute for broadening the range of uses for PAEKs, such as in the form of porous membranes, such insolubility significantly complicates the formation of useful articles, including in the form of porous membranes.

[0005] Indeed, polymer films useful as ultrafiltration and reverse osmosis membrane supports are conventionally formed by dissolving a polymer in a solvent, casting the polymer solution as a thin film onto a support, and then coagulating the polymer by immersing the support and polymer film in a bath of a liquid in which the polymer solvent is miscible but which is not a solvent for the polymer.

[0006] Because of these difficulties, alternative methods for producing PAEK membranes, and particularly PEEK membranes, have been pursued, including the proposed blending of one polymer with a polymeric pore-forming additive to prepare a film from which the additive is then leached to produce a microporous membrane.

[0007] U.S. Patent No. 5,064,580 discloses a method for preparing a microporous membrane from a poly(ether ether ketone) (PEEK) polymer and a plasticizer capable of dissolving at least a portion of the PEEK polymer at extrusion or casting temperatures, the method comprising leaching the membrane to remove at least a portion of the plasticizer.

[0008] U.S. Patent No. 4,721,732 discloses a method for producing porous membranes by partially or completely leaching soluble components from a part made from a blend of miscible polymers. Among the blends, a blend of polyetherimide and poly(aryl ether ketone) is specifically mentioned. A mixture of PEI and PEEK is specifically exemplified for producing a film, which, after leaching with DMF, provides a membrane with an average pore size of 0.03 μm and a maximum pore size of 0.07 μm.

[0009] U.S. Patent No. 6,887,408 discloses a method for making porous articles of poly(aryl ether ketone) (PAEK), specifically mentioning PEEK / PEI blends. The process includes forming a PEEK / PEI blend, forming a shaped article from the blend by extrusion, molding, or casting, chemically treating the shaped article with a specific organic base to decompose the PEI into low-molecular-weight fragments, and removing the low-molecular-weight fragments from the article. Chemical reagents for removing the PEI fragments include, for example, ammonia, hydrazine, N-methyl-2-pyrrolidone (NMP), and N,N-dimethylformamide (DMF).

[0010] On the other hand, polyether ether ketone (PEEK), which has a characteristic repeating unit of the formula -O-Ph-O-Ph-CO-Ph- (where Ph = para-phenylene), is versatile, including as a material for constructing microporous membranes, but its glass transition temperature of about 148°C somewhat limits the ability of membranes made therefrom to withstand continuous operation at temperatures above 150°C.

[0011] Among the known polyaryletherketones (PAEKs) with high glass transition temperatures, copolymers containing a mixture of units -O-Ph-O-Ph-CO-Ph-(I) and -O-Ph-Ph-O-Ph-CO-Ph-(II) have been reported.

[0012] In particular, European Patent Application Publication No. 0 184 458 A (ICIPLC) (filed June 11, 1986) is directed to aromatic polyetherketones containing repeating units: -O-Ph-O-Ph-CO-Ph-(I) and -O-Ph-Ph-O-Ph-CO-Ph-(II) in a relative molar ratio I:II of 95:5 to 60:40, preferably 90:10 to 60:40, which are disclosed as having properties similar to known PAEK materials (e.g., PEK or PEEK) but allowing processing at lower temperatures.

[0013] Furthermore, WO 2016 / 042492 (GHARDA CHEMICALS LIMITED) (filed March 24, 2016) discloses certain polyaryletherketones prepared from 4,4'-difluorobenzophenone and mixtures of biphenol and hydroquinone in a molar ratio of 95:5 to 5:95, and in particular copolymers of PEK and PEDEK containing units of the formula -Ph-CO-Ph-O- and units of the formula -Ph-Ph-O-Ph-CO-Ph-O- in various molar ratios as random or block copolymers.

[0014] Copolymers having units -O-Ph-O-Ph-CO-Ph-(I) and -O-Ph-Ph-O-Ph-CO-Ph-(II) in a molar ratio I:II of 45:55 to 15:85, i.e. containing a majority of -O-Ph-Ph-O-Ph-CO-Ph-(II) units, are known, inter alia, from WO 2018 / 0086873 (Solvay Specialty Polymers USA, LLC) (filed February 1, 2018).

[0015] It is worth noting that the idea of ​​converting PEDEK-PEEK copolymers into membranes has already been outlined in U.S. Patent Application Publication No. 2019 / 0241712 (Solvay Specialty Polymers USA, LLC) (filed February 1, 2018), which describes the synthesis of a polymer, which may be a poly(aryl ether ketone) (PAEK), specifically a PEDEK-PEEK copolymer, and a polymer of formula R a -Ar-X b [Ar is an aromatic moiety which may have a substituent R; and X is (SO - ), (M p+ ) 1 / p or (COO - ), (M p+ ) 1 / p (where M p+ is a metal cation with a valence of p; and b is an integer ranging from 1 to 4; processing the blend into a membrane; and immersing the membrane in water.

[0016] Therefore, there is a continuing search in the art for convenient methods for producing, and membranes therefrom, made from polyaryletherketone polymers other than PEEK, which have an advantageous combination of thermal performance and chemical resistance while maintaining excellent mechanical performance, providing membranes suitable for use in highly demanding applications. Summary of the Invention

[0017] It is an object of the present invention to provide microporous articles, such as flat membranes or hollow fibers, comprising PEDEK-PEEK type copolymers, which exhibit beneficial thermal properties, mechanical properties (i.e., rigidity to prevent pore collapse), chemical resistance, and are known to be insoluble in most common solvents.

[0018] Another object of the present invention is to provide a convenient and efficient method for making said microporous article.

[0019] Applicants have surprisingly discovered that the unique crystallization behavior of PEDEK-PEEK type copolymers allows for the production of microporous articles with unique pore dimensions and properties, while also allowing for their production by a convenient and efficient method with reduced annealing loads. DETAILED DESCRIPTION OF THE INVENTION

[0020] As mentioned above, the first object of the present invention is to - Formula (I): [ka] Repeating units (R PEEK ), and - Formula (II): [ka] Repeating unit (R PEDEK ) (In the above formulas (I) and (II), each of R′ and R″ is equal to or different from each other and, in each occurrence, is a C1-C 1-hydroxy group optionally containing one or more heteroatoms. 12 groups; sulfonic acid and sulfonate groups; phosphonic acid and phosphonate groups; amine and quaternary ammonium groups; each of j' and k'' is equal to or different from each other and, in each occurrence, is independently selected from 0 and an integer from 1 to 4; The repeating units are in a molar ratio (R PEDEK ):(R PEEK 1. A microporous article comprising at least one polyaryletherketone copolymer [copolymer (PEDEK-PEEK)] comprising A microporous article having a mean flow pore diameter (MFD) of at least 0.005 and at most 0.500 μm as measured in accordance with ASTM F316-03.

