JP2020055699A - Amorphous aluminosilicate particle powder and method for producing the same - Google Patents

Abstract

To provide an amorphous aluminosilicate particle powder having a high specific surface area and excellent heat resistance and gas adsorption performance, and to provide a method for producing the same.SOLUTION: In an amorphous aluminosilicate particle powder represented by the general formula a NaO b SiOAlOn HO having a surface area of 650 to 900 m/g, a is in the mol range of 0.05 to 0.29, b is in the mol range of 1.40 to 2.60, n is in the mol range of 0.50 to 1.25, andSi-NMR spectrum in the chemical shift range of -120 to -60 ppm is represented by the superposition of a single peak located at -78.9 to -77.0 ppm and 2 to 6 multiple peaks located at -110 to -79.0 ppm.SELECTED DRAWING: None

Description

  The present invention relates to a heat-resistant amorphous aluminosilicate particle powder having excellent polar gas adsorption performance and a method for producing the same.

Amorphous aluminosilicate has long been known as an amorphous clay mineral, and at the same time, is known to have a large amount of adsorbing water molecules. Therefore, it is still recognized that amorphous aluminosilicate has high water adsorption performance (Non-Patent Documents 1 to 3). It is thought that the amorphous aluminosilicate in the volcanic ash grew by weathering, and the filamentous amorphous aluminosilicate was named imogolite in 1962. Imogolite is several microns in length and about 20 nm in diameter, and has a composition ratio near SiO ₂ .Al ₂ O ₃ .3H ₂ O. Imogolite is amorphous, but its local crystal structure has been discussed and is sometimes referred to as low crystalline. At the atomic level, an octahedral sheet of AlO ₆ or AlO ₃ (OH) ₃ having a gibbsite structure and having a tube shape with an outer diameter of about 2 nm is rounded to form a tube. The octahedron of the AlO ₆ or AlO ₃ (OH) ₃ octahedral sheet has a honeycomb structure, and SiO ₄ or SiO ₃ (OH) tetrahedron exists as a monomer near the vacant Al site. The tubes are strongly overlapped and are observed as a thread having a diameter of about 20 nm.

On the other hand, amorphous aluminosilicate particle powder is called allophane and was discovered in the early 19th century. It is thought that it grew by weathering like imogolite, and it is also pointed out that it has similar low crystallinity. However, the local crystal structure of allophane has not been consensused because it is not as crystalline as imogolite. In allophane, SiO ₄ tetrahedra SiO ₄ tetrahedra monomer and SiO ₄ tetrahedra two sheets from kaolin minerals are present, AlO _x octahedron constitutes the sheet of gibbsite structure AlO ₆ octahedra It is a common recognition of those skilled in the art that not only exists but also partially as AlO ₄ tetrahedron. Allophane forms hollow particles of several nm, and has a composition ratio near 2SiO ₂ .Al ₂ O ₃ .3H ₂ O. The specific surface area is also high, being reported to be about 600 m ² / g. Here, the amount of water described in the general formula is the amount of water of crystallization contained in the local crystal structure of allophane or imogolite, not the amount of adsorbed water. The inventor estimates that such a large amount of water of crystallization is one of the reasons why the heat resistance of the allophane particle powder is low.

  Synthetic amorphous aluminosilicate particle powders have also been actively reported since 1970. The major difference between natural amorphous aluminosilicate particles contained in volcanic ash and the like and synthetic amorphous aluminosilicate particles is the impurity content. Natural amorphous aluminosilicate particles contain a large amount of Fe and Mg. In order to obtain a synthetic amorphous aluminosilicate particle powder, a normal pressure synthesis using an aqueous solvent having a reaction temperature of 100 ° C. or lower and a hydrothermal synthesis exceeding 100 ° C. have been studied.

  In general, amorphous aluminosilicate particles can be obtained by stirring and mixing a water-soluble silicon raw material and a water-soluble aluminum raw material, adjusting the pH to near neutrality, and subjecting the mixed solution to a heating reaction. Amorphous aluminosilicate particles having a high specific surface area and excellent polar gas adsorption performance can repeat the gas adsorption action at room temperature and the adsorption gas desorption action at high temperature. Therefore, the amorphous aluminosilicate particle powder is suitable for an adsorbent for air conditioning. However, for repeated long-term use such as gas adsorption and desorption, it is necessary to suppress the degree and frequency of exposing the amorphous aluminosilicate particles to a high-temperature environment. For example, regeneration of an air-conditioning adsorbent at a low temperature of 100 ° C. or less, that is, an operation of desorbing an adsorbed gas is being studied. In any case, the heat resistance of the amorphous aluminosilicate particle powder is necessary for the above utilization.

  A common form of air-conditioning adsorbent is an adsorption rotor system. In other words, this is a system in which an adsorbent is supported on a support such as paper, resin, or porous ceramic, and processed into a rotor type for use. At the time of this processing, the adsorbent is carried from the adsorbent-containing dispersion. However, since an organic substance such as a dispersant used in the dispersion liquid also remains in the adsorption rotor, there is a step of performing a heat treatment on the adsorption rotor. Therefore, the adsorbent itself is required to have heat resistance even during rotor processing.

  As prior art, Patent Documents 1 and 2 disclose amorphous aluminosilicate particles having a high specific surface area and excellent polar gas adsorption performance. However, it has been found that when the amorphous aluminosilicate particles shown in these publications are fired at 300 ° C. or higher, the specific surface area is greatly reduced, and the amount of adsorbed water vapor is also significantly reduced.

  The water-soluble silicon raw material and the water-soluble aluminum raw material in the production method disclosed in the technique of Patent Document 1 are mixed in consideration of only the molar ratio of silicon and aluminum. Thereafter, the pH was adjusted and desalted, and the reaction was carried out at 110 ° C. or lower to obtain amorphous aluminosilicate particles. However, in this method, it is difficult to obtain heat-resistant amorphous aluminosilicate particles, and gelation occurs at the time of mixing the raw materials, so that production by an industrial process is difficult.

  In addition to the long-term high-temperature reaction described above, a reaction under hydrothermal conditions is also disclosed (Patent Document 2). However, in consideration of industrial mass production, it is necessary to improve the hermeticity of the reaction equipment in the case of hydrothermal reaction at 100 ° C. or higher from the viewpoint of maintenance of high-pressure vessels and work safety. For this reason, it takes time to heat up and cool down the hydrothermal reaction system. Therefore, even in a short time, the hydrothermal treatment is rate-determining in the production process. Therefore, it is necessary to increase the reaction concentration at the time of hydrothermal treatment so as to contribute to the improvement of particle powder production efficiency even when the hydrothermal reaction temperature is high.

C. S. Ross, et al. , "Halloysite and Allophane", Geological Survey, United States Department of the Interior, (1934) 185-G, p. 135-148. Sudo Discourse, "Invitation to Clay Science: The Real Face and Charm of Clay", Sankyo Publishing, June 26, 2000 R. L. Parfitt, "Allophane and imogolite: role in soil biogeochemical process", Clay Minerals, 2009, vol. 44, p. 135-155.

