JP5017802B2 - ORIENTED ZEOLITE CRYSTAL PRODUCTION LIQUID, METHOD FOR PRODUCING ORIENTED ZEOLITE CRYSTAL USING THE SAME, AND SEPARATION LIQUID COMPRISING LIQUID PART OBTAINED BY SEPARATING PRECISION - Google Patents

Description

The present invention relates to an oriented zeolite crystal production liquid , a method for producing an oriented zeolite crystal using the same , and a separation liquid comprising a liquid portion obtained by separating precipitates . More specifically, the present invention relates to an oriented zeolite crystal production liquid for easily and reliably obtaining highly oriented zeolite crystals, and a method for producing oriented zeolite crystals using the same.

Zeolite is a material that has been attracting attention in recent years because it has unique properties such as molecular sieve (molecular sieve gas separation membrane) characteristics, solid acidity, ion exchange capacity, adsorption separation capacity and molecular level pores. . The characteristics of these zeolites are difficult to be exhibited by zeolites obtained from nature, and it is necessary to selectively obtain crystals having a structure suitable for the purpose from various crystal structures of a large number of zeolites. In particular, it is desired to develop a method capable of stably forming the crystal in a film shape and easily obtaining a film firmly fixed to the substrate.
However, zeolite has no self-sintering property and cannot be formed into a film even by general hydrothermal synthesis. For this reason, it is generally obtained through a crystal formation step for forming a crystal and a densification step for growing the crystal into a film. As methods for producing such zeolite crystals, methods disclosed in the following Patent Documents 1 to 3 and the like are known.

Special Table 2000-507909 Japanese National Patent Publication No. 8-509453 JP 2004-307296 A

The zeolite crystal in Patent Document 1 is obtained by applying fine crystals having a large shape anisotropy obtained in advance on a substrate. On the other hand, the zeolite crystal in Patent Document 2 is also obtained through two steps at the same time. In these methods, the reproducibility and storage stability of the production liquid for precipitating zeolite crystals have not been studied. Also, in these production methods, it is usually difficult to obtain highly oriented zeolite crystals. Furthermore, there is a problem that manufacturing takes time and the base material is limited.
The above Patent Document 3 is based on the present inventors. This method is an excellent method by which an excellent oriented zeolite crystal can be obtained easily and reliably, but there is no knowledge about the reproducibility and storage stability of the production liquid for precipitating the zeolite crystal.

  The present invention solves the above-mentioned problems, and is a production liquid capable of producing highly oriented zeolite crystals, which has high reproducibility and further has excellent storage stability, and Another object of the present invention is to provide a method for producing oriented zeolite crystals using the same. Furthermore, it aims at providing the manufacturing method of the oriented zeolite crystal especially suitable for manufacture of the oriented zeolite crystal of a single layer.

The present inventors further examined the method for producing oriented zeolite crystals in Patent Document 3. In the technique relating to Patent Document 3, oriented zeolite crystals, particularly seed crystals, can be obtained very easily, but there is a problem that sufficient reproducibility is difficult to obtain. Therefore, a method for obtaining this oriented zeolite crystal with good reproducibility was examined. As a result, an extremely excellent oriented zeolite crystal production liquid far exceeding the conventional reproducibility and yield was obtained. Furthermore, it was found that this oriented zeolite crystal production liquid was stable enough to be stored after preparation of the liquid, which was difficult in the past, and the present invention was completed.
Furthermore, the inventors have found a method for producing an oriented zeolite crystal that is difficult in the above-mentioned Patent Document 3 to obtain a single-layer oriented zeolite crystal, and completed the present invention.

That is, the present invention is as follows.
(1) An aqueous solution before heating and holding containing a zeolite raw material containing water and a SiO ₂ component, and a zeolite structure-defining component, and the SiO ₂ component is 0.5 to 5.5 parts by mass with respect to 100 parts by mass of the water. An oriented zeolite crystal production liquid obtained by heating and maintaining at a temperature of 110 to 190 ° C. for 15 to 150 hours.
(2) The oriented zeolite crystal production liquid according to (1), wherein a precipitate is formed after the heating and holding, and the liquid is a liquid portion obtained by separating the precipitate.
(3) An aqueous solution before heating and holding, containing a zeolite raw material containing water and a SiO ₂ component, and a zeolite structure-defining component, wherein the SiO ₂ component is 0.5 to 5.5 parts by mass with respect to 100 parts by mass of the water. An oriented zeolite crystal production liquid, wherein precipitates are formed by heating and holding.
( 4 ) The oriented zeolite crystal production liquid according to any one of (1) to ( 3 ), wherein the zeolite structure-defining component is tetrapropylammonium ion.
( 5 ) The zeolite raw material contains a Na component, and the Na component is contained in the aqueous solution before heating and holding in an amount of 0.2 to 2 parts by mass in terms of NaOH with respect to 100 parts by mass of water. The oriented zeolite crystal production liquid according to any one of ( 4 ).
(6) the zeolite raw material contains an Al component, said Al component in the aqueous solution before the heating retention, above Si / Al molar ratio terms is contained to be 5 or more (1) to (5) An oriented zeolite crystal production liquid according to any one of the above.
( 7 ) The oriented zeolite crystal production liquid according to any one of (1) to ( 6 ) is maintained at a temperature of 110 to 220 ° C, and the substrate is immersed in the oriented zeolite crystal production liquid. A method for producing oriented zeolite crystals, comprising a step of depositing oriented zeolite crystals in which straight channels are oriented in a direction perpendicular to the surface of the substrate.
( 8 ) Contains water, a zeolite raw material containing an SiO ₂ component, an Al component and an Na component, and a zeolite structure-defining component, and the blending amount of the SiO ₂ component is 0.05 to 5 with respect to 100 parts by mass of water. The substrate is immersed in an oriented zeolite crystal production liquid that is part by mass and the temperature is 120 ° C. or more and less than 150 ° C., and is arranged in a single layer in which straight channels are oriented in a direction perpendicular to the substrate surface. A method for producing an oriented zeolite crystal, comprising the step of precipitating the oriented zeolite crystal.
(9) A separation liquid comprising a liquid portion obtained by separating the precipitate from the oriented zeolite crystal production liquid according to (3).

According to the oriented zeolite crystal production liquid of the present invention which is heated and held at a predetermined temperature and a predetermined time, oriented zeolite crystals can be produced with good reproducibility. Therefore, oriented zeolite crystals can be obtained efficiently and in high yield. Moreover, this oriented zeolite crystal production liquid can be stored stably. Therefore, the liquid can be prepared under a large amount of stable conditions, and oriented zeolite crystals can be obtained using only the necessary amount when necessary. Furthermore, since the liquid manufactured at one time can be divided and used, the difference in properties between oriented zeolite crystals with different production lots can be suppressed, and stable oriented zeolite crystals can be obtained.
When it consists of a liquid part obtained by separating the precipitate, it is not necessary to remove the precipitate from the oriented zeolite crystal production liquid before producing the oriented zeolite crystal, and the oriented zeolite crystal is more easily prepared. Can be manufactured. Moreover, the difference between manufacturing lots can be more reliably suppressed by performing this removal work collectively.
According to the oriented zeolite crystal production liquid of the present invention in which precipitates are formed by heating and holding, oriented zeolite crystals can be produced with good reproducibility. Therefore, oriented zeolite crystals can be obtained efficiently and in high yield. Moreover, this oriented zeolite crystal production liquid can be stored stably. Therefore, the liquid can be prepared under a large amount of stable conditions, and oriented zeolite crystals can be obtained using only the necessary amount when necessary. Furthermore, since the liquid manufactured at one time can be divided and used, the difference in properties between oriented zeolite crystals with different production lots can be suppressed, and stable oriented zeolite crystals can be obtained.
When the zeolite structure-defining component is tetrapropylammonium ion, a zeolite crystal having particularly high orientation can be obtained, and the crystals can be formed more densely.
When a predetermined amount of the Na component is contained, the size of the crystal particles of the oriented zeolite crystals obtained can be made more uniform.
When a predetermined amount of Al component is contained, the size of the crystal grains of the obtained oriented zeolite crystal can be made more uniform, and higher orientation can be obtained.
According to the method for producing an oriented zeolite crystal of the present invention, it can be produced with good reproducibility, an oriented zeolite crystal can be produced efficiently and in a high yield, and a zeolite crystal excellent in orientation can be produced stably. Further, only the necessary amount can be produced when necessary, and further, the property difference between oriented zeolite crystals with different production lots can be suppressed.
According to another method for producing oriented zeolite crystals of the present invention, oriented zeolite crystals formed in a single layer can be obtained.
In the case of a separation liquid consisting of a liquid part obtained by separating precipitates, it is not necessary to remove the precipitates from the oriented zeolite crystal production liquid before producing oriented zeolite crystals, making orientation easier. Zeolite crystals can be produced. Moreover, the difference between manufacturing lots can be more reliably suppressed by performing this removal work collectively.

