WO2016047124A1

WO2016047124A1 - Method for producing zeolite

Info

Publication number: WO2016047124A1
Application number: PCT/JP2015/004785
Authority: WO
Inventors: 上野　巌; 小杉　直貴
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2014-09-26
Filing date: 2015-09-18
Publication date: 2016-03-31

Abstract

　To provide a method for producing zeolite having better moisture-absorption properties. A method having a step for physically pulverizing zeolite in which the ratio of the Na/Si value at a point at a depth of 10 nm from the surface with respect to the Na/Si value on the surface is 90% or higher, and a step for crystallizing the physically pulverized zeolite. In particular, the zeolite provided for physical pulverization is such that the ratio of the Na/Si value at a point at a depth of 30 nm from the surface with respect to the Na/Si value on the surface is 70% or higher.

Description

Method for producing zeolite

The present disclosure relates to a method for producing fine zeolite having a nano particle size.

Patent Document 1 discloses a method for producing fine zeolite (nanozeolite) in which fine zeolite obtained by pulverizing zeolite is dispersed in an aluminosilicate solution having a specific composition and recrystallized.

JP 2011-246292 A

The present disclosure provides a method for producing a fine zeolite having a particle size that is more excellent in moisture absorption characteristics and having a nano size. The method for producing a nanozeolite according to the present disclosure includes a step of physically pulverizing a zeolite in which a ratio of a Na / Si value at a point having a depth of 10 nm from the surface to a Na / Si value on the surface is 90% or more; Crystallizing the physically ground zeolite.

According to the production method of the present disclosure, it is possible to produce a nanozeolite with better moisture absorption characteristics.

FIG. 1 is a flowchart showing a method for producing nanozeolite according to Embodiment 1. FIG. 2 is a diagram showing the relationship between the depth from the surface and the Na / Si value of zeolite and nanozeolite. FIG. 3 is a schematic view for explaining a physical pulverization process of zeolite by a bead mill pulverizer. FIG. 4 is a schematic diagram for explaining a hydrothermal synthesis process by an autoclave. FIG. 5 is a schematic diagram for explaining an ion exchange process from sodium to magnesium. FIG. 6 is a diagram for explaining a difference in moisture absorption and desorption characteristics between a nanozeolite crystallized by hydrothermal synthesis treatment and a nanozeolite crystallized by heat treatment in the atmosphere. FIG. 7 is a diagram for explaining a hydrothermal synthesis time effective for recrystallization of zeolite. FIG. 8 is a diagram for explaining recrystallization of zeolite by hydrothermal synthesis. FIG. 9 is a diagram for explaining the difference in recrystallization of zeolite due to the difference in the composition of the initial zeolite based on the measurement result of the hygroscopic desorption characteristics. FIG. 10 is a diagram for explaining a difference in recrystallization of zeolite due to a difference in the composition of the initial zeolite based on the X-ray diffraction measurement result. FIG. 11 is a diagram for explaining the replacement conditions in the ion exchange treatment from sodium to magnesium. FIG. 12A is a view showing a scanning electron micrograph showing the particle structure of sodium-based zeolite as an initial input material. FIG. 12B is a scanning electron micrograph showing the particle structure after physically pulverizing sodium-based zeolite. FIG. 12C is a diagram showing a scanning electron micrograph showing the particle structure of a product obtained by subjecting sodium-based zeolite to physical pulverization and then hydrothermal synthesis treatment. FIG. 13A is a view showing a scanning electron micrograph showing the particle structure of calcium-based zeolite as an initial input material. FIG. 13B is a view showing a scanning electron micrograph showing the particle structure after physically pulverizing calcium-based zeolite. FIG. 13C is a view showing a scanning electron micrograph showing the particle structure of a product obtained by subjecting a calcium-based zeolite to physical pulverization and then hydrothermal synthesis treatment. FIG. 14 is a flowchart showing a method for producing nanozeolite when a drying step is not provided after the hydrothermal synthesis step. FIG. 15 is a diagram for explaining a difference in recrystallization of zeolite depending on the presence or absence of a drying step after the hydrothermal synthesis step based on the X-ray diffraction measurement result. FIG. 16 is a diagram for explaining the difference in recrystallization of zeolite depending on the presence or absence of the drying step after the hydrothermal synthesis step based on the measurement result of the moisture absorption and desorption characteristics. FIG. 17 is a diagram for explaining an example of an application in which nano-zeolite is formed into a film.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

In addition, the inventors provide the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims. Absent.