JP 2008-179533 A WO 09/084632 pamphlet

  Amorphous aluminosilicate particles having a high specific surface area, a high adsorption amount to water vapor, and an improvement in water vapor adsorption performance in proportion to relative humidity (RH) have been provided. Is not enough. In addition, it is difficult to say that a highly efficient production method is provided from an industrial point of view in the method for producing the heat-resistant amorphous aluminosilicate particles.

  That is, the above-mentioned Patent Documents 1 and 2 describe amorphous aluminosilicate particle powder excellent in adsorbing a polar gas such as water vapor and a method for synthesizing the same. However, the amorphous aluminosilicate particles obtained by the described synthesis method do not have sufficient heat resistance, and exhibit a gas adsorption / desorption performance during rotor processing or repeated use of adsorption / desorption of polar gas. It is considered that rapid deterioration of the slab can always occur.

  Further, when an attempt was made to increase the concentration of the reaction system by the synthesis methods described in Patent Documents 1 and 2, gelation was caused when the water-soluble silicon raw material and the water-soluble aluminum raw material were mixed. Therefore, in the beaker scale, it is possible to cope with the work of adding water or stirring by manual operation, but this operation involves danger and it is difficult to cope industrially.

  In addition, in the techniques described in Patent Documents 1 and 2, although the pH is adjusted after mixing the water-soluble silicon raw material and the water-soluble aluminum raw material, no concentration after the desalting treatment is suggested. Even if an additional concentration operation is attempted in the above technique, the concentrated slurry loses fluidity at the point when the concentration of the solid content is increased to around 80 g / L, and the inside of the reaction system is made uniform by the subsequent heat treatment. Was difficult.

  The technical problem can be achieved by the present invention as described below.

That is, the present invention provides an amorphous aluminosilicate particle powder having a specific surface area of 650 to 900 m ² / g and represented by a general formula a Na ₂ O · b SiO ₂ · Al ₂ O ₃ .nH ₂ O, a is 0.05 to 0.29, b is 1.40 to 2.60, n is a mol range of 0.50 to 1.25, and ²⁹ Si-NMR in a chemical shift range of -120 to -60 ppm. An amorphous phase, wherein a spectrum is represented by a single peak located at -78.9 to -77.0 ppm and a superposition of two to six peaks located at 110 to -79.0 ppm. Aluminosilicate particles. (Invention 1).

Further, the present invention is the chemical shift -120-60 ppm each peak shape function of a peak showing the ²⁹ Si-NMR spectrum of range is represented by a Gaussian function, the present invention the coefficient of determination ^{R 2} is at least 0.99 2. An amorphous aluminosilicate particle powder according to item 1. (Invention 2).

In the present invention, the chemical shift is in the range of −110.0 to −79.0 ppm, and each peak showing the ²⁹ Si-NMR spectrum is located at −91.9 to −90.0 ppm with respect to the peak having the largest peak area. The amorphous aluminosilicate particle powder according to the first or second aspect of the present invention, wherein an area ratio of a peak having a half width of 5 ppm or less is 0.080 to 0.200. (Invention 3).

  Further, the present invention is the amorphous aluminosilicate particle powder according to any one of the present inventions 1 to 3, wherein a reduction rate of a specific surface area after firing at 300 ° C for 1 hour is 10% or less. (Invention 4).

  Further, the present invention relates to the amorphous aluminosilicate particle powder according to any one of the present inventions 1 to 4, wherein a reduction rate of a water vapor adsorption amount at a relative humidity of 60% after firing at 300 ° C for 1 hour is 12% or less. is there. (Invention 5).

  Further, the present invention provides a first step of preparing a solution containing a water-soluble silicon raw material and an alkali raw material, and adding a water-soluble aluminum raw material to the obtained solution so that the molar ratio of Al / OH in the mixed solution after addition is 2%. 0.0-3.0, the molar ratio of Si / Al is adjusted to 0.7-1.4, and the pH is adjusted to 6.0-8.0. The second step in which the reaction is carried out. The obtained mixed slurry is washed with water and concentrated. Amorphous according to any one of the inventions 1 to 5, further comprising a third step of adjusting the pH to 7.0 to 10.0 with a fourth step, and a fourth step of hydrothermally treating the obtained slurry at a temperature of 170 to 250 ° C. This is a method for producing aluminosilicate particles. (Invention 6).

  Further, the present invention is the production method according to Invention 6, wherein the solid content concentration in the fourth step is from 90 to 300 g / L. (Invention 7).

  Amorphous aluminosilicate particles according to the present invention, including water vapor, ethanol, acetone, a gas of a polar organic solvent such as ethyl acetate, or acetic acid and ammonia, hydrogen sulfide, nitrogen oxides and odor factors. Hazardous gases such as sulfur oxides can be adsorbed and captured. Since the heat resistance of the particle powder is high, it can be applied to a wide range of fields such as a dehumidifier for air conditioning, an adsorbent for recovering an organic solvent, a deodorant, and a harmful gas adsorbent. Further, even if a heating step is performed to desorb the adsorbed gas, there is no problem, and the method is suitable for repeated use of gas adsorption and desorption. Further, the amorphous aluminosilicate particles according to the present invention have a high specific surface area even after firing at 300 ° C. for one hour, and no decrease in water vapor adsorption performance is observed. Therefore, it is also suitable for an adsorbent for an adsorption rotor that requires firing during processing.

  More specifically, even after calcination of the amorphous aluminosilicate particles according to the present invention at 300 ° C. for one hour, the amount of water vapor adsorbed at a relative humidity of 60% remains high. Is 12% or less. The method for producing amorphous aluminosilicate particles according to the present invention is a highly efficient production method from an industrial viewpoint.

2 is a photograph of the amorphous aluminosilicate particles obtained in Example 1 observed by a transmission electron microscope (TEM). 3 is an X-ray diffraction (XRD) profile of the amorphous aluminosilicate particles obtained in Example 1. 3 is a Fourier transform infrared spectroscopy (FT-IR) spectrum of the amorphous aluminosilicate particles obtained in Example 1. 2 is a measured value of a nuclear magnetic resonance (NMR) spectrum of solid ²⁷ Al of the amorphous aluminosilicate particles obtained in Example 1. 2 shows the measured and calculated values of the solid-state ²⁹ Si-NMR spectrum of the amorphous aluminosilicate particles obtained in Example 1.

  The configuration of the present invention will be described in more detail as follows.

  First, the amorphous aluminosilicate particles according to the present invention will be described.

