Complex and its use in organic affinity nanofiltration

Abstract

The present invention provides - on a porous substrate comprising fibers, preferably fibers of a non-conductive material, and in the interstices of the substrate, there is a porous layer (1) made up of oxide particles bonded to one another and partially to the substrate and comprising at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably Al2O3, ZrO2, TiO2 and SiO2, a composite having, at least on one side, another porous layer (2) which is bonded to one another and partly to the layer (1) and which comprises oxide particles which comprise at least one oxide selected from oxides of the elements Al, Zr, Ti and Si, preferably Al2O3, ZrO2, TiO2 and SiO2, The oxide particles present in layer (1) have a larger median particle size than the oxide particles present in layer (2), The median particle size (d 50 ) is 0.5 to 4 μm, The median particle size (d 50 ) is 0.015 to 0.15 μm, preferably 0.04 to 0.06 μm, a composite, wherein a polymer coating (PB) comprising one or more polysiloxanes is present on top of or on top of layer (2); A method for producing the corresponding composite; and Its use, in particular in organophilic nanofiltration Regarding.

Description

Technical Field

[0001] The present invention relates to - a porous layer (1) composed of oxide particles that are bonded to each other, partially bonded to a substrate, and contain at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably Al2O3, ZrO2, TiO2, and SiO2, on and in the gaps of a porous substrate containing fibers, preferably fibers of a non-conductive material, - a composite having, on at least one side, another porous layer (2) that is bonded to each other, partially bonded to layer (1), and contains oxide particles containing at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably Al2O3, ZrO2, TiO2, and SiO2, The oxide particles present in layer (1) have a larger median particle size than the oxide particles present in layer (2), The median particle size (d 50 ) of the oxide particles in layer (1) is 0.5 to 4 μm, The median particle size (d 50 ) of the oxide particles in layer (2) is 0.015 to 0.15 μm, preferably 0.04 to 0.06 μm, a composite in which a polymer coating (PB) containing one or more polysiloxanes is present on the top or upper part of layer (2); a method for producing a corresponding composite; and its use, particularly in organic affinity nanofiltration relates to.

Background Art

[0002] Membranes have hitherto been used for the separation of organic solutions. This also includes separating valuable substances with a higher molecular weight than dissolved impurities, catalysts, or solvents from the solvent.

[0003] At approximately 30 bar (30 * 10 5 Pa), the maximum flow rate (toluene flow rate measured as defined in the examples) is only 50 to 150 L / m 2Since it is h, the applications of the membranes that can be used so far are very limited. Since direct applications in the petrochemical industry are also possible, if this flow rate clearly increases, it will lead to the very wide use of the technology.

[0004] The increase in flow rate can be easily achieved, for example, by performing nanofiltration at a high temperature in the range of 120 to 200 °C. However, there is currently no available membrane material that exhibits sufficiently high thermal stability at an acceptable manufacturing cost.

[0005] For example, known silicone-coated PAN membranes for nanofiltration manufactured by Evonik Resource Efficiency GmbH include the trade names PURAMEM® SELECTIVE, PURAMEM® PERFORMANCE, and PURAMEM® FLUX, and their application methods (application windows) are 20 to 40 bar (20 to 40 * 10 5 Pa) and a maximum temperature of 50 °C.

[0006] Various attempts to manufacture membranes from thermally stable polymers have so far ended in failure. This was mostly due to the existing porous support structure being compressed at high pressure and high temperature, not allowing further flow through the membrane, or, in the worst case, when cracks or fissures occurred in the membrane.

[0007] From the field of gas separation, membranes with fluoropolymer coatings are known. In Patent Document 1, Porogen proposed applying a fluoropolymer layer on a porous PEEK support (PEEK film). The issue at that time was the bonding of the fluoropolymer to the support via functional groups.

[0008] Patent Document 2 proposes an electrical separator having a composite structure composed of a two-dimensional flexible substrate provided with a large number of openings and having a coating film thereon. The material of the substrate is selected from metals, alloys, plastics, glass and carbon fibers, or combinations of such materials, and the coating film is a two-dimensionally continuous porous non-conductive ceramic coating film. The use of the ceramic coating film ensures thermal and chemical stability.

[0009] The fact that such a composite can be modified with a polymer is described, for example, in Patent Document 3. However, the polymer used therein essentially has a spherical structure and needs to be present in the composite.

[0010] Professor James Ekonmy's group issued a report on a research project regarding the production of thin film composite (TFC) membranes. In it, the selected layers are applied to a porous support (e.g., polysulfone or ceramic membrane) (http: / / economy.matse.illinois.edu / membrane.htm).

[0011] Patent Document 4 describes a hybrid membrane in which a ceramic material is modified with an organic separation layer. These are said to be superior in long-term stability to membranes using a polymer carrier, but the surface of the polymer has irregularities. Patent Document 5 describes a similar hybrid membrane, but the ceramic membrane is based on a polymer carrier material, particularly polymer non-woven fabric.

[0012] Multilayer substantially ceramic composite materials are also already known from Patent Document 6. The composite materials described therein are used as battery separators.

[0013] Unpublished Patent Document 7 describes a composite used as a gas separation membrane and having a layer based on a fluorine-containing polymer as a separation active polymer layer.

Prior Art Documents

Patent Documents

[0014] Patent Document 1 International Publication No. 2007 / 149640 A2 Patent Document 2 German Patent Gazette No. 19838800 Patent Document 3 European Patent Publication No. 1925047 A1 Patent Document 4 German Patent Publication No. 10139559 A1 Patent Document 5 German Patent Publication No. 10208278 A1 Patent Document 6 German Patent Publication No. 10255121 A1 Patent Document 7 European Patent Application No. 19217879.6 Summary of the Invention Problems to be Solved by the Invention

[0015] The problem to be solved by the present invention was to provide a membrane material that does not have one or more drawbacks of the membrane materials known from the prior art. Means for Solving the Problems

[0016] Surprisingly, it has been found that by applying a polymer coating containing polysiloxane to a composite having a very smooth surface, a membrane that solves this problem can be obtained.

[0017] Accordingly, the present invention provides a composite as described in the claims and detailed below; a method for producing the composite; and the use of these composites.

[0018] More specifically, the present invention - On a porous substrate containing fibers, preferably fibers of a non-conductive material, and in the gaps of the substrate, there is a porous layer (1) composed of oxide particles that are bonded to each other, partially bonded to the substrate, and contain at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably at least one of Al2O3, ZrO2, TiO2, and SiO2. - It is a composite having, on at least one side, another porous layer (2) that is bonded to each other, partially bonded to layer (1), and contains oxide particles containing at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably at least one of Al2O3, ZrO2, TiO2, and SiO2. The oxide particles present in layer (1) have a larger median particle size than the oxide particles present in layer (2). The median particle size (d 50 ) of the oxide particles in layer (1) is 0.5 to 4 μm. The median particle size (d 50 ) of the oxide particles in layer (2) is 0.015 to 0.15 μm, preferably 0.04 to 0.06 μm. A composite in which a polymer coating (PB) containing one or more polysiloxanes is present on the top or upper part of layer (2); A method for producing the corresponding composite; Its use, particularly in organic affinity nanofiltration; A separation device comprising the composite material according to the present invention or a composite material prepared according to the present invention is provided.

[0019] The composite of the present invention has the advantage of having a very smooth surface with pores, so that a separation-active polymer layer or film having a substantially uniform thickness can be applied everywhere.

[0020] In addition, the composite of the present invention has the advantage that it can be made sufficiently flexible, preferably sufficiently flexible, to be further processed in a conventional manner to obtain membrane modules, in particular so-called spiral modules. These membrane modules are the normal form of use of the membranes. They are assemblies that are easy to handle, whereby the membranes installed therein can be introduced, for example, into industrial plants.

[0021] Due to the uniform thickness, defects such as holes can be eliminated from the entire surface of the separation active layer (polymer coating film), and uniform permeability on the surface can be achieved. This can be detected by point flow measurement using an appropriate gas.

[0022] The (gas) flow rate through the membrane according to the present invention can exceed 200 GPU, preferably exceed 500 GPU in the case of carbon dioxide. The flow rate of 1 GPU is 0.0027 m 3 (STP) / (m 2 h bar) (0.0027 × 10 -5 m 3 (STP) / (m 2 h Pa)).

