JP3510742B2 - Faujasite type zeolite and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a faujasite-type zeolite and a method for producing the same, and more particularly to a plate-like body having a very small zeolite particle size and most zeolites having an aspect ratio of 2 or more. High crystallinity and silica / alumina ratio (Cayvan ratio)
High faujasite type zeolite and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Faujasite-type zeolite is widely used for catalysts and adsorbents for cracking reactions, hydrocracking reactions, and other hydrocarbon conversion reactions. In particular, it has a silica / alumina molar ratio (hereinafter referred to as “Cayvan ratio”). The faujasite-type zeolite having a value of 4.5 or more is excellent in heat resistance and acid resistance, and thus is suitable as a cracking catalyst or a hydrocracking catalyst. The acid resistance, hydrothermal resistance, heat resistance, etc. of faujasite-type zeolite are determined by the Cavan ratio (SiO ₂ /
It is known that these properties are more excellent as the Cayvan ratio is higher, depending on Al ₂ O ₃ molar ratio). Also,
It is known that, depending on the type of the reaction substance, the larger the external specific surface area of the zeolite, the higher the reaction activity is. Therefore, a high-Cayban ratio faujasite type zeolite having a large external specific surface area with a small particle size is desired. There is.

On the other hand, in the production of faujasite-type zeolite, a method of using seeds has been conventionally used for facilitating the crystallization of zeolite, for example, Japanese Patent Laid-Open No. 52-94899. , (A) 12-19Na
₂ O: 1 to 10 Al ₂ O ₃ : 12 to 19 SiO ₂ : 220 to
A slurry of nucleation centers having a molar composition in the range of 900 H ₂ O is prepared, and
_{Na 2 O: Al 2 O 3} : 4~7SiO 2: 40~200H 2
Mixing with a zeolite synthesis mixture having a molar composition in the range O, (c) heating the resulting mixture at a temperature and for a time sufficient to ensure crystallization, and (d) washing the product. A method for producing a faujasite-type zeolite is described, which comprises drying and drying. However, with this method, it was difficult to obtain a faujasite-type zeolite having a high crystallinity, a small particle size, and a large external specific surface area.

As a faujasite-type zeolite having a small particle size, for example, Japanese Unexamined Patent Publication No. 2-116614 discloses a submicron Y-type zeolite and a method for producing the same, but there is no description about the shape of the zeolite. .

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a faujasite-type zeolite having a high crystallinity, a small particle size, a specific particle shape, and a large external specific surface area and a high Caban ratio. To do. Another object of the present invention is to provide a method for producing the aforementioned faujasite-type zeolite by using a specific SiO ₂ —Al ₂ O ₃ composite oxide sol as a raw material and using a specific seed. .

[0006]

The first aspect of the present invention relates to a faujasite-type zeolite which is a plate-like body having an average particle diameter of 0.5 μm or less and an aspect ratio of 2 or more. A second aspect of the present invention is that (a) fine particles of dispersoid are M ₂ O / Al ₂ O ₃ = 0.8 to 3.0 SiO ₂ / Al ₂ O ₃ = 5 to 16 in terms of oxide molar composition ratio (here in, M is an aqueous SiO ₂ -Al ₂ O ₃ composite oxide sol in the range of an alkali metal), (b) M ₂ in oxide molar ratio _{O / Al 2 O 3 = 17} ± 3 SiO 2 / Al ₂ O ₃ = 17 ± 3 H ₂ O / Al ₂ O ₃ = 200 to 3,000 (where M represents an alkali metal), and a transparent aqueous solution containing no gel-like material, ( c) When the alkali metal oxide is insufficient such that the molar ratio of the alkali metal oxide (M ₂ O / Al ₂ O ₃ ) to the total Al ₂ O ₃ is in the range of 2.3 to 3.3. Add an insufficient alkali source and mix, and (d) heat-age the resulting mixture at a temperature at which crystallization occurs for a time sufficient for crystallization, The present invention relates to a method for producing a faujasite-type zeolite.