The amorphous aluminosilicate particles according to the present invention are amorphous as the name implies, and have almost no periodicity of elements. Chemical structure represented by the general formula _{a Na 2 O · b SiO 2} · Al 2 O 3 · n H 2 O. Here, Al ₂ O ₃ in the general formula is 1 mol, the value of b is also called the Cayban ratio (mol ratio of SiO ₂ / Al ₂ O ₃ ), and H ₂ O in the general formula is Represents water of crystallization. Since Si ⁴⁺ and ^{Al 3+} is that there are places to share ^{O 2-} one another, ^{Si 4+} surrounding be electrically neutral, ^{Al 3+} peripheral is charged as a minus monovalent. Therefore, the surroundings of Al ³⁺ are supplemented with M ⁺ ions so as to be electrically neutral. The M ⁺ ions are ion-exchanged depending on the atmosphere, and may be discharged outside the system of the particle powder.

  In the general formula of the amorphous aluminosilicate particles according to the present invention, a is in the range of 0.05 to 0.29 mol. If it is less than 0.05, the abundance of OH groups in the structure increases, and the pores on the surface of the particle powder are blocked, and the specific surface area tends to decrease, which is not preferable. If it exceeds 0.29, the adsorption performance is not significantly affected, but the pH of the powder becomes high, which is not preferable because problems are likely to occur on the processed surface of the particle powder. More preferably, the molar range is from 0.07 to 0.27, and even more preferably, the molar range is from 0.08 to 0.25.

In the general formula of the amorphous aluminosilicate particles according to the present invention, Na of Na ₂ O can be replaced with another element by ion exchange after the synthesis of the amorphous aluminosilicate particles. The elements are Li, Mg, K, Ca, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ag, Cs, and Ba.

In the general formula of the amorphous aluminosilicate particles according to the present invention, b is in the range of 1.40 to 2.60 mol. When the amount is less than 1.40 mol, γ-Al (OH) ₃ particles having a regular gibbsite crystal structure rather than amorphous aluminosilicate particles are mainly contained in the obtained particle powder. For this reason, the pores derived from the amorphous structure of the amorphous aluminosilicate particles are reduced, and the BET specific surface area is undesirably reduced. If the amount exceeds 2.60 mol, amorphous silica is predominant in the obtained particle powder, and the adsorption performance is lowered. That is, the difference between the adsorption performance of amorphous silica and the adsorption performance of water vapor disappears, which is not preferable. When b is less than 1.40 mol or more than 2.60 mol, baking the obtained particle powder at 300 ° C. for 1 hour is not preferable because the specific surface area of the sample is significantly reduced. More preferably, the molar range is 1.50 to 2.50, and even more preferably, the molar range is 1.60 to 2.40.

  In the general formula of the amorphous aluminosilicate particles according to the present invention, n is in the range of 0.50 to 1.25 mol. If it is less than 0.50, the amount of water of crystallization decreases, and a regular crystal structure is formed, and the periodicity of the structure increases. In that case, it is difficult to maintain a high specific surface area. If it exceeds 1.25, the amount of crystallization water in the sample is too large, and it is difficult to obtain a predetermined heat resistance. More preferably, the molar range is 0.60 to 1.15, and even more preferably, the molar range is 0.70 to 1.10.

The amorphous aluminosilicate particles according to the present invention exhibit an amorphous property to the extent that a crystal-derived peak is hardly observed in an X-ray diffraction (XRD) profile, are almost low in crystallinity, and belong to allophane. Preferably it is possible. More preferably, it is preferable to show periodicity of the element arrangement in which 1 to 30 unit cells of kaolinite or halloysite are arranged. From an atomic point of view, AlO ₆ octahedron has a honeycomb-like sheet similar to an octahedral sheet having a gibbsite structure, and a SiO ₄ tetrahedron derived from a kaolin mineral sharing three Os of a SiO ₄ tetrahedron. It has a sheet and a monomeric SiO ₄ tetrahedron.

In the FT-IR spectrum, the amorphous aluminosilicate particles according to the present invention preferably have a vibration spectrum at 930 to 990 cm ⁻¹ derived from Si—O of the SiO ₄ tetrahedral unit. More preferably, it is 940 to 980 cm ^-1 .

The specific surface area of the amorphous aluminosilicate particles according to the present invention is from 650 to 900 m ² / g. Here, the specific surface area is a value measured by the BET method. Hereinafter, the BET specific surface area has the same meaning as the specific surface area. When the BET specific surface area is less than 650 m ² / g, the amount of adsorbed water vapor is undesirably reduced. If the BET specific surface area exceeds 900 m ² / g, there is no problem in gas adsorbing performance, but it is not preferable because powdery dust increases and handling properties deteriorate. A preferred BET specific surface area is 700 to 850 m ² / g.

In the ²⁷ Al-NMR spectrum of the amorphous aluminosilicate particles according to the present invention, the chemical shift is located in the range of −80 to 30 ppm with respect to the main peak intensity located in the range of −15 to 15 ppm. The ratio with respect to the secondary peak intensity is preferably 0.5 or less. The peak located in the range of chemical shift -15 to 15 ppm indicates the presence of AlO ₆ octahedra, and the peak located in the range of -80 to 30 ppm indicates the presence of AlO ₄ tetrahedron. The presence of AlO ₆ octahedron acts to stabilize the structure of allophane. However, the AlO ₄ tetrahedron is substituted for the SiO ₄ tetrahedron of the SiO ₄ tetrahedral sheet in allophane, causing defects in the allophane structure and possibly affecting the heat resistance of the resulting particle powder. A more preferred peak intensity ratio is 0.4 or less, and an even more preferred peak intensity ratio is 0.3 or less.

If the content of Al in the amorphous aluminosilicate particles according to the present invention is 10 mol% or less, another metal element can be introduced instead of Al. The metal elements are Mg, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y and Zr. If it is added in excess of 10 mol%, the arrangement of AlO ₆ octahedron and SiO ₄ tetrahedron is affected, and the specific surface area and heat resistance of the obtained particle powder are undesirably reduced. More preferably, the introduction amount of the metal element is 8 mol% or less, still more preferably, 6 mol% or less.

The ²⁹ Si-NMR spectrum of the amorphous aluminosilicate particles according to the present invention has a single peak located at −78.9 to −77.0 ppm and −110 in a chemical shift range of −120 to −60 ppm. It is represented by the superposition of two to six peaks located at 0.0 to -79.0 ppm. Generally, the chemical shift of the ²⁹ Si-NMR spectrum is due to the degree of polymerization of the SiO ₄ tetrahedron. For example, a single peak located at -78.9~-77.0ppm means that O of SiO ₄ tetrahedra do not share the SiO ₄ tetrahedra adjacent. That is, it means a monomeric SiO ₄ tetrahedron, which is a Q ⁰ value peak.