[0023] Due to the uniform permeability of the membrane surface, preferential flow through some regions of the membrane is avoided, and it is avoided that these regions are particularly rapidly damaged by foreign substances that may be present at non-negligible concentrations and the separation performance rapidly decreases in the corresponding partial regions of the membrane.

[0024] By using an appropriate combination of a substrate containing fibers, in particular a nonwoven substrate, in combination with oxide particles, the tensile strength in the longitudinal direction of the composite according to the present invention can be made greater than 40 N / m.

[0025]

[0026] ​ The composite material according to the present invention and its use as a membrane in organic affinity nanofiltration at high temperature enable direct treatment of the substance stream obtained at high temperature in each manufacturing process. As a result, cumbersome cooling of the substance stream to be treated before organic affinity nanofiltration can be omitted.

[0027] The composite of the present invention; the method according to the present invention for producing the composite; and the use according to the present invention of the composite are described below by way of example, but the present invention is not intended to be limited to these exemplary embodiments. When ranges, general formulas or groups of compounds are defined below, these are intended to include not only the corresponding ranges or groups of compounds explicitly mentioned, but also all sub-ranges and sub-groups of compounds obtained by excluding individual values (ranges) or compounds. When documents are cited in the context of this specification, their contents shall form part of the disclosure of the present invention in its entirety with respect to the matters specifically mentioned. When numbers are indicated as percentages below, these are, unless otherwise specified, weight %. When average values, such as molar mass average values, are reported below, these are, unless otherwise specified, numerical average values. When the properties of materials, such as viscosity, gas flow rate, selectivity, etc., are mentioned below, these are the properties of the materials at 25 °C, unless otherwise specified. When chemical (experimental) formulas are used in the present invention, the specified indices may be not only absolute numbers but also average values. The indices for polymer compounds are preferably average values.

[0028] The composite according to the present invention is - On and in the gaps of a porous substrate containing fibers of a non-conductive material, there is a porous layer (1) composed of oxide particles that are bonded to each other, partially bonded to the substrate, and contain at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably Al2O3, ZrO2, TiO2, and SiO2, more preferably Al2O3 and SiO2. - having, on at least one side, another porous layer (2) that is joined to itself, and is partially joined to layer (1), and contains oxide particles containing at least one oxide selected from oxides of elements Al, Zr, Ti, and Si, preferably Al2O3, ZrO2, TiO2, and SiO2, more preferably Al2O3 and SiO2, The oxide particles present in layer (1) have a larger median particle size than the oxide particles present in layer (2), The median particle size (d 50 ) of the oxide particles in layer (1) is from 0.5 to 4 μm, The median particle size (d 50 ) of the oxide particles in layer (2) is from 0.015 to 0.15 μm, preferably from 0.04 to 0.06 μm, A polymer coating (PB) containing one or more polysiloxanes is present on top of or above layer (2). What polysiloxane means in the context of this specification is an organically modified or unmodified polysiloxane, often also called silicone. Preferred polysiloxanes or silicones are those described in International Publication No. WO 2011 / 067054 A1.

[0029] The median particle size in the layer can be measured by taking a scanning electron micrograph (for example, using a JEOL JSM IT300 scanning electron microscope) and performing image evaluation. Alternatively, the particle size of the particles used can also be measured in accordance with ISO 13320 using a suitable instrument for measuring particle size by static light scattering (Mastersizer Hydro 2000S, Malvern Panalytical, Malvern, UK) before coating and solidification in the dispersion. This apparatus measures the particle size using laser diffraction. For this purpose, it is necessary to examine the refractive index of the particles to be measured and record it in the software. To measure the particle size distribution, the solid material to be measured is dispersed in deionized water by stirring at 1750 rpm and applying ultrasonic waves as necessary. A sufficient number of aliquots of the dispersed sample are pipetted into the dispersion module of the measuring instrument where the laser light shielding is 15% - 20%. Using a Mastersizer Hydro 2000S, the intensities of two laser beams (wavelengths: 633 nm and 466 nm) scattered by the sample are measured. The three-dimensional distribution of the scattering intensity is evaluated by Mie theory. This is used to confirm the particle size and the particle size distribution. The measurement results are also reported as a distribution curve. What is obtained in this way is not only a description of the average particle size but also information regarding the smallest and largest particles in the sample. d 50 represents the median particle size. In relation to this, d 50 refers to the diameter below which 50% of the volume weight size distribution is smaller. Therefore, further parameters are d 10 as the scale of the smallest particles in the sample and d 90 as the scale of the larger particles. d 10 and d 90 The closer they are, the narrower the particle size distribution.

[0030] Oxide particles containing or consisting only of oxides selected from Al2O3 and SiO2 are particularly preferred. Very particularly preferred oxide particles with a median particle size (d 50 ) of 0.015 - 0.15 μm, preferably 0.04 - 0.06 μm, are those based on or containing SiO2. Examples of particularly preferred oxide particles are pyrogenic oxide particles such as those supplied under the brand names Aerosil® or Aeroxide® by Evonik Resource Efficiency, or equivalent products from other suppliers.

[0031] The composite according to the present invention without the polymer coating preferably has a Gurley number of 200 to 1700 seconds, preferably 250 to 1200 seconds, more preferably 300 to 800 seconds. The Gurley number can be measured, for example, before applying the polymer coating.

[0032] The Gurley number is a measure of the permeability of the porous material. It is defined as the time (in seconds) required for 100 cm 3 of air to diffuse through a 1-inch 2 sample under defined conditions. For measurement, a circular sample with a diameter of 44 mm is punched out using a wad punch. The sample to be tested is checked on an illumination stage for defects and, in some cases, holes. Only visually perfect samples are suitable for measurement. Before starting the measurement, it is necessary to ensure that the level is adjusted based on the measuring instrument (Densometer Model No. 4110N, Gurley Precision Instruments, Troy, NY) and that the external cylinder is filled with Gurley Precision Instruments' densometer oil up to the mark. In the test operation of the densometer, it is necessary to measure the time required for a specific amount of air to flow through a specific sample area under a certain gentle pressure. Compressed air is generated by an internal cylinder of a standard weight with a precise diameter and freely flows into the partially oil-filled external cylinder to ensure airtightness.

[0033] The composite according to the present invention preferably has a thickness of 100 to 400 μm, preferably 125 to 200 μm, more preferably 130 to 170 μm. The thickness is measured using a micrometer manufactured by Mitutoyo (Digital Micrometer MDC-25PX, 0 to 25 μm).

[0034] The composite according to the present invention preferably has an average pore diameter of 60 to 140 nm, preferably 75 to 130 nm. The average pore diameter is measured using Porolux 1000 (porometer, Eke, Belgium) by gas flow porometry as described below.

[0035] For this purpose, a circular sample with a diameter of 25 mm is punched out from the material to be analyzed, dried at 100 °C for 1 hour in a drying cabinet to remove moisture from the pores, and then immediately placed in this fluid so as to fill all the existing pores with the Porefil wetting fluid. Then, in order to ensure that all the pores are filled with Porefil, the sample is degassed by briefly applying a reduced pressure (150 mbar or 15 kPa) in a desiccator. The degassed sample is placed in the sample holder of the measuring instrument, and the sample holder is tightened with a screw.

[0036] The measurement of the pore radius distribution is based on the measurement principle of capillary flow porometry. The sample wetted with the wetting liquid and degassed is exposed to an inert gas pressure (nitrogen) that increases step by step in the measurement cell, and the pore diameter corresponding to the applied pressure is emptied by the gas pressure. At the same time, the gas flow rate at the increasing pressure is recorded. In continuous pores, the exchange of the wetting liquid and nitrogen takes place. This is continued until the relevant pore range is covered, that is, until the liquid in the smallest pores present in the measurement region disappears. Subsequently, the pressure in the measurement cell is lowered again, and the measurement is repeated for the sample that has just been dried. The difference between the wetting curve and the drying curve is used to calculate the pore size distribution. The porometry measurement provides information on the largest pore radius present ("bubble point") and the most common and smallest pore diameter.

[0037] The composite according to the present invention preferably has a surface roughness Sq measured as described below on the surface of layer (2) of less than 10 μm, more preferably less than 8 μm.

