Zeolite bulk and its manufacturing method

Abstract

To provide a zeolite bulk body having sufficient strength for replacing ordinary concrete, excellent humidity controlling capability, and excellent air permeability.SOLUTION: The zeolite bulk body comprises aluminosilicate zeolite having a MFI skeleton, in which aluminosilicate zeolite, micropores, mesopores and macropores are formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a zeolite bulk body and a method for producing the same. [Background technology]

[0002] There is strong demand for materials that combine humidity control and breathability as building materials and structures. In particular, humidity-controlling and breathable structural materials that are in a molded (bulk) form rather than a powder that is applied to wall materials, etc., and have high humidity control and breathability are highly desirable, as they can be used in a variety of applications beyond architecture.

[0003] Zeolite is known as a material with humidity-regulating properties. Zeolite is a crystalline aluminosilicate with micropores derived from its crystalline structure, a high specific surface area, and excellent adsorption properties for water and volatile organic compounds, and it also has deodorizing properties on its own. In addition, for example, Patent Document 1 discloses an attempt to obtain a molded body with humidity-regulating properties by mixing zeolite with a metal hydroxide and / or a deodorizing component material mainly composed of a metal hydroxide using a mixing and grinding method and sintering the mixture.

[0004] However, because zeolite is difficult to sinter, it has been difficult to form a bulk body strong enough for use as a structural component while maintaining a crystalline structure that can fully exert its adsorption and deodorizing functions. Furthermore, powdered zeolite has micropores that give it adsorption properties, but it does not fully exert its humidity-regulating function of releasing water vapor when the relative pressure of the water vapor drops.

[0005] A technique for providing a machinable zeolite bulk body using hydrothermal synthesis technology has been developed, and is disclosed, for example, in Patent Document 2. However, this zeolite bulk body is intended for adsorption and ion exchange functions, and there is no mention of moisture conditioning or breathability. In addition, with this method, the shape of the zeolite bulk body produced is determined by the hydrothermal vessel used, making it difficult to produce a versatile product that can produce molded bodies of various shapes using a single hydrothermal vessel.

[0006] For these reasons, there has been a demand for a zeolite bulk material that maintains the adsorption function inherent to zeolite, has high humidity control performance and breathability, and is provided in a molded form. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-242848 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-52997 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a zeolite bulk body that is provided in the form of a molded body and has high humidity control and breathability, and a method for producing the same, as well as a method for producing zeolite bulk bodies of various shapes using a single production apparatus. [Means for solving the problem]

