Filter

Abstract

The present disclosure provides a filter in which a metal organic structure is supported on a base material, wherein: the average value of the amount of an S element with respect to the total amount of a target element included in the filter, as measured by fluorescent X-ray analysis, is 8-30 mol%; the target element is an element other than O and C, said element having a peak intensity of 10 cps or greater in fluorescent X-ray analysis; the peak intensity (cps) of the S element at a plurality of locations of the filter and the peak intensity (cps) of a metal element M constituting the metal organic structure are each measured by fluorescent X-ray analysis; the peak intensities of the S element and the metal element M at each measurement point are plotted, with the peak intensity (cps) of the metal element M being on the horizontal axis and the peak intensity (cps) of the S element being on the vertical axis; and a determination coefficient R 2 of a linear one-dimensional approximation formula derived using the least-squares method is 0.70 or greater.

Description

Filter

[0001] The present disclosure relates to a filter having a metal-organic framework supported on a substrate.

[0002] Metal organic frameworks, also known as porous coordination polymers, are one type of material that form a porous structure through coordination bonds between metal ions and organic ligands, and are expected to be used for gas adsorption / desorption, catalysts, etc.

[0003] For example, Patent Document 1 describes the use of a moisture absorbing plate having a metal organic framework attached to its surface as a component of a humidity control device.

[0004] Korean Patent Publication No. 10-2020-0140435

[0005] Patent Literature 1 describes that a moisture absorbent plate having a moisture absorbent attached to its surface can be manufactured by immersing a moisture absorbent plate in a solution in which a moisture absorbent such as a metal-organic framework is dispersed, removing the plate, drying it, and curing it by heat treatment as necessary. However, the inventors' investigations have revealed that such moisture absorbent plates may not have sufficient performance to adsorb an adsorbate such as water (hereinafter also referred to as adsorption performance).

[0006] Therefore, an object of the present disclosure is to provide a filter having a metal organic framework supported on a substrate, which has excellent adsorption performance.

[0007] The present disclosure that has achieved the above object is as follows: [1] A filter in which a metal organic framework is supported on a substrate, wherein the average amount of S element relative to the total amount of target elements contained in the filter as measured by X-ray fluorescence analysis is 8 to 30 mol %, the target elements are elements other than O and C, and have a peak intensity of 10 cps or more in X-ray fluorescence analysis, and the peak intensity (cps) of the S element and the peak intensity (cps) of a metal element M constituting the metal organic framework are measured at multiple points on the filter by X-ray fluorescence analysis, and the peak intensities of the S element and the metal element M at each measurement point are plotted with the peak intensity (cps) of the metal element M on the horizontal axis and the peak intensity (cps) of the S element on the vertical axis, and the coefficient of determination R of a linear first-order approximation equation obtained by the least squares method is ２ [2] The filter according to [1], wherein the S content per 1 g of the metal-organic framework is 0.1 mmol / g or more. [3] The metal-organic framework is a filter comprising at least one metal element selected from the group consisting of elements in periods 4 to 6 and groups 3 to 12 of the long periodic table, Al, Ga, and In, and R(COO － ) ｎ (R is an n-valent group, n is an integer of 2 or more).

[0008] According to the present disclosure, a filter with excellent adsorption performance can be provided.

[0009] FIG. 2 is a schematic diagram showing the cross-sectional shape of a substrate used in the examples.

[0010] <Filter> The filter of the present disclosure has a metal organic framework (hereinafter may be referred to as MOF) supported on a substrate, and the average amount of S element relative to the total amount of target elements contained in the filter measured by X-ray fluorescence analysis is 8 to 30 mol %. The peak intensity (cps) of the S element and the peak intensity (cps) of the metal element M constituting the metal organic framework were measured at multiple points on the filter by X-ray fluorescence analysis, and the peak intensities of the S element and the metal element M at each measurement point were plotted with the peak intensity (cps) of the metal element M on the horizontal axis and the peak intensity (cps) of the S element on the vertical axis, and the coefficient of determination R of a linear first-order approximation curve was calculated by the least squares method. ２ is 0.70 or more.