The present invention will be described in detail below.
[1] Oriented zeolite crystal production liquid (1)
The oriented zeolite crystal production liquid of the present invention (hereinafter also simply referred to as “the present production liquid”) contains water, a zeolite raw material containing a SiO ₂ component, and a zeolite structure-defining component, and the SiO ₂ component contains the water 100 It was obtained by heating and holding an aqueous solution before heating and holding at 0.5 to 5.5 parts by mass with respect to parts by mass at a temperature of 110 to 190 ° C. for 15 to 150 hours.

The “aqueous solution before heating and holding” is an aqueous solution containing water, a zeolite raw material containing a SiO ₂ component, and a structure-defining component. Moreover, it is the aqueous solution in which the heat | fever holding process mentioned later is not performed. Further, the aqueous solution before heating and holding usually has a pH of 10 or more, so that the SiO ₂ component, the zeolite structure-defining component and the like are dissolved, and becomes a transparent liquid at room temperature (for example, 25 ° C.).

The “zeolite raw material” is a raw material that constitutes oriented zeolite crystals and includes at least a SiO ₂ component.
The “SiO ₂ component” forms a Si skeleton of oriented zeolite crystals and / or generates a component that forms a Si skeleton. No particular limitation is imposed on the SiO ₂ component include silica (fumed silica and colloidal silica, etc.), silicates (alkali metal salts of sodium and potassium salts, etc.), alkoxides like containing silicon and the like. Of these, silica is preferred because it can be obtained at a low cost. SiO ₂ component may be used in combination of two or more may be used alone. The component forming the Si skeleton is a low molecular compound mainly composed of Si, and examples thereof include water-soluble silicon oxides (polysilicate ions, metasilicate ions, orthosilicate ions, etc.).

The content of the SiO ₂ component in the aqueous solution before heating and holding is 0.5 to 5.5 parts by mass (more preferably 0.5 to 5.0 parts by mass) with respect to 100 parts by mass of water when converted to SiO _2. Parts, more preferably 0.6 to 5.0 parts by mass, even more preferably 0.6 to 4.0 parts by mass, particularly preferably 1.0 to 4.0 parts by mass, and more particularly preferably 1.5 to 3.0 parts by mass). If less than 0.5 parts by mass or more than 5.5 parts by mass, zeolite crystals can be obtained, but it becomes difficult to obtain oriented zeolite crystals, and high density (for example, the total area of the substrate surface to be formed) When it is 100%, it is difficult to obtain a product that covers 70% or more), and it is difficult to obtain crystal particles of an appropriate size. In particular, when a single-layer oriented zeolite crystal is intended, the content of SiO ₂ component is 0.5 to 5.0 parts by mass (more preferably 0.6 to 4.0 parts by mass, particularly preferably 1.5 to 2.5 parts by mass) is preferable.

This zeolite raw material may be composed of one compound or two or more compounds. That is, in this zeolite raw material, other zeolite raw material components other than the SiO ₂ component can be used together. When another zeolite raw material component other than the SiO ₂ component is contained, the SiO ₂ component and the other zeolite raw material component may be separate compounds, and _{two of} the SiO ₂ component and the other zeolite raw material component It may be a compound containing more than one component.
As said other zeolite raw material component, Al component, Na component, K component, etc. are mentioned.

The Al component can be used for obtaining oriented zeolite crystals containing Al. The Al component can supply Al constituting the oriented zeolite crystal containing Al.
The type of the Al component is not particularly limited, and examples thereof include various aluminum salts such as Al (NO ₃ ) ₃ , Al (OH) ₃ , AlCl ₃ and AlBr _3, and alkoxides containing Al. Among these, Al (NO ₃ ) ₃ or the like is preferable because of its excellent solubility in water. These Al components may use only 1 type and may use 2 or more types together. Furthermore, these may be hydrated or non-hydrated.
Further, the content of the Al component is such that Si / Al is 5 or more (more preferably 5 to 800, still more preferably 10 to 800, still more preferably 10 to 500, particularly preferably 10 to 400, in terms of molar ratio). 1000 or less) is preferable. In this range, the size of crystal grains can be made more uniform, and high orientation can be obtained. In particular, when the purpose is to produce single-layer oriented zeolite crystals, the content of the Al component is preferably 10 to 400 (more preferably 10 to 200, particularly preferably 20 to 100) in terms of the above. .

The Na component can be used when obtaining oriented zeolite crystals containing Na. The Na component can supply Na constituting an oriented zeolite crystal containing Na.
The type of Na component is not particularly limited, for _example, NaOH, NaNO 3, NaCl, alkoxides, and the like containing sodium salt and Na such as _Na 2 SO ₄ and Na (COOH). Among these, NaOH is preferable because it has excellent solubility in water and functions as a constituent component of the oriented zeolite crystal by blending, and can also adjust the pH of the aqueous solution before heating and holding. These Na components may use only 1 type and may use 2 or more types together.

  Moreover, the compounding quantity of Na component is 0.2-2.0 mass parts (more preferably 0.25-2.0 mass parts, still more preferably 0.2 mass parts with respect to 100 mass parts of water, when converted into NaOH. 3 to 2.0 parts by mass, more preferably 0.4 to 2.0 parts by mass, particularly preferably 0.5 to 2.0 parts by mass, and more preferably 0.5 to 1.5 parts by mass). preferable. Within this range, the size of the crystal particles constituting the obtained oriented zeolite crystal becomes more uniform.

The K component can be used when an oriented zeolite crystal containing K is intended. That is, this K component can supply K constituting the oriented zeolite crystal containing K.
No particular limitation is imposed on the K component, for _example, KOH, KNO 3, _KCl, can be mentioned alkoxides containing K 2 SO ₄ and K (COOH) potassium and K such. Among these, KOH is preferable because it is excellent in solubility in water and can be adjusted in pH similarly to the above NaOH by blending. These K components may use only 1 type and may use 2 or more types together. The K component can contain an amount replaced with an equivalent amount of the Na component. Further, when both the Na component and the K component are contained in the zeolite raw material, the Na component and the K component can be replaced with equal amounts. However, it is preferable to mainly use the Na component for the Na component and the K component.

The “structure-defining component” is a component that defines the structure of the obtained oriented zeolite crystal. As the structure-defining component, a compound that generates a quaternary ammonium ion in an aqueous solution is usually used. As the quaternary ammonium ion, tetrapropylammonium (TPA) ion is preferable. This is because when the aqueous solution contains tetrapropylammonium ions, zeolite crystals with particularly good orientation can be densely precipitated.
In addition, as the structure-defining component that generates tetrapropylammonium ions, for example, tetrapropylammonium ion halides (fluorides, chlorides, bromides, and iodides) and hydroxides can be used. Of these, tetrapropylammonium bromide is particularly preferred. These structure-defining components may be used alone or in combination of two or more.

  The content of the structure-defining component is not particularly limited, but is 0.3 parts by mass or more (more preferably 0.4 parts per 100 parts by mass of water) in terms of tetrapropylammonium bromide (hereinafter simply referred to as “TPABr”). It is preferably contained in an amount of not less than part by mass, more preferably 0.5 to 2.0 parts by mass, usually 10 parts by mass or less. If it is 0.3 parts by mass or more, oriented zeolite crystals can be formed particularly stably, and further, the amount of raw material consumption accompanying crystal production can be kept small.

As described above, the aqueous solution before heating and holding used in the present invention usually has a pH of 10 or more. This pH is preferably 10 to 13.5, more preferably 10 to 12.5, and particularly preferably 10 to 12.
The method for adjusting the pH is not particularly limited. Examples of the pH adjusting method include (1) a method using a zeolite raw material containing other zeolite raw material components other than the SiO ₂ component. That is, it is a method using a zeolite raw material containing a basic compound (a compound that can be made water-soluble to make the pH of the aqueous solution alkaline). Examples of the basic compound include NaOH and KOH, and NaOH is particularly preferable. Further, (2) a method using a basic structure-defining component may be mentioned. Examples of the basic structure-defining component include tetrapropylammonium ion hydroxide (TPAOH).