[0021] Another object of the invention is a method for producing said microporous article, which, according to one embodiment, comprises the steps of processing into an article a polymer composition comprising a copolymer (PEDEK-PEEK) as described above and at least one additional polymer [polymer (P)], heat treating said article under conditions that cause at least partial crystallization of the copolymer (PEDEK-PEEK), and contacting the article with a solvent for the miscible polymer to at least partially remove said polymer (P) to obtain a microporous article.

[0022] microporous articles A first object of the present invention is therefore a microporous article comprising a copolymer (PEDEK-PEEK), as detailed above.

[0023] The term "microporous article" refers to an article that is porous, i.e., it has a well-defined porosity, i.e., it contains pores.

[0024] Microporous articles can generally be characterized by their mean flow pore size and porosity, i.e., the percentage of the total article that is porous.

[0025] The microporous article advantageously has a weight porosity (ε ) of 20 to 95% v / v, preferably 40 to 90% v / v, more preferably 50 to 85% v / v, even more preferably 55 to 80% v / v. m )

[0026] As explained, the term "gravimetric porosity" is intended to mean the volume fraction of voids throughout the total volume of a porous membrane.

[0027] A suitable technique for determining the weight porosity in the porous membrane of the present invention is described, for example, in SMOLDERS, K., et al., Terminology for membrane distillation. Desalination. 1989, vol. 72, pp. 249-262.

[0028] As previously mentioned, the microporous article has a mean flow pore diameter (MFD) of at least 0.005 and at most 0.500 μm, preferably at least 0.008 μm, more preferably at least 0.010 μm, even more preferably at least 0.020 μm, and / or preferably at most 0.250 μm, more preferably at most 0.150 μm, even more preferably at most 0.100 μm, as measured according to ASTM F316-03.

[0029] Advantageously, the microporous article of the present invention is endowed with a narrow pore size distribution, which is particularly advantageous for its filtration / separation performance. It is generally known that the bubble point diameter (BPD) represents the largest pore size* in a membrane. Therefore, the ratio BDP / MFD is important for describing the pore size distribution of the microporous article of the present invention. Therefore, in particular, the microporous article of the present invention has a pore size distribution such that the ratio between the bubble point diameter (BPD) and the mean flow pore diameter (MFD) (ratio BDP / MFD) is less than 4.0, preferably less than 3.5, and more preferably less than 3.0, where BDP and MFD are measured according to ASTM F316-03.

[0030] The microporous articles of the present invention are generally porous membranes, i.e., discrete, usually thin, interfaces that moderate the penetration of chemical species in contact with them. This interface can be molecularly uniform (i.e., completely uniform in structure) (dense membranes) or chemically or physically heterogeneous, for example, containing voids, holes, or pores of finite dimensions (porous membranes).

[0031] Membranes with a uniform structure throughout their thickness, containing pores evenly distributed throughout their thickness, are generally known as symmetric (or isotropic) membranes, while membranes without a uniform distribution of pores throughout their thickness are generally known as asymmetric membranes. Asymmetric membranes may contain a thin, selective layer (0.1-1 μm thick) and a thick, highly porous layer (100-200 μm thick) that acts as a support and has little effect on the separation properties of the membrane.

[0032] The porous membranes of the present invention may be either symmetric or asymmetric membranes.

[0033] The porous membrane of the present invention typically has a weight porosity (ε ) of 20-95% v / v, preferably 40-90% v / v, more preferably 50-85% v / v, and even more preferably 55-80% v / v. m )

[0034] The porous membranes of the present invention can either be free-standing porous membranes or can be assembled into multi-layer assemblies.

[0035] When assembled into a multi-layer assembly, the porous membrane of the present invention may in particular be supported on a substrate layer, which may or may not be partially or completely interpenetrated by the porous membrane of the present invention.

[0036] The nature of the substrate is not particularly limited. The substrate is usually made of a material that has minimal effect on the selectivity of the porous membrane. The substrate layer is preferably made of a nonwoven material, glass fiber, and / or a polymer material, such as polypropylene, polyethylene, and polyethylene terephthalate.

[0037] Membranes can be in the form of flat sheets or in tubular form. Tubular membranes are classified based on their dimensions: - tubular membranes with a diameter of more than 3 mm, - capillary membranes with a diameter comprised between 0.5 mm and 3 mm, - Hollow fibers with a diameter of less than 0.5 mm. Capillary membranes are often also called hollow fibers.

[0038] Hollow fibers are particularly advantageous in applications where a compact module with a large surface area is required, whereas flat sheet membranes are generally preferred where high flux is required.

[0039] The thickness of the porous membrane of the present invention can be adjusted depending on the target field of use. Generally, the porous membrane of the present invention has a thickness of at least 10 μm, preferably at least 15 μm, more preferably at least 20 μm, and / or at most 500 μm, preferably at most 350 μm, even more preferably at most 250 μm.

[0040] Microporous articles of the present invention generally have a permeability of at least 5, preferably at least 10, more preferably at least 15 l / (hxm) at a pressure of 1 bar and a temperature of 23°C. 2 ) water flux permeability.

[0041] Furthermore, the microporous article of the present invention has outstanding mechanical properties; in particular, it has a tensile modulus of greater than 250 MPa, preferably greater than 300 MPa, and more preferably greater than 350 MPa, when measured at room temperature (23°C) according to ASTM D638.

[0042] Surprisingly, the microporous articles of the present invention comprising the copolymer (PEDEK-PEEK) possess ambient temperature tensile properties that are significantly improved over the ambient temperature tensile properties of corresponding, otherwise similar microporous articles comprising the homopolymer (PEEK). This is particularly unexpected because the base construction materials (copolymer (PEDEK-PEEK) and homopolymer (PEEK)) are otherwise known to have substantially similar ambient temperature mechanical performance when these materials are evaluated in the form of injection-molded test specimens.

[0043] Without being bound by this theory, Applicant believes that the unique crystallization behavior of the copolymer (PEDEK-PEEK) may be responsible for ensuring such improved performance, and that significant crystallinity can be induced in the copolymer (PEDEK-PEEK), such as during the process of manufacturing a microporous article (such as the process described below), to achieve such advantageous mechanical performance that would not otherwise be possible when processing the homopolymer (PEEK) into a microporous membrane.

[0044] The microporous article comprises at least one polyaryletherketone copolymer [copolymer (PEDEK-PEEK)], said microporous article comprising said copolymer (PEDEK-PEEK) as a main component.

[0045] The microporous article may contain additional components, but the amount of copolymer (PEDEK-PEEK) is at least 60% by weight, preferably at least 70% by weight, more preferably at least 80% by weight, and even more preferably at least 85% by weight, based on the total weight of the microporous article.

[0046] The microporous article may further comprise other components than the copolymer (PEDEK-PEEK). Among other things, the microporous article may include additives, fillers, stabilizers, colorants, and the like.