[0009] The configuration of the present invention is shown below. (Configuration 1) It has an aluminosilicate zeolite with an MFI framework, The zeolite bulk body has pores formed in the aluminosilicate zeolite, including micropores, mesopores, and macropores. (Configuration 2) The simple average area S of the macropores measured by taking an arbitrary cross section is 5 μm 2 More than 20μm 2 Hereinafter, the standard deviation σ of the area of ​​the macropores is 12 μm 2 More than 20μm 2 2. A zeolite bulk according to claim 1, wherein the pore area when the cumulative frequency of the macropores is 95.4% is 2 to 5 times S+2σ. (Configuration 3) A zeolite bulk body according to configuration 2, wherein the measurement of the macropores is carried out on 10 sets of square cross sections each having a measurement area of ​​120 μm or more and 125 μm or less in length and width. (Configuration 4) 4. The zeolite bulk according to any one of aspects 1 to 3, having a compressive strength of 5 MPa or more and 100 MPa or less. (Configuration 5) 5. The zeolite bulk according to claim 4, having a compressive strength of 20 MPa or more and 50 MPa or less. (Configuration 6) Bulk density: 2.0 g / cm 3 More than 2.5g / cm 3 below, 6. The zeolite bulk according to any one of aspects 1 to 5, having a porosity (open porosity) of 40% or more and 50% or less. (Configuration 7) 7. The zeolite bulk body of any one of claims 1 to 6, wherein a catalyst is supported thereon. (Configuration 8) 8. The zeolite bulk according to claim 7, wherein the catalyst is one or more selected from the group consisting of metals and metal compounds, ceramics, and organic materials. (Configuration 9) mixing an aluminosilicate zeolite powder having an MFI framework, an inorganic binder, and a pore-forming agent for forming interconnected pores; performing a first heat treatment to produce a molded body; subjecting the molded body to a second heat treatment in pressurized steam; A method for producing zeolite bulk bodies, in which calcination is carried out in an oxygen-present environment. (Configuration 10) 10. The method for producing a zeolite bulk according to claim 9, wherein the inorganic binder is colloidal silica. (Configuration 11) 11. A method for producing a zeolite bulk body according to claim 9 or 10, wherein the pore-forming agent for forming interconnected pores is starch. (Configuration 12) 12. A method for producing a zeolite bulk body according to any one of aspects 9 to 11, wherein the temperature of the first heat treatment is 65°C or higher and 100°C or lower. (Configuration 13) A method for producing a zeolite bulk body according to any one of aspects 9 to 12, wherein the pressure of the pressurization is 0.1 MPa or more and 10 MPa or less, and the temperature of the second heat treatment is 100°C or more and 200°C or less. (Configuration 14) 14. A method for producing a zeolite bulk material according to any one of aspects 9 to 13, wherein the calcination temperature is 200°C or higher and 500°C or lower. (Configuration 15) 15. A method for producing a zeolite bulk body according to any one of aspects 9 to 14, wherein the calcination is carried out in an atmospheric environment. [Effects of the Invention]

[0010] According to the present invention, there are provided a zeolite bulk body which is provided in the form of a molded body and has both high humidity control properties and high breathability, and a method for producing the same. Furthermore, a manufacturing method is provided that can produce zeolite bulk bodies of various shapes using a single manufacturing device, and the zeolite bulk bodies provided here have compressive strength comparable to that of general concrete. The zeolite bulk of the present invention can also be used as a gas filter or a water treatment filter. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram showing the structure of the zeolite bulk of the present invention. [Figure 2] FIG. 1 is a flow chart showing the manufacturing process of the zeolite bulk of the present invention. [Figure 3] 1 is a schematic diagram showing the configuration of a manufacturing apparatus used in producing the zeolite bulk of the present invention. [Figure 4] FIG. 2 is an explanatory diagram showing the change in the structure of a starch pore-forming agent when a ceramic porous body having an interconnected pore structure is produced using the starch pore-forming agent. [Figure 5] FIG. 1 is an explanatory diagram showing the schematic structure of a zeolite bulk having the structure of Sample 1-3 of the example. [Figure 6]These are cross-sectional images of the sample prepared in the example, where (a) is the result of measurement using an SEM, and (b) and (c) are the results of measurement using a confocal laser fluorescence microscope. [Figure 7] This is an example of an (internal) cross-sectional image used for measuring the pore area distribution. [Figure 8] FIG. 10 is an explanatory diagram showing a method for measuring pore area distribution. [Figure 9] FIG. 10 is a diagram showing the state of holes in one (internal) cross section in hole area distribution measurement. [Figure 10] FIG. 10 is a characteristic diagram showing the cumulative frequency distribution of hole area. [Figure 11] 1 shows the results of X-ray diffraction measurements of samples prepared in Examples. [Figure 12] FIG. 1 is a characteristic diagram showing the fracture stress (compression strength) of samples prepared in Examples. [Figure 13] FIG. 1 is a characteristic diagram of nitrogen adsorption / desorption isotherms of samples prepared in Examples. [Figure 14] FIG. 10 is an explanatory diagram illustrating the relationship between pore types and adsorption / desorption characteristic curves. [Figure 15] FIG. 1 is a characteristic diagram showing a pore size distribution plotted by BJH based on nitrogen adsorption / desorption isotherms. [Figure 16] FIG. 10 is a characteristic diagram showing the measurement results of water adsorption / desorption isotherms. [Figure 17] FIG. 1 is a diagram showing the configuration of an apparatus used to measure air permeability. [Figure 18] FIG. 10 is a characteristic diagram showing the results of air permeability measurements. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below. The detailed description of the present invention described below may be based on representative aspects, embodiments, and examples, but these are merely examples, and the present invention is not limited to such aspects, embodiments, and examples. Note that "AB" indicates A or above and B or below.