This production liquid is obtained by heating and holding the aqueous solution before heating and holding.
The above “heat holding” refers to applying a temperature of 110 to 190 ° C. for 15 to 150 hours. 135-190 degreeC is preferable, as for the temperature at the time of performing this heat holding | maintenance (henceforth only a "heating holding temperature"), 140-190 degreeC is more preferable, and 150-185 degreeC is especially preferable. If the heating and holding temperature is less than 110 ° C., there may be a case where sufficient improvement in reproducibility of oriented zeolite crystal formation is not observed. On the other hand, when the heat holding temperature exceeds 190 ° C., an unintended reaction such as thermal decomposition of the structure-defining component occurs, and a sufficient improvement in reproducibility may not be recognized.
Further, the time for heating and holding (hereinafter simply referred to as “heating and holding time”) is preferably 15 to 130 hours, more preferably 15 to 100 hours, and particularly preferably 15 to 80 hours. If the heating and holding time is less than 15 hours, the reproducibility improvement of oriented zeolite crystal formation may not be sufficiently observed. On the other hand, the heating and holding time may be 150 hours or more, but it is preferable that the heating and holding time be obtained in a shorter time. That is, for example, the heating and holding time can be usually set to 150 hours or less by a heating and holding method such as heating and holding at a low temperature and then increasing the temperature to promote the reaction to shorten the total time.

Conventionally, even if a solution for depositing oriented zeolite crystals is used for crystal production immediately after preparation, the probability that oriented zeolite crystals are produced is low, and reproducibility may not be sufficiently obtained. That is, even if the same procedure was used to prepare solutions using the same amounts of the same raw materials and the same substrate was immersed under the same conditions, ideal oriented zeolite crystals were not necessarily produced. This probability (ratio of the number of times the oriented zeolite crystal is obtained with respect to the total number of productions) is, for example, about 5 to 10%, resulting in a low yield.
On the other hand, reproducibility can be made remarkably high with this manufacturing liquid. Therefore, oriented zeolite crystals can be stably mass-produced. Moreover, since it has the outstanding storage stability mentioned later, an oriented zeolite crystal can be manufactured especially stably. With this production liquid, oriented zeolite crystals can be produced. For example, the target oriented zeolite crystal can be produced with a probability of about 95% or more (including 100%).

In addition, conventionally, the solution for depositing oriented zeolite crystals has poor storage stability, and even when stored at a low temperature after preparation, precipitates are formed in a short period of time and the liquid composition changes. Could not be manufactured. Furthermore, even if precipitates were removed from this solution, oriented zeolite crystals could not be produced.
On the other hand, this manufacturing liquid can be stored for a long time after it is prepared. Therefore, a solution can be prepared under a stable condition in large quantities. Also, only the necessary amount can be used when necessary. Furthermore, the solution manufactured at once can be used separately, and stable performance can be exhibited even with oriented zeolite crystals having different production lots. This production solution can usually be stored at 25 ° C. for more than 2 months (usually less than half a year). The conditions for storing this production solution are not particularly limited. For example, the temperature is 30 ° C. or less (preferably 25 ° C. or less, more preferably −10 to 25 ° C., particularly preferably −10 to −10 ° C., usually −20 It is preferable to store at a temperature of ℃ or higher.

The production liquid may or may not generate precipitates when the above-mentioned heat holding is performed or after the heat holding. When storing this production solution, it may be stored in a state in which this precipitate is contained, or it may be stored in a state in which the precipitate is removed (not all or part of the precipitate). Also good.
That is, a precipitate is formed after heating and holding, and a separation liquid composed of a liquid portion obtained by separating the precipitate can also be used for production .
The “precipitate” is a solid substance observed in the liquid after being heated and is usually precipitated by heating and holding. Further, the precipitate is usually of a size that can be visually observed, and may be a precipitate, a suspended matter (such as a colloid), or both of them. Although the magnitude | size of a deposit is not specifically limited, Usually, it is 10 nm or more. However, even if the thickness is 10 nm or more, those that cannot be visually observed in the solution after being heated are not included.
The structure (composition, etc.) and amount of this precipitate are not particularly limited, but usually contains Si in the zeolite raw material. Further, when a zeolite raw material containing an Na component is used, Na is contained in the precipitate, and when a zeolite raw material containing an Al component is used, the precipitate contains Al. The composition of the precipitate is not particularly limited. For example, the content of Al and Na is a compound in which Na / Al is 0.75 to 1.35 (more preferably 0.8 to 1.3) in terms of molar ratio. Is obtained. Moreover, it does not correlate with Na / Al in the pre-heated solution, and is a precipitate containing Na and Al in the above range.

The above “removal” means that all or a part of the precipitate is removed. In the case of partial removal, the removal amount is not particularly limited. The removal method is not particularly limited, and methods such as decantation, filtration, centrifugation, and dialysis can be used. These methods may use only 1 type and may use 2 or more types together.
When decantation is used among the above, the time for allowing the solution to stand after heating is usually 1 hour or longer.

  The “liquid part” is a part excluding the precipitates (precipitates and suspended matters) formed by the heating and holding. The liquid portion may contain a fine solid that cannot be visually confirmed as the precipitate. Examples of the fine solid that cannot be visually confirmed include the components that form the Si skeleton described above. That is, polysilicate ion, metasilicate ion, orthosilicate ion and the like can be mentioned.

As described above, the production solution may be stored while containing precipitates, or may be stored after removing the precipitates. However, the production solution is used to produce oriented zeolite crystals. Usually, this precipitate is removed. However, this removal includes all or a part of the removal as well as the removal in the storage.
The reason why the removal is preferable is that this precipitate is considered to be a factor that maintains the solid-liquid equilibrium of the production liquid after being heated. Therefore, it is considered that the balance of solid-liquid equilibrium can be lost by removing at least a part of the precipitate, and a state in which oriented zeolite crystals can be easily produced can be formed. However, the production of oriented zeolite crystals requires high temperature conditions. For this reason, even if it removes a deposit, if it does not hold | maintain at high temperature, this manufacturing liquid can be preserve | saved as mentioned above.

  The oriented zeolite crystal referred to in the present production liquid is a zeolite crystal excellent in orientation. “Excellent orientation” means that the straight channel of the zeolite crystal is oriented in a certain direction. For example, in the MFI-type zeolite crystal, the straight channel is a pore constituted by a 10-membered ring opening in the (010) plane. This orientation can be confirmed, for example, by substantially only obtaining a (010) series peak in the X-ray diffraction measurement. However, when the (501) peak is observed, the (020) peak intensity is preferably 30 times or more (more preferably 40 times or more, and further preferably 50 times or more) of the (501) peak intensity. The (501) peak is the peak that appears most strongly when X-ray diffraction measurement is performed on a zeolite crystal in a powder form (state considered to have the lowest orientation).

The oriented zeolite crystal production liquid of the present invention can be obtained by the production method as described above. That is,
The oriented zeolite crystal production liquid of the present invention contains a zeolite raw material containing water and a SiO ₂ component, and a zeolite structure-defining component, and the SiO ₂ component is 0.6 to 4.0 with respect to 100 parts by mass of the water. It can be obtained by a method for producing an oriented zeolite crystal production liquid, comprising a step of heating and holding the aqueous solution before heating and holding that is part by mass at a temperature of 110 to 190 ° C. for 15 to 150 hours.
Moreover, in this manufacturing method, the precipitate is formed after the said heat holding, and the process of isolate | separating this precipitate can be provided. Furthermore, in this production method, the zeolite structure-defining component can be tetrapropylammonium ion. Moreover, in this manufacturing method, the said zeolite raw material contains Na component, and this Na component is 0.2-2 mass parts in conversion of NaOH with respect to 100 mass parts of water in the said aqueous solution before a heating holding | maintenance. It can be. Furthermore, the zeolite raw material contains an Al component, and the Al component can be contained in the aqueous solution before heating and holding so that Si / Al is 5 or more in terms of molar ratio.
According to this method for producing an oriented zeolite crystal production liquid, the oriented zeolite crystal production liquid of the present invention capable of exhibiting the above various excellent effects can be obtained reliably and simply.

[2] Oriented zeolite crystal production liquid (2)
The oriented zeolite crystal production liquid of the present invention (hereinafter also simply referred to as “this other production liquid”) contains water, a zeolite raw material containing a SiO ₂ component, and a zeolite structure-defining component, and the SiO ₂ component is An oriented zeolite crystal production liquid, wherein a precipitate is formed by heating and holding an aqueous solution before heating and holding of 0.5 to 5.5 parts by mass with respect to 100 parts by mass of water.

Each of the above-mentioned “manufacturing aqueous solution before heating”, “precipitate”, and “oriented zeolite crystal” in the production liquid can be applied as it is.
The heating conditions such as the heating temperature and the heating time are not limited for the above “heat holding”. That is, heating and holding may be performed so that a precipitate is obtained. For example, heating and holding may be performed in a multistage process or in a single process. Performing in a multistage process is when heating and holding at a plurality of different predetermined temperatures. Each of these steps may be performed continuously or intermittently. In addition, performing in a single step refers to the case where the heating and holding in the production liquid is performed and the case where the heating and holding is performed while continuously changing the temperature.