The faujasite-type zeolite according to the present invention has a very small particle size, and its average particle size is 0.
It is 5 μm or less, usually 0.05 to 0.5 μm, preferably 0.05 to 0.45 μm, and has a feature of high crystallinity. Zeolites having an average particle size larger than 0.5 μm are not preferable because the external specific surface area becomes small. The average particle diameter in the present invention is determined by measuring at least 100 diameters (longest diameter) from electron micrographs of zeolite particles. The shape of the faujasite-type zeolite is usually a cubic shape,
The faujasite-type zeolite of the present invention is a plate-like body having an aspect ratio of 2 or more. The central shape among them is more like a hexagonal plate. It is presumed that such a shape is a shape in the middle of growing into a cube. In the present invention, 50% or more, preferably 60% or more, more preferably 8% or more of the zeolite having a hexagonal plate-like shape among all faujasite-type zeolites is used.
It is preferably 0% or more.

Further, the plate-like shape in the present invention has a plate-like diameter /
It is desirable that the plate-like thickness ratio (aspect ratio) is 2 or more, preferably in the range of 3 to 500.

Aqueous SiO ₂ --Al ₂ O used in the present invention
_{In the 3} composite oxide sol, the dispersoid fine particles have an oxide molar composition ratio of M ₂ O / Al ₂ O ₃ = 0.8 to 4.0, preferably 1.0 to 2.0 SiO ₂ / Al ₂ O _3. = 5-16, preferably in the range of 8-11 (where M represents an alkali metal), and the dispersoid concentration is 1-50 wt%, preferably 10-30 wt.
It is desirable to be in the range of%. SiO ₂ -Al ₂ O in which the oxide molar composition ratio of the dispersoid particles is out of the above range
_{3 With a} complex oxide sol, the desired zeolite may not be obtained.

The aqueous SiO ₂ —Al ₂ O ₃ composite oxide sol of the present invention is a sol in which fine particles containing silica and alumina are dispersed in water, and the dispersoid concentration is adjusted to 20 wt%. Rotation speed of the product sol by centrifuge 3
A solid content of 0.5 vol% or less when precipitated at 500 rpm for 10 minutes.

Such a SiO ₂ -Al ₂ O ₃ composite oxide sol is produced by the method described in, for example, Japanese Patent Application Laid-Open No. 5-132309. That is, an alkali metal, ammonium or organic base silicate and an alkali-soluble alumina compound are simultaneously added to an alkaline aqueous solution having a pH of 10 or more at respective predetermined ratios, and the p
By generating colloidal particles without controlling H, SiO ₂ −
An Al ₂ O ₃ composite oxide sol can be prepared.

The fine particles as the dispersoid of the SiO ₂ —Al ₂ O ₃ composite oxide sol used in the present invention preferably have an average particle diameter in the range of 5 to 200 nm. When the average particle diameter of the fine particles is smaller than 5 nm, the stability of the composite oxide sol may be poor, and when it is larger than 200 nm, the desired zeolite may not be obtained. The preferable average particle size of the fine particles is 10 to 100.
It is in the range of nm.

The transparent aqueous solution (hereinafter sometimes referred to as seed) containing no gel-like material used in the present invention has an oxide molar composition ratio of M ₂ O / Al ₂ O ₃ = 17 ± 3, preferably 16 ± 3. 2 SiO ₂ / Al ₂ O ₃ = 17 ± 3, preferably 17 ± 2 H ₂ O / Al ₂ O ₃ = 200 to 3,000, preferably 200 to 2,000, particularly preferably 300 to 1,000 (wherein M represents an alkali metal), a liquid reaction mixture of a silica source, an alumina source and an alkali source in a range of preferably 10 to 60 ° C., more preferably 20 to 40 ° C., preferably 1 It is a transparent aqueous solution prepared by aging for at least 2 hours, more preferably for 2 to 48 hours, preferably without stirring.

It is important that the transparent aqueous solution is a transparent aqueous solution having an oxide molar composition in the above range and comprising a gelling material-free low polymer of aluminosilicate. If the oxide molar composition of the seed is outside the above range, or if it is an aqueous solution containing a gelled substance and having poor transparency even within the above range, the desired effect of the present invention is obtained. I can't.

In the present invention, a transparent aqueous solution containing no gel is defined as a solid content of 0.1 vol% or less when the aqueous solution is treated with a centrifuge at a rotation speed of 3500 rpm for 10 minutes. Then, the solution has a light transmittance of 80% or more at a wavelength of 500 nm. Here, the light transmittance means the relative value of the transmittance of light having the same wavelength as the wavelength of the aqueous solution when the transmittance at a wavelength of 500 nm in water having a thickness of 1 cm is 100%.