[0013] (Embodiment 1) In the first embodiment, the structure and characteristics of the zeolite bulk of the present invention, as well as a method for producing the material, will be described.

[0014] <Structure and Features> As shown in Figure 1, the zeolite bulk 101 of the present invention is characterized by having an aluminosilicate zeolite 11 with an MFI framework, i.e., a framework structure code of MFI (ZSM-5 (Zeolite Socony Mobil-5)), and having micropores 12, mesopores 13, and macropores 14 formed in the aluminosilicate zeolite 11. Here, micropores refer to pores with diameters of less than 2 nm, mesopores refer to pores with diameters of 2 nm or more but less than 50 nm, and macropores refer to pores with diameters of 50 nm or more. Furthermore, for macropores measured by taking an arbitrary cross section, the simple average area S of the macropores is 5 μm 2 More than 20μm 2 Hereinafter, the standard deviation σ of the area of ​​the macropores is 12 μm 2 More than 20μm 2 Hereinafter, it is preferable that the area of ​​the pores when the cumulative frequency of the macropores is 95.4% is 2 to 5 times S+2σ. Here, the simple average area S is 7 μm 2 More than 15μm 2 Less than 7 μm is more preferable 2 More than 12μm 2 Even more preferably, the standard deviation σ of the area is 14 μm 2 More than 18μm 2 The area of ​​the holes when the cumulative frequency is 95.4% is more preferably 2.5 times or more and 4 times or less of S+2σ. The area of ​​the pores can be measured, for example, by measuring the macropores 14 in ten sets of square cross sections each having a measurement area of ​​120 μm to 125 μm in length and width.

[0015] When the macropores 14 are within the above numerical range, the moisture-regulating function of zeolite as a material is maintained, and high levels of air permeability, mechanical strength as a bulk material, and compressive strength can be ensured. For example, air permeability of 1.2 cc / min or more can be achieved, and compressive strength equivalent to that of general concrete can be achieved. This is because the area of ​​the macropores 14 is appropriate to achieve both breathability and mechanical strength, and also because an appropriate number of communicating pores, in which a plurality of pores are connected to each other, are formed. When macropores 14 are randomly sized and individually formed, the area of ​​the pores with a cumulative frequency of 95.4% is statistically S + 2σ, assuming a normal distribution. If the area of ​​the pores with a cumulative frequency of 95.4% is more than twice S + 2σ, this means that a large number of pores larger than this condition have been formed; specifically, this means that interconnected pores, in which multiple pores are connected, have been formed. The formation of interconnected pores ensures breathability. Numerous studies have shown that if the area of ​​the pores with a cumulative frequency of 95.4% exceeds five times S + 2σ, the number of weak points that can cause fracture in the bulk increases, resulting in a decrease in mechanical strength.

[0016] The compressive strength of the zeolite bulk material 101 is preferably 5 MPa or more and 100 MPa or less, and more preferably 20 MPa or more and 50 MPa or less. With a strength in this range, comparable to that of general concrete, high breathability and moisture conditioning properties can be obtained. Here, the compressive strength is measured, for example, in accordance with the JIS H7902 standard. The zeolite bulk body 101 has a bulk density of 2.0 g / cm 3 More than 2.5g / cm 3 The porosity (open porosity) is preferably 40% to 50%. Within this range, a zeolite bulk body having high humidity control and breathability, and breaking strength equal to or greater than that of general concrete, can be obtained.