  When performing heating and holding in a multistage process, it may be performed in a two-stage process, in a three-stage process, or may be performed in a larger number of processes than a three-stage process (usually 10-stage process or less To do). Moreover, when performing heat holding in a multistage process, it can heat-hold at the temperature of 100-150 degreeC (further 110-140 degreeC, especially 110-130 degreeC) in a 1st heat holding process, for example. In this case, the temperature can be maintained for 15 to 100 hours (further 15 to 70 hours, particularly 15 to 40 hours). Furthermore, in the second heating and holding step, for example, the heating and holding can be performed at a temperature of 130 to 190 ° C. (further, 150 to 190 ° C., particularly 150 to 180 ° C.). In this case, the temperature can be maintained for 1 to 135 hours (further 5 to 40 hours, particularly 10 to 24 hours).

The effect that the reproducibility by the other production liquid can be remarkably increased, the effect that it can be stored for a long time after preparation, and the like are the same as the effects in the production liquid.
Moreover, it is the same as the said manufacturing liquid that the deposit obtained in this other manufacturing liquid does not need to be removed even if it removes. Further, “removal” and “liquid portion” at this time can be applied as they are in the production liquid.

The other oriented zeolite crystal production liquid of the present invention can be obtained by the production method as described above. That is,
The oriented zeolite crystal production liquid of the present invention contains a zeolite raw material containing water and a SiO ₂ component, and a zeolite structure-defining component, and the SiO ₂ component is 0.6 to 4.0 with respect to 100 parts by mass of the water. It can be obtained with an oriented zeolite crystal production liquid comprising a step of heating and holding the aqueous solution before heating and holding that is part by mass to form precipitates.
Moreover, in this manufacturing method, the process of isolate | separating a precipitate after the said heating holding can be provided. Furthermore, in this production method, the zeolite structure-defining component can be tetrapropylammonium ion. Moreover, in this manufacturing method, the said zeolite raw material contains Na component, and this Na component is 0.2-2 mass parts in conversion of NaOH with respect to 100 mass parts of water in the said aqueous solution before a heating holding | maintenance. It can be. Furthermore, the zeolite raw material contains an Al component, and the Al component can be contained in the aqueous solution before heating and holding so that Si / Al is 5 or more in terms of molar ratio.
According to this method for producing an oriented zeolite crystal production liquid, the oriented zeolite crystal production liquid of the present invention capable of exhibiting the above various excellent effects can be obtained reliably and simply.

[2] Method for producing oriented zeolite crystals (1)
The method for producing oriented zeolite crystals of the present invention comprises maintaining the oriented zeolite crystal production liquid of the present invention at a temperature of 110 to 220 ° C., immersing the substrate in the oriented zeolite crystal production liquid, and On the other hand, the method comprises a step of depositing oriented zeolite crystals in which straight channels are oriented in the vertical direction.

The “temperature” is 110 to 220 ° C. This temperature is preferably 120 to 200 ° C, more preferably 120 to 190 ° C, and particularly preferably 150 to 190 ° C. In this temperature range, oriented zeolite crystals are produced.
The “holding” is not particularly limited as long as the target oriented zeolite crystal can be obtained, and the holding time and the like are not particularly limited, but usually 5 hours or longer (preferably 8 hours or longer, more preferably 18 hours or longer, Usually 60 hours or less). However, the holding in this temperature range is usually performed continuously. After the oriented zeolite crystal production is started by maintaining in the above temperature range, if the temperature falls below the above temperature range, the crystal (especially seed crystal) density may decrease, which is not preferable. On the other hand, if it exceeds the above temperature range, the orientation may decrease, which is not preferable. In addition, the temperature fluctuation within the said temperature range while hold | maintaining is not specifically limited. That is, for example, oriented zeolite crystals can be obtained by holding at different temperatures.

  The “substrate” is not particularly limited in material, shape and size as long as it can precipitate oriented zeolite crystals. As the material constituting the substrate, zirconia, alumina (such as α-alumina, γ-alumina and anodized alumina), metal (such as stainless steel and nickel), glass, and the like can be used. Among these, zirconia, alumina, and metal are preferable, and zirconia and alumina are more preferable. Of these, alumina is particularly preferred. Zirconia and alumina are both excellent substrates, but alumina has a tendency to be further superior to zirconia in terms of bondability with oriented zeolite crystals. When alumina is used for the substrate, the substrate itself may be a component that supplies Al constituting the oriented zeolite crystal. In this case, it is preferable to reduce the amount of the Al component so that the amount of the Al component in the aqueous solution is within the above preferable range in Si / Al in terms of molar ratio.

  The “immersion” is usually performed by immersing the entire substrate in the production liquid, but it is sufficient that at least the surface of the substrate on which the oriented zeolite crystals are precipitated is immersed in the production liquid. Moreover, only one part may be immersed first, and another part may be immersed later, and you may make it precipitate on both different parts. Furthermore, it can be slowly rotated in the aqueous solution so that it can be uniformly deposited. Further, the immersion time is not particularly limited, but is the same as the above holding time. By setting the immersion time in the above range, oriented zeolite crystals can be precipitated particularly densely.

  In this production method, in order to maintain the production liquid in the above temperature range, a sealed container that can withstand the vapor pressure at the above temperature is usually required. Although the material which comprises this airtight container is not specifically limited, It is preferable that an inner wall is comprised with the material to which a zeolite crystal does not adhere. That is, for example, a fluororesin {for example, Teflon (registered trademark)} is preferable. This is because the zeolite crystals may adhere to the inner wall and then peel off and drop to grow on the surface of the substrate, which may disturb the orientation of the zeolite crystals.

Furthermore, the oriented zeolite crystals that can be produced by this production method are usually crystals in which crystal particles are not sufficiently connected to each other and there is room for further crystal growth in the plane direction of the substrate. That is, it is a so-called seed crystal (orientated zeolite seed crystal). The size of the crystal grains of the oriented zeolite crystal is not particularly limited, but is usually a maximum average length of 4 μm or less and an average thickness of 1 μm or less.
Usually, it is difficult to grow oriented zeolite crystals into a film by this production method. This is because there is a limit to the zeolite raw material that can be stored (dissolved) in the production liquid, and the raw material is consumed as the crystal grows, and the amount necessary for crystal formation cannot be stored. Conceivable. The oriented zeolite crystal formed by this production method can be further grown by the growth method described later to form an oriented zeolite crystal film.

  Moreover, the structure of the oriented zeolite crystal obtained by the production method of the present invention is usually MFI type. The MFI type includes both a non-silicalite type containing Al and a silicalite type containing substantially no Al. Among these, the MFI type is suitable for the production of a non-silicalite type, and particularly so-called ZSM-5. Suitable for the production of type zeolite. However, depending on the content and temperature of each component (particularly structure-defining component) in the aqueous solution, a zeolite with other structure (for example, MOR type) may be obtained instead of the MFI type.

  Moreover, in this manufacturing method, in addition to performing the process of immersing a base | substrate in this manufacturing liquid, another process can be provided. As other steps, for example, a washing step of washing the substrate pulled up from the production liquid (substrate on which oriented zeolite crystals are formed) can be mentioned. Moreover, the drying process which dries the base | substrate with which this oriented zeolite crystal was formed is mentioned. By performing these steps, the structure-defining component incorporated into the crystal can be removed. However, in the growth method to be described later, a substrate after being subjected to these steps (substrate on which oriented zeolite crystals are formed) may be used. It may be used.

[3] Method for producing oriented zeolite crystals (2)
It contains water, a zeolite raw material containing an SiO ₂ component, an Al component and an Na component, and a zeolite structure-defining component, and the blending amount of the SiO ₂ component is 0.05 to 5 parts by mass with respect to 100 parts by mass of water. An orientation in which a substrate is immersed in an oriented zeolite crystal production liquid having a temperature of 120 ° C. or more and less than 150 ° C., and arranged in a single layer in which straight channels are oriented in a direction perpendicular to the surface of the substrate. Characterized by comprising a step of precipitating a crystalline zeolite crystal.

The “oriented zeolite crystal production liquid” is a liquid in which water, a zeolite raw material containing an SiO ₂ component, an Al component, and an Na component, and a structure-defining component are blended. Further, the same heat holding as in the above production liquid may or may not be performed. Further, the blending order of each of water, zeolite raw material and structure-defining component to be blended in the production liquid is not particularly limited. Furthermore, in the blending of the zeolite raw material, each component such as SiO ₂ component may be blended separately, and these components may be blended together, and further, a solid containing all necessary components. May be blended.

The “zeolite raw material” is a variety of raw materials that constitute the oriented zeolite crystal. This zeolite raw material contains at least three components of SiO ₂ component, Al component and Na component. As the “SiO ₂ component”, the “Al component”, and the “Na component”, each component in the production liquid can be applied as it is.
However, the amount of SiO ₂ component, 0.05 to 5 parts by weight per 100 parts by weight of water when converted into SiO ₂ (preferably 0.5 to 3 parts by weight, more preferably 1 to 3 parts by weight More preferably, it is 1-2 mass parts). If it is less than 0.05 part by mass, formation of the zeolite crystal itself tends to be difficult, and if it exceeds 5 parts by mass, it becomes difficult to obtain an oriented zeolite crystal in a single layer. In this range, highly oriented and high density oriented zeolite crystals can be obtained.