[0047] It is generally understood that microporous articles may contain residues from the template leaching process used for their manufacture. Thus, in addition to a majority amount of copolymer (PEDEK-PEEK), the microporous article may contain a minor amount of polymer (P), as detailed below.

[0048] Generally, said microporous article comprises an amount of polymer (P) in an amount of at most 15% by weight, preferably at most 12% by weight, more preferably at most 10% by weight relative to the total weight of the microporous article.

[0049] According to certain preferred embodiments, the microporous article consists essentially of a majority amount of copolymer (PEDEK-PEEK) and a minor amount of polymer (P), it being understood that small amounts, generally up to 1% by weight (based on the total weight of the microporous article), of other components, impurities or suspect components can be tolerated, provided they do not substantially alter the advantageous properties of the microporous article.

[0050] Copolymer (PEDEK-PEEK) The copolymer (PEDEK-PEEK) has a molar ratio (R PEDEK ):(R PEEK ) in which the repeating units (R PEDEK ) and (R PEEK A copolymer (PEDEK-PEEK) that has been found to be particularly advantageous is one containing (R PEDEK ):(R PEEK ) in the molar ratio of the repeating units (R PEDEK ) and (R PEEK ) is included.

[0051] In the copolymer (PEDEK-PEEK), the repeating unit (R PEDEK ) and (R PEEK ) is usually at least 70 mol %, preferably at least 80 mol %, even more preferably at least 90 mol %, and most preferably at least 95 mol %, based on the total number of moles of repeating units.

[0052] The copolymer (PEDEK-PEEK) is composed of the repeating units (R PEEK ) and (R PEDEK ) and a different repeating unit (R PAEK In such cases, the repeating unit (R PAEK The amount of repeating units (R PEEK ) and (R PEDEK ) is present in an amount of at least 95 mole % based on the total number of moles of repeat units in the copolymer (PEDEK-PEEK).

[0053] The copolymer (PEDEK-PEEK) contains repeating units (R PEEK ) and (R PEDEK ) and a different repeating unit (R PAEK ) are present, these repeating units (R PAEK ) are usually expressed by the following formulas (KA) to (KM): [ka] [ka] [ka] Follow. (In each of the above formulas (KA) to (KM), each R' is equal to or different from each other and, in each occurrence, is a C1 to C6 alkyl group optionally containing one or more heteroatoms. 12groups; sulfonic acid and sulfonate groups; phosphonic acid and phosphonate groups; amine and quaternary ammonium groups; each j' is equal to or different from one another and, in each occurrence, is independently selected from 0 and an integer from 1 to 4, preferably j' is equal to zero. Follow one of the following.

[0054] Nevertheless, the copolymer (PEDEK-PEEK) contains the repeating units (R PEEK ) and (R PEDEK The phrase "consisting essentially of" in reference to copolymer (PEDEK-PEEK) is intended to indicate that defects, end groups, and monomeric impurities may be incorporated into copolymer (PEDEK-PEEK) in small amounts (e.g., less than 1 wt.%) so as to advantageously not adversely affect the performance of the same in the blends of the present invention.

[0055] The repeating unit (R PEEK In the repeating units (R), the link between the phenyl groups is usually in the para position of each of the phenyl rings. Furthermore, it is generally preferred that each j' is zero, or in other words, that each of the phenyl rings does not have any further substituents in addition to the catenary ether group or ketone bridging group. According to these preferred embodiments, the repeating units (R PEEK ) is represented by formula (Ia): [ka] Follow.

[0056] Similarly, the repeating unit (R PEDEK In the repeating units (R), the link between the phenyl groups is usually at the para position of each of the phenyl rings. Furthermore, it is generally preferred that each k" is zero, or in other words, that each of the phenyl rings does not have any further substituents in addition to the catenary ether or ketone bridging group. According to these preferred embodiments, the repeating units (RPEDEK ) is represented by formula (IIb): [ka] Follow.

[0057] Method for manufacturing a microporous article The microporous articles of the present invention are advantageously produced by the method of the present invention, as detailed above.

[0058] As previously mentioned, the method for producing said microporous article comprises the steps of: 1. - processing into a solid article a polymer composition comprising a copolymer (PEDEK-PEEK) as previously described and at least one additional polymer [polymer (P)]; Step 2. - heat treating the solid article under conditions that cause at least partial crystallization of the copolymer (PEDEK-PEEK); and Step 3. - The method comprises contacting the heat-treated article resulting from step 2 with a solvent for said polymer (P) to at least partially remove said polymer (P) to obtain a microporous article.

[0059] Step 1 consists of processing the polymer composition [composition (C)] into an article. This step generally consists of processing said composition (C) from the melt phase.

[0060] Melt forming is commonly used to process said composition (C) into articles by film extrusion, preferably by flat cast film extrusion or by blown film extrusion.

[0061] Composition (C) is first prepared by melt compounding by mixing the copolymer (PEDEK-PEEK) and the polymer (P). Generally, melt compounding is carried out in an extruder. Composition (C) is typically extruded through a die at a temperature approximately above the melting point of the copolymer (PEDEK-PEEK), thereby providing strands, which are typically cut to provide pellets. According to this technique, composition (C) is extruded through a die to obtain a molten tape, which is then calibrated and stretched in two directions to obtain the required thickness and width. A twin-screw extruder is a preferred device for performing melt compounding to provide composition (C).

[0062] In step 1, as described above, composition (C) is processed by melt molding.

[0063] Melt forming is commonly used to process said composition (C) into articles by film extrusion, preferably by flat cast film extrusion or by blown film extrusion.

[0064] In flat film or sheet production, the primary objective is to spread a continuous molten stream of composition (C) from an extruder into a die having a wide cross section and a small gap, typically a rectangular die. Upon exiting the die, the molten extrudate of composition (C) is brought into contact with rollers (which may be cooled or heated) and solidifies to provide a solid article.

[0065] In this step 1, the melt extrudate so obtained can be stretched either in the molten phase or after its solidification upon cooling to provide a solid article. Hot blown film extrusion can also be used to provide said solid article.

[0066] Polymer (P) As mentioned above, step 1 consists in processing a polymer composition comprising a copolymer (PEDEK-PEEK) as described above and at least one additional polymer, referred to as polymer (P), whose selection will be made by those skilled in the art taking into account the solubility characteristics required in the process of the present invention.

[0067] Taking into account the solubility requirements, the polymer (P) is advantageously chosen from amorphous polymers, i.e. polymers with a heat of fusion of less than 5 J / g, nevertheless, embodiments are still possible in which the polymer (P) has semi-crystalline characteristics.

[0068] Generally, the polymer (P) is chosen among those capable of forming a homogeneous or compatible blend with the copolymer (PEDEK-PEEK) detailed above.