On the other hand, a plurality of peaks located at -110.0 to -79.0 ppm represent differences in the number of SiO ₄ tetrahedra sharing O of an arbitrary SiO ₄ tetrahedron, that is, the degree of polymerization of the SiO ₄ tetrahedron. And that Si of the SiO ₄ tetrahedron sharing O is replaced by Al and present as an AlO ₄ tetrahedron. The number of sharing SiO ₄ tetrahedra and O to SiO ₄ tetrahedra are adjacent is 1-3, each called peak of Q ¹ to Q ³ value. Here, considering that the XRD profile suggests the existence of a SiO ₄ tetrahedral sheet in which three SiO ₄ tetrahedrons share O, a plurality of sheets located at −110.0 to −79.0 ppm are considered. one peak is likely peak Q ³ value. Further, the presence of AlO ₄ tetrahedron is suggested from the ²⁷ Al-NMR spectrum. Thus, the main peaks which can be expressed by superposition of the position peak 2-6 one of a plurality of peaks in -110.0~-79.0ppm is the peak of the ^{Q 3} value, other peak of Q ¹ to Q ² value Also, there is a possibility that the peaks of the Q ^{1 to} Q ³ values involve the AlO ₄ tetrahedron. As a result, a maximum of six peaks can be expressed. Here, the minimum number of peaks was used so that curve fitting could be sufficiently performed. On the other hand, in the spectrum obtained at -110.0 to -79.0 ppm, a single peak did not provide a sufficient fitting result. Therefore, the number of peaks that can be expressed by more preferable superposition is preferably 2 to 4, and more preferably 2, 3.

In the amorphous aluminosilicate particle powder according to the present invention, the peak shape function of each peak showing a ²⁹ Si-NMR spectrum in the chemical shift range of −120 to −60 ppm is represented by a Gaussian function, and the coefficient of determination R ² is It is preferably 0.99 or more. As the peak shape function other candidates, but it may be a Lorentzian or pseudo Voight function, the coefficient of determination R ² is close to 1, selects the Gaussian function as a simple function. Further, if the coefficient of determination R ² does not approach the 1 increases, more and it did not increase the peak shape function. The coefficient of determination ^{R 2} is more preferably 0.992 or more.

The ²⁹ Si-NMR spectrum of the amorphous aluminosilicate particles according to the present invention in the chemical shift range of −110 to −79.0 ppm will be described in more detail. In each of the peaks in the above range, the area ratio of the peak having a half width of 5 ppm or less located at -91.9 to -90.0 ppm to the peak having the largest peak area is 0.080 to 0.200. Is preferred. Here, -91.9~-90.0ppm half width 5ppm or less of the peak located corresponds to the peak of the ^{Q 3} value derived from the sequence of uniform SiO ₄ tetrahedra and inventor believes. Therefore, in order for the peak to increase the heat resistance of the amorphous aluminosilicate particles, the SiO ₄ tetrahedron in the SiO ₄ tetrahedral sheet needs to be more uniform as the allophane structure. That is, the peak width of the peak of Q ³ values obtained is narrow, the peak area ratio needs to be high. On the other hand, the peak having the largest peak area may correspond to the peak of the Q ³ value. However, the peak has a large half-value width due to disorder of the SiO ₄ tetrahedron and the AlO ₄ tetrahedron, and is considered to contribute to the instability of the allophane structure as compared with the peak of the pure Q ³ value. Therefore, it is not preferable because the thermal stability of the particles the ratio of peak areas of Q ³ value to the peak of the Q ³ value AlO ₄ tetrahedra are involved is obtained as below 0.080 is lowered. Further, a particle powder having the area ratio exceeding 0.200 could not be produced. A more preferred range is from 0.082 to 0.195.

  The reduction rate of the specific surface area of the amorphous aluminosilicate particles according to the present invention after firing at 300 ° C. for 1 hour is preferably 10% or less. Here, the reduction rate is a value obtained by dividing the difference between the BET specific surface area of the particle powder of the present invention and the BET specific surface area of the fired particle powder by the BET specific surface area of the particle powder of the present invention, and is expressed as a percentage. It is. If the decrease rate of the specific surface area exceeds 10%, it means that the quality of the particle powder is directly deteriorated, and it is not preferable because the deterioration is caused even when the gas is adsorbed and desorbed repeatedly. A more preferred specific surface area reduction rate is 9.5% or less, and still more preferably 9.0% or less. The lower limit of the reduction rate is 0%, but may be 1%.

  The shape of the primary particles of the amorphous aluminosilicate particles according to the present invention is preferably granular or plate-like. The average primary particle diameter of the particle powder is preferably 1 to 50 nm. More preferably, it is 2 to 30 nm.

  The reduction rate of the amount of water vapor adsorbed at a relative humidity of 60% after firing the amorphous aluminosilicate particles according to the present invention at 300 ° C. for 1 hour is preferably 12% or less. Here, the reduction rate is a value obtained by dividing the difference between the water vapor adsorption amounts of the particle powder of the present invention and the fired particle powder by the water vapor adsorption amount of the particle powder of the present invention, and expressed as a percentage. Value. If it exceeds 12%, the heat resistance is low and it is almost the same as other inexpensive adsorbents, and it is not preferable because superiority cannot be exhibited. A more preferable reduction rate of the amount of adsorbed water vapor is 11.5% or less, and further more preferably 11% or less. The lower limit of the reduction rate is 0%, but may be 1%.

  Next, a method for producing the amorphous aluminosilicate particles according to the present invention will be described.

  The method for producing an amorphous aluminosilicate particle powder according to the present invention comprises a first step of preparing a solution containing a water-soluble silicon raw material and an alkali raw material, and mixing after addition by adding a water-soluble aluminum raw material to the obtained solution. The mole ratio of Al / OH in the solution is adjusted to 2.0 to 3.0, the mole ratio of Si / Al is adjusted to 0.7 to 1.4, and the pH is adjusted to 6.0 to 8.0. A production process having a step, a third step of adjusting the pH to 7.0 to 10.0 by washing and concentrating the obtained mixed slurry, and a fourth step of hydrothermally treating the obtained slurry at a temperature of 170 to 250 ° C. Preferably, there is.

In the method for producing amorphous aluminosilicate particles according to the present invention, the water-soluble silicon raw material used in the first step may be sodium orthosilicate, water glass, tetraethyl orthosilicate (TEOS), or the like. Examples of the alkali raw material include aqueous sodium carbonate, aqueous potassium carbonate, and aqueous ammonium carbonate as an aqueous alkali carbonate solution, and sodium hydroxide, potassium hydroxide, and the like can be used as an aqueous alkali hydroxide solution. Here, the amount of Si and the amount of OH are determined by the raw material preparation. However, in the case of 1 mol of CO ₃ ^2- ions in the aqueous alkali carbonate solution, the amount of OH is estimated to be 1 mol.

  In the method for producing amorphous aluminosilicate particles according to the present invention, the water-soluble aluminum raw material used in the second step may be aluminum sulfate, aluminum nitrate, aluminum chloride or the like. A mixed solution can be prepared by mixing the aluminum raw material with the aqueous solution obtained in the first step. The reaction starts by the mixing, and the mixed solution can be a mixed slurry.

  It is possible to mix and use 10 mol% or less of a metal salt raw material with respect to the water-soluble aluminum raw material used in the second step. The metal elements are Mg, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y and Zr. Any of chloride, sulfate and nitrate of each element may be used, but a water-soluble salt is preferable.