[0038] The surface roughness is measured based on a 2 cm x 2 cm measurement area measured by a confocal microscope (http: / / ak-rauheit.de / files / 3D%20Kenngr%F6%DFen.pdf). This measurement can be carried out, for example, using a confocal microscope μsurf expert manufactured by Nanofocus (Overhausen). This is done by using an 800xs type lens and scanning a 3 x 3 image. The evaluation is carried out using μsoft analysis premium 7.4.8164 evaluation software on an unfiltered surface in accordance with DIN ISO25178. The Rdq value is determined in accordance with DIN ISO4287.

[0039] A preferred composite according to the present invention has a Gardiner number of 200 to 1700 seconds, preferably 250 to 1200 seconds, more preferably 300 to 800 seconds, a thickness of 100 to 400 μm, preferably 125 to 200 μm, more preferably 130 to 170 μm, an average pore diameter of 60 to 140 nm, preferably 75 to 130 nm, and / or, preferably and, a surface roughness Sbq of less than 10 μm, more preferably less than 8 μm, and a composite having the most preferred parameters for each is particularly preferred.

[0040] In the composite according to the present invention, the base material is preferably a non-woven fabric, knit, or laid scrim, preferably a non-woven fabric or laid scrim, more preferably a non-woven fabric. The fibers preferably have a size of 1 to 200 g / km. The fibers preferably consist of polyacrylonitrile, polyamide, polyester, and / or polyolefin, preferably polyacrylonitrile. The fibers are more preferably 10 to 80 g / km in size, most preferably 50 g / km, and consist of polyacrylonitrile, polyamide, polyester, and / or polyolefin, preferably polyester, particularly polyethylene terephthalate.

[0041] The base material preferably has a thickness of 50 to 150 μm, preferably 100 to 130 μm. The base material preferably has a basis weight of 40 to 150 g / m2 Preferably 50 to 120 g / m 2 Preferably 50 to 100 g / m 2 Most preferably 60 g / m 2 is. The base material is more preferably 50 to 150 μm thick, preferably 100 to 130 μm thick, and the basis weight is 40 to 150 g / m 2 Preferably 50 to 120 g / m 2 Preferably 50 to 100 g / m 2 Most preferably 60 g / m 2 is.

[0042] Particularly preferred base materials are those having all the parameters mentioned, and most preferably those having each of the most preferred parameters mentioned.

[0043] Particularly suitable polymer coatings containing polysiloxane have a high intrinsic gas permeability exceeding 200 barrers (cm 3 / cm * s * cmHg) for CO2. Preferred polysiloxanes or silicones are, for example, polydimethylsiloxane, polyethylmethylsilicone, nitrile silicone, polytrimethylsilylpropene, or corresponding copolymers. The polymer coating (PB) preferably has a thickness of 0.05 μm to 10 μm, preferably 3 μm to 8 μm.

[0044] For the rapid characterization of composites having a polymer coating, these were described by simple and reliable measurements of the selectivity and flow rate of clean gases. For this purpose, a test piece of a 40 mm diameter membrane was introduced into a measuring cell for flat membranes. Next, the pressure of an appropriate gas was applied to this membrane stepwise (first methane, then carbon dioxide) on the high-pressure side. The measurements were carried out at a differential pressure across the membrane of 2 to 25 bar (2 to 25 * 10 5 Pa). A Bronkhorst mass flow meter was used to quantify the amount of gas permeated.

[0045] The obtained data was standardized using the geometric data of the membrane measurement cell and expressed in relative terms. The clean gas selectivity was calculated using the ratio of the permeation gas amounts of different gases at the same transmembrane differential pressure. For a defect-free membrane, the value of carbon dioxide relative to methane must be greater than 2.7. By appropriately standardizing the individual carbon dioxide fluxes through the membrane, the average permeability can be easily calculated, which, for a defect-free polymer coating that is sufficiently thin and prepared by the above method, (always in combination with a clean gas selectivity exceeding 2.7) exceeds 500 GPU.

[0046] The composite according to the present invention preferably has a toluene flow rate at 130 °C and a transmembrane differential pressure of 30 bar (30 * 10 5 Pa) as measured as defined in the examples, exceeding 130 L / m 2 h, preferably exceeding 250 L / m 2 h, more preferably exceeding 300 L / m 2 h, and most preferably exceeding 400 L / m 2 h.

[0047] The composite of the present invention is notable in terms of good stability during handling. This reduces, for example, the incidence of defects / damage to the composite that can occur during introduction into a gas mixture separation device. Typical defects / damage are breakage of the ceramic due to kinking or handling with sharp objects.

[0048] The composite of the present invention preferably does not have any layer or coating containing a fluorine-containing polymer.

[0049] The composite according to the present invention is preferably flexible. In the context of this specification, "flexible" means that the composite can be wound around a bar or tube up to 15 mm in diameter without being damaged. A particularly preferred composite according to the present invention can be wound around a rod or bar with a minimum diameter of up to 5 mm without being damaged. That the corresponding composite has been spared from damage can be easily demonstrated by measuring the gas flow rate of nitrogen. In this connection, if the gas flow rate measured with nitrogen increases by more than 100%, it is considered that the composite has a defect / damage. Thanks to the flexibility of the composite according to the present invention, these can be introduced into the typical module form of a flat membrane in a very simple way and are particularly suitable for use in spiral modules, plate or frame modules, pocket modules, and other devices designed for flat membranes.

[0050] Thanks to the partial ceramic structure of the composite according to the present invention, these also have the advantage that there is preferably little or no change in thickness and / or porosity under compressive stress. This has the advantage that even under high compressive stress, the entire composite enables substantially constant flow performance in GPU units, and the compressive porous structure does not cause a decrease in flow at high pressure. To measure the change in thickness and / or porosity, a circular sample with a diameter of 35 mm can be cut out from the composite according to the present invention and a pressure of up to 52 bar (52 * 10 5 Pa) can be applied with a hydraulic press while measuring the thickness (using an instrument manufactured by INSTRON). Using a graph plotting the thickness as a function of the compressive pressure, after repeating the compressive stress and relaxation three times, the change in the thickness of the elastic component can be calculated. In the case of the composite according to the present invention, this is preferably less than 8%, more preferably less than 7%.

[0051] The composite according to the present invention can be manufactured by various methods. Preferably, the composite according to the present invention is obtained by the method according to the present invention described below.

[0052] The method according to the present invention for manufacturing a composite, preferably the composite according to the present invention, is characterized by the following steps. - Step (a): A step of applying the coating composition (BM1) to a substrate having fibers and the gaps between the fibers, the coating composition being produced by combining the following (a1), (a2), and (a3). (a1) Oxides of elements Ti, Al, Zr, and / or Si, preferably Al2O3, ZrO2, TiO2, and SiO2, more preferably oxides of elements Al and Si, selected and having a median particle size (d 50 ) of 0.5 to 4 μm, and dispersing the oxide particles in water, an inorganic acid, preferably nitric acid, and a dispersion aid to produce a dispersion (D1) of the oxide particles; (a2) Oxides of elements Ti, Al, Zr, and / or Si, preferably oxides of elements Al and Si, selected and having a median particle size (d 50 ) of 15 to 150 nm, preferably 40 to 60 nm, and mixing the oxide particles with water to produce a dispersion (D2) of the oxide particles; (a3) A binder formulation (BF1) produced by mixing at least two organofunctional silanes with an alkanol, preferably ethanol, an inorganic acid, preferably boric acid, and water. - Step (b): A step of curing the coating composition (BM1) at a temperature of 100°C to 275°C, preferably 120°C to 240°C, to produce the first layer (S1'). - Step (c): Optionally, a step of applying the coating composition (BM2) to at least the layer (S1'), the coating composition being produced by combining the following (c1), (c2), and (c3). (c1) Oxides of elements Ti, Al, Zr, and / or Si, preferably Al2O3, ZrO2, TiO2, and SiO2, more preferably oxides of elements Al and Si, selected and having a median particle size (d 50 ) of 0.5 to 4 μm, and dispersing the oxide particles in water, an inorganic acid, preferably nitric acid, and a dispersion aid to produce a dispersion (D3) of the oxide particles; (c2) Oxides of elements Ti, Al, Zr and / or Si, preferably Al2O3, ZrO2, TiO2 and SiO2, more preferably oxides of elements Al and Si, and having a median particle size (d 50 ) of 15 to 150 nm, preferably 40 to 60 nm, are mixed with water to produce a dispersion (D4) of oxide particles; (c3) A binder composition (BF2) produced by mixing at least two organofunctional silanes with an alkanol, preferably ethanol, an inorganic acid, preferably boric acid, and water. - Step (d): A step of curing the coating composition (BM2) at a temperature of 100°C to 275°C, preferably 120°C to 240°C, if necessary, to produce the second layer (S2'). - Step (e): A step of applying the coating composition (BM3) to the layer (S1') or, if present, the layer (S2'), wherein the coating composition (BM3) is produced by combining water and an inorganic acid with the following (e1) and (e2). (e1) An aqueous dispersion (D5) containing oxide particles produced by mixing oxides of elements Ti, Al, Zr and / or Si, preferably Al2O3, ZrO2, TiO2 and SiO2, more preferably oxides of elements Al and Si, and having a median particle size (d 50 ) of 25 to 100 nm, preferably 40 to 60 nm, with water, and ethanol; (e2) A binder composition (BF3) containing at least two organofunctional silanes. - Step (f): A step of curing the coating composition at a temperature of 100°C to 275°C, preferably 120°C to 240°C, to produce the layer (S3'). - Step (g): A step of applying the coating composition (BM4) to the layer (S3'), if necessary, wherein the coating composition (BM4) is produced by combining water and an inorganic acid with the following (g1) and (g2). (D6) An aqueous dispersion containing oxide particles selected from oxides of elements Ti, Al, Zr and / or Si, preferably oxides of elements Al and Si, and having a median particle size of 15 to 150 nm, preferably 40 to 60 nm, and ethanol; (BF4) A binder formulation containing at least two organofunctional silanes. - Step (h): A step of curing the coating composition at a temperature of 100 to 275 °C, preferably 120 to 240 °C, if necessary, to produce layer (S4’). - Step (i): A step of applying a polymer coating containing polysiloxane to layer (S3’), or layer (S4’) if it exists.

