Filter

Abstract

To provide a filter that carries metal-organic frameworks in a substrate, and is excellent in adsorptivity.SOLUTION: A filter in which metal organic frameworks are carried in a substrate is such that: a coefficient of variation measured by fluorescent X-ray analysis, of an amount (mol%) of metal elements of the metal organic structure to the total amount of object elements contained in the filter is more than 0% and 50% or less: and the object element is an element excluding O and C, and has a peak strength in the fluorescent X-ray analysis of 1 cps or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Metal organic frameworks (MOFs), also known as porous coordination polymers, are a type of material that form porous structures through coordination bonds between metal ions and organic ligands. They are expected to be used in applications that take advantage of their gas adsorption and desorption properties, as well as in catalysts.

[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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication No. 10-2020-0140435 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 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 adsorbates 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. [Means for solving the problem]

[0007] The present disclosure that achieves the above object is as follows. [1] A filter in which a metal organic framework is supported on a substrate, the coefficient of variation of the amount (mol%) of the metal element M of the metal organic framework relative to the total amount of target elements contained in the filter, as measured by X-ray fluorescence analysis, is more than 0% and 50% or less; The target element is an element other than O and C, and has a peak intensity of 1 cps or more in fluorescent X-ray analysis. [2] The substrate does not contain the same metal element as the metal element M contained in the metal organic framework, or The filter according to [1], wherein the substrate contains a metal element Lx that is the same as the metal element contained as the metal element M of the metal organic framework, and the content of the metal element Lx is 5 mol % or less of all metal elements contained in the substrate. [3] The substrate contains a metal element L, and the metal element L is at least one metal selected from the group consisting of Mg, Ca, Si, Fe, Na, and Al; The filter according to [1] or [2], wherein the metal element M of the metal organic framework is at least one 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. [4] The filter according to any one of [1] to [3], wherein the metal element M is Al. [5] The organic ligand constituting the metal organic framework is R(COO - ) n (R is an n-valent group, and n is an integer of 2 or more). [Effects of the Invention]

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

[0009] [Figure 1]FIG. 2 is a schematic diagram showing the cross-sectional shape of a substrate used in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] <filter> The filter of the present disclosure has a metal organic framework supported on a substrate, and the coefficient of variation of the amount (mol %) of the metal element M in the metal organic framework relative to the total amount of the target elements contained in the filter is more than 0% and 50% or less. The amount (mol %) of the metal element M relative to the total amount of the target elements contained in the filter is measured by X-ray fluorescence analysis, and the coefficient of variation is calculated from the measurement results of the amount of the metal element M at multiple measurement points. The target element is an element other than O and C, and has a peak intensity of 1 cps or more in X-ray fluorescence analysis. The X-ray fluorescence analysis is performed using the apparatus and conditions described in the Examples below.

[0011] When the coefficient of variation of the amount (mol %) of the metal element M in the metal-organic framework is within the above range, a filter with excellent adsorption performance for moisture, etc. can be realized. The coefficient of variation is preferably 40% or less, more preferably 35% or less, even more preferably 30% or less, and particularly preferably 20% or less. The coefficient of variation may be 10% or more. When there are multiple types of metal element M, it is sufficient that the total amount satisfies the above range of the coefficient of variation.

[0012] 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.

[0013] When the composition of the supported MOF is unknown, it is possible to identify the metal element M of the MOF, 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 the element whose concentration near the filter surface is higher than the concentration inside the substrate in the concentration profile in the depth direction is the metal element of the MOF.

[0014] The amount of MOF supported per unit area of ​​the filter is, for example, 45 g / m 2 or more, 60 g / m 2 The above is more preferable, and the upper limit of the MOF loading per unit area of ​​the filter is 200 g / m 2 It may be the following:

[0015] 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 11.0% or more, more preferably 12.0% or more, and even more preferably 13.0% or more, and may be 20% or less.

[0016] <Metal organic structure> MOFs are composed of metals and organic ligands. Examples of the metal element M constituting MOFs 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, and preferably 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, with Al being particularly preferred.

[0017] 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), and most preferably an aromatic hydrocarbon group. 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.

[0018] 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 contain one or more functional groups X which are -OH and / or -NH.

[0019] 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.

[0020] 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.

[0021] Examples of the aliphatic heterocyclic hydrocarbon group include groups in which n hydrogen atoms have been removed from pyrrolidine, piperidine, piperazine, or morpholine.

[0022] The 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.

[0023] 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.

[0024] [ka]

[0025] In the formulae (A-1) to (A-9), at least one of the hydrogen atoms bonded to the carbon atoms may be substituted with -OH and / or -NH2, or the hydrogen atoms bonded to the carbon atoms may not be substituted.