[0069] It is generally accepted that polymer blends can generally be divided into three categories: 1. Immiscible or heterogeneous polymer blends in which the constituent polymers exist in separate phases and each has its own observed glass transition temperature. 2. Compatible polymer blends, which are immiscible polymer blends that exhibit macroscopically uniform physical properties caused by sufficiently strong interactions between the component polymers. 3. Miscible or homogeneous polymer blends with a single phase structure, having one glass transition temperature.

[0070] According to certain embodiments, the polymer (P) is selected from polymers that can form compatible blends with the copolymer (PEDEK-PEEK), i.e., polymers that eliminate the potential complications associated with many heterogeneous two-phase blends that are not completely miscible but can exhibit unstable and variable phase domain sizes and morphologies that often translate into variability in the physical and mechanical properties of the blend. In such cases, compatibility can result in partial miscibility, which may still provide a significant amorphous phase, but which does not result in improved T from the predominant constituent single polymer component (polymer (P) or copolymer (PEDEK-PEEK)).g where it is understood that an individual polymer may have both amorphous and crystalline portions, where any crystalline portion may exist as a separate phase.

[0071] According to another embodiment, the polymer (P) is selected from polymers capable of forming miscible blends, i.e. polymer (P) that when combined with the copolymer (PEDEK-PEEK) gives a blend with a single amorphous phase, exhibiting a single glass transition temperature.

[0072] The polymer (P) is advantageously at least one poly(etherimide). This alternative polymer may in particular be a poly(aryl ether ketone) different from a copolymer (PEDEK-PEEK), such as PEK (i.e., a polymer having the aforementioned units (KB)) or PEKEKK (i.e., a polymer having the aforementioned units (KG)).

[0073] Poly(ether imide) [polymer (PEI)] As mentioned above, according to certain preferred embodiments, the polymer (P) is a poly(etherimide) [polymer (PEI)]. The terms "poly(etherimide)" and / or "polymer (PEI)" refer to at least 50 mole % of repeating units (R 1 ) containing at least one aromatic ring, at least one imide group as such and / or in its amic acid form, and at least one ether group, based on the total number of moles in the polymer. PEI ) means a polymer containing repeating units (R PEI ) may optionally further comprise at least one amide group that is not included in the amic acid form of the imide group.

[0074] Usually, the repeating unit (R PEI ) are represented by the following formulae (I), (II), (III), (IV), (V) and mixtures thereof: [ka] [ka] [In the formula, Ar is a tetravalent aromatic moiety and is selected from the group consisting of substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; Ar' is a trivalent aromatic moiety and is selected from the group consisting of substituted, unsubstituted, saturated, unsaturated, aromatic monocyclic and aromatic polycyclic radicals having 5 to 50 C atoms; and - R, for example, (a) Aromatic hydrocarbon radicals having 6 to 20 carbon atoms and their halogenated derivatives; (b) a straight-chain or branched-chain alkylene radical having 2 to 20 carbon atoms; (c) a cycloalkylene radical having 3 to 20 carbon atoms; and (d) Formula (VI): [ka] (In the formula, - Y is alkylene of 1 to 6 carbon atoms, such as -C(CH3)2 and -C n H 2n - (n is an integer of 1 to 6); perfluoroalkylene of 1 to 6 carbon atoms, such as -C(CF3)2 and -C n F 2n -(n is an integer from 1 to 6); cycloalkylene of 4 to 8 carbon atoms; alkylidene of 1 to 6 carbon atoms; cycloalkylidene of 4 to 8 carbon atoms; -O-; -S-; -C(O)-; -SO2-; -SO-, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkaline earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkaline earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium, and - i is independently for each R" zero or an integer ranging from 1 to 4. Divalent radical of and wherein the divalent organic radical is selected from the group consisting of substituted and unsubstituted divalent organic radicals selected from the group consisting of provided that at least one of Ar, Ar′ and R comprises at least one ether group, and said ether group is present in the polymer chain backbone.

[0075] In the above formula, Ar typically has the formula: [ka] (In the formula, X is a divalent moiety having a divalent bond at the 3,3', 3,4', 4,3'' or 4,4' positions and is an alkylene of 1 to 6 carbon atoms, such as -C(CH3)2 and -C n H 2n - (n is an integer of 1 to 6); perfluoroalkylene of 1 to 6 carbon atoms, such as -C(CF3)2 and -C n F 2n -(n is an integer from 1 to 6); cycloalkylene of 4 to 8 carbon atoms; alkylidene of 1 to 6 carbon atoms; cycloalkylidene of 4 to 8 carbon atoms; -O-; -S-; -C(O)-; -SO2-; -SO-; or X is a group of formula -O-Ar"-O-, where Ar" is an aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms. is selected from the group consisting of:

[0076] In the above formula, Ar' is typically a group of the formula: [ka] (In the formula, X is a divalent moiety having a divalent bond at the 3,3', 3,4', 4,3'' or 4,4' positions and is an alkylene of 1 to 6 carbon atoms, such as -C(CH3)2 and -C n H 2n - (n is an integer of 1 to 6); perfluoroalkylene of 1 to 6 carbon atoms, such as -C(CF3)2 and -C n F 2n -(n is an integer from 1 to 6); cycloalkylene of 4 to 8 carbon atoms; alkylidene of 1 to 6 carbon atoms; cycloalkylidene of 4 to 8 carbon atoms; -O-; -S-; -C(O)-; -SO2-; -SO-; or X is a group of formula -O-Ar"-O-, where Ar" is an aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms. is selected from the group consisting of:

[0077] Typically, at least 50 mol%, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeat units in the polymer (PEI) are repeat units (R PEI )

[0078] According to a particular embodiment, the polymer (PEI) comprises at least 50 mole % of a compound of formula (VII), based on the total number of moles in the polymer: [ka] [In the formula, - R, for example, (a) Aromatic hydrocarbon radicals having 6 to 20 carbon atoms and their halogenated derivatives; (b) a straight-chain or branched-chain alkylene radical having 2 to 20 carbon atoms; (c) a cycloalkylene radical having 3 to 20 carbon atoms; and (d) Formula (VI): [ka] (In the formula, - Y is alkylene of 1 to 6 carbon atoms, such as -C(CH3)2 and -C n H 2n - (n is an integer of 1 to 6); perfluoroalkylene of 1 to 6 carbon atoms, such as -C(CF3)2 and -C n F 2n -(n is an integer from 1 to 6); cycloalkylene of 4 to 8 carbon atoms; alkylidene of 1 to 6 carbon atoms; cycloalkylidene of 4 to 8 carbon atoms; -O-; -S-; -C(O)-; -SO2-; -SO-, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkaline earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkaline earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium, and - i is independently for each R" zero or an integer ranging from 1 to 4. Divalent radical of and wherein the divalent organic radical is selected from the group consisting of substituted and unsubstituted divalent organic radicals selected from the group consisting of T can be either -O- or -O-Ar''-O-; wherein the divalent bond of the -O- or -O-Ar"-O- group can be in the 3,3', 3,4', 4,3' or 4,4' positions, and Ar" is an aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, such as a substituted or unsubstituted phenylene, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthalene group, or a moiety containing two substituted or unsubstituted phenylene groups. It is a polymer containing repeating units (RPEI).