[0053] Polysiloxane refers to an organically modified or unmodified polysiloxane, often also called silicone.

[0054] The composite according to the present invention preferably does not include any step of applying a layer or coating containing a fluorine-containing polymer.

[0055] The median particle size (d 50 ) is 15 to 150 nm, preferably 40 to 60 nm, and the oxide particles that are very particularly preferably used are based on SiO2 or consist of SiO2. The corresponding particles are available, for example, from Evonik Resource Efficiency GmbH under the name Aerosil® Ox50.

[0056] In the production of the binder complexes BF1 to BF2, it is preferable to use a sufficient amount of acid such that the pH is from 2 to 5. In the production of the coating film compositions BM1 to BM4, it is preferable to use a sufficient amount of acid such that the pH is from 2.5 to 5. When producing a binder complex using AMEO, the pH is preferably above 8, preferably from 8.5 to 9.5. In particular, when using AMEO in the binder complex, it may be advantageous to combine the individual constituent steps of the production of the binder complex so that the raw materials of the binder complex are directly metered into the coating film composition without an intermediate step. However, this procedure can also be used for the formulation of all other coating film compositions.

[0057] The dispersing aid to be used may be any suitable dispersing aid. It is preferable to use a dispersing aid sold under the name DOLAPIX by Zschimmer & Schwarz GmbH & Co KG or under the name TEGO® Dispers by Evonik Resource Efficiency GmbH. The dispersing aid to be used is more preferably, for example, a carboxylic acid compound sold under the name DOLAPIX CE 64 by Zschimer & Schwarz GmbH & Co KG.

[0058] In the method according to the invention, it may be advantageous and thus preferable to carry out optional steps (c) and (d) and steps (g) and (h) because a composite body with a low surface roughness, preferably with a surface roughness Sq less than 10 μm, more preferably less than 8 μm, can be obtained more easily and reliably. Therefore, it is particularly preferable to carry out both steps (c) and (d) and steps (g) and (h). In this way, it is also possible to reliably avoid defects in the composite body, i.e., sites where, for example, the average pore diameter, Gurley number, thickness and / or surface roughness deviate clearly from the claimed or preferably described values.

[0059] The organic functional silane to be used, preferably an alkoxy-functional silane, more preferably a methoxy and / or ethoxy-functional silane, is preferably 3-glycidoxytrimethoxysilane, methyltriethoxysilane, octyltriethoxysilane, aminopropyltriethoxysilane, and / or tetraethoxysilane. The organic functional silane to be used is preferably 3-glycidoxytrimethoxysilane, methyltriethoxysilane, and tetraethoxysilane. In the binder formulation (BF1) and / or (BF2), preferably (BF2), 3-glycidoxytrimethoxysilane, methyltriethoxysilane, and tetraethoxysilane are used at a mass ratio of 2 to 4:0.5 to 1.5:1, more preferably 2.5 to 3.5:0.75 to 1.25:1, and most preferably 3:1:1. In the binder formulation (BF3) and / or (BF4), preferably (BF4), 3-glycidoxytrimethoxysilane, methyltriethoxysilane, and tetraethoxysilane are used at a mass ratio of 0.5 to 1.5:1.5 to 2.5:1, more preferably 0.75 to 1.25:1.75 to 2.25:1, and most preferably 1:2:1.

[0060] It may be advantageous if the coating compositions (BM3) and (BM4) are the same composition. Similarly, it may be advantageous if the coating compositions (BM1) and (BM2) are the same composition. In this way, by producing the layers (S1') and (S2'), or the layers (S3') and (S4'), a layer (1) or (2) with a uniform structure can be obtained. This also helps to avoid a large number of defects in the composite.

[0061] The substrate used in the method according to the present invention is preferably a polymer non-woven fabric containing fibers selected from polyacrylonitrile, polyester, polyamide, and / or polyolefin, preferably polyester, more preferably polyethylene terephthalate. The substrate preferably used has preferably the above parameters, particularly the parameters described as particularly preferred.

[0062] The coating composition can be cured by passing it, for example, through a hot air oven, an IR oven, or another oven. The coating compositions BM1 to BM4 are preferably cured at a temperature of 100 to 275 °C, more preferably at a temperature of 120 to 240 °C.

[0063] Alternatively, the polymer film can be produced, for example, by applying a solution of a silicone polymer to layer (S3’) or layer (S4’) if present, and / or to the polymer layer. The solution preferably contains 3 wt% to 10 wt% of the polymer. Suitable solvents when using silicone are, in particular, siloxane compounds, preferably hexamethyldisiloxane, but toluene or isooctane can also be used. When using silicone as the polymer, it is preferable to utilize a multi-component system that can be procured, for example, from Momentive, Panacol, or Evonik Hanse Chemie GmbH. For example, silicone RTV-615 manufactured by Momentive can be used.

[0064] A typical formulation of an addition-crosslinking silicone manufactured by Evonik Hanse Chemie GmbH consists of solution A and solution B with various compositions, and they may be combined in a ratio of 1:10 to 10:1 according to requirements. Solution A may contain a platinum catalyst (platinum-siloxane complex), a vinyl-functional polydimethylsiloxane having a desired molecular weight and a desired vinyl group content, a vinyl-functional QM resin having a desired molecular weight, and silica particles in variable ratios. Solution B contains an SiH-containing polydimethylsiloxane (crosslinking agent) having a desired molecular weight and a desired SiH group content, 0.02 wt% of an inhibitor (e.g., alkynol, divinyltetramethyldisiloxane, methylvinylcyclotetrasiloxane), and may also contain a vinyl-functional polydimethylsiloxane having a desired molecular weight and a desired vinyl group content, a vinyl-functional QM resin having a desired molecular weight, and silica particles in variable ratios.

[0065] The silicone formulation may also be a moisture-cured silicone system. Suitable polymer formulations preferably contain 3% to 7% by weight of the crosslinkable silicone in a solvent suitable for each silicone.

[0066] Drying of the coating film containing or consisting only of polysiloxane is preferably carried out at 50 to 150 °C for 1 to 30 minutes.

[0067] In the production of the polysiloxane solution, not only the polymer and solution concentration but also the mixing time of the polymer components in the solvent are preferably selected so that the mixture penetrates only slightly or preferably not at all into the pore structure of the composite. This can be confirmed by simple preliminary experiments by those skilled in the art.