(Embodiment 1)
The first embodiment is an example of a method for producing nanozeolite in the present disclosure. FIG. 1 is a flowchart showing a method for producing nanozeolite according to Embodiment 1. A method for producing nanozeolite will be described in order according to the flowchart shown in FIG. A nanozeolite is a zeolite having a particle size of nano size, and in the present embodiment, a zeolite having a particle size of nano size is defined as nano zeolite.

[1. Zeolite raw material slurry generation)
First, a slurry is produced by mixing sodium-based zeolite (hereinafter referred to as Na-based zeolite) serving as a main raw material with H ₂ O (S100). LTA (A-type zeolite: | Na ⁺ ₁₂ (H ₂ O) ₂₇ | ₈ [Al ₁₂ Si ₁₂ O ₄₈ ] ₈ ) is used as the Na-based zeolite that is the initial input material. In the Na-based zeolite, the relationship between the depth from the surface and the Na / Si value, which is the composition ratio, satisfies a predetermined condition.

FIG. 2 is a diagram showing the relationship between the depth from the surface and the Na / Si value of zeolite and nanozeolite. In FIG. 2, the vertical axis indicates the Na / Si value, and the horizontal axis indicates the depth from the surface of the zeolite and nanozeolite (the surface depth is 0 nm, and the Na / Si value on the surface is 1). .00).

In FIG. 2, (A_int) is a plot of the Na / Si value with respect to the depth from the surface of the zeolite A, and (B_int) is the Na / Si value with respect to the depth from the surface of the zeolite B. It is a plot. Zeolite A and zeolite B are both LTA, but the relationship between the depth from the surface and the Na / Si value is different. That is, the ratio of the Na / Si value at the point where the depth from the surface is 10 nm to the Na / Si value at the surface is 90% in the zeolite A, and the Na / Si value at the point where the depth from the surface is 30 nm. The percentage is 70%. On the other hand, the comparison target zeolite B has a ratio of Na / Si value at a point where the depth from the surface is 10 nm to Na / Si value on the surface is 65%, and Na at a point where the depth from the surface is 30 nm. The ratio of / Si value is also 65%.

In FIG. 2, (A_nano) is a plot of the Na / Si value versus the depth from the surface of the nanozeolite A produced from zeolite A, and (B_nano) is the nanozeolite produced from zeolite B. B is a plot of Na / Si values versus depth from the surface.

As shown in FIG. 2, it can be seen that nanozeolite B has a larger gradient of Na / Si value in the depth direction from the surface (Na / Si value is greatly reduced) than nanozeolite A. . The inventors have discovered that the gradient of Na / Si value with respect to the depth direction from the surface affects the hygroscopic properties of the nanozeolite, such as the depth from the surface and Na / Si, such as zeolite A. From the zeolite having a relationship with the value, it has been found that nano-zeolite having good moisture absorption characteristics can be produced.

In Embodiment 1, zeolite A, which is a Na-based zeolite, is used as an initial charging material. Thereby, as above-mentioned, the production | generation of the nanozeolite which has a favorable hygroscopic property is possible.

As shown in FIG. 1, zeolite A (initial particle size 5 μm, 100 g) and H ₂ O (100 g) are mixed to form a slurry. Then, zirconia (ZrO 2) cobblestone (particle size 100 μm, 400 g) is charged into the slurry. The particle diameter of Na-based zeolite as the initial input material is not particularly limited, and for example, a particle having a size of about 0.1 to 10 μm can be used.

[2. Grinding with a bead mill
Then, the slurry produced | generated in S100 is thrown into a bead mill grinder, and the physical grinding | pulverization of the zeolite A is performed (S110).

FIG. 3 is a schematic view for explaining a physical grinding process of zeolite by a bead mill grinder. As shown in FIG. 3, physical pulverization by the bead mill pulverizer 100 is performed using a slurry tank 130 and a pipe 140. The bead mill pulverizer 100 includes a rotary blade capable of physically pulverizing the input material. When the rotary blade rotates at high speed, the input material can be physically pulverized to the nanoscale. The bead mill pulverizer 100 has a slurry supply port 110 and a slurry discharge port 120. The slurry supply port 110 and the slurry discharge port 120 are each connected to a pipe 140. Hereinafter, a specific physical pulverization process by the bead mill pulverizer 100 will be described.