[0079] According to certain embodiments of the present disclosure, Ar″ is of the general formula (VI) detailed above, for example, Ar″ is of the formula (XIX): [ka] Follow.

[0080] The polymer (PEI) according to this preferred embodiment is prepared by reacting a diamino compound of formula H2N-R-NH2(XX) (wherein R is as previously defined) with a diamino compound of formula (XXI): [ka] where T is as previously defined. They can be prepared by any of the methods well known to those skilled in the art, including reaction of any of the above with an aromatic bis(ether anhydride).

[0081] Generally, this preparation can be carried out at temperatures ranging from 20°C to 250°C in solvents such as o-dichlorobenzene, m-cresol / toluene, N,N-dimethylacetamide.

[0082] Alternatively, these polymers (PEI) can be prepared by simultaneously melt polymerizing any dianhydride of formula (XXI) and any diamino compound of formula (XX) while heating the mixture of these components at an elevated temperature.

[0083] Examples of the aromatic bis(ether acid anhydride) of formula (XXI) include: 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)diphenyl ether dianhydride; 1,3-bis(2,3-dicarboxyphenoxy)benzene dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)diphenyl sulfide dianhydride; 1,4-bis(2,3-dicarboxyphenoxy)benzene dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)benzophenone dianhydride; 4,4'-bis(2,3-dicarboxyphenoxy)diphenylsulfone dianhydride; 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl ether dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride; 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride; 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride; 4,4'-bis(3,4-dicarboxyphenoxy)benzophenone dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4-dicarboxyphenoxy)diphenyl-2,2-propane dianhydride; and Mixtures of such dianhydrides Examples include:

[0084] The organic diamine of formula (XX) is selected from the group consisting of m-phenylenediamine, p-phenylenediamine, 2,2-bis(p-aminophenyl)propane, 4,4'-diaminodiphenyl-methane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, and mixtures thereof; preferably, the organic diamine of formula (XX) is selected from the group consisting of m-phenylenediamine and p-phenylenediamine, and mixtures thereof.

[0085] According to a particularly preferred embodiment, the polymer (PEI) comprises at least 50 mole % of the imide or its corresponding amic acid form, based on the total number of moles in the polymer, of formula (XXIII) or (XXIV): [ka] Repeating units (R PEI ) is a polymer containing

[0086] In preferred embodiments, at least 50 mol%, at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol%, at least 95 mol%, at least 99 mol% or all of the repeat units in the PEI are repeat units of formula (XXIII) or (XXIV) (R PEI )

[0087] Such aromatic polyimides are commercially available, among others, from Sabic Innovative Plastics as ULTEM® polyetherimides.

[0088] The solid article resulting from step 1 may contain, in addition to the copolymer (PEDEK-PEEK) and polymer (P), various additives that may be included to impart any desired properties to the non-leaching polymer. For example, stabilizers, flame retardants, pigments, plasticizers, etc. may be present. Other polymers may also be added to impart desired properties.

[0089] Nevertheless, it is generally preferred that the solid article resulting from step 1 consists essentially of copolymer (PEDEK-PEEK) and polymer (P), it being understood that small amounts, e.g., less than 1% by weight, of other components such as impurities or other suspect compounds can be tolerated, provided their presence does not affect the overall performance of said solid article.

[0090] The weight percent of polymer (P), i.e., the leached component, is generally in an amount of about 10% to about 90% by weight, preferably about 30% to about 75% by weight, more preferably about 40% to about 70% by weight, and even more preferably about 55% to about 68% by weight, based on the combined weight of polymer (P) and copolymer (PEDEK-PEEK). Conversely, therefore, the weight percent of copolymer (PEDEK-PEEK), i.e., the target component of the microporous article, is generally in an amount of about 90% to about 10% by weight, and preferably about 70% to about 25% by weight, more preferably about 60% to about 30% by weight, and even more preferably about 45% to about 32% by weight, based on the combined weight of polymer (P) and copolymer (PEDEK-PEEK).

[0091] In step 2, the solid article is heat treated under conditions that cause at least partial crystallization of the copolymer (PEDEK-PEEK).

[0092] As a result of this step 2, the non-leaching polymer, i.e., copolymer (PEDEK-PEEK), is in a partially crystalline state. This has been found to be particularly advantageous in fabricating the microporous articles of the present invention in order to reduce or control the shrinkage of the pore size of the article. Indeed, unlike what is observed for homopolymers consisting only of PEEK-type units, a distinguishing feature of the copolymer (PEDEK-PEEK) is that it possesses an advantageous crystallization capacity that allows it to crystallize rapidly and significantly when in the presence of a miscible or compatible polymer (P).

[0093] This unique crystalline behavior provides highly advantageous properties to the microporous membrane obtained from the annealed solid article of step 2, such as improved dimensional stability and improved mechanical properties.

[0094] Furthermore, unlike the lengthy and harsh thermal annealing conditions required to manufacture PEEK membranes, following similar procedures, solid articles can be heat treated for shorter times and under less harsh (less severe) conditions, thus making the overall manufacturing process simpler and more effective.

[0095] The heat treatment of step 2 is carried out at a temperature of at least 200°C, preferably at least 250°C, more preferably at least 280°C and / or at a temperature of at most 370°C, preferably at most 365°C, more preferably at most 350°C.

[0096] The heat treatment of step 2 is carried out for a period of at least 1 minute, preferably at least 2 minutes, more preferably at least 3 minutes, and / or for a period of at most 120 minutes, preferably at most 60 minutes, more preferably at most 30 minutes.

[0097] As mentioned above, step 3 of the method of the present invention comprises contacting the heat-treated article obtained from step 2 with a solvent for said polymer (P) to at least partially remove said polymer (P) to obtain a microporous article.

[0098] In step 3, the heat-treated (also referred to as "annealed") article is treated with a solvent that is a solvent for the polymer (P) and a non-solvent for the copolymer (PEDEK-PEEK). At least a portion of the polymer (P) dissolves in the solvent and is removed upon removal of the solvent. Thus, the polymer (P) that is soluble in the solvent is referred to as the leachable component, and the polymer that is removed by the process is referred to as the polymer that is leached or extracted from the article.

[0099] The annealed article is generally treated with a solvent that does not substantially dissolve, extract, or leach the copolymer (PEDEK-PEEK), i.e., it must be a "non-solvent" for the copolymer (PEDEK-PEEK). However, the non-solvent may, within the scope of the present invention, swell the non-leaching copolymer (PEDEK-PEEK) while in the solvent. Furthermore, it is within the scope of the present invention that the non-solvent may remove low molecular weight portions of the non-leaching copolymer (PEDEK-PEEK).