[0017] When the catalyst 15 is loaded in the pores of the zeolite bulk body 101, the zeolite bulk body has excellent humidity control and breathability, and becomes an excellent catalytic filter. Here, the pores that load the catalyst are mainly mesopores 13. The catalyst may be one or more selected from the group consisting of metals and metal compounds, ceramics, and organic materials. For example, by supporting platinum (Pt) nanoparticles, it becomes possible to provide an environmental gas filter that efficiently adsorbs and decomposes NOx and VOCs (volatile organic compounds).

[0018] <Manufacturing method> The method for producing the zeolite bulk body 101 will be explained with reference to FIGS.

[0019] First, aluminosilicate zeolite powder, an inorganic binder, and a pore-forming agent for forming interconnected pores are prepared and mixed (FIG. 2, step S11). Examples of the mixing method include ball mill mixing and homogenizer dispersion.

[0020] Here, the aluminosilicate zeolite powder used is an aluminosilicate zeolite powder having an MFI framework, specifically ZSM-5 (Zeolite Socony Mobile-5) and silicalite-1. Examples of inorganic binders include colloidal silica, alumina sol, and zirconia sol. Colloidal silica suspended in water is preferable from the standpoint of cost and ease of handling, but methanol and isopropyl alcohol can also be used. The weight ratio of silica solids to the suspension solvent, such as water, is preferably 20% to 40%. An example of a pore-forming agent for forming interconnected pores is starch. Preferred examples of starch include rice starch and corn starch, and the weight ratio of the solid content to water is preferably 10% to 30%. The mixing ratio is preferably such that the weight ratio (Y / X) of colloidal silica Y to aluminosilicate zeolite powder X is 25% to 50%, and the weight ratio (Z / X) of interconnected pore-forming agent Z to aluminosilicate zeolite powder X is 10% to 30%. Within these ranges, high humidity control properties, breathability, and mechanical strength (compressive strength) can all be achieved.

[0021] Next, the mixture is subjected to a first heat treatment to produce a molded body (step S12). In the present invention, the outer shape of the product can be shaped during this molding process, which is one of the features of the present invention, as it is possible to supply zeolite bulk bodies of various shapes using a single manufacturing device. The first heat treatment method can be performed using a thermo-hygrostat or a constant-temperature dryer. The preferred temperature range is 80°C to 100°C, and the heat treatment time is 10 to 30 minutes. In this process, the interconnected-pore-forming pore-forming agent contained in the mixture gelatinizes (α-starchization). As shown in Figure 5(c), the interconnected-pore-forming pore-forming agent forms a network and undergoes retrogradation (β-starchization) during the cooling process at room temperature. For reference, Figure 4 shows the process of starch gelatinization and subsequent network formation. Figure 4(a) shows a gel state in which rice starch 33, consisting of (branched) amylopectin 31a and (linear) amylose 32, is surrounded by water molecules 34. Figure 4(b) shows that heating-induced gelatinization (α-starchization) causes some water molecules 34 to be incorporated into rice starch 33, while amylose 35a exists outside rice starch 33. Figure 4(c) shows the state in which cooling results in a networked β-starch structure, where 35b is amylose and 31b is amylopectin.

[0022] Thereafter, a second heat treatment is carried out in pressurized steam (step S13). The pressure is preferably 8 MPa to 10 MPa, the water vapor partial pressure is preferably 0.5 MPa to 1.1 MPa, the temperature is preferably 150° C. to 180° C., and the heat treatment time is preferably 12 hours to 24 hours. The pressurized steam heat treatment device is not particularly limited, and for example, a conventional device such as that shown in Fig. 3 can be used. In Fig. 3, 51 denotes an autoclave, 52 denotes a green body, 53 denotes a jig (support), and 54 denotes water. In this process, part of the networked starch is removed from inside the zeolite bulk body, and the zeolite and the binder are linked together to form an interconnected pore structure inside the bulk body.