[0011] The average amount of S element relative to the total amount of target elements contained in the filter can be measured by X-ray fluorescence analysis, and the target elements are elements other than O and C that have a peak intensity of 10 cps or more in X-ray fluorescence analysis. The S element contained in the filter includes S derived from metal sulfates used as raw materials for producing MOFs. The amount of S element (mol %) relative to the total amount of target elements can be determined using the apparatus used in the examples described below and the software attached to the apparatus.

[0012] The average amount of S element relative to the total amount of the target elements may be 9 to 25 mol %, 10 to 23 mol %, or 12 to 20 mol %.

[0013] In addition, in the filter of the present disclosure, the peak intensity (cps) of the S element and the peak intensity (cps) of the metal element M constituting the MOF were measured at multiple points on the filter by fluorescent X-ray analysis, and the peak intensities of the S element and the metal element M at each measurement point were plotted with the peak intensity (cps) of the metal element M on the horizontal axis and the peak intensity (cps) of the S element on the vertical axis. The coefficient of determination R of the linear first-order approximation curve was calculated by the least squares method. ２ is 0.70 or more. This means that where the metal element M constituting the MOF is present, the S element is also present, and there is an approximately proportional relationship between the amount of the metal element M and the amount of the S element.

[0014] When metal sulfates are used as raw materials for producing MOFs, S elements derived from the sulfates may be mixed in. When this S element is present together with the MOF (i.e., together with the metal element M constituting the MOF), for example, inside or on the surface of the pore structure of the MOF, the filter carrying the MOF exhibits good water absorption. However, when the amount of S element is low at the location where the metal element M is present, or when no S element is present at the location where the metal element M is present, or when excessive S element is present at the location where the metal element M is present, the water absorption of the filter deteriorates.

[0015] The coefficient of determination R ２ is preferably 0.80 or more, more preferably 0.85 or more, and even more preferably 0.90 or more, and the upper limit is most preferably 1, but may be 0.99 or less. That is, the coefficient of determination R ２ is preferably 0.80 to 1, more preferably 0.85 to 0.99, and even more preferably 0.90 to 0.99.

[0016] In the present disclosure, the average value of the above-mentioned S element content is 9 to 25 mol % and the coefficient of determination R ２ is preferably 0.80 to 1, the average amount of S element is 10 to 23 mol%, and the coefficient of determination R ２ is more preferably 0.85 to 0.99, the average amount of S element is 12 to 20 mol%, and the coefficient of determination R ２ It is more preferable that the value is 0.90 to 0.99.

[0017] In this specification, the term "metal" also includes elements that may be classified as metalloids, such as boron, silicon, germanium, arsenic, antimony, tellurium, selenium, polonium, and astatine.

[0018] The metal element M of the MOF can be identified, for example, by cutting the filter at a cross section where the substrate and the MOF supported on the substrate can be observed, and measuring the concentration profile in the depth direction using SEM-EDX or the like. In the filter of the present disclosure, the MOF is supported on the surface of the substrate, and therefore, in the concentration profile in the depth direction, the element whose concentration near the filter surface is higher than the concentration inside the substrate is the metal element of the MOF.

[0019] The amount of MOF supported per unit area of ​​the filter is, for example, 45 g / m ２ or more, and 60 g / m ２ More preferably, 80 g / m or more ２ The above is more preferable, and the upper limit of the amount of MOF supported per unit area of ​​the filter is not particularly limited, but is preferably 120 g / m ２ The MOF loading per unit area of ​​the filter may be 45 g / m or less. ２ ~120g / m ２ or 60 g / m ２ ~120g / m ２ or 80 g / m ２ ~120g / m ２ may be.

[0020] The filter of the present disclosure can achieve a water absorption rate of 9.5% or more, as described in the Examples below. The water absorption rate is preferably 12.0% or more, more preferably 13.0% or more, even more preferably 14.0% or more, and may be 20% or less. In other words, the water absorption rate is preferably 9.5 to 20%, more preferably 12.0 to 20%, even more preferably 13.0 to 20%, and even more preferably 14.0 to 20%.