Furthermore, as for the compounding quantity of Al component, Si / Al is 80-1000 (more preferably 140-800, still more preferably 200-800) in terms of molar ratio. In this range, the crystal size is particularly stable and high orientation is obtained.
Moreover, the compounding quantity of Na component is 0.05-2.0 mass parts (more preferably 0.2-1.5 mass parts, still more preferably 0.2 mass parts with respect to 100 mass parts of water, when converted into NaOH. 3 to 01.5 parts by mass). In this range, the size of crystal grains becomes more uniform.
As the zeolite raw material, the K component may be mentioned as a component other than the SiO ₂ component, the Al component, and the Na component as in the case of the production liquid.

As the “structure-defining component”, each component in the production liquid can be applied as it is. However, the content of the structure-defining component is 0.3 parts by mass or more (more preferably 0.4 parts by mass or more) with respect to 100 parts by mass of water in terms of tetrapropylammonium bromide (hereinafter simply referred to as “TPABr”). More preferably 0.5 to 2.0 parts by mass). Within this range, oriented zeolite crystals can be produced particularly stably, and the consumption of raw materials can be kept small.
Moreover, the temperature of this manufacturing liquid is 110 degreeC or more and less than 150 degreeC (preferably 110 degreeC or more and less than 150 degreeC, More preferably, it is 110-140 degreeC, More preferably, it is 120-135 degreeC, Most preferably, it is 130-135 degreeC). is there. If it is less than 110 ° C., formation of zeolite crystals tends to be difficult, and if it is 150 ° C. or more, it tends to be difficult to obtain oriented zeolite crystals in a single layer.

As the “substrate”, the substrate in the other method for producing oriented zeolite crystals can be applied as it is.
For the “immersion”, the immersion in the other method for producing oriented zeolite crystals can be applied as it is.
Furthermore, in this production method, a closed container that can withstand the vapor pressure at the above-mentioned temperature is usually required as in the other production methods. About this airtight container, the airtight container in the said other manufacturing method is applicable as it is.

Oriented zeolite crystals obtained by the production method of the present invention are crystals arranged in a single layer on the surface of a substrate. The “single layer” means that there is almost no overlap between zeolite crystals. Usually, when the entire zeolite crystal plane is 100%, the area ratio of the single layer portion is 80% or more (more preferably 90% or more). This area ratio can be obtained by measuring the area ratio of a single layer portion in an actually measured 20 μm square image in a magnified image using an electron microscope on the surface of the substrate on which the zeolite crystal is formed. .
Further, like the other production methods, the oriented zeolite crystals that can be produced by this production method are so-called seed crystals, and can be grown by a growth method described later to form an oriented zeolite crystal film. It is also the same that the structure of the oriented zeolite crystal obtained by this production method is usually MFI type.
Moreover, the same other process can be provided similarly to the said other manufacturing method.

[4] Growth method of oriented zeolite crystals The oriented zeolite crystals obtained by the production method of the present invention are
Water, a zeolite raw material containing SiO ₂ component, Al component and Na component, and a zeolite structure-defining component are blended,
The upper part is 120 to 220 ° C. and is heated and held in a solution state, and the lower part is above the heterogeneous liquid for crystal growth that is kept at a lower temperature than the upper part and contains gel and / or solids. Immerse the oriented zeolite crystals deposited on the substrate inside,
An oriented zeolite crystal can be further grown by a method for growing an oriented zeolite crystal comprising a crystal growth step for growing the oriented zeolite crystal.
According to this growth method, the zeolite crystal excellent in the orientation obtained by the production method of the present invention can be further grown.

The “zeolite raw material” is a raw material for crystal growth of oriented zeolite crystals. This zeolite raw material contains at least three components of SiO ₂ component, Al component and Na component. As the “SiO ₂ component”, the “Al component”, and the “Na component”, the respective components in the respective production methods can be applied as they are. In addition, as the “structure-defining component”, the structure-defining component in each of the production methods can be applied as it is. Each component such as SiO ₂ component and the structure-defining component in the zeolite raw material may be blended with each other, or may be blended using a solid or the like containing two or more kinds of each component. There may be.
However, as will be described later, the content of each component in the heterogeneous liquid for crystal growth is not particularly limited. As will be described later, in the heterogeneous liquid for crystal growth, there is a raw material storage environment containing gel and / or solid matter, and a large amount of zeolite raw material is stored in a solid state in this environment. Because.

The “crystal growth heterogeneous liquid” is a mixture of water, a zeolite raw material, and a structure-defining component. The medium constituting the heterogeneous liquid for crystal growth may be water alone or may contain other media (alcohols and the like).
Further, the heterogeneous liquid for crystal growth includes an upper part that is heated and held in a solution state and a lower part that is held in a state containing gel and / or solids.
The “above” is an environment in which the oriented zeolite crystal can be grown while being kept in a solution state. This solution state portion does not contain gel and / or solid content. That is, the zeolite raw material and the structure defining component are dissolved and contained. This solution state can be obtained by maintaining the temperature of the target portion at 120 to 200 ° C. This holding temperature can be further set to 120 to 190 ° C., in particular 120 to 180 ° C., in particular 120 to 175 ° C. In addition, solid content means what can be confirmed with the naked eye, and the thing smaller than the precipitate in the said manufacturing liquid is not contained. For example, particles of less than 10 nm are not included in the solid content.

The “downward” is an environment where gel and / or solids are contained and no crystal growth of oriented zeolite crystals occurs. The “gel” and the “solid content” contained in the lower part are mainly composed of a zeolite raw material. Examples of the gel include a compound formed by gelation of SiO ₂ , and the solid content is a tablet obtained by tableting a powdery zeolite raw material component (tablet containing each zeolite raw material separately) And may be tablets containing all zeolite raw materials). One or two or more zeolite raw materials constituting the gel and the solid content may be used. When each component contained in the crystal growth environment is used for crystal growth, the gel and the solid content are gradually dissolved and supplied from the raw material storage environment to the crystal growth environment.
This lower temperature is lower than the lowest upper temperature, and is not particularly limited as long as it is a temperature that generates a solid content or the like. This temperature can be, for example, less than 120 ° C.

The method of forming the temperature difference (temperature gradient) between the upper side and the lower side is not particularly limited. For example, [1] The whole system is placed in a thermostatic bath where the whole system can be heated, and the upper part from the part where the oriented zeolite crystals are immersed A method of further heating, [2] A method in which the whole system is placed in a constant temperature bath, and the upper part is further heated from the portion where the oriented zeolite crystals are immersed, and the lower part is cooled, [3] the oriented zeolite crystals are immersed It is possible to use a method of heating the upper part from the above-mentioned part and heating the lower part at a lower temperature than the upper part, [4] a method of placing the whole system in a constant temperature bath and cooling only the lower part, and the like.
Moreover, you may perform the heating and cooling in each method of said [1]-[4] by what kind of method. For example, for heating, a method using various heaters (such as a heating wire), a method using a thermostatic bath, and a high-temperature heat medium (various fluids such as liquid, viscous material, solid-liquid coexisting material, and gas) in the pipe. It can be performed by a circulating method or the like. Moreover, the heater, piping, etc. in each case may be installed in the outer side of the container holding the heterogeneous liquid for crystal growth, and may be installed in the inner side. Similarly, cooling can be performed by a method of circulating a low-temperature refrigerant (various fluids such as a liquid, a viscous material, a solid-liquid coexisting material, and a gas) in the pipe, a method using a thermostatic bath, and the like.

  The “oriented zeolite crystals deposited on the substrate” are disposed in the upper part of the heterogeneous liquid for crystal growth. That is, the oriented zeolite crystal to be grown only needs to be immersed in the solution portion. However, the distance from the surface of the oriented zeolite crystal to be grown to the lower part (for example, a region below 120 ° C.) is not particularly limited, but can be, for example, 40 mm or less (further 30 mm or less, particularly 20 mm or less). Within this range, the zeolite raw material can be stably stored, and the upper environment is not disturbed. The upper and lower portions can be formed in a container having no boundary, but a partition can be provided by a porous body, a permeable membrane, or the like.