[0023] Thereafter, calcination is carried out in an oxygen-containing environment (step S14) to produce a zeolite bulk body. The atmosphere is preferred as an oxygen-containing environment because it is simple and cost-effective, but any environment containing oxygen is acceptable, not limited to the atmosphere. Here, the pressure is preferably 0.1 MPa or more and 0.2 MPa or less, the amount of oxygen is 20% or more and 40% or less, the temperature is 450°C or more and 550°C or less, and the heat treatment time is 18 hours or more and 24 hours or less.

[0024] The key here is to maintain the inherent adsorption function of zeolite by performing the heat treatment below the temperature at which zeolite begins to decompose. Although the calcination is performed at such a relatively low temperature, the second heat treatment in pressurized steam partially removes the pore-forming agent while the zeolite is still networked, forming interconnected pores of an appropriate size, making it possible to supply zeolite bulk that combines moisture control, breathability, and compressive strength.

[0025] It should be noted that the present invention is not limited to the above-described embodiments, which are merely examples for explaining the present invention, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included within the technical scope of the present invention. [Example]

[0026] The present invention will be described in more detail below using examples, but the present invention is not necessarily limited to the following examples.

[0027] Example 1 In Example 1, a zeolite bulk sample was prepared and its properties were evaluated.

[0028] <Sample preparation> First, a commercial ZSM-5 (Zeolite Socony Mobile-5) zeolite powder (HSZ-800 840HOA proton type, Tosoh) and an aqueous dispersion of colloidal silica (Snowtex ST-S, Nissan Chemical) were mixed in a ball mill for 24 hours. The solids concentration in the slurry was 39-42 vol%, and the weight ratio of the solid components was ZSM-5:SiO2 = 2:1.

[0029] Next, starch (rice starch powder, manufactured by Sigma-Aldrich) was mixed into the slurry at a concentration of 0 or 20 wt % based on the solid weight as a pore-forming agent for forming interconnected pores using a stirring defoamer. The mixture was then cast into an acrylic mold and heated in steam at 80°C for 0 or 10 minutes. Thereafter, the mixture was dried at room temperature by natural drying and solidification to prepare a molded body. Next, the produced molded body was treated with water vapor in an autoclave at 180°C for 24 hours. The steam-treated compact was then degreased in air at 450°C for 24 hours to obtain a solidified zeolite (zeolite bulk).

[0030] Here, the following three types of samples were prepared. Sample 1: A sample positioned as a comparative example in which no starch was added and no heating in steam at 80°C was performed. Sample 2: Starch is added at 20 wt% of the solid content weight, but this sample is positioned as a reference example and is not heated in steam at 80°C. Sample 3: A sample positioned as an example in which starch was added at 20 wt% based on the solid content weight and heated in steam at 80°C for 10 minutes. To make the state of each sample easier to understand, the state is shown schematically in Figures 5(a) to (c). Figure 5(a) shows a state in which only zeolite (aluminosilicate zeolite) 11 powder is aggregated, Figure 5(b) shows a state in which starch is mixed with zeolite 11 powder and then the starch is removed, leaving pores 21, and Figure 5(c) shows a state in which the starch is removed, forming pores 22 and forming a network of pores 22. When pores 22 are networked, they form interconnected pores, as described below.

[0031] <Characteristics evaluation> 1.Shape The morphology was investigated by two methods: cross-sectional SEM observation and confocal laser scanning fluorescence microscope (CLSFM) observation using the immersion transillumination method.

[0032] A JSM-6500 (manufactured by JEOL) was used as the SEM (Scanning Electron Microscope), and observation was performed at 4 kV.

[0033] Immersion illuminance is a method of observing a sample by immersing it in a liquid with the same refractive index as the sample, suppressing light scattering. By dissolving a fluorescent agent in the immersion liquid, the internal state of the sample can be observed using a fluorescence microscope. Here, we used methyl 2-furancarboxylate, which has a refractive index of 1.48-1.49, as the immersion liquid, and Rhodamin B as the fluorescent agent. Note that the refractive index of zeolite is 1.47-1.5, and the immersion liquid used here has a refractive index within that range. The confocal laser fluorescence microscope used was a TCS SP5 (manufactured by Leica Microsystems). The laser wavelength was 543 nm, and the objective lens F-number was 0.36 (NA: 1.4). In this measurement, cross-sectional images at each focal plane are acquired and analyzed in 3D, allowing for display as a 3D image. Images were acquired and evaluated in 0.13 μm steps along the optical axis (Z direction).