[0021] <Metal Organic Framework> MOFs are composed of metals and organic ligands. Examples of the metal element M constituting the MOF include at least one element selected from the group consisting of elements in periods 4 to 6 and groups 3 to 12 of the long-form periodic table, Al, Ga, and In. At least one element selected from the group consisting of Al, Ga, In, Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn is preferred, with Al being particularly preferred.

[0022] The organic ligands include R(COO － ) ｎ(R is an n-valent group, n is an integer of 2 or more). R is preferably an aliphatic chain hydrocarbon group, an aliphatic cyclic hydrocarbon group, an aliphatic heterocyclic hydrocarbon group (a group in which one or more carbon atoms of an aliphatic cyclic hydrocarbon group are replaced with heteroatoms), an aromatic hydrocarbon group, or an aromatic heterocyclic hydrocarbon group (a group in which one or more carbon atoms of an aromatic hydrocarbon group are replaced with heteroatoms), with an aromatic hydrocarbon group being most preferred. The number of carbon atoms in R is preferably 2 to 30, more preferably 4 to 24, and even more preferably 6 to 18. n is preferably 2 or more and 4 or less, more preferably 2 or more and 3 or less, and most preferably 2.

[0023] The above-mentioned aliphatic chain hydrocarbon group, aliphatic cyclic hydrocarbon group, aliphatic heterocyclic hydrocarbon group, aromatic hydrocarbon group, and aromatic heterocyclic hydrocarbon group may further include —OH and / or —NH ２ The compound may contain one or more functional groups X.

[0024] The aliphatic chain hydrocarbon group may be linear or branched, and may be a saturated or unsaturated hydrocarbon group. Examples of the aliphatic chain hydrocarbon group include groups obtained by removing n hydrogen atoms from ethane, ethylene, acetylene, butane, butene, or hexane.

[0025] Examples of the aliphatic cyclic hydrocarbon group include groups in which n hydrogen atoms have been removed from cyclopropane, cyclobutane, cyclohexane, cyclooctane, norbornene, or adamantane.

[0026] Examples of the aliphatic heterocyclic hydrocarbon group include groups in which n hydrogen atoms have been removed from pyrrolidine, piperidine, piperazine, or morpholine.

[0027] Preferred ranges for the number of carbon atoms in the aromatic hydrocarbon group are, in order, 6 or more and 30 or less, 6 or more and 24 or less, 6 or more and 18 or less, 6 or more and 12 or less, and 6 or more and 10 or less. Specifically, the aromatic hydrocarbon group is a group in which n (preferably 2 or 3) hydrogen atoms have been removed from benzene or biphenyl, and particularly a group in which n (preferably 2 or 3) hydrogen atoms have been removed from benzene.

[0028] The aromatic hydrocarbon group is preferably any one of the following formulae (A-1) to (A-9), more preferably any one of the formulae (A-1) to (A-3), and even more preferably formula (A-2). In the following formulae (A-1) to (A-9), * represents a bond.

[0029]

[0030] In the formulae (A-1) to (A-9), at least one of the hydrogen atoms bonded to the carbon atom is —OH and / or —NH ２ The hydrogen atom bonded to the carbon atom may be substituted with a substituted aryl group, or the hydrogen atom bonded to the carbon atom may not be substituted.

[0031] Examples of the aromatic heterocyclic hydrocarbon group include groups in which n hydrogen atoms have been removed from pyrrole, pyrazole, imidazole, thiazole, oxazole, pyridine, pyrimidine, pyridazine, pyrazine, or triazine.

[0032] The metals and organic ligands constituting the MOF can be appropriately combined within the above-mentioned preferred ranges. For example, the metal may be at least one selected from the group consisting of Al, Ga, In, Ti, Zr, Hf, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and the organic ligand may be R(COO － ) ｎ In the MOF, R is an aromatic hydrocarbon group and n is 2 or 3, and the metal is Al and the organic ligand is R(COO － ) ｎ In this case, R is any one of the above formulae (A-1) to (A-3), and n is 2.