In the present invention, the above-mentioned SiO ₂ -Al ₂ O ₃ composite oxide sol is mixed with the above-mentioned transparent aqueous solution which does not contain a gelled substance, and further, an alkali metal oxide for all Al ₂ O ₃ is mixed. (M ₂ O / Al ₂ O ₃ ) molar ratio is 2.3-
When the alkali metal oxide is insufficient so as to be in the range of 3.3, the insufficient alkali source is added and mixed, and the obtained mixture is heated at a temperature at which crystallization occurs for a time sufficient for crystallization. Mature. Examples of the alkali source include sodium hydroxide, sodium aluminate, potassium hydroxide and the like. The above-mentioned SiO ₂ -Al ₂ O ₃ composite oxide sol and the above-mentioned transparent aqueous solution containing no gel-like substance are mixed to obtain an alkali metal oxide (M ₂ O / Al ₂ O) for all Al ₂ O ₃ .
_When the molar ratio of ₃ ) is within the range of 2.3 to 3.3, it is not necessary to add the alkali source.

In the above mixture, the molar ratio of alkali metal oxide (M ₂ O / Al ₂ O ₃ ) to total Al ₂ O ₃ is 2.3.
When it is out of the range of from 3.3 to 3.3, zeolite such as p-type zeolite and gmelinite may be by-produced, which is not preferable.

The mixing ratio of the clear aqueous solution which does not contain the above-mentioned gel-like material and the composite oxide sol described above Al ₂ in Al ₂ O ₃ composite oxide sol in a clear aqueous solution containing no gel-like material The molar ratio with O ₃ is preferably in the range of 0.005 / 1 to 0.3 / 1. If this ratio is less than 0.005 / 1, it takes a long time to crystallize the zeolite,
If it exceeds 0.3 / 1, crystallization can be accomplished in a short time, but a large amount of silica-alumina source of zeolite is used, which is not economical.

In the present invention, a reaction mixture obtained by mixing the above-mentioned SiO ₂ -Al ₂ O ₃ composite oxide sol with the above-mentioned transparent aqueous solution containing no gel and an alkali source are well known. The method is heat-aged at a temperature at which crystallization occurs in the method and for a time sufficient for crystallization. Generally, it is heat-aged at a temperature of 80 ° C. or higher, preferably 95 to 98 ° C. for 1 to 200 hours with intermittent stirring. In the present invention, the molar composition ratio of oxide in the above-mentioned reaction mixture is preferably in the following range. M ₂ O / Al ₂ O ₃ = 2.3 to 3.3, preferably
_{2.5~3.0 SiO 2 / Al 2 O 3} = 5~17, preferably, 8-1
2 H ₂ O / Al ₂ O ₃ = 80 to 500, preferably 10
0-300

The zeolite crystallized by heating and aging is recovered by separating the filtrate by a well-known method, washing and drying.

The faujasite-type zeolite obtained by the method of the present invention is a plate-like body having an average particle size of 0.5 μm or less and an aspect ratio of 2 or more, high crystallinity and high specific surface area, Since the ratio is in the range of 4.5 to 6.5, it can be suitably used for applications such as adsorbents, catalysts or catalyst carriers.

[0022]

The present invention will be described in detail below with reference to examples.
The present invention is not limited to this.

Example 1 (Preparation of transparent aqueous solution containing no gel) Na ₂ O
While stirring, a solution of 46.36 g of sodium aluminate solution containing 17% by weight and 22% by weight of Al ₂ O ₃ was added.
1882.4 g of 88 wt% sodium hydroxide aqueous solution was added. While stirring this solution, the silica concentration is 24 wt%
No. 3 water glass (4450 g). At this time, no gel-like material was observed, and the composition was Na ₂ O / Al ₂ O ₃ = 15.9 SiO ₂ / Al ₂ O ₃ = 17.8 H ₂ O / Al ₂ O in terms of oxide molar ratio. ₃ = 330. This was stirred for about 1 hour and then left standing at 30 ° C. for 12 hours to obtain a transparent aqueous solution containing no gel. The amount of solids precipitated when this solution was treated with a centrifuge at 3500 rpm for 10 minutes (hereinafter referred to as the amount of precipitation)
Is 0.05 vol% or less, and the wavelength of the aqueous solution is 500 nm.
The transmittance was 85.3%. This transmittance is measured with a spectrophotometer U-200 (manufactured by Hitachi Ltd.).