[0034] The results are shown in Figure 6, where Figure 6(a) is an SEM image, Figure 6(b) is a CLSFM image of one focal plane inside the sample, and Figure 6(c) is a 3D image constructed from the CLSFM image. It can be seen that the internal structure (pore structure) changes depending on the manufacturing conditions.

[0035] 2. Macropore area distribution The distribution of macropore area was determined using cross-sectional images acquired with the confocal laser fluorescence microscope. The procedure is described below. Image processing was performed using ImageJ (Rasband, WS, ImageJ, US National Institutes of Health, Bethesda, Maryland, USA, https: / / imagej.nih.gov / ij / i997-2021; Schneider, CA, Rasband, WS, Eliceiri, KW, "NIH Image to ImageJ: 25 Years of Image Analysis," Nature Methods 9, 671-675, 2012).

[0036] First, as shown in Figure 7, cross-sectional images of Sample 2 and Sample 3 were acquired using the confocal laser fluorescence microscope. Specifically, as shown in Figure 8, two images were acquired in a 122.75 μm x 122.75 μm region, separated by 0.13 μm in the depth direction, forming a set. A total of 10 sets of images were acquired at 2.6 μm intervals. The brightness of the two images, separated by 0.13 μm in the depth direction, was adjusted by equalizing the pixel histograms, and the two images were simply added together to highlight the areas corresponding to the holes. The image in the center of Figure 8(b) is an example of this added image, and the two background images are images separated by 0.13 μm in depth that served as the basis for the synthesis. However, this two-image synthesis process is not necessarily required. Next, the image was smoothed using a Gaussian filter, and then binarized to extract the contours of the holes. After binarization, spike noise was removed to improve the accuracy of the contour extraction. The same processing was then performed on all 10 sets of images, and the area of ​​each hole, which was the black area, was measured using the Analyze Particles function of ImageJ, and the data was analyzed.

[0037] The state of pores 1 in one cross section determined by the above method is shown in Figure 9. It can be seen that there are many elongated pores of irregular shape that are thought to be interconnected pores. Table 1 shows the average value S of the hole area, the standard deviation σ, S+2σ, the hole size D at 95.4% frequency in Figure 10, and D / (S+2σ).

[0038] [Table 1]

[0039] From these results, Sample 3, which is an example, has a simple average pore area of ​​9.41 μm 2 is 10.10 μm for sample 2, which is a reference example. 2 Although there is not a large difference between the values, D / (S+2σ) is 2.92, nearly double that of Sample 2, and nearly three times larger than when the pore area distribution is assumed to be a normal distribution. When combined with the image data, it is clear that Sample 3, an example of the present invention, is characterized by the formation of interconnected pores.

[0040] 3. Crystal Structure The crystal structures of the prepared samples 1-3 and the reference raw zeolite ZSM-5 were investigated by powder X-ray diffraction. A Miniflex 600 (manufactured by RIGAKU) was used as the X-ray diffraction (XRD) device, and measurements were taken at diffraction angles of 10 to 50° with a step of 0.02°. The results are shown in Figure 11. As a result, the diffraction peaks of the solidified product matched those of the raw zeolite powder. This confirmed that the ZSM-5 crystal structure was maintained in Sample 1-3. For reference, Figure 11 also includes data from the ICDD database for ZSM-5.

[0041] 4. Density, open porosity, strength The apparent density, bulk density, open porosity, and fracture stress of the prepared zeolite bulk samples 1-3 were measured. The results are shown in Table 2. The addition of starch increased the open porosity. It was also demonstrated that the samples under all conditions had a fracture strength of over 30 MPa, which is comparable to that of ordinary concrete.