[0033] The molar ratio (metal ion / organic ligand) of metal ions (total amount if there are multiple types) to organic ligands (total amount if there are multiple types) is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, particularly preferably 0.9 or more, and is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, particularly preferably 2.5 or less. The molar ratio is preferably 0.1 to 5, more preferably 0.3 to 4, even more preferably 0.5 to 3, and even more preferably 0.9 to 2.5. When the organic ligands constituting the MOF are the above R(COO － ) ｎ When the carboxylate is represented by R(COO － ) ｎ The amount of metal constituting the MOF is preferably 0.6×n to 1.5×n moles, more preferably 0.8×n to 1.2×n moles, relative to 1 mole of the metal.

[0034] The amount of S (mmol / g) per 1 g of MOF is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, even more preferably 0.25 mmol / g or more, and may be 0.4 mmol / g or less. The amount of S per 1 g of MOF is preferably 0.1 to 0.4 mmol / g, more preferably 0.2 to 0.4 mmol / g, and even more preferably 0.25 to 0.4 mmol / g. The amount of S per 1 g of MOF can be controlled by adjusting the amount of raw materials for the MOF (particularly the amount of metal sulfate), the type of solvent used in producing the MOF, etc.

[0035] The BET specific surface area of ​​the MOF is, for example, 450 to 800 m ２ / g, and 500 to 750m ２ / g, and more preferably 530 to 700m ２ / g, and more preferably 580 to 700m ２ The BET specific surface area of ​​the MOF can be controlled by adjusting the concentrations of the metal compound and organic compound, which are raw materials for the MOF, in the solvent, the reaction temperature, the reaction time, etc.

[0036] Furthermore, the D50 of the MOF based on the scattered light intensity is preferably 150 to 1000 nm, more preferably 200 to 700 nm, even more preferably 200 to 500 nm, and particularly preferably 200 to 400 nm.

[0037] MOFs can be produced by a conventional method, for example, by reacting a metal compound containing metal ions constituting the MOF with an organic compound serving as an organic ligand in a solvent. More specifically, it is preferable to prepare a solution B in which a metal compound containing metal ions is completely dissolved, and a solution A in which an organic compound serving as an organic ligand is completely dissolved, and then dropwise add one of them to the other to react them.

[0038] The metal compound containing metal ions constituting the MOF includes a metal sulfate. The metal compound containing metal ions constituting the MOF may further include at least one selected from the group consisting of a metal nitrate, acetate, chloride, bromide, and alkoxide in addition to the metal sulfate. The organic compound that becomes the organic ligand constituting the MOF is R(COOH) ｎ (R and n are the same as above) is preferable.

[0039] The solvent is preferably water; an alcohol solvent such as methanol or ethanol; or an amide solvent such as N,N-dimethylformamide, and the like, and one of these may be used alone or in combination. In particular, when a metal compound containing a metal ion constituting the MOF is reacted with an organic compound that will become an organic ligand constituting the MOF in the presence of water as a solvent, the reaction is preferably carried out in the presence of a tertiary amine such as triethylamine.

[0040] After the reaction is complete (preferably after the dropwise addition is complete), the reaction mixture is refluxed, stirred, or left to stand at room temperature (e.g., 25°C) to 200°C for about 5 minutes to 100 hours, and the reaction product is separated from the solvent by centrifugation or filtration, washed, and dried to obtain the desired MOF.

[0041] <Substrate> The elements contained in the substrate are not particularly limited, but it is preferable that the substrate contains a metal element X, and the metal element X is preferably at least one selected from the group consisting of Mg, Ca, Si, Fe, Na, and Al. The substrate more preferably contains an oxide containing one or more selected from the group consisting of Mg, Ca, Si, Fe, Na, and Al, Al (simple Al), or an Al alloy, and even more preferably contains an oxide containing one or more selected from the group consisting of Mg, Ca, Si, Fe, Na, and Al. The total amount of Mg, Ca, Si, Fe, Na, and Al among all metal elements contained in the substrate is preferably 95 mass% or more, more preferably 98 mass% or more, and even more preferably 99 mass% or more. Furthermore, the total amount of Si oxide and Ca oxide relative to 100% by mass of the total amount of oxides of Mg, Ca, Si, Fe, Na, and Al contained in the substrate is preferably 90% by mass or more, more preferably 95% by mass or more, and the upper limit may be 99.9% by mass, i.e., preferably 90 to 99.9% by mass, more preferably 95 to 99.9% by mass. The composition of the substrate means that which is determined from the results of SEM-EDX analysis of the substrate surface.