  In the mixed solution after the addition of the water-soluble aluminum raw material, the molar ratio of Al / OH is preferably 2.0 to 3.0. When it is less than 2.0, it is difficult to cause a uniform reaction by causing a viscosity increase or a gelation at the time of adding the raw materials, which is not preferable. If it exceeds 3.0, the adsorption performance of the amorphous aluminosilicate particles obtained through the subsequent steps is undesirably reduced. A more preferred molar ratio of Al / OH is 2.1 to 2.9, and still more preferably 2.2 to 2.8.

  In the mixed solution after the addition of the water-soluble aluminum raw material, the molar ratio of Si / Al is preferably 0.7 to 1.4. If it is less than 0.7, crystalline aluminosilicate is generated at the time of passing through the fourth step, and the amount of adsorption and the specific surface area are undesirably reduced. If the ratio exceeds 1.4, the obtained particle powder is considerably amorphous, and an amorphous aluminosilicate particle powder having a low specific surface area is not preferable. More preferably, the molar ratio of Si / Al is 0.8 to 1.35, and still more preferably, the molar ratio of Si / Al is 0.9 to 1.3.

  The pH adjustment in the second step needs to be performed after the addition of all the raw materials described above. As the acid for adjusting the pH, hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, acetic acid and the like can be used. Examples of the alkali for pH adjustment include an aqueous solution of an alkali carbonate, an aqueous solution of sodium carbonate, an aqueous solution of potassium carbonate, an aqueous solution of ammonium carbonate, and the like.For an aqueous solution of an alkali hydroxide, sodium hydroxide, potassium hydroxide, and the like can be used. . The pH range after the adjustment is preferably 6.0 to 8.0. When the pH to be adjusted is less than 6.0 or more than 8.0, the specific surface area of the particle powder obtained through the fourth step decreases, and the gas adsorption performance also decreases. A more preferred pH is 6.2-7.9, and even more preferably 6.5-7.8. The reaction time after the pH adjustment is preferably 10 minutes to 3 hours. The standard of the reaction time is the time at which the pH is stabilized, and even if left for a long time, the performance of the obtained particle powder is not significantly affected. More preferably, it is 15 minutes to 2 hours 30 minutes.

  By adjusting the order and amount of addition of the raw materials as mentioned in the first step, it is possible to prevent the mixed slurry obtained in the second step from thickening or gelling. When the solid concentration is less than 50 g / L, the viscosity after addition of the raw material is low, and there is no problem in production. However, if a concentration higher than that is adopted in order to enhance the productivity, gelation occurs after the addition of the raw materials, and production has been impossible. Therefore, in the second step of the present invention, the solid content concentration of the mixed slurry of the raw materials is preferably 50 to 110 g / L. Within this range, it is possible to transfer the tank for washing and concentrating the slurry, which is the third step, without causing the mixed slurry to thicken or gel. Here, the solid content concentration is calculated by a method of calculating the volume of the mixed slurry and calculating from the weight of the solid content after drying the mixed slurry, as described later.

  In the method for producing amorphous aluminosilicate particles according to the present invention, the end point of the slurry washing in the third step is preferably measured by the electric conductivity of the filtrate. The value of the electrical conductivity at the end point is preferably 50 μS / cm to 800 μS / cm. If it is less than 50 μS / cm, it takes a long time to reach it, so that it is not preferable from the viewpoint of productivity. If it is more than 800 μS / cm, the adsorption performance of the amorphous aluminosilicate particles obtained through the subsequent steps is undesirably reduced.

  It is preferable to adjust the pH of the mixed slurry to 7.0 to 10.0 by washing with slurry and concentration. If it is less than 7.0 or more than 10.0, the adsorption performance of the amorphous aluminosilicate particles obtained through the subsequent steps is undesirably reduced. More preferably, the pH is 7.2 to 9.8, and even more preferably, the pH is 7.5 to 9.5.

  Further, the viscosity in the slurry obtained in the third step is preferably in the range of 1 to 400 mPa · s. When the viscosity is less than 1 mPa · s, the slurry becomes a low-concentration slurry, and the amount of particle powder obtained per batch is small, which is not preferable from the viewpoint of productivity. If it exceeds 400 mPa · s, it is difficult to say that the slurry has high handling properties. More preferably, it is in the range of 10 to 350 mPa · s.

  The solid content concentration in the slurry in the fourth step can be adjusted by washing and concentration in the third step. That is, the solid content concentration in the slurry obtained in the third step is preferably from 90 to 300 g / L. Here, the slurry concentration is a value obtained by drying the slurry after the fourth step and dividing the obtained solid content by the volume of the slurry before drying. The solid content concentration in the mixed slurry in the second step is calculated in the same manner. If it is less than 90 g / L, the reaction concentration in the fourth step is low and the production efficiency is poor, so that it is not preferable. If the concentration is higher than 300 g / L, the fluidity of the slurry deteriorates, and the slurry cannot be transferred to the equipment of the third to fourth steps, which is not preferable. It is more preferably from 100 to 280 g / L, and still more preferably from 110 to 260 g / L.

  In the method for producing amorphous aluminosilicate particles according to the present invention, the temperature of the hydrothermal treatment in the fourth step is preferably 170 to 250 ° C. If the temperature is lower than 170 ° C., in order to satisfy various properties (specific surface area and the like) of the obtained particle powder, the time of the hydrothermal treatment is longer than the sum of the temperature raising time and the cooling time. As a result, the production efficiency of the particle powder per unit time decreases, which is not preferable. If the temperature is higher than 250 ° C., crystalline kaolinite is generated, the BET specific surface area is low, and the adsorption performance is undesirably reduced. A more preferred hydrothermal treatment temperature is 180 to 240 ° C, and a still more preferred hydrothermal treatment temperature is 190 to 230 ° C.

  The time of the hydrothermal treatment in the fourth step is preferably 1 to 8 hours. If the time is less than 1 hour, the adsorption performance of the obtained amorphous aluminosilicate particles is undesirably reduced. If the time is longer than 8 hours, it is difficult to perform the processing in the first to fourth steps in a 24-hour cycle, which leads to a reduction in the production rate, which is not preferable. A more preferred hydrothermal treatment time is 2 to 6 hours.

  After completion of the fourth step, washing, drying and pulverization can be performed by a conventional method. By this operation, a particle powder is obtained.

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An important point in the present invention is that the amorphous aluminosilicate particles according to the present invention have a very small reduction ratio of the specific surface area and the amount of water vapor adsorption before and after calcination at 300 ° C. for one hour, and have heat resistance. It is a fact. Further, in the method for producing amorphous aluminosilicate particles according to the present invention, the solid content concentration during the hydrothermal reaction can be as high as 90 to 300 g / L, and the productivity of the particle powder is increased. The fact is that you can.