  Further, the oriented zeolite crystals deposited on the substrate may be immersed in any direction such as up, down, left, and right of the container. However, in order to grow in a higher orientation, it is preferable that the oriented zeolite crystal is directed downward. That is, when the crystal growth surface is immersed downward, it is possible to prevent newly formed crystal nuclei from depositing on the crystal growth surface and lowering the orientation. Further, new crystal nuclei settle down and are used again as a zeolite raw material, so that the zeolite raw material can be used without waste. In addition, since it is not affected by newly formed crystal nuclei, when obtaining a highly oriented zeolite film, even if a high solute concentration environment is used, even if a high solute concentration environment is used, the orientation from the low solute concentration is not reduced. A wide range of environments can be used.

Furthermore, the environment in which the upper part is 120 ° C. or more and 200 ° C. or less and the lower part is less than 120 ° C. includes water, a zeolite raw material containing a SiO ₂ component, an Al component, and a Na component, and a structure-defining component, 0.6 to 8.0 parts by mass (more preferably 1.0 to 4.0 parts by weight, more preferably 1.0 to 2.0 parts by mass) with respect to these SiO ₂ component 100 parts by weight of water blended This is effective when using a heterogeneous liquid for crystal growth. Further, in addition to these conditions, the Al component is blended in an Si / Al molar ratio of 30 to 1000 (more preferably 100 to 800, still more preferably 150 to 800), and the Na component is added to 100 parts by mass of water. On the other hand, when using a heterogeneous liquid for crystal growth mixed with 0.05 to 4.0 parts by mass (more preferably 0.05 to 2.0 parts by mass, still more preferably 0.05 to 0.8 parts by mass) Especially effective. This production method using the environment and the heterogeneous liquid for crystal growth is effective for the growth of MFI type oriented zeolite crystals.
Further, the content of the structure-defining component blended in the heterogeneous liquid for crystal growth is not particularly limited, but is 0.3 parts by mass or more (more preferably 0.4 parts by mass) with respect to 100 parts by mass of water in terms of TPABr. Part or more, more preferably 0.4 to 0.8 parts by mass). Furthermore, although the pH of the heterogeneous liquid for crystal growth is not particularly limited, it is usually 10.0 to 13.5 (preferably 10.0 to 12.5, preferably in a heterogeneous state including a solid content at a temperature of 30 ° C. More preferably, it is 10.0-12.0).

The above “immersion” is usually performed so that the entire oriented zeolite crystal is immersed in the solution state portion, but at least the growth surface of the oriented zeolite crystal is immersed in the solution state portion of the heterogeneous liquid for crystal growth. You can go to Further, in order to promote the growth evenly, it can be rotated in a non-uniform liquid for crystal growth.
The immersion time is not particularly limited, but is usually at least 5 hours or more (more preferably 24 hours or more, still more preferably 40 hours or more). Although it depends on the composition and pH of the heterogeneous liquid for crystal growth, a zeolite membrane can be formed if it is 5 hours or longer.

  In this growth method, the container in which the heterogeneous liquid for crystal growth is put is not particularly limited, but usually a sealed container is used. By being an airtight container, water evaporation and a high heat retention effect can be obtained, and the solution state portion of the heterogeneous liquid for crystal growth can be easily held in a form suitable for forming a zeolite membrane. About this airtight container, the airtight container in the manufacturing method of the said oriented zeolite crystal can be applied as it is.

Further, this growth method can be used even if the oriented zeolite crystal is a seed crystal, closer to a more grown zeolite membrane, or even a zeolite membrane. The seed crystal has a polygonal shape in which many of each crystal particle are present independently. On the other hand, the zeolite membrane is in the form of a film in which adjacent crystal particles are continuously connected to each other, and the end of the crystal in the portion where the crystals are not connected has a rounded shape.
According to this growth method, when the oriented zeolite crystal is a seed crystal, the plane area of each crystal particle is grown 1.2 times or more (more preferably 1.3 times or more, particularly 1.5 times or more). be able to. Further, the obtained zeolite membrane usually has an average film thickness of 1 μm or more (more preferably 1 to 5 μm).

  In this growth method, in addition to the step of growing oriented zeolite crystals within the solution state portion of the heterogeneous liquid for crystal growth, other steps can be provided. Other steps include, for example, a step of removing structure-defining components from the grown oriented zeolite crystal, a step of fixing various chemical substances in the pores of the grown oriented zeolite crystal, and a grown Examples include a step of exchanging the cation in the oriented zeolite crystal with another cation.

Hereinafter, the present invention will be described specifically by way of examples.
[1] Oriented zeolite crystal production liquid and production of oriented zeolite crystals (1) Heated and retained production liquid (Production liquid 1, Production liquid 2)
(I) Example in which oriented zeolite crystals arranged in multiple layers were obtained {Examples 1 to 3 (Production Solution 1)}
Each zeolite raw material in an amount shown in Table 1 were (SiO ₂ component, Na component, Al component) an aqueous solution prepared by blending to prepare. Thereafter, the prepared aqueous solution was poured into a pressurizable stainless steel sealed container whose inner wall was coated with a fluororesin, and then sealed with a lid. The sealed container was then allowed to stand in an autoclave, heated and held at 175 ° C. (self-pressurized) for 18 hours, and then allowed to cool to obtain an oriented zeolite crystal production liquid (production liquid 1). Precipitation of precipitates was observed in the resulting production liquid 1. This precipitate was allowed to stand at a temperature of 25 ° C. for 1 hour, and then the supernatant was removed by decantation.
The removed precipitate was naturally dried and then qualitatively and quantitatively analyzed by mass spectrum. As a result, Na was 0.49 mass%, Al was 0.4 mass%, and the balance (SiO ₂ etc.) was 99.11%.

Example 1: Production solution 1, heating and holding condition 175 ° C. × 18 hours
Precipitation conditions 175 ° C. × 18 hours Example 2; Production solution 1, heating and holding conditions 175 ° C. × 18 hours,
Precipitation conditions 175 ° C. × 18 hours Example 3; production solution 1, heating and holding conditions 175 ° C. × 18 hours,
Deposition conditions 175 ° C. × 18 hours

In addition, powdered fumed silica (manufactured by Sigma Aldrich Japan, product name “SILICA FUMED”) was used as the SiO ₂ component in Table 1 above. Moreover, NaOH was used as the Na component. Further, Al (NO ₃ ) ₃ · 9H ₂ O was used as the Al component. Further, powdered tetrapropylammonium bromide (manufactured by Aldrich Chemical Company, product name “Tetrepropylammonium bromide”) was used as a structure-defining component. Thereafter, the same applies to all manufacturing solutions.

After that, a pressurizable stainless steel sealed container (inner height of 8.5 cm, inner diameter of 3.4 cm, inner volume) provided with a scaffold capable of fixing the substrate at a height of 1 cm from the inner bottom and having an inner wall coated with a fluororesin. 60 ml) were prepared. The production liquid 1 prepared previously was put into each sealed container. Next, the surface-polished alumina substrate (plate: vertical 0.5 cm, horizontal 0.5 cm, thickness 0.2 cm, mirror-finished surface) was fixed to the scaffold in the reaction vessel, and then sealed with a lid, It left still in an autoclave and the temperature in each container was hold | maintained at 175 degreeC (self-pressurized) for 18 hours.
After 18 hours, each alumina substrate (Examples 1 to 3) was taken out from the sealed container, and the crystal state was visually observed in an image (hereinafter simply referred to as “SEM image”) whose surface was enlarged by an electron microscope. FIGS. 1 to 3 are explanatory diagrams of the SEM image of Example 1 used at this time.
As a result, as shown in FIGS. 1 to 3, it can be seen that the zeolite crystal is formed with a multi-layered zeolite crystal (seed crystal) so as to cover the substrate evenly at a high density. This appearance was very similar in Example 2 and Example 3 (not shown).

The XRD result of Example 1 is shown in FIG. From this result, the ratio of (020) peak intensity to (501) peak intensity (this peak intensity is taken as 100 [counts / s]) is 68.1, and (501) peak intensity ( It can be seen that an extremely high value (about 170 times) is obtained as compared with the ratio of (020) peak intensity to 0.4 (this peak intensity is 100 [counts / s]), which is excellent. . Further, in Example 2, the peak intensity ratio was 68.0, which was about 170 times the same peak intensity ratio in the powdered zeolite crystal by ASTM, and it was found that the film had excellent orientation. Further, in Example 3, the peak intensity ratio was 69, which was about 170 times the same peak intensity ratio in the powdered zeolite crystal by ASTM, and was found to have excellent orientation.
Furthermore, when the production liquid 1 was used, excellent oriented zeolite crystals that approximated both appearance and XRD measurement results were obtained in all three productions. Therefore, it can be seen that oriented zeolite crystals of the same quality can be produced efficiently and stably.

(Ii) Example in which oriented zeolite crystals arranged in a single layer were obtained {Example 4 (Production Solution 2)}
Each zeolite raw material in an amount shown in Table 2 (SiO ₂ component, Na component, Al component) an aqueous solution prepared by blending to prepare. Thereafter, the container was heated and held at 175 ° C. for 72 hours using the same sealed container as in the above [1] (1) (i). Then, it stood to cool and the manufacturing liquid 2 was obtained. Precipitates were observed in the obtained production liquid 2, and these precipitates were removed by decantation.