[0042] The substrate preferably has a columnar shape having one or more holes passing through in the axial direction, and the outer shape of the column is preferably, for example, a cylindrical, rectangular, or elliptical cylinder. The number of through holes is preferably two or more, and the hole shape in a cross section perpendicular to the axial direction is preferably a circle, a triangle, a square, or a hexagon. The cross-sectional area of ​​the cross section perpendicular to the axial direction of the substrate is 300 to 40,000 mm ２ is preferable, and 500 to 10,000 mm ２ The length of the substrate (axial length of the through-hole) is preferably 10 to 200 mm, more preferably 20 to 150 mm. ２ The number of cells (holes) per square centimeter is 10 to 150 cells / cm. ２ is preferably 20 to 100 cells / cm ２ More preferably, 30 to 80 cells / cm ２ The area (average value) of one cell in a cross section perpendicular to the axial direction of the substrate is 0.5 to 10 mm ２is preferable, and 1 to 8 mm ２ More preferably, 2 to 6 mm ２ The thickness of the inner wall separating the cells is preferably 1 to 10,000 μm, more preferably 10 to 105,000 μm, and even more preferably 100 to 2,000 μm. The thickness of the outer wall of the substrate is also preferably within the above range. The total surface area of ​​the inner wall and outer wall of the substrate, including the front and back surfaces, is preferably 0.01 to 2 m. ２ It is preferable that the thickness is 0.02 to 1.8 m. ２ It is more preferable that:

[0043] The shape, cross-sectional area, and cross-sectional area of ​​the above-mentioned substrate are ２ It is preferable that the substrate has a combination of one or more of the preferred requirements of the number of cells per cell, the area of ​​one cell (average value), the thickness of the inner and outer walls, and the total area including the front and back of the inner and outer walls, and that the water absorption measured as described in the examples below is 9.5% or more, 11.0% or more, 12.0% or more, or 13.0% or more (the upper limit is, for example, 20% or less).

[0044] <Method for Manufacturing a Filter> The filter of the present disclosure can be manufactured by impregnating a substrate with a slurry containing MOFs, then withdrawing the slurry and drying it. It is particularly important to appropriately adjust the MOF concentration in the slurry and the number of applications, as well as to adjust the amount of MOF supported per unit area of ​​the substrate. More specifically, it is preferable to either apply a slurry having a high MOF concentration (e.g., 20 to 40% by mass) to the substrate once and dry it; apply a slurry having a high MOF concentration (e.g., 20 to 40% by mass) to the substrate and dry it (first time), and then apply a slurry having a lower MOF concentration (e.g., 10% by mass or more but less than 20% by mass) to the substrate and dry it (second time); or repeat the process of applying a slurry having a low MOF concentration (e.g., 10% by mass or more but less than 20% by mass) to the substrate and drying it twice or more, ensuring that the MOF concentration of the second or subsequent applications is not higher than that of the previous application. The preferred range of the MOF loading per unit area of ​​the substrate is as described above. The MOF loading per unit area of ​​the substrate can be adjusted by adjusting the time for which the substrate is immersed in the MOF-containing slurry, or by adjusting the amount of slurry by applying vibration to the substrate after immersion in the MOF-containing slurry.

[0045] The slurry preferably contains, in addition to MOFs, a solvent, an emulsifier, a dispersant, and a pH adjuster. The drying temperature and time for the substrate impregnated with the MOF-containing slurry are, for example, 30 to 600°C and 1 to 24 hours.

[0046] <Applications> The filter of the present disclosure is suitable for adsorbing and removing gases and organic molecules, and can also be used as a replaceable cartridge as a component of a humidity control device, etc. Examples of gases include water (water vapor), carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gases, hydrogen sulfide, ammonia, sulfur oxides, nitrogen oxides, and siloxanes. Examples of organic molecules include hydrocarbons having 5 to 8 carbon atoms, alcohols having 1 to 8 carbon atoms, aldehydes having 1 to 8 carbon atoms, carboxylic acids having 1 to 8 carbon atoms, ketones having 1 to 8 carbon atoms, amines having 1 to 8 carbon atoms, esters having 1 to 8 carbon atoms, and amides having 1 to 8 carbon atoms. The organic molecules may contain an aromatic ring.