[0100] The solvent treatment is preferably carried out by immersing the annealed article in a bath containing the solvent. The annealed article is immersed in the bath for a time sufficient to remove the desired amount of polymer (P). Typically, the annealed article is maintained in contact with the solvent for about 1 minute to about 8 hours or more, preferably about 10 minutes to about 4 hours. Alternatively, the annealed article is suspended in the vapors of the boiling solvent.

[0101] The temperature at which the solvent treatment step is carried out depends on the solvent used and the polymer (P) used. In most cases, the solvent is maintained at a temperature from about ambient temperature to below about the boiling point of the solvent.

[0102] Those skilled in the art will be able to readily select a solvent that is a non-solvent for the copolymer (PEDEK-PEEK). For example, the polymer (P) can be leached using non-toxic solvents such as methylene chloride, dimethylacetamide (DMAC), dimethylformamide (DMF), N-methylpyrrolidone, methyl l-lactate, ethyl lactate, propylene carbonate, tributyl o-acetylcitrate, tributyl citrate, triethyl phosphate, and gamma-butyrolactone (GBL).

[0103] In these respects, the essentially insolubility of the copolymer (PEDEK-PEEK) in almost all common organic solvents is an advantage.

[0104] When the polymer (P) is a polymer (PEI), N-methylpyrrolidone (NMP), methylene chloride and gamma-butyrolactone (GBL) are possible solvents that can be used in step 3.

[0105] In particular, when the polymer (P) is the polymer (PEI), methylene chloride at ambient temperature is an efficient solvent.

[0106] Generally, it is desirable to leach out substantially all of the soluble polymer (P) to result in a microporous article having the physical and mechanical properties of the copolymer (PEDEK-PEEK).

[0107] However, in certain circumstances, it may be advantageous to leach only a portion of the soluble polymer (P), the presence of which can result in the microporous article having, for example, greater flexibility, greater wettability, etc. than would be exhibited by a microporous article substantially free of polymer (P).

[0108] Generally, however, the final microporous article should contain no more than about 10 weight percent polymer (P), based on the weight of the microporous article.

[0109] It is not necessary to remove the solvent to use the microporous article of the present invention. For example, a microporous article of the present invention that has been leached with dimethylformamide (DMF) may be placed directly in an aqueous solution for filtration purposes without removing the contained solvent. Optionally, however, the solvent is removed from the article. Removal can be carried out by continuous removal while the microporous article is being treated with the solvent, for example, by distillation, or after the extraction is complete by evaporation, vacuum, heat, filtration, freeze-drying, or any other technique known to those skilled in the art for solvent removal.

[0110] Typically, after solvent treatment, the processing solvent and dissolved polymer (P) are removed from the microporous article by washing it with a second solvent that is miscible with the first solvent and removes the processing solvent and dissolved polymer (P) upon washing with the second solvent.

[0111] The microporous article can then be dried, if necessary, to remove the second solvent. The choice of second solvent depends on the first solvent used for leaching (and the properties of the polymer (P) component being leached from the excipient). Isopropanol or a mixture of isopropanol and water has been found to be particularly effective for removing dichloromethylene / polymer (PEI) residues from microporous membranes.

[0112] The microporous articles of the present invention are useful for filtering particulate matter suspended in liquid and gas dispersions or suspensions. They are particularly useful in harsh environments, when exposed to aggressive chemicals during filtration, or in cleaning and maintenance of filter devices containing the same. The microporous articles of the present invention can be used in many fields, such as water purification in the chemical industry, biological fluid purification, wastewater treatment, osmotic distillation, and process fluid filtration.

[0113] The following examples are representative of the invention but are not intended to be limiting. Substitutions of materials and conditions that are obvious from this disclosure are to be made in contemplation of the invention.

[0114] raw materials The copolymer used (PEDEK-PEEK) was a PEDEK-PEEK copolymer derived from the polycondensation of 4,4'-difluorobenzophenone (DFBP), 4,4'-dihydroxydiphenyl, also known as biphenol, and hydroquinone. This copolymer contains a high percentage of biphenol residues relative to the hydroquinone moieties in the total stoichiometric amount of biphenol in the polymerization. PEDEK represents the polymer repeat unit resulting from the polycondensation of biphenol and 4,4'-difluorobenzophenone. While copolymers (PEDEK-PEEK) that can be used in the practice of this invention can vary in the molar ratio of PEDEK repeat units to PEEK repeat units within the polymer backbone, the examples used copolymers with a PEDEK-PEEK molar ratio of 75:25 (hereinafter referred to as PEDEK-PEEK copolymer). The PEDEK-PEEK copolymer exhibited a tensile strength of 1000 s at 420 °C and 1000 s when measured using a capillary rheometer according to ASTM D3835. -1 It has a melt viscosity of 345 Pa·s.

[0115] The polymer (PEI) used was SABIC's ULTEM® 1000 PEI, a standard grade of PEI for general-purpose extrusion and injection molding applications. This grade is reported by the manufacturer to have a melt flow rate of approximately 9 g / 10 min, as measured using a melt indexer according to ASTM D1238 at 377°C with a 6.6 kg weight.

[0116] Preparation Example 1(a) - Formulation of Copolymer (PEDEK-PEEK) / Polymer (PEI) Blends Blends of copolymer (PEDEK-PEEK) and polymer (PEI) were prepared in pellet form by melt compounding using a 26 mm Coperion® co-rotating, partially intermeshing twin-screw extruder with a 48:1 L / D ratio. The extruder had 12 barrel sections, with barrel sections 2 through 12 heated to a temperature setting of 380°C. A 3-mm diameter pinhole die was used, and the die temperature was also set at 380°C. The extruder was operated at a throughput of 30-35 lb / hr (approximately 13-14 kg / hr) and a screw speed of 225 rpm. The extruder torque readings were maintained in the range of 75-85% during compounding for all compositions. A vacuum vent was applied to barrel section 10 during compounding at a vacuum level greater than 25 inHg to remove moisture and any residual volatiles from the compounds. The extrudate from each run was stranded, cooled in a water trough, and then pelletized into pellets approximately 2.7 mm in diameter and 3.0 mm in length.

[0117] A copolymer (PEDEK-PEEK) / polymer (PEI) 35 / 65 wt% blend was thus prepared.

[0118] Preparation Example 2C(a) (Comparative) - Formulation of PEEK / Polymer (PEI) Blends The PEEK homopolymer resin used was KETASPIRE® KT-820NL in pellet form. The procedure followed to prepare the blend was the same as described above for the copolymer (PEDEK-PEEK) / polymer (PEI) blend, with the following modifications: barrel sections 2-7 were heated at a temperature setting of 370°C, barrel sections 8-12 were heated at a temperature setting of 360°C, the die temperature setting was 375°C, and the screw speed was 200 rpm. A 35 / 65 wt% homopolymer PEEK / polymer (PEI) blend was thus prepared.