First, the bead mill pulverizer 100 is driven, and pulverization is performed for about 3 hours until the average particle size of zeolite A reaches 120 nm. The slurry flow rate at this time is 10 kg / hour, and the slurry viscosity is 10 mPa / second.

The bead mill pulverizer 100 is connected to a slurry tank 130. By putting H ₂ O into the slurry tank 130, the slurry circulates between the bead mill pulverizer 100 and the slurry tank 130 via the pipe 140.

When the pulverization operation has passed for 2 hours, the pipe 140 connected to the slurry tank 130 is once retracted from the slurry tank 130 to another storage container. During this time, since the bead mill pulverizer 100 is driven, the amount of slurry in the slurry tank 130 decreases. When the amount of slurry in the slurry tank 130 becomes zero, 100 g of H ₂ O is added to the slurry tank 130. Then, when the H ₂ O in the slurry tank 130 is exhausted, the driving of the bead mill pulverizer 100 is stopped. Thereby, the inside of the bead mill grinder 100 is washed with H ₂ O.

At this time, the previously used zirconia cobblestone (particle size: 100 μm) is laminated on the bottom of the bead mill pulverizer 100, and this is taken out. Once the inside of the bead mill pulverizer 100 is washed with water, another new zirconia cobblestone (particle size 50 μm, 400 g) is charged from a cobblestone inlet (not shown) of the bead mill pulverizer 100. Then, the pipe 140 that has been withdrawn is reconnected to the slurry tank 130, and the slurry that has been withdrawn previously in the storage container is reintroduced into the slurry tank 130, and at the same time, the driving of the bead mill crusher 100 is resumed. In this state, grinding is performed for about 1 hour until the average particle size of zeolite A reaches 70 nm. The slurry flow rate at this time is 10 kg / hour, and the slurry viscosity is 6 mPa / second.

Thereafter, the previously used zirconia boulder (particle size 50 μm) is taken out of the bead mill pulverizer 100, and another new zirconia cobblestone (particle size 30 μm, 450 g) is put in instead. Further, 100 g of H ₂ O is added, and pulverization is performed until the average particle size of zeolite A is less than 50 nm for about 1 hour. The slurry flow rate at this time is 10 kg / hour, and the slurry viscosity is 4 mPa / second. The average particle size of the pulverized Na-based zeolite is not particularly limited, but it is beneficial to be about 30 to 100 nm, for example.

Then, 100 g of H ₂ O is added, and all the slurry is taken out from the bead mill pulverizer 100. The process for removing the slurry is the same as described above. As a result, about 500 g of an amorphous slurry having 100 g of zeolite and 400 g of H ₂ O in total is generated.

The amorphous slurry immediately after being taken out from the bead mill pulverizer 100 is gelled. Therefore, before moving to the next step (hydrothermal synthesis step), this gelled amorphous slurry is placed on a pod stand and rotated. Thereby, gelatinization is relieved and an amorphous slurry comes to exhibit fluidity.

In addition, what is necessary is just to adjust suitably the drive time of the bead mill grinder 100 at the time of each said grinding | pulverization operation | work, slurry flow volume, and slurry viscosity, respectively so that Na type zeolite after a grinding | pulverization may become a desired average particle diameter.

[3. (Hydrothermal synthesis in the autoclave in the dryer)
Subsequently, the amorphous slurry produced in S110 is hydrothermally synthesized in the autoclave 200 in the dryer and crystallized (S120). In the present disclosure, crystallization is also referred to as recrystallization.

FIG. 4 is a schematic diagram for explaining a hydrothermal synthesis process (recrystallization process) by an autoclave. The autoclave 200 is made of a stainless steel container.

First, 50 g of amorphous slurry exhibiting fluidity generated in the previous step is put into a stainless steel container (SUS316, capacity 100 cc, temperature resistance 200 ° C., pressure resistance 50 MPa) constituting the autoclave 200. The stainless steel container has a sealed structure that is sealed by a lid provided with a safety valve. Inside the stainless steel container, a fluororesin container is enclosed. The amorphous slurry is put into a fluorine resin container, and the stainless steel container is sealed. This is placed in a dryer and sealed, and the internal temperature of the dryer is set to 180 ° C. When heating is started, the inside of the dryer rises from room temperature 25 ° C. and reaches 180 ° C. after about 15 minutes. Leave the inside temperature at 180 ° C. for 24 hours. Thereby, hydrothermal synthesis of the amorphous slurry is performed. As long as the hydrothermal synthesis of the amorphous slurry is sufficiently performed, there is no particular limitation on the temperature of the hydrothermal synthesis (the temperature inside the dryer) and the time, but for example, about 150 to 200 ° C. and 15 to 24 It is beneficial to be on the order of hours.