(Preparation of complex oxide sol) Average particle size 50
Å, 350 g of silica sol having a silica concentration of 20 wt% was diluted with 6650 g of pure water and heated to 80 ° C. To this diluted sol, 1.5 wt% of demineralized silicic acid solution as SiO ₂ 35
000 g and 35000 g of 0.3 wt% sodium aluminate aqueous solution as Al ₂ O ₃ were added at the same time. The addition rate of each was 97 g / min, during which the temperature of the diluted sol was maintained at 80 ° C. After the addition was completed, the sol was cooled to room temperature and subjected to ultrafiltration and heating to concentrate SiO ₂ · Al ₂
2738 g of O ₃ composite oxide sol was obtained.

The following composition was obtained as a result of measuring the dispersoid fine particles of this composite oxide sol based on the chemical analysis method. The water content was calculated from the loss on ignition at 1000 ° C. for 1 hour. SiO ₂ 18.18 wt% (SiO ₂ / Al ₂
O ₃ molar ratio = 8.4) Al ₂ O ₃ 3.66 wt% Na ₂ O 2.76 wt% (Na ₂ O / Al ₂
O ₃ molar ratio = 1.2) H ₂ O 75.40 wt%

(Preparation of Reaction Mixture) Said SiO ₂ .Al ₂
While stirring 2738 g of the O ₃ composite oxide sol, 228.2 g of a 48 wt% sodium hydroxide aqueous solution was added to the sol.
Was gradually added and thoroughly mixed with stirring. While stirring, the above-mentioned “clear aqueous solution containing no gel” 14
2.9 g was added and mixed with stirring for 3 hours at room temperature. The composition of the gel-like reaction mixture thus obtained had an oxide molar ratio of Na ₂ O / Al ₂ O ₃ = 2.87 SiO ₂ / Al ₂ O ₃ = 8.61 H ₂ O / Al ₂ O ₃ = 129.

This gel-like reaction mixture was transferred to a crystallization tank and aged for crystallization for 96 hours at 95 to 98 ° C. without stirring for crystallization. After completion of aging, the crystal product was taken out, filtered, washed and dried to obtain faujasite type zeolite (A).

This zeolite (A) was crystallized by X-ray diffraction, lattice constant, composition by chemical analysis, BET.
The specific surface area by the method, the shape by the electron microscope and the average particle diameter were determined. The results are shown in Table 1. An electron micrograph of the zeolite (A) is shown in FIG.

Example 2 (Preparation of composite oxide sol) 350 g of silica sol having an average particle size of 50 Å and a silica concentration of 20 wt% was diluted with 6650 g of pure water and heated to 80 ° C. SiO in this diluted sol
0.3 wt% of a sodium aluminate aqueous solution 35000g were simultaneously added as 2.0 wt% of the dilution water glass solution 35000g and for Al ₂ O _{3 2.} The addition rate of each was 97 g / min, during which the temperature of the diluted sol was maintained at 80 ° C. After completion of the addition, the sol was cooled to room temperature, and subjected to an ultrafiltration and heat concentration to obtain 3397 g of a SiO ₂ · Al ₂ O ₃ composite oxide sol.

The composition of this composite oxide sol was as follows as a result of measurement based on a chemical analysis method. SiO ₂ 18.02 wt% (SiO ₂ / Al ₂ O ₃
Molar ratio = 10.4) Al ₂ O ₃ 2.95 wt% Na ₂ O 2.56 wt% (Na ₂ O / Al ₂ O ₃
Molar ratio = 1.4) H ₂ O 76.47 wt%

(Preparation of Reaction Mixture) Said SiO ₂ .Al ₂
While stirring 3397 g of O ₃ composite oxide sol, 48w
250 g of t% sodium hydroxide aqueous solution and Na ₂ O 17
A mixed solution of 116.8 g of a sodium aluminate solution containing wt% and Al ₂ O _{3 of} 22 wt% was gradually added and sufficiently mixed with stirring. To this, 142.9 g of "a transparent aqueous solution containing no gel-like substance" of Example 1 was added with stirring, and the mixture was stirred and mixed at room temperature for 3 hours. The composition of the gel-like reaction mixture thus obtained had an oxide molar ratio of Na ₂ O / Al ₂ O ₃ = 2.79 SiO ₂ / Al ₂ O ₃ = 8.39 H ₂ O / Al ₂ O ₃ = 130.