[0068] Before applying each polymer coating film, it may be advantageous to treat the layer / structure to which the coating film is to be applied with plasma, preferably corona (air plasma). For the treatment of a coating film containing a rubbery polymer, 50 to 900 W min / m 2 , preferably 100 to 300 W min / m 2 , and for the treatment of a ceramic layer (i.e., one containing oxide particles), it is preferably set at 300 to 900 W min / m 2 of power. Equipment suitable for corona treatment is available from Softal (Hamburg).

[0069] The method for producing the composite according to the present invention can be carried out continuously or batchwise. This method is preferably carried out as a roll-to-roll process. Unroll a substrate or a substrate coated one or more times from a roll, guide it through a device for performing one or more steps or sub-steps, and after solidifying the coating layer, wind up the substrate coated one or more times or the composite of the present invention. It is preferable to carry out all steps (a) to (i) and, where appropriate, the corresponding sub-steps in such a way. In winding up the composite, it may be advantageous if the roll contains an intermediate layer that prevents the adhesion or damage of layer (S1') or (S4'), or any polymer layer present. For example, polyethylene terephthalate nonwoven fabric is suitable as an intermediate layer that is also used as a substrate, for example. When the method according to the present invention is carried out as a roll-to-roll process, the web speed is preferably 1 to 500 mm / second, preferably 20 to 50 mm / second.

[0070] By the method according to the present invention, it is possible to obtain the composite according to the present invention. Accordingly, the present invention further provides a separation device comprising the composite according to the present invention or a composite produced according to the present invention.

[0071] The composite according to the present invention or a composite produced according to the present invention may be used, for example, in organic affinity nanofiltration, preferably as an organosilicon nanofiltration membrane, more preferably for separating organic compounds from an organic solvent-containing material stream. In this case, preferably 95% of the molecules having a molecular weight exceeding 800 g / mol are retained by the membrane and are thus separated from the solvent. The solvent preferably has a molecular weight of less than 250 g / mol, preferably less than 150 g / mol, more preferably less than 120 g / mol. Examples of such solvents are, for example, tetrahydrofuran, hexane, heptane, mesitylene, isopropanol, toluene, dichloromethane, acetone, and ethyl acetate.

[0072] Organic nanofiltration or separation can be carried out at a temperature exceeding 100 °C, preferably exceeding 120 °C, more preferably exceeding 150 °C. It may be advantageous if the temperature does not exceed 300 °C, preferably 250 °C, and most preferably 200 °C. More specifically, by using the composite material according to the present invention or the composite material manufactured according to the present invention as a membrane, or by using the separation device according to the present invention, a substance stream having a temperature within the mentioned range, that is, higher than 100 °C and not exceeding 300 °C, preferably higher than 120 °C and not exceeding 250 °C, more preferably higher than 150 °C and not exceeding 200 °C, can be directly processed.

[0073] The present invention will be described in detail with reference to FIGS. 1 to 4. In FIG. 1, TF means the toluene flow rate. In FIGS. 2 and 3, RH means the retention rate, and in both cases, it is measured as defined in Experimental Example 5. FIG. 4 shows the basic structure of the cross-flow filtration device used for measuring the toluene flow rate and the retention rate. Shown is the connection of the storage container VB, the membrane cells 1 and 2 (MZ1, MZ2), the supply pump FP, the permeate pump PP, and the permeate containers 1 and 2 (PB1 and PB2).

[0074] The present invention is illustrated by the following examples, but is not limited thereto.

Brief Description of the Drawings

[0075]

Figure 1

Figure 2

Figure 3

Figure 4

Examples

[0076]

Table 1a

[0077]

Table 1b

[0078] Experimental Example 1: Production of the composite material according to the present invention Experimental Example 1a: Production of Binder Formulation I First, 14.22 g of ethanol and 2.84 g of boric acid were placed in a 250 mL beaker and stirred with a magnetic stirrer. As soon as the boric acid was almost completely dissolved, 18.16 g of GLYEO (equivalent to 15.5 g of GLYMO), 5.14 g of TEOS, and 5.14 g of MTES could be successively added. (This part needed to be changed in each case to change the experimental conditions.) After thoroughly mixing this, 0.03 g of water was added to initiate hydrolysis. After stirring this mixture with a magnetic stirrer for 15 hours, another 7.1 g of water was added while stirring. The silane binder formulation thus prepared was stirred for an additional 5 hours until the "pre-hydrolysis" weakened before use.

[0079] Experimental Example 1b: Production of Particle Formulation I 11 kg of water was placed in a hobbock. Ox50 (5 kg) was added while rotating. This mixture was slowly stirred for 1 hour. To further reduce the particle size, the mixture was passed through a UIP1000 ultrasonic flow cell at a rate of 12 L / hour for 6 hours. The particle size d 50 was measured as specified in the specification to be less than 60 nm. The solid content was approximately 30% by mass.

[0080] Experimental Example 1c: Production of Coating Composition I 97 g of water, 0.44 g of Dolapix CE64, and 1.84 g of a 65% by mass nitric acid solution were successively placed in a 1000 mL beaker and mixed with each other using a magnetic stirrer. 200 g of finely divided alumina (ct1200SG) was added little by little to this mixture while stirring constantly. All the components were weighed, and once they were well mixed, the dispersion was treated with an ultrasonic dispersion finger (Hielscher UP200) to break up all the existing aggregates. 42 g of ethanol was added to this dispersion, and then the mixture was stirred for at least an additional 15 hours. After 15 hours had passed, 13.5 g of a 30% OX50 dispersion prepared according to Experimental Example 1b and 8.74 g of water, or 4 g of Aerosil Ox50 and 18 g of water were added. Subsequently, 52.6 g of the prepared silane binder formulation was added, and the entire dispersion was left to age by standing still for at least another 15 hours. The resulting coating composition had a solids content of 58.7% and could be used in coating experiments in this form.

[0081] Experimental Example 1d: Production of Binder Formulation II First, 10.45 g of ethanol and 0.84 of boric acid were placed in a 250 mL beaker and stirred with each other using a magnetic stirrer. As soon as the boric acid had mostly dissolved, 5.89 g of GLYEO, 5.0 g of TEOS, and 10 g of MTES could be added successively. (This part had to be changed in each case in order to vary the experimental conditions.) After mixing this well, 0.03 g of water was added to initiate hydrolysis. After stirring this mixture with a magnetic stirrer for 1 hour, another 5.19 g of deionized water was added while stirring. The silane binder formulation II prepared in this way was stirred for an additional 15 hours before use.

[0082] Experimental Example 1e: Production of Coating Composition II First, 101.35 g of the Ox50 dispersion from Experimental Example 1b was placed in a 1000 mL beaker, and then 299.88 g of deionized water and 3 g of a 65 mass% nitric acid solution were added successively, and the mixture was stirred with a magnetic stirrer for 15 hours.

[0083] 37.39 g of the prepared (silane) binder formulation II and 150.4 g of ethanol were added to this dispersion. Subsequently, this mixture was stirred for an additional 2 days.

[0084] The obtained coating composition II has a solid content of about 5.7% of Ox50 and can be used in coating experiments in this form.

[0085] Experimental Example 1f: Coating Method A strip of the object to be coated (fabric, non-woven fabric, or knitted fabric) with a width of 10 cm and a length of about 1 m was prepared. Alternatively, the product obtained from the above coating operation can also be used. However, in this case, preferably, it must always be ensured that the same side is processed in the subsequent processing steps.

[0086] Using a pulley mechanism, an automatic film stretching device manufactured by Zehntner was modified so that the web material to be coated was pulled vertically upward at a specified speed of 42 mm / second and drawn out from the dip coating device. In the dip coating device, one side of the material web is bent through a roll so that it does not come into contact with the coating dispersion, and the opposite side of the material web is transported through a tank filled with the dispersion.

[0087] For coating, the mixed dispersion (coating composition I or II) was introduced into a tank having a rotating roll on which the material web was stretched. The filling level of the tank was adjusted so that the solution only immersed 45° of the roll circumference. To guide the material web well and prevent the dispersion from flowing along the material web, the web tension was made greater than 0.1 N / cm of the material web width. The material web was guided into the dispersion at a speed of 42 mm / second, at room temperature, and at standard pressure.