[0119] Preparative Example 1(b) - Extrusion of a film ("precursor") of a 35 / 65 wt% copolymer (PEDEK-PEEK) / polymer (PEI) blend Pellets of the blend prepared as described in Example 1(a) were dried overnight at 150°C before extrusion. Films were extruded using a Brabender single-screw extruder with a diameter (D) of 19 mm, a length 25 times that of D, and four temperature zones (T1-T4). The extruder was equipped with a head with a width of 10 cm and a thickness of 0.5 mm. The film was quenched with a chill roll at 150°C at a distance of 0.5 cm from the extrusion head. The extrusion conditions are detailed in the table below.

[0120] [Table 1]

[0121] Preparative Example 2C(b) - Extrusion of a film ("precursor") of a 35 / 65 wt% homopolymer (PEEK) / polymer (PEI) blend Pellets of the blend prepared as detailed in Example 2C(a) were dried overnight at 150°C before extrusion. Films were extruded using the same equipment as described in Example 1(b), except they were quenched at 140°C. The extrusion conditions are detailed in the table below.

[0122] [Table 2]

[0123] Annealing of the film ("precursor") of Preparation Example 1(c) Annealing of the films prepared as described above was carried out in a ventilated oven. The precursor films were heat treated at a temperature of 320°C for 30 minutes (condition "A") or 5 minutes (condition "B") to increase the crystalline fraction, which can be measured, inter alia, by DSC.

[0124] Comparative Preparation Example 2C(c)—Annealing of the Film (“Precursor”) The same procedure was followed as described in Example 1(c).

[0125] Preparation Example 1(d) - Extraction of Annealed Film to Obtain Porous Membrane The annealed precursor film obtained as detailed in Example 1(c) (Conditions A and B) was immersed in a bath of dichloromethane (CHCl) for 3 hours, after which the film was rinsed several times in isopropanol (IPA) to remove residual CHCl. ​​Finally, the microporous membrane so obtained was dried at room temperature in a fume hood.

[0126] Comparative Preparation Example 2C(d) - Extraction of Annealed Films to Obtain Porous Membranes The annealed precursor film obtained as detailed in Example 2C(c) (Conditions A and B) was treated as detailed in Example 1(d) above to obtain a microporous membrane.

[0127] Microporous membrane characterization Measurement of residual exudable polymer (PEI) content The annealed precursor films were weighed before and after extraction as detailed above in Examples 1(d) and 2C(d).

[0128] The residual weight is defined as: Res(%)=(W fin / W in )×100- (In the formula, W in is the weight of the annealed film before extraction of CH2Cl2, and W fin is the weight of the microporous membrane after extraction).

[0129] Residual weights above the nominal weight of the copolymer (PEDEK-PEEK) in the original blends of Examples 1(a) and 2C(a) were found to indicate the presence of residual polymer (PEI).

[0130] Permeability measurements The water flux (J) through a microporous membrane at a given pressure is defined as the volume permeated per unit area per unit time. Flux is calculated using the following formula:

number

[0131] Water flux measurements were performed at room temperature using high-purity MilliQ water in a dead-end configuration under a constant nitrogen pressure of 1 bar. Membrane disks with an active area of ​​11.3 cm2 were cut from the membrane sheet (pre-soaked in IPA) and placed on a metal plate. For each material, the flux is the average of at least five different disks. The flux is expressed in units of LMH (liters per square meter x hour).

[0132] Gravimetric porosity measurement The weight porosity of the membrane (ε m ) is defined as the pore volume divided by the total volume of the membrane. Membrane weight porosity (ε m ) was measured according to the gravimetric method detailed below. The completely dried membrane specimens were weighed and soaked in isopropyl alcohol (IPA) for 24 h. After this time, excess liquid was removed with tissue paper and the membrane weight was measured again. 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

[0133] Measurement of tensile properties The mechanical properties of the microporous membranes were evaluated at room temperature (23°C) according to ASTM D 638 standard procedure (Type V, grip distance = 25.4 mm, initial length Lo = 21.5 mm). The determined values ​​are the average of repeated measurements performed on five specimens of each sample. The elastic modulus, breaking strain and breaking stress are detailed in Table 3 below.

[0134] Pore ​​size measurement The bubble point diameter (i.e., corresponding to the largest pore diameter), the smallest pore diameter, and the mean flow pore diameter of the membrane were determined using a capillary flow porometer "Porolux 1000" (Porometer-Belgium) according to ASTM F0316 method.

[0135] For each measurement, a membrane disk sample (diameter = 25 mm) was first thoroughly wetted with Fluorinert® FC43 liquid (which is a fluorinated liquid with a very low surface tension of 16 dynes / cm) for several hours and placed in the instrument's sample holder. Inert gas (nitrogen) was supplied to the sample under increasing pressure. The values ​​reported in Table 4 are the average of repeated measurements made on three different specimens.

[0136] As mentioned above, the bubble point diameter (BPD) is the maximum pore size in a membrane. The mean flow pore diameter (MFD) is the average pore size calculated by the half-dry method described in ASTM F316-03. The ratio of these two quantities (BPD / MFD) represents the uniformity of the pore size distribution; the smaller this ratio, the more uniform the pore size distribution and, therefore, the more favorable the filtration / separation performance of the microporous membrane.

[0137] The results are summarized in the table below.

[0138] [Table 3]

[0139] [Table 4] Pores are known to have sizes (detection limit) smaller than 26 nm and are therefore too small for meaningful measurements, requiring excessive pressure for their determination.

[0140] Tables 3 and 4 above clearly demonstrate that the short annealing times that are highly preferred when industrializing the production of microporous membranes are only effective in providing good membranes when applied to copolymers (PEDEK-PEEK) and not to homopolymers (PEEK).

[0141] Furthermore, while having essentially similar flux and similar porosity and pore distribution, the microporous membranes of the present invention made from the copolymer (PEDEK-PEEK) are endowed with significantly improved mechanical properties, as particularly demonstrated by their tensile modulus, which significantly exceeds that of the corresponding membrane made from the homopolymer (PEEK) (see Example 1(d)A and B versus Example 2C(d)A). This is particularly unexpected, since it is well known that the base polymers exhibit the opposite trend. Table 5 below summarizes the mechanical properties measured on injection-molded specimens made from the same copolymer (PEDEK-PEEK) and the same homopolymer (PEEK) when used to make microporous membranes.

[0142] [Table 5]

[0143] Here, microporous membranes made from copolymers (PEDEK-PEEK) have tensile moduli that are nearly twice as high as those exhibited by comparable microporous membranes made from homopolymers (PEEK) at similar weight porosities (65-70%) and thicknesses (300-400 μm), which is therefore entirely unexpected when considering the mechanical properties of the underlying constituent materials.