After the hydrothermal synthesis is completed, the slurry is taken out from the autoclave 200. First, a stainless steel container is taken out from the 180 ° C. chamber, and the stainless steel container is put into water (room temperature) and rapidly cooled. After confirming that the temperature of the stainless steel container has dropped to near room temperature, loosen the safety valve to leak the internal pressure and remove the lid. After adding water to the fluororesin container contained in the stainless steel container, the slurry is taken out into another fluororesin container. By adding water to the fluororesin container, the slurry near the bottom of the fluororesin container can also be taken out.

[4. Dry)
Subsequently, the slurry after hydrothermal synthesis in S120 is taken out and dried (S130). First, the fluororesin container into which the taken slurry is put is covered with an aluminum foil to prevent bumping and dust mixing. Then, the fluororesin container is placed in a dryer and left at 180 ° C. for 2 to 3 hours. There is no particular limitation on the drying temperature for drying the slurry after hydrothermal synthesis, but it is beneficial to be about 150 to 200 ° C., for example.

Thereafter, the fluororesin container is taken out of the dryer and left to reach room temperature to obtain Na-based nanozeolite. Since the dry powder of the slurry is solidified in the fluororesin container, it is crushed in a mortar and the particle diameter is adjusted so that the average particle diameter is 50 nm through a mesh pass.

[5. (Ion exchange from sodium to magnesium)
Subsequently, ion exchange from sodium to magnesium is performed on the Na-based nanozeolite obtained in S130 (S140). FIG. 5 is a schematic diagram for explaining an ion exchange process from sodium to magnesium.

As shown in FIG. 5, first, 10 g of the dried powder of Na-based nanozeolite obtained in S < _b > 130, 30 g of magnesium chloride, and 400 g of H ₂ O are mixed in a glass container 210. Then, the glass container 210 is placed on a hot plate and stirred for about half a day by a rotor while heating to about 60 ° C.

When the stirring is stopped, the nanozeolite precipitates at the bottom of the glass container 210. Therefore, the supernatant liquid in the glass container 210 is discarded, and 200 g of H ₂ O is put into the glass container 210 again. A glass container 210 is placed on a hot plate and stirred for about 10 to 15 minutes with a rotor while heating to about 60 ° C. When the stirring is stopped, the nanozeolite precipitates at the bottom of the glass container 210. Therefore, the supernatant liquid in the glass container 210 is discarded. This series of steps is repeated about 5 times. It is advantageous to adjust the temperature of the reaction system during the ion exchange treatment to about 40 to 80 ° C. and the treatment time to about 6 to 8 hours. Since the glass container 210 is transparent, it can be easily observed from the outside that the nanozeolite is precipitated.

The sodium (alkali metal) contained in the Na-based zeolite as the initial input material is likely to cause ion migration, and may cause defects when the obtained Na-based nanozeolite is applied to an electronic component. As in the method for producing nanozeolite according to Embodiment 1, the Mg-based nanozeolite obtained by ion exchange with magnesium (alkaline earth metal) having less ion migration than sodium is applied to an electronic component. This is more beneficial because there is no defect.

[6. Dry)
Then, after repeating a series of ion exchange processes about 5 times in S140, the nanozeolite precipitated on the bottom of the glass container 210 is transferred to the fluororesin container. At this time, the fluororesin container is covered with aluminum foil to prevent bumping and dust mixing. Then, the fluororesin container is placed in a dryer and left at 180 ° C. for 2 to 3 hours for drying (S150). After the drying is completed, the fluororesin container is taken out from the dryer and left until the fluororesin container reaches room temperature. Since the dry powder of the slurry is solidified in the fluororesin container, it is crushed in a mortar and the particle diameter is adjusted so that the average particle diameter is 50 nm through a mesh pass. Thereby, Mg-based nanozeolite can be obtained. The drying temperature at the time of drying the slurry after ion exchange is not particularly limited, but it is beneficial to be about 150 to 200 ° C., for example.

Hereinafter, various measurement results regarding the nanozeolite produced as described above will be described.