[0088] Finally, the material web was left hanging vertically in a well-ventilated place for an additional 30 minutes, and then placed on a grid and dried and solidified at 120°C for 1 hour in a drying cabinet.

[0089] The dried material web can be coated again, or the completed composite can then be cut to an appropriate size by cutting or punching for each test or use.

[0090] To manufacture the composite material of the present invention, the coating film was applied twice continuously with Coating Composition I and twice with Coating Composition II. Coating Composition I and II used in all experimental examples may be the same or different. In order to confirm the optimal raw materials (substrate, coating composition, particle formulation, binder formulation, etc.), in preliminary experiments, the coating film was applied once or multiple times as appropriate with only Coating Composition I. The corresponding table describes the number of coating film operations respectively.

[0091] Regarding the experiment according to Experimental Example 1, it was similarly conducted using different particle formulations, different Coating Compositions I and II, different binder mixtures I and II, and different process parameters. Tables 2a to 2l show the raw materials and amounts used, as well as the process parameters used in each case.

[0092] [Table 2a]

[0093] [Table 2b]

[0094] [Table 2c]

[0095] [Table 2d]

[0096] [Table 2e]

[0097] [Table 2f]

[0098]

Table 2g

[0099]

Table 2h

[0100]

Table 2i

[0101]

Table 2j

[0102]

Table 2k

[0103]

Table 2l

[0104] Experimental Example 2: Characterization of the Composite The composites produced in the experimental example were characterized as follows. The results are summarized in Table 3.

[0105] Roughness: The minimum Rdq (Rdq min.), maximum Rdq (Rdq max.), and SDQ were measured as described in detail above.

[0106] Composites A - D: All composites have individual regions showing low roughness (minimum Rdq) and individual regions showing high roughness (maximum Rdq). Therefore, these values are not sufficiently reliable for use in making decisions regarding the optimal substrate.

[0107] From the images taken within the measurement range of the coarseness value, it can be directly inferred that for the composite D based on monofilament weaving, due to structural reasons of a large total thickness, the height and depth change periodically. Therefore, since a smooth surface cannot be obtained with this material, this material was further evaluated.

[0108] The glass fiber weave (substrate C) has the lowest minimum RDq and maximum Rdq and low coarseness compared to composites A - D, making it very suitable. However, the ceramic layer on the glass fiber weave tends to crack because the gaps between filaments, especially individual fibers, are not sufficiently impregnated by the coating composition.

[0109] The "wet" non - woven fabrics (substrates A and B) and paper are suitable as substrates because they are characterized by a very smooth structure (no protruding fibers). However, when using individual thick fibers, since these need to be very substantially filled (closed), great care must be taken with the gaps between the fibers. Therefore, particularly suitable substrates are PET non - woven fabric and carbon fiber non - woven fabric. The PET non - woven fabric is more suitable for further research because the coating film is smoother (due to small RDq and SDQ).

[0110] Spunbond non - woven fabric and melt - blown non - woven fabric are not very suitable, similar to the dry needle - felt used only in preliminary tests. Furthermore, since a sufficiently smooth surface cannot be obtained with only individual coating films, a multi - layer structure often needs to be selected. The first layer particularly functions to fill the gaps between the fibers. After that, the layer needs to be made smoother.

[0111] Composites E - J: Double - coating films with particles of various sizes show the range of use of various particles. ct1200SG (composite E) and MZS1 (composite H) are most suitable for sufficiently filling the gaps in the substrate with ceramic, as is evident from the low Gardner number. The finer the particles and the larger the particles, the less sufficient the filling of the gaps between the fibers (ct3000SG - composite G or MZS3 - composite I).

[0112] The particle mixture of MZS1 and MZS3 provides a relatively good surface quality (refer to the minimum / maximum value of Rdq and the SDQ value in this regard), which is combined with a larger average pore radius (MFP).

[0113] As the resulting composite material is required to have pores less than 100 nm and the gaps between the fibers of the substrate are sufficiently filled, the subsequent operations were carried out especially using ct1200SG (composite A or E) (however, MZS1 - composite H is also equally suitable). In summary, it can be said that particles with a d of 0.5 - 5.0 μm in particle size distribution can be processed. 50 can be processed.

[0114] Composites K - Q: When a layer of fine Ox50 particles is further applied to the surface of ct1200SG, the average pore diameter decreases and the surface quality improves. The composition of the particle content with respect to the silane binder content was changed.

[0115] Depending on the change in the content of the silane binder, no clear trend can be shown regarding the surface quality of the coating film. In order to ensure good bonding between the particles, in many additional experimental examples, the maximum binder content that can still achieve relatively small pores (MFP) was used.

[0116] Composites R - X: Comparing the various particles used, first, it can be seen that the silane binder containing silicon dioxide particles (composites R, T, U) provides a very good smooth surface. However, due to the particle structure, Aerosil 90 (composite T) and Aerosil 200 (composite U), like aluminum oxide Alu C (composite S), have primary particles aggregated, so they are not very suitable. Aerosil Ox 50 (composite R) has the optimal particles (particle size) according to the pores of the basic structure to be coated. Furthermore, Aerosil Ox 50 provides the smallest pores (MFP = 0.11 μm).

[0117] Titanium dioxide P25 (Composite V) forms a very poor quality surface because it can only be stabilized to a limited extent in the dispersion using a binder system under the selected conditions. Zirconium oxide from Roth (Composite W) is substantially as suitable as Aerosil Ox50. Levasil (Composite X) has very small and very stable SiO2 particles, but because these are very small, they penetrate the pores of the base structure (ct1200SG). Therefore, there is little difference between the surface quality of ct1200SG (Composite E) and the surface quality of this sample.

[0118] Composites 2A - 2H: Comparatively hydrophilic silane mixtures with a relatively high proportion of TEOS and GLYEO (Composites 2A, 2D, and 2C) were found to result in coatings that are as smooth as those of composites with relatively hydrophobic silane mixtures having a relatively high proportion of MTES (Composites 2G and 2H). Only composites manufactured with a clearly increased proportion of the crosslinked TEOS component, such as Composites 2B and 2C (where the proportion of TEOS exceeds 25% (m / m)), exhibit a poorer surface quality. The results do not seem to be essentially dependent on the selected particle system. This means that when using various particles, it is not an absolute result, but the trends are the same regarding the composition of various silanes.

[0119] When the surface is very hydrophilic and water droplets are absorbed, a non - measurable contact angle (nm) is shown in Table 3.

[0120] Composites 2I and 2K: The production of a mixture with an aminosilane is not possible in the described form. To enable the preparation of the sample, the silane mixture must be introduced, without pre - hydrolysis, into a vessel where the particle dispersion is already being stirred and hydrolyzed (one - pot method). Otherwise, the pre - hydrolyzate solidifies, i.e., forms a gel. When observing this change during the process, in principle, it is possible to replace GLYEO, which is an adhesion promoting component, with AMEO. More specifically, in this way (and depending on the established pH after the change), it is possible to easily use other particle systems such as P25, for example.

[0121] Various alkylsilanes (IBTEO), in contrast to MTES, have a greater tendency to form aggregates. This results in a very non-uniform surface.

[0122] [Table 3]

[0123] Experimental Example 3: Continuous process for producing a composite In a continuous coating process in a corresponding production system, for example, manufactured by Mattis, having a support unwinder, a coating unit, a dryer, and a winder with tension control, in order to produce the composite according to the present invention (similar to A), the coating composition BM-I-a was prepared in a 70 L stainless steel stirring vessel with a batch size 125 times larger as described above. Then, this was applied to a polyester nonwoven support (05-TH-60W nonwoven fabric) with a width of about 30 cm and a maximum length of 500 m while maintaining a tension of more than 1 N / cm for the material web width by the dip coating method, and in the process, the support was also impregnated. This was introduced into a 5 m long air circulation oven located approximately 50 cm downstream of the dip coating apparatus, and the composite material was dried at 140°C. The material web speed was 1.5 m / min.

[0124] After drying the material web, it was wound up with a predetermined tension, and then a second treatment was performed in another coating operation while maintaining all process parameters. The obtained composite K-VK-1 (similar to composite A) is described by the parameters specified in Table 4.