Example 4: Production solution 2, heating and holding conditions 175 ° C. × 72 hours,
Deposition conditions 130 ° C. × 24 hours + 175 ° C. × 18 hours

Thereafter, a sealed container is prepared in the same manner as in the above [1] (1) (i), the production liquid 2 is put into the sealed container, and a zirconia substrate (plate shape: 0.5 cm in length, 0.5 cm in width, thickness) (0.2 cm long, mirror-finished surface) and sealed with a lid, heated in an autoclave at 130 ° C (self-pressurized) for 24 hours, and then raised to 175 ° C over 10 minutes. And heated at 175 ° C. for 18 hours.
Thereafter, the zirconia substrate was taken out from the sealed container, and the surface of the zirconia substrate was visually observed in an SEM image enlarged by an electron microscope. FIG. 5 shows an explanatory diagram of the SEM image of Example 4 used at this time. As can be seen from FIG. 5, the zeolite crystals are arranged in a single layer, and the zeolite crystals are formed so as to cover the zirconia substrate evenly at a high density, and an excellent single-layer oriented zeolite crystal is obtained. Further, the XRD result of Example 4 is shown in FIG. From this result, the (501) peak is so small as to be hardly recognized, whereas the (020) peak is as large as 1517 counts / s, which is larger and significantly higher than the similar peak intensity ratio in Example 1. It turns out that it has orientation.

(2) Manufacturing liquid that is not heated and held (reproduction liquid of composition of manufacturing liquid 1)
{Comparative Example 1 (Production Solution 3)}
Production liquid 3 obtained by subtracting the amount of each component predicted to be precipitated in advance based on the analysis result of the precipitate taken out from the production liquid 1 (with heating and holding) of [1] (1) (i) above Was prepared according to the formulation shown in Table 3 below. That is, the production liquid 3 which is a pseudo production liquid that reproduces the composition of the production liquid 1 of the above [1] (1) (i) after removing the precipitate without heating and holding was prepared.
Comparative Example 1; production solution 3, heating and holding conditions-no heating and holding,
Deposition conditions 175 ° C. × 18 hours

The obtained production solution 3 was not heated and held, but was kept at 175 ° C. (self-pressurized) for 18 hours on the surface of the alumina substrate in the same manner as in the above [1] (1) (i) to form zeolite crystals. . The crystal state was visually observed in the SEM image obtained by enlarging the surface of the obtained alumina substrate with an electron microscope. 7 and 8 are explanatory diagrams of SEM images of Comparative Example 1 used at this time. As a result, although zeolite crystals were obtained, the formation density was extremely low. From the XRD measured in Comparative Example 1, the peak intensity ratio similar to the above was 1.3. This is a value that remains at 3.25 times the peak intensity ratio of 0.4 in the powdered zeolite crystal by ASTM, and it can be seen that the orientation is not obtained.
Therefore, it can be seen that even if the composition of the production solution after heating and holding is reproduced without heating and holding, the target oriented zeolite crystal cannot be obtained.

(3) Preservability of heated and maintained production liquid {Example 5 (Production liquid 1-1), Example 6 (Production liquid 1-2)}
A production liquid 1 was obtained in the same manner as in the above [1] (1) (i). The precipitate in the obtained production liquid 1 was similarly removed. Thereafter, a part of the production liquid 1 was stored at a temperature of 25 ° C. for 60 days to obtain a production liquid 1-1. Moreover, the remainder of the manufacturing liquid 1 was preserve | saved for 180 days at the temperature of 5 degreeC, and the manufacturing liquid 1-2 was obtained.
Thereafter, in the same manner as in the above [1] (1) (i), the production liquid 1-1 and the production liquid 1-2 are respectively put in two sealed containers, and the alumina substrate is fixed in each sealed container, Sealed with a lid. Thereafter, the sealed container was left in the autoclave, and the temperature in the container was maintained at 175 ° C. (self-pressurized) for 18 hours. After 18 hours, the alumina substrate was taken out from the sealed container, and the crystal state was visually observed in an SEM image in which each surface was enlarged by an electron microscope.

As a result, in any of Example 5 and Example 6, a zeolite crystal very similar to Example 1 in appearance was obtained. Similarly, zeolite crystals were formed so as to cover the substrate evenly at a high density.
Further, from the XRD results for Example 5 and Example 6, in Example 5, the ratio of (020) peak intensity to (501) peak intensity is 68, which is about 170 of the same peak intensity ratio in powder zeolite crystals by ASTM. It is double that it is almost the same as in Example 1, and it can be seen that it has excellent orientation. Also in Example 6, the peak intensity ratio is 68, which is about 170 times the same peak intensity ratio in powdered zeolite crystals by ASTM, is almost the same as Example 1, and has excellent orientation. I understand.
Therefore, it can be seen that the oriented zeolite crystal production liquid held by heating according to the present invention is excellent in storage stability.

[2] Production liquid for obtaining oriented zeolite crystals arranged in a single layer without heating and holding (1) Production under appropriate temperature conditions {(Example 7 (Production liquid 4)}
Each zeolite raw material (SiO ₂ component, Na component, Al component) was blended at a blending ratio shown in Table 4 below to prepare an oriented zeolite crystal production liquid (production liquid 4).
Example 7: Production liquid 4, precipitation conditions 130 ° C. × 72 hours Comparative example 2: Production liquid 4, precipitation conditions 175 ° C. × 18 hours

  Thereafter, the production liquid 4 was put into the same sealed container as the above [1] (1) (i), the zirconia alumina substrate was fixed in the sealed container, and the lid was sealed. Subsequently, it was left still in an autoclave, and the temperature in the container was maintained at 130 ° C. (self-pressurized) for 72 hours.

  After 72 hours, the zirconia substrate was taken out from the sealed container, and the crystal state of the surface was visually observed on the SEM image. FIGS. 9 to 11 (Example 7) are explanatory diagrams based on the SEM images used at this time. 9 and 10 are explanatory diagrams based on the SEM image obtained by photographing the crystal from the plane direction, and FIG. 11 is an explanatory diagram based on the SEM image photographed from the cross-sectional direction. In FIG. 11, square crystals arranged in the lateral direction at the center are oriented zeolite crystals, the white part below the crystal is the zirconia substrate, and the gray part above the crystal is for protecting the sample surface. It is the glass plate used.

(2) Production under excessively high temperature conditions {Comparative Example 2 (Production Solution 4)}
In the same manner as in the above [2] (1), the production liquid 4 was put into a sealed container, and the zirconia substrate was fixed inside and sealed. Subsequently, it was left still in an autoclave, and the temperature in the container was maintained at 175 ° C. (self-pressurized) for 18 hours.
After the elapse of 18 hours, the zirconia substrate was taken out from the sealed container, and the crystal state of the surface was visually observed on the SEM image. An explanatory diagram based on the SEM image used at this time is shown in FIG. 12 (Comparative Example 2).

(3) Effect of Example 7 and Comparative Example 2 From the results of FIGS. 8 to 11, it can be seen from FIG. 12 that in Comparative Example 2 held at a temperature of 150 ° C. or higher, single-layer zeolite crystals were not obtained. On the other hand, in Example 7, as shown in FIG. 11, it turns out that the zeolite crystal formed in the ideal ideal single layer without the overlap in a cross-sectional direction is obtained. 9 and 10, it can be seen that the zeolite crystals are formed with a sufficient crystal formation density that occupies about 70% of the surface of the zirconia substrate. This single-layer oriented zeolite crystal can be further grown to a single-layer oriented zeolite crystal film by performing a crystal growth step (that is, for example, the growth method of the oriented zeolite crystal). it can.

Further, X-ray diffraction measurement (hereinafter, simply referred to as “XRD”) of the crystal forming surface of the zirconia substrate of Example 7 was performed, and the peak intensities of the (020) peak and (501) peak were compared, and (501) peak The ratio of (020) peak intensity to intensity was converted. This XRD chart is shown in FIG. 13 (Example 7).
FIG. 13 shows that the peak intensity ratio is 37.0, the (020) peak intensity is extremely large with respect to the (501) peak intensity, and the crystal is excellent in orientation. That is, it can be seen that a single-layer oriented zeolite crystal is obtained.

[3] Growth of Oriented Zeolite Crystals (1) Description of Reaction Apparatus A reaction apparatus A shown in FIG. 14 includes a pressurizable stainless steel reaction vessel 10 whose inner wall is coated with a fluororesin, and an upper outer periphery of the reaction vessel. A heater 20 that is wound around and generates heat when energized, and a cooling jacket 30 that surrounds the lower outer periphery of the reaction vessel and exhibits a cooling action by circulating the refrigerant.