Although the reason why the heat resistance of the amorphous aluminosilicate particles according to the present invention is improved is not clear, the amount of water of crystallization in the particles can be reduced, and AlO ₆ octahedron having a gibbsite structure while having low crystallinity is obtained. The inventor presumes that a structure having a sheet and a SiO ₄ tetrahedral sheet derived from SiO ₄ tetrahedral monomer and kaolin mineral was adopted. It is presumed that such a structure was achieved by the high-concentration hydrothermal reaction described above.

  A typical embodiment of the present invention is as follows.

  The specific surface area of the sample was measured by the BET method. The measurement was carried out using a multisorb (manufactured by Kantachrome Instruments Japan). As a pretreatment condition, the sample was degassed at 120 ° C. for 2 hours while passing nitrogen gas through the sample.

  In order to measure the heat resistance of the sample, 2 g of the sample was weighed into a porcelain crucible, and baked in a box-type electric furnace at a heating rate of 10 ° C./min, a reaching temperature of 300 ° C. for 1 hour. After taking out the porcelain crucible, it was allowed to cool, the BET specific surface area was measured, and the specific surface area reduction rate was calculated. The sample was calcined at 300 ° C. for one hour in the measurement of the rate of decrease in the amount of adsorbed water vapor described later, in the same manner.

An X-ray fluorescence analyzer Rigaku RIX2100 was used to measure the contents of Na, Si, and Al in the sample. Each was considered as Na ₂ O, SiO ₂ , and Al ₂ O ₃ .

The amount of water of crystallization in the structure of the sample was determined by the following method. First, 2 g of the particle powder was weighed into a porcelain crucible and heated at 150 ° C. for 20 hours in a box dryer. Thereafter, the sample was allowed to cool in a desiccator having a humidity of less than 10%, the dry weight of the sample was measured, and this was defined as the weight (A). Next, the porcelain crucible that had been allowed to cool was placed in a box-type sintering furnace that had been heated to 700 ° C. in advance and held for 1 hour. Thereafter, the sample was allowed to cool in the desiccator again and the sample was weighed, and this was defined as weight (B). The value determined by the formula of {weight (A) -weight (B)} / weight (A) × 100 was defined as the ignition loss (unit: weight%). The value of Na obtained in X-ray fluorescence, Si, using the content of Al, the coefficients of the general formula _{a Na 2 O · b SiO 2} · Al 2 O 3 · n H 2 O calculated in mol .

  The average primary particle size of the sample was measured with a TEM device JEM-F200 (manufactured by JEOL Ltd.). The average primary particle size was estimated from representative particles.

  XRD apparatus D8 ADVANCE (manufactured by BRUKER) for identifying the crystal phase of the sample (tube: Cu, tube voltage: 40 kV, tube current: 40 mA, goniometer: wide-angle goniometer, sampling width: 0.010 °, scanning speed: 6) ° / min, divergence slit: 0.2 °, light receiving slit: 0.03 mm).

The spectrum relating to the vibration mode of the chemical bond between the elements of the sample was measured using Nicolet iS5 manufactured by FT-IR Thermo Fisher Scientific Co., Ltd. The resolution was 4 cm ⁻¹ , the number of integration was 16 times, and the measurement was performed by ATR (total reflection measurement) method.

The chemical shift and coordination state of nuclide ²⁷ Al in the sample were evaluated using an NMR apparatus ECA400 (manufactured by JEOL Ltd.). The magnetic field strength is 9.39T (400 MHz). The measurement was carried out using a DD (Dipolar Decoupling) method and a 3.2 mm sample tube rotated at a frequency of 21 kHz. The number of integration was 1024 times, and aluminum nitrate was used as an external standard substance (0 ppm).

The chemical shift and coordination state of nuclide ²⁹ Si in the sample were evaluated using an NMR apparatus ECA400 (manufactured by JEOL Ltd.). The magnetic field strength is 9.39T (400 MHz). The measurement was carried out using a cross polarization (CP) method and a 3.2 mm sample tube rotated at a frequency of 6 kHz. The number of times of integration was 1500 times, and polydimethylsiloxane was used as an external standard substance (-34 ppm).

In the data of the sample according to the present invention, focusing on the range of the chemical shift of ²⁹ Si from −120 to −60 ppm, a single peak located at −78.9 to −77.0 ppm and a single peak at −110 to −79.0 ppm It was confirmed that the peak was represented by a superposition of two to six peaks. Peak shape function used is a Gaussian function to calculate the coefficient of determination R ² in the fitting. With respect to the peak at the j-th position from the value of the low chemical shift, peak parameters were named as peak area Sj, peak position Pj, half width Wj, and peak height Hj. That is, j = 1 is a peak located at −110 to −92.0 ppm, j = 2 is a peak located at −91.9 to −90.0 ppm, and j = 3 is a peak located at −89.9 to −79.0 ppm. The peak located, j = 4, is the peak located at -78.9 to -77.0 ppm. For j = 5 to 7 is to bring the coefficient of determination R ² to 1, and used in any position. Here, the absolute value of the peak intensity has no physical meaning, and the peak area Sj and the peak intensity Hj have meaning as an area ratio and an intensity ratio in the same spectrum. The half-value width of the peak at j = 2 is as small as 5 ppm or less, and in consideration of the kaolin mineral measurement data reported in Reference 1 and the like, it is inferred to be a peak of the Q ³ value derived from a uniform SiO ₄ tetrahedral sheet. . Also, k-th peak has the largest peak area located -110~-79.0ppm also the possibility of the peak of the ^{Q 3} value. However, it is considered that the half-width of the k-th peak was extremely high because the Al substitution and the SiO ₄ tetrahedron were uneven and had structural defects. Therefore, the area ratio of S2 / Sk was used as a parameter related to heat resistance.

The fitting of the peak located at 110 to -79.0 ppm will be described in more detail. Increase the number of peaks of the Gaussian function, the value of the coefficient of determination R ² was also possible to close to 1. However, with respect to the coefficient of determination R ² value 0.99, when it exceeds it, higher, it did not increase the number of peaks of the Gaussian function. Therefore, although the peak located at −110 to −79.0 ppm could be fitted with a maximum of six Gaussian functions, the fitting was performed with a smaller number of peaks for convenience.

Reference 1 T. Watanabe, et al. , ^{"29 Si- and 27 Al-MAS /} NMR study of the thermal transformations of Kaolinite " Clay Minerals (1987) vol. 22, p. 37-48.

The amount of water vapor adsorbed on the sample was measured using a bell soap aqua3 (manufactured by Microtrac Bell Co., Ltd.) before and after firing at 300 ° C. for 1 hour (ie, untreated). After filling the measurement sample into the sample folder, the pressure was previously reduced by a vacuum pump. At the same time, the folder was heated at a temperature of 120 ° C. for 2.5 hours, and it was confirmed that the internal pressure of the folder was reduced to 10 ⁻² kPa. Then, the amount of water vapor adsorption was measured at a temperature of 25 ° C. using nitrogen-substituted ones and relative humidity as a parameter.