[0125] a) Hydrophilic composite Subsequently, this complex K-VK-1 was coated twice with a coating composition BM-II-e produced on a scale enlarged by about 10 times in the same system operated with the same machine parameters. The resulting continuously produced complex K-VK-2 (similar to complex R) is described by the parameters specified in Table 4.

[0126] b) Hydrophobic complex Subsequently, complex K-VK-1 was coated twice with a coating composition BM-II-x produced on a scale enlarged by about 10 times in the same system operated with the same machine parameters. The resulting continuously produced complex K-VK-3 (similar to complex 2H) is described by the parameters specified in Table 4.

[0127] [Table 4]

[0128] Experimental Example 4: Complex having a polysiloxane-containing polymer layer a) Production of polymer solution (PL-1) First, 10 g of Component A (RTV-615A) in 90 g of hexamethyldisiloxane was placed in a round-bottom flask and heated to 60°C. When the predetermined temperature was reached, 1 g of Component B (RTV-615B) in 10 g of hexamethyldisiloxane was added. The components were stirred very well under these conditions for 2 hours and then allowed to cool. After dilution with hexamethyldisiloxane until the content of hexamethyldisiloxane in the solution reached 92% by weight, the viscosity was examined. This was initially 13 mPa·s, but changed over time and continuously increased. This solution was processed, and as soon as the viscosity was in the range of 5 to 50 mPa·s, a coating film was applied to the complex. The viscosity was measured using a rotational viscometer model: Kinexus KNX2112m manufactured by Malvern Instruments Limited (Worcestershire, UK) at a shear rate of 100 seconds -1 and a temperature of 25°C. The pot life of the ideal processing window is about 2 hours.

[0129] b) Production of Polymer Solution (PL-2) A solution was obtained by mixing Solution A and Solution B in a 1:1 (by weight) ratio. Solution A contained vinyl dimethyl polysiloxane / vinyl-QM resin mixture VQM906 (99.8% by weight) and catalyst 511 (0.2% by weight). Solution B contained vinyl-functional polydimethylsiloxane VS165,000 (52.99% by weight), SiH-containing polydimethylsiloxane crosslinking agent 120 (38.99% by weight), vinyl dimethyl polysiloxane / vinyl-QM resin mixture VQM906 (8% by weight), and inhibitor methyl butynol (0.02% by weight). This mixture was diluted with hexamethyldisiloxane immediately before use so that the solution to be used had an 85% by weight hexamethyldisiloxane content and a viscosity of 9 mPa·s. The latter (viscosity) was measured using a rotational viscometer model: Kinexus KNX2112m manufactured by Malvern Instruments Limited (Worcestershire, UK) at a shear rate of 100 s -1 and a temperature of 25°C.

[0130] c) Production of Polymer Solution (PL-3) First, 10 g of Component A (RTV-615A) in 90 g of hexamethyldisiloxane was placed in a round-bottom flask and heated to 60°C. When the predetermined temperature was reached, 1 g of Component B (RTV-615B) in 10 g of hexamethyldisiloxane was added. The components were stirred very well under these conditions for 2 hours and then allowed to cool. After dilution until the hexamethyldisiloxane content in the solution reached 95% by weight, the viscosity was examined. This was initially 6 mPa·s but changed over time and continuously increased. This solution was processed, and as soon as the viscosity was in the range of 5 - 50 mPa·s, a coating film was applied to the composite. The latter (viscosity) was measured using a rotational viscometer model: Kinexus KNX2112m manufactured by Malvern Instruments Limited (Worcestershire, UK) at a shear rate of 100 s -1 and a temperature of 25°C. The pot life of the ideal processing window is approximately 2 hours.

[0131] d) Production of Polymer Solution (PL-4) The solution prepared as in a) was diluted to 95 wt% instead of 92 wt% with hexamethyldisiloxane. After homogenizing for 2 hours, this was used for the coating film.

[0132] e) Coating of the composite with the polymer The composite was pre-dried at 100 °C for at least 2 hours in a drying cabinet and then a coating film was applied by the dip coating method as already described in Experimental Example 1f. For this purpose, an automatic film stretching device manufactured by Zehntner was modified using a pulley mechanism to pull the web material to be coated vertically upwards from the dip coating device at a defined speed of 42 mm / s. In that dip coating device, one side of the material web is bent via a roll so that it does not come into contact with the coating film solution, and the opposite side of the material web is transported through a tank filled with the solution.

[0133] For the coating film, the mixed solution was introduced into the tank. This tank had a rotating roll on which the material web was stretched. The filling level of the tank was adjusted so that the roll circumference was only immersed in the solution by 45°. To guide the material web well and prevent the solution from flowing along the material web, the web tension was set to approximately 0.1 N / cm of the material web width. The material web was guided through the solution at a speed of 42 mm / s at room temperature and standard pressure. After applying the coating film, the material web was left hanging in the device at room temperature for an additional 15 minutes to evaporate most of the solvent.

[0134] Characterization was carried out only after drying the material web overnight at 120 °C in a drying cabinet. The correlation between the composite used and the coating film solution can be seen from Table 6.

[0135] For some of the various composite materials, instead of pre-drying at 100 °C, they were treated with corona. For this purpose, the composite was fixed to a non-conductive PET nonwoven fabric 05-TH-60W manufactured by Sojitz with its front side facing up and transported through a corona treatment system (manufactured by Softal (Hamburg)) at a speed of 1.5 m / min. The power of the corona treatment can be steplessly adjusted. The experimental settings can also be seen from Table 6.

[0136] To provide evidence of a perfect coating film with the polymer solution, all composites were characterized by measuring the clean gas selectivity of CO2 / CH4 and the CO2 flow rate (performed as described above). The results are shown in Table 6.

[0137] [[Table 6]]

[0138] Composites P-VK-1 to P-VK-3 have very excellent resistance to the handling of the composites. This reduces the possibility of defects or damage occurring in the composites when introduced into the solvent separation device. Typical defects or damages are the breakage of the ceramic due to kinking or handling with sharp objects.

[0139] All composites P-VK-1 to P-VK-3 are flexible and can be wound around bars or tubes with a diameter of up to 15 mm without breaking. Composites P-VK-1 to P-VK-3 can be wound around with a minimum diameter of up to 5 mm without breaking. That the corresponding composite is not broken can be easily demonstrated by measuring the clean gas selectivity, which is the same before and after treatment. In this case, if the clean gas selectivity has decreased by 2 units, it is evaluated as a "defect of the composite".

[0140] Thanks to the flexibility of the composites, they can be introduced into the typical module form of flat membranes in a very simple way and are particularly suitable for use in spiral modules, plate and frame modules, pocket modules, and other devices designed for flat membranes.

[0141] Experimental Example 5: Testing of the Composite with a Polysiloxane-Containing Polymer Layer For further characterization, some membranes were examined by the so-called MWCO (molecular weight cut-off) method in toluene. This method is described, inter alia, in International Publication No. WO 2011 / 067054 A1, but is also described on pages 120 - 125 of Journal of Membrane Science 291 (2007). For this purpose, the membranes were tested by cross-flow filtration using toluene as a solvent in which polystyrenes of different molecular weights were dissolved at a total concentration of 1 g / L. The basic structure of this apparatus is shown in Figure 4. The permeate flow (toluene) was monitored and quantified by gravimetry over 3 hours. After 3 hours, a portion of the last collected permeate was taken and collected in a separate specimen bottle for molecular weight measurement. This was done by an HPLC system.

[0142] Unless otherwise stated, the tests were carried out in a cross-flow filtration device at a transmembrane pressure (TMP) of 30 bar (30 * 10 5 Pa) and a temperature of 30 °C, while continuously pumping the permeate flow back to the storage container. The membrane cells used in these experiments were obtained from Evonik Membrane Extraction Technologies.

[0143] Table 7 shows, as a result of this test, the molecular weights at which a retention rate of 90% was achieved. Some of the membranes tested were pretreated (Experimental Examples 5a and 5b). The results of these tests are shown below, in Figures 1 - 3 and Table 7.

[0144] a) Thermal stability Some of the composites obtained in Experimental Example 4e were stored in a drying cabinet at 150 °C for 72 hours (composite: P-VK-1-temp). Subsequently, the characterization of the membrane properties was repeated. Compared to the non-heat-treated composites, there were no significant changes in either the flow rate or the retention rate.