FIG. 6 shows the difference in moisture absorption and desorption characteristics at 25 ° C. between nanozeolite crystallized by hydrothermal synthesis treatment of physically pulverized zeolite and nanozeolite crystallized by heat treatment in air. It is a figure for demonstrating. The vertical axis Va (cm ³ (STP) / g) in FIG. 6 is a value obtained by converting the amount of moisture absorbed per 1 g of the sample into the volume of gas in the standard state (0 ° C., 1 atm). That is, Va represents the volume of water vapor that 1 g of zeolite adsorbs in the standard state. The horizontal axis P / P _{0 in} FIG. 6 is the relative pressure, P ₀ is the saturated vapor pressure (kPa) at the measurement temperature (25 ° C.), and P is the absolute pressure (kPa).

In FIG. 6, (A_int_d) and (A_int_a) plot the measurement results of zeolite A, which is the initial input material. (A_nano1_d) and (A_nano1_a) are plots of measurement results of nanozeolite A produced by subjecting zeolite A to physical pulverization with a bead mill pulverizer and hydrothermal synthesis treatment (180 ° C., 15 hours). (A_nano2_d) and (A_nano2_a) are plots of the measurement results of nanozeolite A produced by physically pulverizing zeolite A with a bead mill pulverizer and then heat-treating it in the atmosphere (400 ° C.). Note that (A_int_d), (A_nano1_d), and (A_nano2_d) are plots of desorption characteristics, and (A_int_a), (A_nano1_a), and (A_nano2_a) are plots of adsorption characteristics.

As shown in FIG. 6, it can be seen that when the heat treatment is performed in the air, the hygroscopic property of the nanozeolite A is not expressed as much as the zeolite A as the initial input material. On the other hand, it can be seen that nanozeolites A exhibiting the same hygroscopic property as zeolite A as the initial input material can be obtained by performing the hydrothermal synthesis treatment.

FIG. 7 is a diagram for explaining the hydrothermal synthesis time effective for recrystallization of physically pulverized zeolite based on the X-ray diffraction (hereinafter referred to as XRD) measurement result. In FIG. 7, (A_int) is an XRD measurement result of the initial zeolite. (A_nano1_x1) is an XRD measurement result of nanozeolite when hydrothermal synthesis is performed for 24 hours. (A_nano1_x2) is an XRD measurement result of the nanozeolite when hydrothermal synthesis is performed for 36 hours. (A_nano1_x3) is an XRD measurement result of nanozeolite when hydrothermal synthesis is performed for 48 hours.

As can be seen from FIG. 7, when the hydrothermal synthesis time exceeds 48 hours, the crystal structure changes. Therefore, it is beneficial that the hydrothermal synthesis time is shorter than 48 hours. In the present disclosure, the hydrothermal synthesis is performed by setting the hydrothermal synthesis time to a particularly useful 15 to 24 hours.

FIG. 8 is a diagram for explaining recrystallization of zeolite by hydrothermal synthesis based on the XRD measurement results. In FIG. 8, (A_int) is an XRD measurement result of the initial zeolite A. (A_nano1_y1) is an XRD measurement result of zeolite A immediately after being physically pulverized by a bead mill pulverizer. (A_nano1_y2) is an XRD measurement result of nanozeolite A after physical pulverization with a bead mill and hydrothermal synthesis (180 ° C., 15 hours). (A_nano1_y3) is an XRD measurement result of nanozeolite A after physical pulverization with a bead mill and heat treatment (400 ° C.) in the atmosphere.

As shown in (A_int), the initial zeolite A shows crystallinity. However, immediately after physical pulverization with a bead mill, it can be seen that the crystallinity is lost as shown in (A_nano1_y1).

When hydrothermal synthesis is performed after physical pulverization, it can be seen that crystallinity is recognized again as indicated by (A_nano1_y2). On the other hand, when the heat treatment is performed in the air after the physical pulverization, the crystallinity remains lost as shown in (A_nano1_y3). In addition, after physically pulverizing zeolite A with a bead mill pulverizer, (i) when heated in a microwave oven, (ii) when simply dried, (iii) hydrothermal synthesis under conditions of 180 ° C. and less than 8 hours It can be seen that the crystallinity is still lost as in the case of the XRD measurement result of (A_nano1_y3).

Therefore, it can be understood that the physically pulverized zeolite A can be effectively recrystallized by performing hydrothermal synthesis treatment (180 ° C., 15 hours) after physically pulverizing the zeolite A with a bead mill pulverizer. .