  The viscosity of the slurry at the time of sample production was measured at 50 rpm using an E-type viscometer (TVE-35H manufactured by Toki Sangyo Co., Ltd.).

Example 1 Production of Amorphous Aluminosilicate Particle Powder Into a reaction vessel having an internal volume of 800 L, 120 L of 5.0 mol / L sodium 3 silicate solution was added as Si, and then 25 L of 10 N NaOH solution was added. And stirred to complete the first step.

Next, 295 L of a 2.0 mol / L aluminum chloride solution as Al was prepared in a 400 L supply tank. The aluminum chloride solution was stirred while being added to the above reaction vessel, and all 295 L were mixed. It charged Si / Al molar ratio after the raw material mixing 1.02 (charged silica-alumina ratio _SiO 2 / _Al 2 _{O 3} is 2.04 molar ratio), Al / OH molar ratio was 2.36. Here, OH is a charged value of NaOH added in the first step. Thereafter, the temperature of the mixed solution was raised to 40 ° C., and the pH was measured. Since the pH was 4.31, a 6N NaOH solution was added until the pH reached 7.1, and the reaction was allowed to proceed. The second step was terminated when the pH value was stabilized within a range of 7.1 ± 0.1 for 30 minutes.

  The obtained mixed slurry was washed with water at a temperature of 40 ° C. using a filter thickener. The filtrate was washed with water until the electric conductivity of the filtrate became 300 μS / cm or less, and the third step was completed when the slurry was concentrated to 530 L. The pH of the concentrated slurry was 8.5, the solid concentration of the slurry was 150 g / L, and the viscosity was 57 mPa · s.

  The slurry obtained in the third step was transferred to an 800 L autoclave. Thereafter, the slurry was heated at a heating rate of 1 ° C./min, and the slurry maintained at 180 ° C. was subjected to a hydrothermal reaction over 6 hours. Thereafter, the autoclave was allowed to cool, and the fourth step was completed. The slurry after the reaction was washed with a filter thickener to 300 μS / cm or less, and the slurry was put in a box drier. After drying and grinding at a drying temperature of 110 ° C., an amorphous aluminosilicate particle powder according to the present invention was obtained. The slurry immediately after the fourth step is dried to calculate a solid content concentration of the slurry of 150 g / L.

The BET specific surface area of the obtained sample was 753 m ² / g. From measurements of ignition loss and elemental content of a fluorescent X-ray analysis, the general formula _{a Na 2 O · b SiO 2} · Al 2 O 3 · n H 2 O in a, was calculated values of b, and n , And 0.13, 1.98, and 1.04 mol, respectively, and the carbane ratio b was substantially the same as the charged carbane ratio of the starting material.

FIG. 1 shows a TEM photograph of the obtained sample. Primary particles of about 5 nm strongly formed aggregates. Further, as shown in the XRD profile of the obtained sample in FIG. 2, the sample also contained a Halo peak. Therefore, the sample was amorphous and low crystalline, and was also regarded as allophane also from the primary particle size of the TEM. It was a low crystalline aluminosilicate in which broad peaks could be confirmed at around 21 °, 26 °, 37 °, 40 °, 54 °, and 63 ° as 2θ in the XRD profile. As a result of analysis, the obtained profile was a profile in which 1 to 30 unit cells of halloysite or kaolinite were arranged, and there was a possibility of low-crystalline kaolin. This suggested the existence of an AlO ₆ octahedral sheet having a gibbsite structure and the existence of a SiO ₄ tetrahedral sheet having a Q ³ value in ²⁹ Si-NMR.

FIG. 3 shows the FT-IR spectrum of the obtained sample. The horizontal axis is the wave number and the vertical axis is the absorbance. 1200～800Cm ^-1, and 560 cm ^-1 and around 450cm peak around ^-1 was confirmed. And Sankounisuru et Reference 3 and the like, in 1200～800Cm ^-1, shoulder 1100 cm ^-1 represents a high polymerization degree of SiO ₄ tetrahedra, suggesting the presence of a SiO ₄ tetrahedron sheets. This was a result of supporting the presence of the SiO ₄ tetrahedral sheet indicated by XRD. The two peaks near 980 cm ^-1 and 900 cm ^-1 have the same spectrum as that of imogolite, which suggests the presence of a SiO ₄ tetrahedral monomer, that is, the presence of a Q ⁰ value peak in ²⁹ Si-NMR. Was.

FIG. 4 shows a ²⁷ Al-NMR spectrum of the obtained sample. The peak around 0 ppm is due to the AlO ₆ octahedron, and the peak around 60 ppm is due to the AlO ₄ tetrahedron. The measured value is represented by symbol ■, and the solid line indicates the value calculated by fitting. Here, the calculated value is a value obtained by superimposing the four Gaussian functions shown in the figure. Gaussian curves 1, 2, 3, and 4 were named in order from the right. The peak derived from AlO ₆ octahedron is the superposition of Gaussian curves 1 and 2, and the peak derived from AlO ₄ tetrahedron is the superposition of Gaussian curves 3 and 4. The ratio of the former superimposed peak area to the latter superimposed peak area was 0.47. Therefore, in the obtained sample, AlO ₆ octahedron was mainly contained. Also, the AlO ₄ tetrahedron may have replaced the SiO ₄ tetrahedron.

FIG. 5 shows the ²⁹ Si-NMR spectrum of the obtained sample. The measured value is represented by the symbol ■, and the solid line indicates the value calculated by the fitting. Here, the calculated value is a superposition of curves by each Gaussian function of j = 1 to 4. As shown in the figure, the ²⁹ Si-NMR spectrum in the chemical shift range of -120 to -60 ppm has a single peak located at -78.9 to -77.0 ppm and a peak located at -1110 to -79.0 ppm. This was represented by the superposition of three peaks. The coefficient of determination ^{R 2} is close to 0.994 and 1, could be fitted. That is, the number of peaks of the Gaussian function was not increased any more. j = 2 of the half-value width of the peak is small and 3.05 ppm, and corresponds to the peak of ^{Q 3} value derived from the sequence of uniform SiO ₄ tetrahedron. It was presumed that this SiO ₄ tetrahedron formed a sheet and contributed to the stability of the allophane structure. j = 3 peaks but half width and area is larger than the other peaks, the values of chemical shifts are -89.49Ppm, it can be inferred that the peak of the Q ³ value having structural defects. Therefore, k = 3, and the area ratio S2 / Sk showed a high value of 0.090. Further, j = 4 peak values of chemical shifts are -78.31Ppm, it peaked from ^{Q 0} imogolite like SiO ₄ tetrahedral monomers.

  At a temperature of 25 ° C. and a relative humidity (RH) of 60%, the amount of water vapor adsorbed with respect to the weight of the obtained sample was 49.6 wt%.