This gel-like reaction mixture was transferred to a crystallization tank and aged by heating at 95 to 98 ° C. for 96 hours for crystallization. After aging, the crystal product is taken out, filtered, washed,
It was dried to obtain faujasite-type zeolite (B).
Table 1 shows the properties of this zeolite (B).

Comparative Example 1 (Preparation of liquid containing gel-like material) Na ₂ O 17 wt%,
To 463.6 g of a sodium aluminate solution containing 22 wt% of Al ₂ O ₃ was added 3771.2 g of a 21.35 wt% aqueous sodium hydroxide solution while stirring. This solution was added to 3675 g of No. 3 water glass having a silica concentration of 24 wt% while stirring to generate a gel. The composition of the liquid containing this gel was Na ₂ O / Al ₂ O ₃ = 15.9 SiO ₂ / Al ₂ O ₃ = 14.7 H ₂ O / Al ₂ O ₃ = 330 in terms of oxide molar ratio. there were. Further, this was stirred for about 1 hour and then left to stand at 30 ° C. for 12 hours to obtain a liquid containing a gel. In addition, when the liquid containing this gel-like material was treated with a centrifuge at 3500 rpm for 10 minutes, the amount of precipitated solid content (hereinafter referred to as the amount of precipitation) was 50.5 vol% and the wavelength of the liquid was 5
The transmittance at 00 nm was 0.01% or less and it was opaque.

(Preparation of gel-like reaction product) 3 as SiO ₂
809.3 g of silica sol containing 0 wt% was added to pure water 29
The mixture was diluted with 5.9 g, and 1023.4 g of No. 3 water glass having a silica concentration of 24 wt% was mixed. Then, to this liquid, with stirring, Na ₂ O 17 wt%, Al ₂ O ₃ 2
455.5 g of sodium aluminate solution containing 2 wt%
Was added to obtain a gel reaction product having the following oxide composition. SiO ₂ 18.90 wt% (SiO ₂ / Al ₂ O ₃ molar ratio = 8.29) Al ₂ O ₃ 3.88 wt% Na ₂ O 6.04 wt% (Na ₂ O / Al ₂ O ₃ molar ratio = 2. 56) H ₂ O 71.18 wt%

(Preparation of Reaction Mixture) A solution 13 containing the above-mentioned gel-like material while stirring the above-mentioned gel-like reaction material.
9.5 g was added and mixed with stirring for 3 hours at room temperature. The composition of the gel-like reaction mixture thus obtained had an oxide molar ratio of Na ₂ O / Al ₂ O ₃ = 2.8 SiO ₂ / Al ₂ O ₃ = 8.4 H ₂ O / Al ₂ O ₃ = 108.

This was transferred to a crystallization tank and heated at 95-98 ° C. for 5 hours.
It was heated and aged for 0 hours. After completion of the aging, the crystal product was taken out, filtered, washed and dried to obtain faujasite-type zeolite (C). Table 1 shows the properties of this zeolite (C). An electron micrograph of the zeolite (C) is shown in FIG.

Comparative Example 2 (Preparation of gel-like reaction product) 1023.4 g of No. 3 water glass having a silica concentration of 24 wt% was diluted by adding 622.6 g of pure water, and further solid silica 47 of 50 wt% as SiO ₂ was added.
9.2 g was added and thoroughly mixed with stirring. While stirring, 455.5 g of a sodium aluminate solution containing 17 wt% of Na ₂ O and 22 wt% of Al ₂ O ₃ was added to this solution to obtain a gel reaction product having the following oxide composition. SiO ₂ 18.80 wt% (SiO ₂ / Al ₂ O ₃ molar ratio = 8.23) Al ₂ O ₃ 3.88 wt% Na ₂ O 6.05 wt% (Na ₂ O / Al ₂ O ₃ molar ratio = 2. 57) H ₂ O 71.26 wt%

(Preparation of Reaction Mixture) To the gel reaction product, 142.9 g of a transparent aqueous solution containing no gel product prepared in Example 1 was added, and the mixture was stirred and mixed at room temperature for 3 hours.
A gel-like reaction mixture having the following oxide molar composition was obtained. Na ₂ O / Al ₂ O ₃ = 2.8 SiO ₂ / Al ₂ O ₃ = 8.4 H ₂ O / Al ₂ O ₃ = 108

The gel-like reaction mixture was transferred to a crystallization tank and aged by heating at 95 to 98 ° C. for 50 hours. After completion of the aging, the crystal product was taken out, filtered, washed and dried to obtain faujasite-type zeolite (D). Table 1 shows the properties of this zeolite (D).