[0042] [Table 2]

[0043] The apparent density and bulk density were measured by the Archimedes method using kerosene as the solvent during measurement. The open porosity was estimated from the difference between the apparent density and the bulk density. The fracture stress was measured using an AG-I 50kN autograph (Shimadzu). The compression measurements were performed on cylindrical specimens with a diameter of 10 mm and a height of 10 mm at a crosshead speed of 0.6 mm / min. Measurements were performed seven or more times (n) per condition, and the average fracture stress (MPa) and standard deviation were calculated. For reference, the measurement data in Table 1 are shown in Figure 12.

[0044] 5. Pore size distribution and specific surface area The pore size distribution and specific surface area were measured by nitrogen adsorption / desorption isotherm measurement at -196°C. The results of nitrogen adsorption / desorption isotherm measurements are shown in Figure 13. The measurement was carried out using a PMA-601 (SepraTek) measuring device. In the prepared sample 1-3, a hysteresis curve was confirmed, which was not observed in the raw zeolite powder. It is generally known that the adsorption / desorption isotherm draws a curve as shown in Figure 14, which varies with the size of the pores formed in the sample. The fact that a hysteresis curve characteristic was obtained for sample 1-3 indicates that the solidified body of sample 1-3 contains pores larger than mesopores. Table 3 shows the specific surface area calculated by the BET method from the nitrogen adsorption / desorption isotherm.

[0045] [Table 3]

[0046] From these results, it can be seen that although sample 1-3 has a smaller specific surface area than the raw zeolite powder, it has a specific surface area of ​​300 m 2 It was confirmed that the material has a high specific surface area of ​​approximately 1 / g. Furthermore, a BJH plot created from the nitrogen adsorption / desorption isotherm is shown in Figure 15. From this result, the presence of mesopores of 6-9 nm was confirmed in Sample 1-3.

[0047] 6.Water vapor adsorption characteristics To examine the water vapor adsorption characteristics of the prepared zeolite solidified sample 1-3, water adsorption / desorption isotherms were measured at 25° C. The results are shown in FIG. It was confirmed that the amount of water adsorbed by the solidified body of Sample 1-3 in the high relative pressure range was greater than that of the raw zeolite powder. A hysteresis curve was also observed, which was not observed in the raw zeolite powder. This property indicates that Sample 1-3 has the ability to control environmental humidity. Furthermore, the adsorption / desorption isotherms changed depending on the amount of starch added during testing and whether or not the sample was heat-treated in steam at 80°C. This is thought to be due to changes in the internal pore structure caused by the treatment. Sample 3, in which interconnected pores were formed by the addition of starch and heat-treatment in steam at 80°C, was confirmed to have the highest water vapor adsorption amount.

[0048] 7. Breathable The air permeability of the zeolite bulk was investigated by measuring the nitrogen gas permeation rate. The measurements were as follows (see Figure 17). A 6 mm diameter hole was drilled in a 0.1 mm thick polyethylene terephthalate (PET) film, and a 13 mm diameter, 2 mm high disk-shaped zeolite bulk body was attached to the PET film with epoxy resin, aligning the center of the hole with the center of the solidified body. The epoxy resin was applied only to the part of the zeolite solidified body that was in contact with the PET film, so as not to adhere to the part exposed through the hole in the PET film. The zeolite solidified body attached to a PET film was placed in the chamber of a measuring device, Permeation Membrane Analyzer (PMA-601, manufactured by SepraTek), the PET film side was evacuated with an oil pump, and nitrogen gas at 0.2 MPa was flowed from the zeolite solidified body side.The flow rate (sccm) of nitrogen gas per unit time under standard conditions was calculated from the pressure change in the chamber using the analysis software attached to the measuring device.