[0047] The present disclosure will be described in more detail below with reference to examples. The present disclosure is not limited to the following examples, and can of course be implemented with appropriate modifications within the scope of the above and below-described aims, all of which are included in the technical scope of the present disclosure.

[0048] [Measurement of D50 based on scattered light intensity of MOF] 1 mg to 2 mg of MOF was weighed and diluted with 1.5 mL of a mixed solution of water and acetone (water / acetone = 1 / 1 volume ratio) to prepare a measurement sample with an MOF concentration in the range of 0.67 to 1.34 g / L. The measurement sample was irradiated with ultrasound for 1 minute, and then the D50 based on scattered light intensity of MOF was measured using the following apparatus and conditions. Apparatus: Zetasizer Nano ZS manufactured by Malvern Panalytical, Measurement wavelength: 633 nm, Measurement angle: 173°

[0049] [Measurement of BET specific surface area of ​​MOF] Since the adsorption area occupied by nitrogen molecules is known in advance, the amount of gas molecules adsorbed only on the sample surface was measured, and the surface area of ​​the MOF sample was measured using the BET adsorption isotherm. Sample preparation: To remove water from the sample, the sample was heated overnight under reduced pressure at 10 Pa or less and 200°C. Apparatus: BELSORP-mini manufactured by Microtrac BEL Co., Ltd. Pretreatment conditions: (a-i) A glass rod for reducing the volume (for standard sample tubes) was placed in the standard sample tube and plugged with a quick seal. This sample tube set was prepared with the samples to be measured (up to three samples per measurement), connected to a pretreatment device (BELPREP VACII), and the air in the sample tube was evacuated. Then, N ２ Gas (purity 99.999% or higher) is introduced up to atmospheric pressure. (a-ii) The sample tube is then removed from the pretreatment device, and its weight is measured three times using a precision balance (displaying four or more decimal places), and the average (W1) is obtained. When using a precision balance, an ionizer is used to eliminate the effects of static electricity. (a-iii) Approximately 50 mg of the sample to be measured is weighed onto a piece of wrapping paper, and the sample is placed directly into the spherical part at the bottom of the standard sample tube using a long-legged funnel. (a-iv) The glass rod is returned to the sample tube, and after sealing it with a quick seal, the total weight is measured once to provisionally confirm the amount of sample added. (a-v) The sample tube containing the sample is connected to the pretreatment device, and the sample tube is evacuated. (a-vi) After the pressure inside the sample tube has reached a sufficiently low level, heating begins (vacuuming continues). Measurement conditions: (bi) After the pretreatment (vacuum heating) is completed, the sample tube is cooled while kept under reduced pressure, and after it reaches room temperature, N ２ The gas is introduced up to atmospheric pressure and then removed from the device. (b-ii) The weight of the sample tube containing the pre-treated sample is measured three times using a precision balance, and the average (W2) is obtained. The weight of the sample is obtained by calculating W2 - W1. (b-iii) The sample weight and N at liquid nitrogen temperature are entered into the measurement software. ２ Enter the gas information (such as the second virial coefficient), enter the relative pressure you want to measure, and press the measurement start button. Then, follow the software's instructions to set up a Dewar vessel filled with liquid nitrogen and a sample tube, and then perform the measurement.

[0050] [MOF loading (g / m２ The weight of the filter substrate before supporting the MOF and the weight of the filter after supporting the MOF were measured, and the difference in weight was calculated by multiplying the surface area (m ２ ) The amount of MOF supported per unit area of ​​the filter was calculated.