[0145] b) Solvent stability The composite obtained in Experimental Example 4e was stored in mesitylene at 150 °C for 72 hours (composite: P-VK-1-solv). Thereafter, the membrane characteristics were characterized again. Compared with the results of the untreated composite, there were no significant changes in either the flow rate or the retention rate.

[0146] c) Separation characteristics at high temperature The composite obtained in Experimental Example 4e was used at a high temperature with an intermembrane differential pressure of 30 bar (30 * 10 5 Pa). There was a clear change in the flow rate and only a slight change in the retention rate. The measurement results are shown below. Specimen P-VK-1-130 °C was examined for the permeation characteristics of toluene and the retention capacity of polystyrene at a temperature of 130 °C. Specimen P-VK-1-30 °C is the comparative value of the specimen examined at 30 °C. The examination was always carried out at a permeation pressure of 5 bar (5 * 10 5 Pa) over 3 hours, and the flow rate after 3 hours was recorded. The results of the change in the retention rate are shown in Figure 3. The measurement results of the toluene flow rate and the retention rate are shown in Table 7.

[0147]

Table 7

[0148] The results in Figures 1 to 3 and Table 7 indicate that due to the ceramic structure of composites P-VK-1 to P-VK-3, their thickness and porosity do not substantially change under compressive stress at high temperature. This is important because the entire composite according to the present invention has a substantially constant toluene flow rate even under high compressive stress at high temperature, and the flow does not decrease at high pressure due to the compression of the porous structure.

[0149] Experimental Example 6: Investigation of changes in particle size distribution at various processing stages In addition, research was conducted on how much the particle size distribution changes during the manufacturing process of the coating composition. For this purpose, the particle formulations (PF) used in the previous experimental examples were analyzed in terms of their average particle size (d50). The measurement results are shown in Table 8a. Next, the coating composition (BM) was manufactured as described in the previous experimental examples. The average particle size of the coating composition was measured. The measurement results are shown in Table 8b. Table 8c records the d50 values of the particles used according to the manufacturer.

[0150] The quantitative evaluation of the measured values is shown in Table 9.

[0151] In summary, from the results shown in Tables 8a, 8b, 8c, and 9, it can be speculated that the differences in particle size at various processing stages (PF~BM) are solely due to the stabilization of the particles in each dispersion.

[0152]

Table 8a

[0153]

Table 8b

[0154]

Table 8c

[0155]

Table 9

Claims

1. - On a porous substrate containing fibers of a non-conductive material and in the gaps of the substrate, there is a porous layer (1) composed of oxide particles that are bonded to each other, partially bonded to the substrate, and contain at least one oxide selected from oxides of elements Al, Zr, and Si. - It is a flexible composite having, on at least one side, another porous layer (2) that is bonded to each other, partially bonded to the layer (1), and contains oxide particles containing at least one oxide selected from oxides of elements Al, Zr, and Si. The central particle size of the oxide particles present in the layer (1) is larger than that of the oxide particles present in the layer (2). The central particle size (d50) of the oxide particles of the layer (1), measured in accordance with ISO 13320, is 0.5 to 4 μm. The central particle size (d50) of the oxide particles of the layer (2), measured in accordance with ISO 13320, is 0.015 to 0.15 μm. A polymer coating film (PB) containing one or more polysiloxanes is present on the top or upper part of the layer (2). The substrate is a non-woven fabric, knit, or laid scrim. "Flexible" means that the composite can be wound around a bar or tube with a diameter of up to 15 mm without being damaged.

2. The toluene flow rate at 130 °C and an intermembrane differential pressure of 30 bar (30 * 10 ５ Pa) exceeds 130 L / m ２ h, the composite according to claim 1.

3. The composite according to claim 1 or claim 2, having a thickness of 100 to 400 μm.

4. The composite according to any one of claims 1 to 3, wherein the fibers have a size of 1 to 200 g / km.

5. The base material has a thickness of 50 to 150 μm and a basis weight of 40 to 150 g / m ２ The composite body according to any one of claims 1 to 4, which is such.

6. The composite according to any one of claims 1 to 5, having an average pore diameter of 60 to 140 nm.

7. The composite according to any one of claims 1 to 6, wherein the surface roughness Sdq of the surface of the layer (2) is less than 10 μm.

8. The following steps: - Step (a): Applying a coating composition (BM1) to a substrate having fibers and in the gaps between the fibers, the coating composition comprising: (a1) A dispersion (D1) of oxide particles generated by mixing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a central particle size (d50) of 0.5 to 4 μm with water, an inorganic acid, and a dispersion aid; (a2) A dispersion (D2) of oxide particles generated by mixing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a central particle size (d50) of 15 to 150 nm with water. Binder composition (BF1) produced by mixing at least two organofunctional silanes with an alkanol, an inorganic acid, and water The step of producing by combining - Step (b): The step of curing the coating composition (BM1) at a temperature of 100°C to 275°C to produce the first layer (S1'); - Step (e): Applying the coating composition (BM3) to the first layer (S1') or, if present, the second layer (S2'), the coating composition (BM3) comprising water and an inorganic acid, as follows: (e1) An aqueous dispersion (D5) comprising oxide particles produced by mixing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a median particle size (d50) of 15 to 150 nm with water, and ethanol, and (e2) A binder composition (BF3) comprising at least two organofunctional silanes The step of producing by combining - Step (f): The step of curing the coating composition at a temperature of 100°C to 275°C to produce the layer (S3'); and - Step (i): The step of applying a polymer coating film containing polysiloxane to the layer (S3'), or, if present, the layer (S4') A method for producing a flexible composite, The organofunctional silanes used are 3-glycidyloxytriethoxysilane, methyltriethoxysilane, and tetraethoxysilane, The substrate used is a polymer nonwoven fabric containing fibers selected from polyacrylonitrile, polyester, polyamide, and / or polyolefin, "Flexible" means that the composite can be wound around a bar or tube with a diameter of up to 15 mm without being damaged. Method

9. Furthermore, the method according to claim 8, characterized by having one or more of the following steps. - Step (c): Applying the coating composition (BM2) to at least the layer (S1'), the coating composition (BM2) comprising: (c1) A dispersion (D3) of oxide particles produced by mixing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a median particle size (d50) of 0.5 to 4 μm with water, an inorganic acid, and a dispersion aid; (c2) A dispersion (D4) of oxide particles produced by mixing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a median particle size (d50) of 15 to 150 nm with water (c3) A binder composition (BF2) produced by mixing at least two organofunctional silanes with an alkanol, an inorganic acid, and water The step of producing by combining - Step (d): A step of curing the coating composition (BM2) at a temperature of 100°C to 275°C to produce the second layer (S2'). - Step (g): Applying the coating composition (BM4) to the layer (S3'), the coating composition (BM4) comprising water and an inorganic acid, as follows: (g1) An aqueous dispersion (D6) containing oxide particles selected from oxides of elements Al, Zr, and / or Si and having a median particle size of 15 to 150 nm and ethanol, and (g2) A binder composition (BF4) containing at least two organofunctional silanes The step of producing by combining - Step (h): A step of curing the coating composition at a temperature of 100 to 275°C to produce the layer (S4').

10. The method according to claim 8 or 9, wherein 3-glycidyloxytriethoxysilane, methyltriethoxysilane, and tetraethoxysilane are used in a mass ratio of 2 to 4:0.5 to 1.5:1 in the binder compositions (BF1) and (BF2).

11. The method according to any one of claims 8 to 10, wherein 3-glycidyloxytriethoxysilane, methyltriethoxysilane, and tetraethoxysilane are used in a mass ratio of 0.5 to 1.5:1.5 to 2.5:1 in the binder compositions (BF3) and (BF4).

12. The method according to any one of claims 8 to 11, wherein the coating compositions (BM3) and (BM4) are the same composition.

13. The method according to any one of claims 8 to 12, wherein the coating compositions (BM1) and (BM2) are the same composition.

14. The method according to any one of claims 8 to 13, wherein the curing is performed by passing through a hot air oven, an IR oven, or another oven.

15. Use of the composite according to any one of claims 1 to 7, or the composite produced according to any one of claims 8 to 14, in organic affinity nanofiltration.

16. The use according to claim 15, wherein the use is the separation of an organic compound from an organic solvent-containing material stream in the organic affinity nanofiltration, and the separation is performed at a temperature exceeding 100°C.

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