[0049] The measurement results of the nitrogen gas permeation amount are shown in FIG. From these results, it was confirmed that Sample 3, which is an example and has communicating holes formed therein, has a larger amount of nitrogen gas permeated per unit time than Samples 1 and 2, and is therefore superior in breathability. [Industrial Applicability]

[0050] The present invention provides a zeolite bulk material that has sufficient strength to replace ordinary concrete and also has moisture-regulating and ventilation functions. The humidity-conditioning member of the present invention can control humidity and ventilation without using electricity like an air conditioner, and can also be used as a wall material, and is expected to be used in many places. Furthermore, the zeolite bulk of the present invention can also be used as a gas filter or a water treatment filter, which has excellent strength. Therefore, it is believed that it will contribute to industry, regardless of whether it is for consumer or industrial use. [Explanation of symbols]

[0051] 1: Hole 11: Zeolite, aluminosilicate zeolite 12: Micropores 13: Mesopores 14: Macropores 15: Functional nanoparticles 21: Pore 22: Pore 31a: (branched) amylopectin 31b: Amylopectin (gelatinized) 32: (Linear) amylose 33: Rice starch 34: Water molecules 35a: Amylose (at the time of gelatinization) 35b: Amylose (retrograded) 51: Autoclave 52: Molded body (Green Body) 53: Jig (support) 54:Water 101: Zeolite bulk

Claims

1. It has an aluminosilicate zeolite with an MFI framework, The aluminosilicate zeolite has pores formed therein, including micropores, mesopores, and macropores; A zeolite bulk body having a compressive strength of 20 MPa or more and 50 MPa or less.

2. The simple average area S of the macropores measured by taking an arbitrary cross section is 5 μm ２ 20 μm or more ２ Hereinafter, the standard deviation σ of the area of ​​the macropores is 12 μm ２ 20 μm or more ２ A zeolite bulk body as described in claim 1, wherein the pore area when the cumulative frequency of the macropores is 95.4% is 2 to 5 times S+2σ.

3. The zeolite bulk body according to claim 2, wherein the measurement of the macropores is carried out on 10 sets of square cross sections each having a measurement area of ​​120 μm or more and 125 μm or less in length and width.

4. Bulk density: 2.0 g / cm ３ 2.5g / cm or more ３ below, A zeolite bulk body according to any one of claims 1 to 3, having a porosity (open porosity) of 40% or more and 50% or less.

5. A zeolite bulk body according to any one of claims 1 to 4, which is supported on a catalyst.

6. The zeolite bulk according to claim 5, wherein the catalyst is one or more selected from the group consisting of metals and metal compounds, ceramics, and organic materials.

7. mixing an aluminosilicate zeolite powder having an MFI framework, an inorganic binder which is colloidal silica, and a pore-forming agent which is starch; performing a first heat treatment to produce a molded body; subjecting the molded body to a second heat treatment in pressurized steam; Firing in an oxygen-containing environment It encompasses the mixing step includes mixing the aluminosilicate zeolite powder, the inorganic binder, and the interconnected-pore-forming pore-forming agent so that a weight ratio (Y / X) of the colloidal silica Y to the aluminosilicate zeolite powder X is 25% or more and 50% or less, and a weight ratio (Z / X) of the interconnected-pore-forming pore-forming agent Z to the aluminosilicate zeolite powder X is 10% or more and 30% or less, In producing the molded body, the first heat treatment conditions are in the range of 80° C. or higher and 100° C. or lower and 10 minutes or longer and 30 minutes or shorter, In performing the second heat treatment, the conditions of the second heat treatment in the pressurized steam are a pressure of 8 MPa or more and 10 MPa or less, a steam partial pressure of 0.5 MPa or more and 1.1 MPa or less, a temperature of 150°C or more and 180°C or less, and a time of 12 hours or more and 24 hours or less, A method for producing a zeolite bulk body, wherein the firing conditions are a pressure of 0.1 MPa or more and 0.2 MPa or less, an oxygen content of 20% or more and 40% or less, a temperature of 450°C or more and 550°C or less, and a time of 18 hours or more and 24 hours or less.

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