[0051] [Measurement of S amount per 1 g of MOF] The MOF obtained in the following Preparation Example was combusted under the following conditions using the automatic sample combustion apparatus described below, and the generated gas was absorbed into a solution, and then the solution was analyzed by ion chromatography described below. The S concentration on a mass basis was obtained by the analysis, and then converted into the amount of S per 1 g of MOF (mmol / g). <Automatic sample combustion apparatus> Automatic sample combustion apparatus, ion chromatograph pretreatment device AQF2100H manufactured by Mitsubishi Chemical Analytech Co., Ltd. Reaction tube temperature (outer tube / inner tube): 1050°C / 1000°C Carrier gas: Ar 200 mL / min, O ２ Flow rate of humidifying Ar: 150 mL / min <Ion chromatograph> Thermo Fisher Scientific Dionex ICS1600 ion chromatograph system Column used: TSKgel SuperIC-Anion HS, 4.6 x 100 mm Temperature: 40°C Eluent: 1.0 mmol / L Na ２ CO ３ , 9.0 mmol / L NaHCO ３ Injection volume: 20μL Flow rate: 0.9mL / min

[0052] [Average value of S element content (mol%) and coefficient of determination R of linear approximation curve ２] X-ray fluorescence (XRF) analysis was performed on the surfaces of the filters produced in the Examples and Comparative Examples using the following apparatus and under the following measurement conditions, and elements other than O and C that had a peak intensity of 10 cps or more in the X-ray fluorescence analysis were measured as all elements contained in the filter. The target elements in the Examples and Comparative Examples below were Mg, Ca, Si, Fe, S, Na, and Al. Apparatus: XGT-7200VNM, manufactured by HORIBA, Ltd. X-ray irradiation diameter: 1.2 mm Measurement mode: point analysis Measurement time: 10 sec / point Measurement points: 24 x 20 = 480 points at 1.25 mm pitch on each of the front and back surfaces (480 points x 2 in total on both surfaces) Environment: vacuum environment

[0053] The amount of S element (mol%) relative to the above target elements was calculated using software attached to the above device, and the average value of the amount of S element (mol%) measured at 480 points x 2 was obtained. In addition, the peak intensity (cps) of the metal element M (Al in the following Examples and Comparative Examples) constituting the metal organic framework and the peak intensity (cps) of the S element at each measurement point were plotted on a graph with the peak intensity (cps) of the metal element M on the horizontal axis and the peak intensity (cps) of the S element on the vertical axis, and the coefficient of determination R of the linear first-order approximation curve obtained by the least squares method was calculated. ２ asked for.

[0054] [Measurement of Water Absorption] In the examples and comparative examples, the weight of the filter carrying MOF and the weight of the substrate before carrying MOF were measured, and the amount of MOF carried on the filter, W ＭＯＦ was calculated. In addition, the filters produced in the examples and comparative examples were subjected to pretreatment by holding them in an air atmosphere at 100°C for 2 hours, and then their weights W1 were measured. Thereafter, the filters were allowed to cool in an environment of 25°C and 50% relative humidity, and then left to stand at 25°C and 50% relative humidity for 12 hours, after which their weights W2 were measured. The water absorption of the filters was then calculated using the following formula: Water absorption (%) = 100 x (W2 - W1) / W ＭＯＦ

[0055] (Preparation Example 1-1: Preparation of Metal Organic Framework 1) 3.91 mol of isophthalic acid and 3,200 mL of N,N-dimethylformamide were mixed at 25° C. to prepare a solution A.２ (SO ４ ) ３ ・nH ２ Solution B was prepared by mixing 3.75 mol of 0 (n = 14 to 18) with 4,800 mL of ion-exchanged water. Solution B was added dropwise to solution A at 25°C over 45 minutes. The resulting mixture was then refluxed at 135°C for 12 hours to obtain a suspension. This was filtered under pressure, and the resulting solid was washed three times with 1,500 mL of N,N-dimethylformamide and three times with 1,500 mL of methanol, and then vacuum-dried at 50°C for three hours to obtain 865.23 g of a metal-organic framework (hereinafter also referred to as MOF1) (yield: 94%). The BET specific surface area of ​​MOF1 was 612 m ２ / g.