[0026] 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.

[0027] 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 present invention, preferred MOFs are carboxylates in which R is an aromatic hydrocarbon group and n is 2 or 3, the metal is Al, and the organic ligand is R(COO - ) nAn MOF in which R is any one of the above formulae (A-1) to (A-3) and n is 2 is more preferred.

[0028] The molar ratio (expressed as metal ion / organic ligand) of metal ion (total amount, if there are multiple types) to organic ligand (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, and particularly preferably 0.9 or more, and is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2.5 or less.

[0029] The organic ligands that make up the MOF are the above R(COO-) n If the carboxylate is represented by R(COO-) n The amount of metal constituting the MOF is preferably 0.8×n to 1.2×n moles per mole of the metal.

[0030] The BET specific surface area of ​​MOF is, for example, 450 to 5000 m 2 / g, 450-800m 2 / g, and 500 to 750m 2 / g, and more preferably 530 to 700m 2 / g, and more preferably 580 to 700m 2 / g is particularly preferred.

[0031] 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 cause the two to react with each other.

[0032] The metal compound containing the metal ion constituting the MOF is preferably a metal sulfate, nitrate, acetate, chloride, bromide or alkoxide, more preferably a 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.

[0033] The solvent is preferably water; an alcohol solvent such as methanol or ethanol; or an amide solvent such as N,N-dimethylformamide. A single solvent may be used, or two or more solvents may be mixed. When a metal compound containing a metal ion constituting the MOF is reacted with an organic compound serving as an organic ligand constituting the MOF in the presence of water, the reaction is preferably carried out in the presence of a tertiary amine such as triethylamine.

[0034] After the reaction is complete (preferably after the dropwise addition is complete), the reaction mixture is refluxed, stirred, or left to stand for approximately 5 minutes to 100 hours at room temperature (e.g., 25°C) to 200°C, and the reaction product is separated from the solvent by centrifugation or filtration, washed, and dried to obtain the desired MOF.

[0035] <Base material> The substrate preferably contains a metal element L, and the metal element L 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. The substrate further 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% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more. Furthermore, the total amount of Si oxide and Ca oxide relative to the total amount (100% by mass) of the 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. The composition of the substrate is determined from the results of SEM-EDX analysis of the substrate surface.

[0036] The substrate does not contain the same metal element as the metal element M of the metal-organic framework, or the substrate contains the same metal element Lx as the metal element M of the metal-organic framework, and the content of the metal element Lx is preferably 5 mol% or less, more preferably 3 mol% or less, and more preferably 2.5 mol% or less, of the total metal elements contained in the substrate. The lower limit is preferably 0%, but may be about 0.05 mol%. As described above, the total metal elements contained in the substrate refer to elements whose intensity ratio to the strongest intensity in fluorescent X-ray analysis is 0.01% or more. Furthermore, the identification and measurement of the content of elements in the substrate can be performed by cutting a filter at a cross section where the substrate and the MOF supported on the substrate can be observed, and then measuring the concentration profile in the depth direction using SEM-EDX or the like to identify the substrate portion.

[0037] The substrate preferably has a columnar shape having one or more through-holes, and the columnar shape is preferably, for example, a circular, rectangular, or elliptical columnar shape. 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, triangle, square, or hexagon. When the substrate has a columnar shape with one or more through-holes, the X-ray fluorescence analysis is preferably performed on the substrate surface perpendicular to the axial direction of the through-holes. The cross-sectional area of ​​the substrate perpendicular to the axial direction of the through-hole 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-holes) is preferably 10 to 200 mm, more preferably 20 to 150 mm. Cross-sectional area of ​​the substrate perpendicular to the axial direction of the through-hole: 1 cm 2 The number of cells (holes) per square centimeter is 10 to 150 cells / cm. 2 is preferred, and 20 to 100 cells / cm 2 More preferably, 30 to 80 cells / cm 2 is more preferred. The average area of ​​one cell in the cross section of the substrate perpendicular to the axial direction of the through-hole is 0.5 to 10 mm 2 is preferable, and 1 to 8 mm 2 More preferably, 2 to 6 mm 2 is more preferred. 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 substrate, including the front and back of the inner and outer walls, is 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:

[0038] The shape, cross-sectional area, and cross-sectional area of ​​the substrate mentioned above are 1 cm 2It 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 per 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).