FIG. 9 is a diagram for explaining the difference in recrystallization of zeolite due to the difference in the composition of the initial zeolite based on the measurement result of the moisture absorption and desorption characteristics at 25 ° C. Specifically, the zeolite A and zeolite B, which are both LTA, but have different Na / Si gradients in the depth direction from the surface, and the hygroscopic desorption characteristics of the produced nanozeolite A and nanozeolite B are shown. Yes.

In FIG. 9, (A_int_d) and (A_int_a) plot the measurement results of zeolite A, which is the initial input material. (B_nano_d) and (B_nano_a) are plots of the measurement results of zeolite B, which is the initial input material. (A_nano1_a) is a plot of measurement results of nanozeolite A produced by physical pulverization of zeolite A with a bead mill and then hydrothermal synthesis (180 ° C., 15 hours). (B_nano1_d) and (B_nano1_a) are plots of the measurement results of nanozeolite B produced by hydrothermal synthesis (180 ° C., 15 hours) after physically pulverizing zeolite B with a bead mill pulverizer. Note that (A_int_d), (B_nano_d), and (B_nano1_d) are plots of desorption characteristics, and (A_int_a), (B_nano_a), (A_nano1_a), and (B_nano1_a) are plots of adsorption characteristics.

As shown in FIG. 9, nanozeolite A exhibits moisture absorption characteristics equivalent to zeolite A, which is the initial input material. On the other hand, it can be seen that nano-zeolite B has lower moisture absorption characteristics than zeolite B, which is the initial input material. Thus, in order to obtain nano-zeolite exhibiting effective moisture absorption characteristics, the gradient of Na / Si value with respect to the depth direction from the surface of the zeolite as the initial input material (the depth between the surface and the Na / Si value) (Relationship) is an important factor.

FIG. 10 is a diagram for explaining the difference in recrystallization of zeolite due to the difference in the initial zeolite composition based on the XRD measurement results. Specifically, XRD measurement results of zeolite A and zeolite B, which are both LTA, but have different Na / Si value gradients in the depth direction from the surface, and produced nanozeolite A and nanozeolite B are shown. Yes.

In FIG. 10, (A_int) is an XRD measurement result of zeolite A which is an initial input material. (B_int) is an XRD measurement result of zeolite B which is the initial input material. (A_nano) is an XRD measurement result of nanozeolite A produced by physically pulverizing zeolite A with a bead mill and then subjecting it to hydrothermal synthesis (180 ° C., 15 hours). (B_nano) is an XRD measurement result of nano-zeolite B produced by physical pulverization of zeolite B with a bead mill pulverizer and hydrothermal synthesis treatment (180 ° C., 15 hours).

As shown in FIG. 10, nanozeolite A shows the same XRD measurement results as zeolite A, which is the initial input material. On the other hand, it can be seen that the nano-zeolite B has a different XRD measurement result from the zeolite B which is the initial input material. Thereby, in order to obtain nano-zeolite that is effectively recrystallized, the gradient of Na / Si value with respect to the depth direction from the surface of the zeolite as the initial input material (the depth between the surface and the Na / Si value) (Relationship) is an important factor.

FIG. 11 is a diagram for explaining the replacement conditions in the ion exchange treatment from sodium to magnesium. In FIG. 11, the vertical axis represents the atomic concentration (%), and the horizontal axis represents the replacement condition. In FIG. 11, Na is a plot of the atomic concentration of sodium under each substitution condition, and Mg is a plot of the atomic concentration of magnesium under each substitution condition.

As shown in FIG. 11, in the nanozeolite A before the ion exchange treatment (“initial stage of substitution conditions”), the atomic concentration of sodium is 10% and the atomic concentration of magnesium is 0%. Next, when this nanozeolite A was put into a magnesium chloride (MgCl 2) aqueous solution and stirred at room temperature for 2 hours (substitution condition “RT”), the atomic concentration of sodium was 9%, and the atomic concentration of magnesium Is 1.5%. Further, when the aqueous solution is heated to 60 to 70 ° C. and stirred for 2 hours (substitution condition “boiled water bath”), the atomic concentration of sodium is 4.5% and the atomic concentration of magnesium is 7%. Furthermore, when magnesium chloride was added during the hot water bath and stirred for 2 hours (substitution condition “hot water bath + MgCl 2 added”), the atomic concentration of sodium was 2.2% and the atomic concentration of magnesium was 9.5%. is there. From the above results, when the magnesium chloride aqueous solution is boiled and magnesium chloride is further added, the atomic concentration of sodium in the nanozeolite can be further reduced. When such a nanozeolite is applied to an electronic component, problems can be further reduced.