The BET specific surface area of the sample after firing at 300 ° C. for 1 hour was 712 m ² / g, and the amount of water vapor adsorbed was 48.8 wt% at RH = 60%. The specific surface area and the amount of water vapor adsorption were hardly affected by the calcination at 300 ° C. for one hour, and showed high values. That is, the specific surface area and the rate of decrease in the amount of water vapor adsorption were extremely low at 5.4% and 1.6%, respectively, indicating that the sample had high heat resistance.

Table 1 shows the manufacturing conditions of the sample, Table 2 shows the specific surface area and composition formula of the obtained sample, Table 3 shows the parameters related to the peak obtained in the ²⁹ Si-NMR spectrum, Table 4 shows the amount of water vapor adsorption, 300 ° C. 1 shows the amount of water vapor adsorbed and the specific surface area after sintering for -1 hour, and their reduction rate. Tables 1 to 4 also show numerical values of Examples and Comparative Examples described later.

Examples 2-3, Comparative Examples 1-5
As shown in Table 1, the types of the water-soluble silicon raw materials in the first and second steps, the types and the charging ratios of the alkaline raw materials to be mixed, the types and the charging ratios of the water-soluble aluminum, and the pH, and the solids in the third step A sample of amorphous aluminosilicate particles was prepared in the same manner as in Example 1 except that the concentration, pH, viscosity, and the temperature and time of the hydrothermal treatment in the fourth step were variously changed.

Comparative Examples 6 to 12
Comparative Examples 6 to 12 are existing crystalline aluminosilicate compounds, amorphous aluminosilicate compounds, and amorphous silica. That is, Comparative Example 6 was a synthetic zeolite of sodium A type, Comparative Example 7 was a synthetic zeolite of sodium X type, Comparative Example 8 was a natural zeolite produced from Itaya district in Yamagata Prefecture, the main component of which was clinoptilolite, and mordenite was used as an auxiliary component. Is included. Comparative Examples 9 to 10 are allophane produced from natural soil. Comparative Example 11 is an amorphous silica produced using a precipitation method. Comparative Example 12 is amorphous silica produced using a gelling method.

Comparative Examples 6, 7, and 8 are crystalline zeolites, each having a Caban ratio b of 1.94 mol, 2.32 mol, and 9.92 mol, and a specific surface area of 1.1 m ² / g, 416 m ² / g, and 66 m ² / g, out of the scope of the present invention. Further, the water vapor adsorption amount (RH = 60%) was lower than the examples of 20.7 wt%, 25.5 wt%, and 9.8 wt%, respectively. Comparative Examples 11 and 12 were amorphous synthetic silicas having specific surface areas of 184 m ² / g and 666 m ² / g, which were outside the scope of the present invention. Further, the obtained water vapor adsorption amounts (RH = 60%) were 8.1 wt% and 30.2 wt%, which were lower than those of the examples.

As shown in Table 2, except for Comparative Example 4, the specific surface area of the sample was out of the range of the present invention and small. Therefore, these samples were found to be unsuitable for gas adsorbents. In addition, as shown in Table 3, Comparative Examples 9 and 10 had one peak located at a chemical shift of −110 to −79.0 ppm, had a very large half-value width W3, a low peak height H3, and were barely. The peak was broad enough to be recognized. The coefficient of determination R ² is as small as 0.8 or less, even if the fitting is increased 2, three the number of peaks of the Gaussian function, the coefficient of determination R ² was increased at all. Therefore, the number of peaks located at −110 to −79.0 ppm was set to one. Comparative Examples 9 and 10 are generally called protoimogolite. In Comparative Example 5, when j = 2, there was no peak having a half width of 5 ppm or less, and the values of S2 / Sk (k = 1 and 3) in Comparative Examples 2 and 4 were 0.070 and 0. 0.050.

  As shown in Table 4, the untreated water vapor adsorption amounts (RH = 60%) of Comparative Examples 1 to 5 were 27.4. ０．２40.2 wt%, which was lower than the value of the example. In addition, the water vapor adsorption amount (RH = 60%) after firing at 300 ° C. for 1 hour showed a much lower value of 16.5 to 34.2 wt%. This can be presumed to be because the reduction rate of the specific surface area was a high value exceeding 10%. The sample of the example showed that the heat resistance was higher than the sample of the comparative example.

  The amorphous aluminosilicate particles according to the present invention were able to improve the heat resistance, which was conventionally low, without lowering the adsorption performance. Therefore, the durability against repeated use of adsorption and desorption of adsorbed gas such as water vapor and the workability during adsorption rotor processing have been improved, and the possibility of versatile use has been expanded. . In addition, the method for producing a particle powder according to the present invention can improve the concentration at the time of a hydrothermal reaction, which further contributes to improvement in production efficiency.

Claims (7)

In the amorphous aluminosilicate particles represented by the formula _{a Na 2 O · b SiO 2} · Al 2 O 3 · n H 2 O having a specific surface area 650~900m ² / g, a is 0.05 0.29, b is 1.40 to 2.60, n is in the mol range of 0.50 to 1.25, and the ²⁹ Si-NMR spectrum in the chemical shift range of -120 to -60 ppm is -78.9. Amorphous aluminosilicate particles powder represented by a superposition of a single peak located at ~ -77.0 ppm and two to six peaks located at -110 to -79.0 ppm . ^{2. The} amorphous material according to claim 1, wherein a peak shape function of each peak showing a ²⁹ Si-NMR spectrum in a chemical shift range of -120 to -60 ppm is represented by a Gaussian function, and a coefficient of determination R2 is 0.99 or more. Aluminosilicate particle powder. Chemical shift: range of -110.0 to -79.0 ppm ^{29 In} each peak showing the ²⁹ Si-NMR spectrum, the half width at 5 ppm or less located at -91.9 to -90.0 ppm relative to the peak having the largest peak area The amorphous aluminosilicate particle powder according to claim 1 or 2, wherein the area ratio with respect to the peak is 0.080 to 0.200. The amorphous aluminosilicate particle powder according to any one of claims 1 to 3, wherein a reduction rate of a specific surface area after firing at 300 ° C for 1 hour is 10% or less. The amorphous aluminosilicate particle powder according to any one of claims 1 to 4, wherein a reduction rate of a water vapor adsorption amount at a relative humidity of 60% after firing at 300 ° C for 1 hour is 12% or less. A first step of preparing a solution containing a water-soluble silicon raw material and an alkali raw material, by adding a water-soluble aluminum raw material to the obtained solution, so that the molar ratio of Al / OH in the mixed solution after the addition is 2.0 to 3.0; , The molar ratio of Si / Al is adjusted to 0.7 to 1.4, the pH is adjusted to 6.0 to 8.0, and the second step in which the reaction is carried out. The resulting mixed slurry is washed with water and concentrated to adjust the pH to 7.0. The amorphous aluminosilicate particle powder according to any one of claims 1 to 5, further comprising a third step of adjusting the temperature of the obtained slurry to 10.0 and a fourth step of hydrothermally treating the obtained slurry at a temperature of 170 to 250 ° C. Production method. 7. The method according to claim 6, wherein the solid content in the fourth step is 90 to 300 g / L.