[0039] <Filter manufacturing method> The filter of the present disclosure can be manufactured by impregnating a substrate with a slurry containing MOFs, removing the slurry, and then drying it. It is particularly important to appropriately adjust the MOF concentration in the slurry and the number of coatings, as well as the MOF loading per unit area of ​​the substrate. More specifically, it is preferable to apply a slurry with a high MOF concentration (e.g., 20-40% by mass) to the substrate once and dry it; apply a slurry with a high MOF concentration (e.g., 20-40% by mass) to the substrate and dry it (first time), and then apply a slurry with 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 with a low MOF concentration (e.g., 10% by mass or more but less than 20% by mass) to the substrate and dry it twice or more, ensuring that the second and subsequent slurries do not have a higher MOF concentration than the previous slurry. The preferred range of the MOF loading per unit area of ​​the substrate is as described above. The amount of MOF supported per unit area of ​​the substrate can be adjusted by adjusting the time 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.

[0040] The slurry preferably contains a solvent, an emulsifier, a dispersant, and a pH adjuster in addition to the MOF, and the pH of the slurry is preferably 4 to 5. 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.

[0041] <Application> The filter of the present disclosure is suitable for adsorption and removal of 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. [Example]

[0042] 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 encompassed within the technical scope of the present disclosure.

[0043] [Measurement of BET specific surface area of ​​MOF] Since the adsorption area of ​​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 under reduced pressure at 10 Pa or less and 200°C overnight. Equipment: Microtrac BEL Co., Ltd. BELSORP-mini Pretreatment conditions: (ai) Place a volume-reducing glass rod (for standard sample tubes) in the standard sample tube and plug it with a quick seal. Prepare this sample tube set with the samples to be measured (up to three samples per measurement), connect it to the pretreatment device (BELPREP VACII), evacuate the air from inside the sample tube, and then introduce N2 gas (purity 99.999% or higher) up to atmospheric pressure. (a-ii) Then, remove the sample tube from the pretreatment machine and measure its weight three times using a precision balance (displaying four or more decimal places) to obtain the average (W1). When using a precision balance, use an ionizer to eliminate the effects of static electricity. (a-iii) Weigh out approximately 50 mg of the sample to be measured onto a piece of medicine paper, and use a long-footed funnel to place the sample directly into the spherical part at the bottom of the standard sample tube. (a-iv) Return the glass rod to the sample tube, plug it with a quick seal, and then measure the total weight once to provisionally confirm the amount of sample added. (av) The sample tube containing the sample is connected to the pretreatment device, and the inside of 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 being kept under reduced pressure, and after it has returned to room temperature, N2 gas is introduced up to atmospheric pressure and the tube is removed from the apparatus. (b-ii) After pretreatment, measure the weight of the sample tube containing the sample three times using a precision balance and obtain the average (W2). Calculate W2 - W1 to obtain the weight of the sample. (b-iii) Enter the sample weight and information on N2 gas at liquid nitrogen temperature (such as the second virial coefficient) into the measurement software, enter the relative pressure you want to measure, and press the measurement start button. Then, follow the instructions in the software to install a Dewar vessel filled with liquid nitrogen and a sample tube, and perform the measurement.

[0044] [MOF loading (g / m 2 ) Measurement 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 as the surface area (m 2 ) was used to calculate the amount of MOF supported per unit area of ​​the filter.

[0045] [Measurement of coefficient of variation] X-ray fluorescence (XRF) analysis was performed on the surfaces of the filters produced in the Examples and Comparative Examples, and elements other than O and C that had a peak intensity of 1 cps or more in the X-ray fluorescence analysis were defined as all elements contained in the filters. The target elements in the Examples and Comparative Examples below were Mg, Ca, Si, Fe, S, Na, and Al. The proportion (percentage on a molar basis) of the metal element M (Al in the Examples below) contained in the MOF relative to all elements contained in the filter was determined at each measurement point, and the coefficient of variation of the concentration of the metal element M contained in the MOF was calculated using the following formula: Coefficient of variation RSD (%) = 100 × standard deviation of metal element M concentration B / average metal element M concentration A

[0046] The measurement conditions for the XRF analysis are as follows, and the element ratios were calculated using the software attached to the following apparatus. Equipment: Horiba, Ltd., XGT-7200VNM X-ray irradiation diameter: 1.2mm Tube voltage: 50kV Tube current: Auto mode (automatically adjusts to the optimum DT% (dead time)) Measurement mode: Point analysis Measurement time: 10 seconds / point Measurement points: 24 x 20, total 480 points, with a 1.25 mm pitch Environment: vacuum environment

[0047] [Water absorption measurement] In the examples and comparative examples, the weight of the filter carrying the MOF and the weight of the substrate before carrying the MOF were measured, and the amount of MOF carried on the filter, W MOF was calculated. The filters prepared in the examples and comparative examples were subjected to pretreatment by being held at 100°C for 2 hours in an air atmosphere, 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 rate of the filter was calculated using the following formula: Water absorption rate (%)=100×(W2-W1) / WMOF