[0056] (Preparation Example 1-2: Preparation of Metal-Organic Framework 2) 3.50 mol of isophthalic acid, 9.94 mol of triethylamine, and 8,060 mL of water were mixed to prepare a solution A. ２ (SO ４ ) ３ ・nH ２ Solution B was prepared by mixing 2.54 mol of 0 (n = 14 to 18) with 540 mL of ion-exchanged water. Solution B was added dropwise to solution A at 25°C over 45 minutes. The resulting mixture was then refluxed at 100°C for 12 hours to obtain a suspension. This was filtered under pressure, and the resulting solid was washed twice with 2,000 mL of ion-exchanged water and twice with 2,000 mL of methanol, and then vacuum-dried at 100°C for 6 hours to obtain 721.97 g of a metal-organic framework (hereinafter also referred to as MOF2) (yield: 97.9%). The BET specific surface area of ​​MOF2 was 660 m ２ / g.

[0057] (Preparation Example 1-3: Preparation of Metal Organic Framework 3) 3.45 mol of isophthalic acid, 9.66 mol of triethylamine, and 7,440 mL of water were mixed to prepare a solution A. ２ (SO ４ ) ３ containing Al ２ (SO ４ ) ３The aqueous solution was added dropwise to solution A at 25°C over 45 minutes. The resulting mixture was then refluxed at 100°C for 12 hours to obtain a suspension. This was filtered under pressure, and the solid was washed twice with 2,000 mL of ion-exchanged water and vacuum-dried at 100°C for 6 hours to obtain 715 g of a metal-organic framework (hereinafter also referred to as MOF3) (yield: 99.5%). The BET specific surface area of ​​MOF3 was 640 m ２ / g.

[0058] Example 1 MOF1 prepared in Preparation Example 1-1 was mixed with a solvent to prepare a slurry with a concentration of 14.4 mass%, and a substrate having dimensions of 30 mm × 25 mm × length 50 mm and containing wollastonite on the surface was immersed in the slurry, pulled out, and then dried (first time). This operation was repeated a second, third, and fourth time to prepare filters in which the metal-organic framework was supported on the substrate by immersion and drying, except that the concentration of the metal-organic framework in the slurry was changed to the concentration shown in Table 1.

[0059] The substrate is composed of a corrugated corrugated core 1 as shown in Figure 1, and a cover sheet 2 and backing sheet 3 bonded to the corrugated core 1. The corrugation height h of the corrugation is approximately 1.7 mm, the corrugation width p (pitch) is approximately 2.7 mm, and the number of layers is 17. Furthermore, fluorescent X-ray analysis of the substrate alone detected Mg, Ca, Si, Fe, Na, and Al.

[0060] Examples 2 to 4, Comparative Example 1 Filters in which a metal-organic framework was supported on a substrate were produced in the same manner as in Example 1, except that a substrate having a size shown in Table 1 was immersed in a slurry at the slurry concentration and for the number of times shown in Table 1, followed by drying. The pH of the slurries containing the metal-organic framework used in Examples 1 to 4 and Comparative Example 1 was 4 to 5.

[0061] The results are shown in Table 1.

[0062]

[0063] 1: Cord 2: Cover 3: Backing paper h: Cord height p: Cord width (pitch)

Claims

1. A filter having a metal organic framework supported on a substrate, wherein the average amount of S element relative to the total amount of target elements contained in the filter as measured by X-ray fluorescence analysis is 8 to 30 mol %, wherein the target element is an element other than O and C, and has a peak intensity of 10 cps or more in X-ray fluorescence analysis, wherein the peak intensity (cps) of the S element and the peak intensity (cps) of the metal element M constituting the metal organic framework are measured at multiple points on the filter by X-ray fluorescence analysis, and the peak intensities of the S element and the metal element M at each measurement point are plotted with the peak intensity (cps) of the metal element M on the horizontal axis and the peak intensity (cps) of the S element on the vertical axis, and the coefficient of determination R of a linear first-order approximation equation obtained by the least squares method is ２ A filter having a value of 0.70 or greater.

2. The filter according to claim 1, wherein the S content per 1 g of the metal-organic framework is 0.1 mmol / g or more.

3. The metal organic framework comprises at least one metal element selected from the group consisting of elements in periods 4 to 6 and groups 3 to 12 of the long-form periodic table, Al, Ga, and In, and R(COO － ) ｎ 3. The filter according to claim 1, wherein the organic ligand comprises at least one selected from the group consisting of carboxylates represented by the formula (I) (where R is an n-valent group, and n is an integer of 2 or more).

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