The reaction vessel 10 includes a main body 11 and a lid 12.
The main body 11 has an outer height of about 9.5 cm, an outer diameter of about 4.5 cm, an inner height of about 8.5 cm, and an inner diameter of about 3.5 cm. Moreover, the collar part 111 is provided in the position of about 6 cm from an outer bottom, and the screw part for screwing the cover part 12 in the position of about 8-9.5 cm from an outer bottom is provided.
The lid 12 has an outer height of about 4.5 cm, an outer diameter of about 6.5 cm, an inner height of about 4.0 cm, and an inner diameter of about 5.5 cm. Further, the lid portion includes a thermometer insertion case portion 121 that reaches about 2 cm from the inner bottom of the main body when attached to the main body. This thermometer insertion case part 121 is welded so as not to be released even when the inside of the reaction vessel is in a pressurized state. A thermometer 40 is inserted into the thermometer insertion case 121, and the temperature at a desired position in the height direction in the container can be measured by moving the thermometer up and down in the case. Furthermore, the oriented zeolite crystal fixing | fixed part 122 which fixes the base | substrate with which the oriented zeolite crystal was formed in the position of 6-8 cm from an inner bottom is provided.

The heater 20 includes a heat wire that generates heat when energized, and a control unit that controls the temperature of the heat wire. The heater 20 was used by screwing the main body portion 11 and the lid portion 12 and then winding a heat wire in a spiral shape so as to cover the outside of the lid portion 12 from the upper end of the flange portion 111 of the main body portion 11.
The cooling jacket 30 can circulate the refrigerant 31 inside by a pump disposed outside the autoclave. The cooling jacket 30 was used by covering the lower side from the lower end of the flange 111 of the main body 11 of the reaction vessel 10.

(2) Growth of Oriented Zeolite Crystal A heterogeneous liquid for crystal growth (pH 10.4) was prepared by blending each amount of zeolite raw materials shown in Table 5 below. Thereafter, the heterogeneous liquid for crystal growth 70 was put into the main body 11 of the container shown in FIG. Next, the alumina substrate 50 on which the oriented zeolite crystals of Example 1 obtained in [1] (1) (i) above are formed on the oriented zeolite crystal fixing part 122, and the crystal forming surface is the bottom of the reaction vessel. It was fixed so as to face (downward). Next, the lid portion 12 is screwed into the main body portion 11, the heat ray of the heater 20 is wound above the flange portion 111, the portion below the flange portion 111 is placed in the cooling jacket 30, and the entire reactor A is further placed in the autoclave. Placed on. Then, in the heterogeneous liquid for crystal growth, the temperature above the portion where the oriented zeolite crystal 60 is immersed (D1 in FIG. 14) is kept at 175 ° C., and below the portion where the oriented zeolite crystal 60 is immersed (FIG. 14). The temperature of medium D2) was kept at 20 ° C. Specifically, the portion below the portion where the oriented zeolite crystal 60 was immersed was downward from a position of 1 cm from the surface of the oriented zeolite crystal 60 toward the bottom of the reaction vessel. Further, a gel 71 was formed below this. This state was allowed to stand for 45 hours to grow oriented zeolite crystals.

From the XRD results for the oriented zeolite crystal of Example 2 grown in (2) above, the ratio of (020) peak intensity to (501) peak intensity is 68, and the same peak intensity ratio in powder zeolite crystals by ASTM It is about 170 times as large as that of Example 1, and it can be seen that excellent orientation is maintained.
As a result, according to this growth method, it can be seen that growth can be performed while maintaining the orientation of the oriented zeolite crystal obtained using the production liquid of the present invention.

  The present invention can be used for light-emitting elements, chemical sensors, gas separation membranes, quantum effect elements, and the like. In addition, automobile related fields (exhaust gas purification, various sensors, light emitting devices and fuel gas purification, etc.), synthetic chemistry related fields (catalyst, separation and purification, etc.), petroleum related fields (purification, separation and catalyst, etc.), household appliance related fields ( Adsorption, drying, deodorization, antibacterial, etc.), environment-related fields (adsorption, drying, deodorization, antibacterial, etc.) and medical-related fields.

It is explanatory drawing by the SEM image which expanded the orientational zeolite crystal of Example 1 500 times, and image | photographed in the plane direction. It is explanatory drawing by the SEM image which expanded the orientation zeolite crystal of Example 1 500 times, and image | photographed to the cross-sectional direction. It is explanatory drawing by the SEM image which expanded the orientation zeolite crystal of Example 1 3000 times, and image | photographed in the cross-sectional direction. FIG. 3 is an explanatory diagram of an XRD chart of Example 1. It is explanatory drawing by the SEM image which expanded the crystal | crystallization of Example 4 3000 times, and image | photographed in the plane direction. It is explanatory drawing by the XRD chart of Example 4. FIG. It is explanatory drawing by the SEM image which expanded the crystal | crystallization of the comparative example 1 500 times, and image | photographed in the plane direction. It is explanatory drawing by the SEM image which expanded the crystal | crystallization of the comparative example 1 3000 times, and image | photographed in the plane direction. It is explanatory drawing by the SEM image which expanded the orientation zeolite crystal of Example 7 by 3000 time, and image | photographed in the plane direction. It is explanatory drawing by the SEM image which expanded the orientation zeolite crystal of Example 7 1000 times, and image | photographed it in the plane direction. It is explanatory drawing by the SEM image which expanded the orientation zeolite crystal of Example 7 2500 times, and image | photographed in the cross-sectional direction. It is explanatory drawing by the SEM image which expanded the crystal | crystallization of the comparative example 2 5000 times, and image | photographed in the plane direction. 10 is an explanatory diagram of an XRD chart of Example 7. FIG. It is explanatory drawing which shows typically the reactor used for the growth of the oriented zeolite crystal in the Example.

Explanation of symbols

  A; reactor, 10; sealed container, 11; main body part, 111; collar part, 12; lid part, 121; thermometer insertion case part, 122; oriented zeolite crystal fixing part, 20; heater, 30; Jacket, 31; Refrigerant, 40; Thermometer, 50; Substrate, 60; Oriented zeolite crystal, 70; Heterogeneous liquid for crystal growth.

Claims (9)

An aqueous solution before heating and holding, containing a zeolite raw material containing water and a SiO ₂ component, and a zeolite structure-defining component, wherein the SiO ₂ component is 0.5 to 5.5 parts by mass with respect to 100 parts by mass of the water. An oriented zeolite crystal production liquid obtained by heating and maintaining at a temperature of 190 ° C. for 15 to 150 hours.   The oriented zeolite crystal production liquid according to claim 1, wherein a precipitate is formed after the heating and holding, and the liquid is a liquid portion obtained by separating the precipitate. Contains water and an SiO ₂ component-containing zeolite raw material and a zeolite structure-defining component, and the SiO ₂ component is heated and held before heating and holding in an amount of 0.5 to 5.5 parts by mass with respect to 100 parts by mass of the water. An oriented zeolite crystal production liquid characterized in that precipitates are formed. The oriented zeolite crystal production liquid according to any one of claims 1 to 3 , wherein the zeolite structure-defining component is tetrapropylammonium ion. Said zeolite raw material containing Na component, the Na component in the aqueous solution prior to the heating and holding, of claims 1 to 4, with respect to 100 parts by mass of water contained 0.2 to 2 parts by terms of NaOH The oriented zeolite crystal production liquid according to any one of the above. The zeolite raw material contains an Al component, said Al component in the aqueous solution before the heating holding, in any one of claims 1 to 5 Si / Al is contained to be 5 or more in a molar ratio in terms The orientation zeolite crystal production liquid described. The oriented zeolite crystal production liquid according to any one of claims 1 to 6 is maintained at a temperature of 110 to 220 ° C, a substrate is immersed in the oriented zeolite crystal production liquid, and the surface of the substrate is immersed in the oriented zeolite crystal production liquid. A method for producing oriented zeolite crystals, comprising a step of depositing oriented zeolite crystals having straight channels oriented in a vertical direction. It contains water, a zeolite raw material containing an SiO ₂ component, an Al component and an Na component, and a zeolite structure-defining component, and the blending amount of the SiO ₂ component is 0.05 to 5 parts by mass with respect to 100 parts by mass of water. An orientation in which a substrate is immersed in an oriented zeolite crystal production liquid having a temperature of 120 ° C. or more and less than 150 ° C., and arranged in a single layer in which straight channels are oriented in a direction perpendicular to the surface of the substrate. A method for producing an oriented zeolite crystal, comprising the step of precipitating a crystalline zeolite crystal. A separation liquid comprising a liquid portion obtained by separating the precipitate from the oriented zeolite crystal production liquid according to claim 3 .