[0048] (Preparation Example 1-1: Preparation of Metal-Organic Framework 1) In a 13 L autoclave, 3.91 mol of isophthalic acid was mixed with 3200 mL of DMF (N,N-dimethylformamide) at 25 °C until completely dissolved, yielding Solution A. Separately, 3.75 mol of Al2(SO4)3·nH2O (n = 14-18) was mixed with 4800 mL of ion-exchanged water to prepare Solution B. Solution B was added dropwise to Solution A over 45 minutes at 25 °C. The resulting mixture was then refluxed at 135 °C for 12 hours to obtain a suspension. This was then pressure-filtered, and the precipitated solid was pressure-filtered and washed three times with 1500 mL of DMF and three times with 1500 mL of methanol. The resulting filter cake was dried in a vacuum oven at 50 °C for 3 hours to obtain 865.23 g of the product (MOF1) (yield: 94%).

[0049] (Preparation Example 1-2: Preparation of Metal-Organic Framework 2) Solution A was prepared by dissolving 3.50 mol of isophthalic acid and 9.94 mol of triethylamine in 8060 mL of water in a 13 L autoclave. Solution B was prepared by mixing 2.54 mol of Al2(SO4)3·nH2O (n = 14-18) with 540 mL of ion-exchanged water to completely dissolve the components. Solution B was added dropwise to solution A at 25 °C over 45 minutes. The mixture was then refluxed at 100 °C for 12 hours to obtain a suspension. This was then pressure filtered, and the precipitated solid was washed twice with 2000 mL of ion-exchanged water and twice with 2000 mL of methanol. The resulting filter cake was dried in a vacuum oven at 100 °C for 6 hours to obtain 721.97 g of the product (MOF2) (yield: 97.9%).

[0050] (Preparation Example 2: Preparation of slurry containing metal-organic framework) The metal-organic framework obtained in Preparation Example 1-1 or Preparation Example 1-2 and a solvent were mixed to prepare a slurry containing the metal-organic framework having a pH of 4 to 5.

[0051] Example 1 A substrate having dimensions of 30 mm × 25 mm × length 50 mm and containing wollastonite on its surface was immersed in a slurry prepared by mixing a metal-organic framework in an amount to give the concentration shown in Table 1 below in the same manner as in Preparation Example 2, then pulled out and dried (first immersion). This operation was repeated a second, third, and fourth time for immersion and drying, except that the concentration of the metal-organic framework in the slurry was changed to the concentration shown in Table 1, to produce filters in which the metal-organic framework was supported on the substrate.

[0052] 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 core is approximately 1.7 mm, and the corrugation width p (pitch) is approximately 2.7 mm, forming a laminated structure of 17 layers. Furthermore, fluorescent X-ray analysis of the substrate alone detected Mg, Ca, Si, Fe, Na, and Al, with the amount of Al being 2.1 mol% of all metal elements contained in the substrate.

[0053] Examples 2 and 3, Comparative Example 1 A filter in which a metal-organic framework was supported on a substrate was produced in the same manner as in Example 1, except that a substrate having a size shown in Table 1 was immersed in the slurry at the slurry concentration and for the number of times shown in Table 1, and then dried.

[0054] The results are shown in Table 1.

[0055] [Table 1] [Explanation of symbols]

[0056] 1...Center core 2. Cover 3. Backing paper h: Height of the core step p: Width of the core step (pitch)

Claims

1. A filter in which a metal organic framework is supported on a substrate, the coefficient of variation of the amount (mol %) of the metal element M of the metal organic framework relative to the total amount of target elements contained in the filter, as measured by fluorescent X-ray analysis, is more than 0% and 50% or less; The target element is an element other than O and C, and has a peak intensity of 1 cps or more in fluorescent X-ray analysis.

2. The substrate does not contain the same metal element as the metal element contained as the metal element M of the metal organic framework, or 2. The filter according to claim 1, wherein the substrate contains a metal element Lx that is the same as the metal element contained as the metal element M in the metal organic framework, and the content of the metal element Lx is 5 mol % or less of all metal elements contained in the substrate.

3. the substrate contains a metal element L, and the metal element L is at least one metal selected from the group consisting of Mg, Ca, Si, Fe, Na, and Al; 3. The filter according to claim 1 or 2, wherein the metal element M of the metal organic framework is at least one 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.

4. 3. The filter according to claim 1, wherein the metal element M is Al.

5. The organic ligand constituting the metal organic framework is R(COO － ) ｎ 5. The filter according to claim 4, wherein R is an n-valent group, and n is an integer of 2 or more.

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