FIG. 12 is a scanning electron microscope (hereinafter referred to as SEM) photograph in the process of producing nanozeolite using Na-based zeolite as the initial input material. FIG. 12A is an SEM photograph of Na-based zeolite as the initial input material. FIG. 12B is an SEM photograph after physically pulverizing Na-based zeolite with a bead mill. FIG. 12C is an SEM photograph of a product obtained by physically pulverizing Na-based zeolite with a bead mill and then subjecting it to hydrothermal synthesis (180 ° C., 15 hours).

As shown in FIG. 12A, it can be seen that the Na-based zeolite as the initial input material has a crystal structure. However, as shown in FIG. 12B, it can be seen that the physical structure pulverizes the Na-based zeolite, but the crystal structure is lost. Then, as shown in FIG. 12C, it can be seen that by performing a hydrothermal synthesis treatment, recrystallization is performed in a nano-structured state, and Na-based nanozeolite having the same crystal structure as the initial input material is generated.

FIGS. 13A to 13C are SEM photographs in the process of producing nano-zeolite when calcium-based zeolite (hereinafter referred to as Ca-based zeolite) is used as an initial input material as an example of alkaline earth metal-based zeolite instead of magnesium-based zeolite. is there. FIG. 13A is an SEM photograph of Ca-based zeolite that is the initial input material. FIG. 13B is an SEM photograph after physical pulverization of Ca-based zeolite with a bead mill. FIG. 13C is an SEM photograph of a product obtained by physically pulverizing Ca-based zeolite with a bead mill and then subjecting it to hydrothermal synthesis (180 ° C., 15 hours).

As shown in FIG. 13A, it can be seen that the Ca-based zeolite as the initial input material has a crystal structure. However, as shown in FIG. 13B, it can be seen that by physically pulverizing, the Ca-based zeolite is nano-sized, but the crystal structure is lost. Then, as shown in FIG. 13C, it is understood that the Ca-based zeolite is recrystallized by performing the hydrothermal synthesis treatment, but the product has a crystal structure different from that of the initial charge material.

In addition, although the SEM photograph of Ca-type zeolite was shown here, the same result is shown also with the magnesium-type zeolite which is the same alkaline-earth metal type zeolite.

From this result, it can be seen that even if alkaline earth metal-based zeolite is used as the initial input material, it is not possible to obtain nano-zeolite having desired moisture absorption characteristics. In the case of Na-based zeolite, it can be effectively crystallized by subjecting it to gelation followed by hydrothermal synthesis treatment. On the other hand, in the case of an alkaline earth metal-based zeolite, even if it is not gelled and crystallized by hydrothermal synthesis treatment, as shown in FIG. 13C, it is different from the initial charge material of another structure. It will change into a crystal having characteristics. Therefore, when using Na-based zeolite instead of alkaline earth metal-based zeolite as an initial input material and applying the produced Na-based nanozeolite to an electronic component, as shown in FIG. It can be seen that it is beneficial to perform an ion exchange treatment.

FIG. 14 is a flowchart showing a method for producing nanozeolite when a drying step is not provided after the hydrothermal synthesis step. Steps S200 to S220 in FIG. 14 correspond to steps S100 to S120 in FIG. Further, each step of S230 to S240 in FIG. 14 corresponds to each step of S140 to S150 in FIG. That is, in the flowchart shown in FIG. 14, the drying step (S130) after the hydrothermal synthesis step is deleted from the flowchart shown in FIG. The inventors have found that the presence or absence of a drying step after the hydrothermal synthesis step affects the recrystallization of the zeolite. This will be described in detail below.

FIG. 15 is a diagram for explaining a difference in recrystallization of zeolite depending on the presence or absence of a drying step after the hydrothermal synthesis step based on the XRD measurement result. In FIG. 15, (A_nano) is an XRD measurement result of nano-zeolite A produced by subjecting zeolite A to physical pulverization with a bead mill pulverizer and hydrothermal synthesis treatment (180 ° C., 15 hours). (A_nano_D) is the result of XRD measurement of nanozeolite A produced by hydrothermal synthesis treatment (180 ° C., 15 hours) followed by drying treatment and further ion exchange treatment, as shown in the flowchart of FIG. It is. (A_nano_N) is a result of XRD measurement of nanozeolite A produced by performing an ion exchange treatment without performing a drying treatment after a hydrothermal synthesis treatment (180 ° C., 15 hours) as shown in the flowchart of FIG. It is.