[0144] As far as Example 2C(d)-B is concerned, this example clearly demonstrates that shorter annealing times are not effective in providing good membranes when processing homopolymers (PEEK). In this case, the resulting membranes have undetectable pore sizes, resulting in very low flux. Furthermore, the residual amount of leachable components is significant, as shown by residual weight determination. Although the presence of residual polymer (PEI) is known to be detrimental to the chemical resistance of microporous membranes, in measuring the mechanical properties of as-prepared membranes, this can be seen as slightly improving the ductility of the membranes.

Claims

1. Formula (I): 【Chemistry 1】 Repeating units (R ＰＥＥＫ ), and - Formula (II): 【Chemistry 2】 Repeating units (R ＰＥＤＥＫ ) (In the above formulas (I) and (II), each of R′ and R″ is equal to or different from each other and, at each occurrence, optionally contains one or more heteroatoms. １ ~C １２ groups; sulfonic acid and sulfonate groups; phosphonic acid and phosphonate groups; amine and quaternary ammonium groups; each of j' and k'' is equal to or different from one another and, in each occurrence, is independently selected from 0 and an integer from 1 to 4; The repeating units are in a molar ratio of 55:45 to 99:1 (R ＰＥＤＥＫ ): (R ＰＥＥＫ ) included in A microporous article comprising at least one polyaryletherketone copolymer [copolymer (PEDEK-PEEK)] comprising: A microporous article having a mean flow pore diameter (MFD) of at least 0.005 and at most 0.500 μm as measured in accordance with ASTM F316-03.

2. Gravimetric porosity (ε) of 20-95% v / v ｍ 10. The microporous article of claim 1, wherein the microporous article comprises:

3. 3. The microporous article of claim 1 or 2, having a mean flow pore diameter (MFD) of at least 0.008 μm and / or at most 0.250 μm, as measured according to ASTM F316-03.

4. At a pressure of 1 bar and a temperature of 23°C, it has a viscosity of at least 5 l / (h x m ２ 4. The microporous article of claim 1, wherein the microporous article has a water flux permeability of 100% or less.

5. The microporous article of any one of claims 1 to 4, having a tensile modulus greater than 250 MPa when measured at room temperature (23°C) according to ASTM D638.

6. The microporous article of any one of claims 1 to 5, which is a membrane selected from the group consisting of symmetric membranes and asymmetric membranes.

7. the membrane is in the form of a flat sheet; or - tubular membranes with a diameter of more than 3 mm; - capillary membranes with a diameter comprised between 0.5 mm and 3 mm; and - hollow fibres with a diameter of less than 0.5 mm 7. The microporous article of claim 6 in the form of a tubular membrane selected from the group consisting of:

8. the copolymer (PEDEK-PEEK) has a molar ratio (R ＰＥＤＥＫ ): (R ＰＥＥＫ ) in which the repeating unit (R ＰＥＤＥＫ ) and (R ＰＥＥＫ and / or In the copolymer (PEDEK-PEEK), the repeating unit (R ＰＥＤＥＫ ) and (R ＰＥＥＫ ) is at least 70 mole % based on the total number of moles of repeat units; and / or the copolymer (PEDEK-PEEK) has the following formulae (KA) to (KM): 【Transformation 3】 【Chemistry 4】 (In each of the above formulas (KA) to (KM), each R′ is equal to or different from each other, and in each occurrence is a C １ ~C １２ groups; sulfonic acid and sulfonate groups; phosphonic acid and phosphonate groups; amine and quaternary ammonium groups; and each j' is equal to or different from one another and, in each occurrence, is independently selected from 0 and integers 1 to 4. A repeating unit (R ＰＡＥＫ ) a repeating unit (R ＰＥＥＫ ) and (R ＰＥＤＥＫ ) and a repeating unit (R ＰＡＥＫ The microporous article of any one of claims 1 to 7, further comprising:

9. The copolymer (PEDEK-PEEK) has a repeating unit (R ＰＥＥＫ ) and (R ＰＥＤＥＫ ) and / or consisting essentially of repeating units of formula (I) (R ＰＥＥＫ ), the bonds between the phenyl groups are in the para position of each of the phenyl rings; and / or each j′ is zero; and / or the repeating unit (R ＰＥＥＫ ) is represented by formula (Ia): 【Transformation 5】 and / or a repeating unit of formula (II) (R ＰＥＤＥＫ ), the bonds between the phenyl groups are in the para position of each of the phenyl rings; and / or each k" is zero; and / or the repeating unit (R ＰＥＤＥＫ ) is represented by formula (IIb): 【Transformation 6】 The microporous article according to any one of claims 1 to 8.

10. A method for producing the microporous article of any one of claims 1 to 9, comprising: Step 1. - Processing a polymer composition [composition (C)] comprising a copolymer (PEDEK-PEEK) and at least one additional polymer [polymer (P)] into a solid article; Step 2. - Heat treating the solid article under conditions that cause at least partial crystallization of the copolymer (PEDEK-PEEK); and Step 3. - contacting the heat-treated article resulting from step 2 with a solvent for said polymer (P) to at least partially remove said polymer (P) to obtain a microporous article. A method comprising:

11. 11. The method of claim 10, wherein melt-forming is used in step 1 to process the composition (C) into an article by film extrusion.

12. 12. The method according to claim 10 or 11, wherein the polymer (P) is selected from amorphous polymers, i.e. polymers having a heat of fusion of less than 5 J / g, and / or the polymer (P) is selected from the group consisting of polymers that can form a miscible blend with the copolymer (PEDEK-PEEK), or the polymer (P) is selected from polymers that can form a miscible blend, i.e. polymers (P) that, when combined with the copolymer (PEDEK-PEEK), provide a blend with a single amorphous phase that exhibits a single glass transition temperature.

13. The polymer (P) contains at least 50 mol % of repeating units (R ) containing at least one aromatic ring, at least one imide group in its amide acid form, and at least one ether group, based on the total number of moles in the polymer. ＰＥＩ 13. The method of claim 12, wherein the polymer is a poly(etherimide) polymer [polymer(PEI)] comprising:

14. The polymer (PEI) comprises at least 50 mole % of a copolymer of formula (XVIII), based on the total number of moles in the polymer: 【Chemistry 10】 [In the formula, R is selected from the group consisting of substituted and unsubstituted divalent organic radicals; T can be either —O— or —O—Ar″—O—; The divalent bonds of the -O- or -O-Ar"-O- group can be in the 3,3', 3,4', 4,3', or 4,4' positions, and Ar" is an aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having from 5 to 50 carbon atoms. Repeating units (R ＰＥＩ 14. The method of claim 13, wherein the polymer comprises:

15. The polymer (PEI) comprises at least 50 mole % of the imide or its corresponding amic acid form, based on the total number of moles in the polymer, of formula (XXIII) or (XXIV): 【Chemistry 13】 Repeating units (R ＰＥＩ 14. The method of claim 13, wherein the polymer comprises:

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