As shown in (A_nano_D), when a drying process is performed after the hydrothermal synthesis process, an XRD measurement result equivalent to the result shown in (A_nano) is obtained. On the other hand, as shown in (A_nano_N), when the drying process is not performed after the hydrothermal synthesis process, an XRD measurement result different from the results shown in (A_nano) and (A_nano_D) is obtained. Specifically, in the XRD measurement result indicated by (A_nano_N), some of the peaks recognized in the XRD measurement result indicated by (A_nano) and (A_nano_D) disappear. The disappearance of this peak means a decrease in moisture absorption characteristics. Therefore, it can be seen that when the drying step is provided after the hydrothermal synthesis step, nanozeolite with more excellent hygroscopic properties can be produced than when the drying step is not provided after the hydrothermal synthesis step.

FIG. 16 is a diagram for explaining the difference in recrystallization of zeolite depending on the presence or absence of the drying step after the hydrothermal synthesis step, based on the measurement result of the moisture absorption and desorption characteristics at 25 ° C. In FIG. 16, A_nano3_d and A_nano3_a are plots of the measurement results of the nanozeolite produced by hydrothermal synthesis treatment (180 ° C., 15 hours) followed by drying treatment, as shown in the flowchart of FIG. is there. As shown in the flowchart of FIG. 14, A_nano1_d and A_nano1_a are plots of the measurement results of the nanozeolite produced after the hydrothermal synthesis process (180 ° C., 15 hours) and without the drying process. A_nano3_d and A_nano1_d are plots of desorption characteristics, and A_nano3_a and A_nano1_a are plots of adsorption characteristics.

As shown in FIG. 16, when a drying step is provided after the hydrothermal synthesis step, nanozeolite with better moisture absorption characteristics is produced than when a drying step is not provided after the hydrothermal synthesis step. I know you get.

As described above, rather than performing an ion exchange treatment from sodium to magnesium immediately after the hydrothermal synthesis treatment, it is preferable to perform the drying treatment after the hydrothermal synthesis treatment and then the ion exchange treatment. Thus, a nanozeolite exhibiting more excellent hygroscopic properties can be obtained.

FIG. 17 is a diagram for explaining an example of an application in which nano-zeolite is formed into a film. Zeolite exhibits a white color due to light scattering in the bulk, but the light transmittance can be improved by making it nano-sized and dispersed. Therefore, as shown in FIG. 17, there is an application example in which a resin composition in which nano-zeolite is dispersed in a resin is applied to a substrate, baked, and formed into a film. Thereby, the nanozeolite manufactured by the manufacturing method in the present disclosure can be used as a barrier thin film of an electronic component such as an organic light emitting diode that requires moisture resistance and water resistance.

(Other embodiments)
As described above, the first embodiment has been described as an example of the technique in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

Therefore, among the constituent elements described in the accompanying drawings and the detailed description, not only essential constituent elements but also non-essential constituent elements may be included to exemplify the above technique. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

Further, the first embodiment described above is for exemplifying the technique in the present disclosure, and is not limited thereto, and various modifications, replacements, additions, omissions, etc. are made within the scope of the claims or an equivalent scope thereof. The present invention can also be applied to other embodiments. Moreover, it is also possible to combine each component demonstrated in the said Embodiment 1, and it can also be set as a new embodiment.

The nano-zeolite produced by the production method according to the present disclosure can be applied to various fields such as an electronic field, a packaging field, a clothing field, and a medical field such as a barrier thin film of an electronic component.

100 Bead Mill Crusher 110 Slurry Supply Port 120 Slurry Discharge Port 130 Slurry Tank 140 Pipe 200 Autoclave 210 Glass Container

Claims

Physically pulverizing zeolite having a Na / Si value ratio of 90% or more at a point having a depth of 10 nm from the surface with respect to the Na / Si value on the surface;
And a step of crystallizing the physically pulverized zeolite.
2. The production of zeolite according to claim 1, wherein the zeolite used for the physical pulverization has a ratio of Na / Si value at a point where the depth from the surface is 30 nm to the Na / Si value on the surface is 70% or more. Method.
The method for producing a zeolite according to claim 1 or 2, wherein the crystallization is performed by a hydrothermal synthesis treatment.
Manufacture of zeolite for physically pulverizing zeolite having a Na / Si value of 90% or more at a depth of 10 nm from the surface relative to Na / Si value on the surface, and crystallizing the physically pulverized zeolite Method.