[0040]

[Table 1] ^{* 1} : Crystallinity is the total peak height (H) of (331), (511), (440), (533), (642) and (555) planes of X-ray diffraction, and is commercially available as a standard. The total peak height (H ₀ ) of the Y-type zeolite (SK-40 manufactured by Union Carbide) on the same plane was calculated with the crystallinity being 100, and was calculated by the following formula. Crystallinity = H / H ₀ × 100 (%) ^{* 2} : The average particle diameter was measured from an electron microscope photograph.

The embodiments of the present invention will be listed below. (1) The average particle size is 0.5 μm or less, and the aspect ratio is 2
Faujasite-type zeolite, which is the above plate-like body. (2) The faujasite-type zeolite according to item 1 above, which has a Cavan ratio of 4.5 to 6.5. (3) (a) Fine particles of dispersoid are M ₂ O / Al ₂ O ₃ = 0.8 to 3.0 SiO ₂ / Al ₂ O ₃ = 5 to 16 in terms of oxide molar composition ratio (where M is Aqueous SiO ₂ -Al ₂ O ₃ composite oxide sol in the range of (indicating alkali metal) and (b) oxide molar composition ratio of M ₂ O / Al ₂ O ₃ = 17 ± 3 SiO ₂ / Al ₂ O ₃ = 17 ± 3 H ₂ O / Al ₂ O ₃ = 200 to 3,000 (where M represents an alkali metal), a transparent aqueous solution containing no gel, and (c) total Al as the molar ratio of alkali metal oxide to _{2 O 3 (M 2 O /} Al 2 O 3) is in the range of 2.3 to 3.3, the alkali source insufficient when the alkali metal oxides is insufficient Is added and mixed, and (d) the resulting mixture is heat-aged at a temperature at which crystallization occurs and for a time sufficient for crystallization. And a method for producing a faujasite-type zeolite. (4) the mixing ratio of the clear aqueous solution not containing the SiO ₂ -Al ₂ O ₃ composite oxide sol and gel-like material is SiO ₂ -
The molar ratio of Al ₂ O ₃ Al ₂ O ₃ composite oxide transparent aqueous solution and Al ₂ O ₃ in the sol is 1: 0.005: 0.3
The method for producing a faujasite-type zeolite according to the above (3), which is in the range of 1. (5) The method for producing a faujasite-type zeolite according to the above (3) or (4), wherein the mixture is aged at a temperature of 80 to 98 ° C. with intermittent stirring for a time sufficient for crystallization. (6) The fine particles of the dispersoid of the complex oxide sol have an oxide molar composition ratio of M ₂ O / Al ₂ O ₃ = 1.0 to 2.0 SiO ₂ / Al ₂ O ₃ = 8 to 11 (where , M is an alkali metal). The method for producing a faujasite-type zeolite according to the above (3), (4) or (5). (7) The oxide molar composition ratio of the transparent aqueous solution containing no gel is M ₂ O / Al ₂ O ₃ = 16 ± 2 SiO ₂ / Al ₂ O ₃ = 17 ± 2 H ₂ O / Al ₂ O _The method for producing a faujasite-type zeolite according to the above item (3), (4), (5) or (6), wherein ₃ = 200 to 2,000 (where M represents an alkali metal). (8) The transparent aqueous solution containing no gelled substance is a liquid reaction mixture obtained by mixing a silica source, an alumina source and an alkali source in a predetermined oxide molar composition ratio at 10 to 60 ° C. The method for producing the faujasite-type zeolite according to the above (3), (4), (5), (6) or (7), which is obtained by aging at least 1 hour at the temperature. (9) The method for producing a faujasite-type zeolite according to the above item (8), wherein the aging is carried out under conditions without stirring. (10) An adsorbent containing the faujasite-type zeolite as described in (1) or (2) above as a main component. (11) A catalyst or catalyst carrier containing the faujasite-type zeolite according to the above item (1) or (2) as a main component.

[0042]

[Effect] As shown in Table 1 and FIG. 1, the faujasite-type zeolite of the present invention has a high degree of crystallinity, a hexagonal plate-like shape and a small average particle size, and therefore has a large external specific surface area. It is suitable for use as a catalyst or adsorbent.

[Brief description of drawings]

FIG. 1 is an electron micrograph showing the structure of a ceramic material composed of the faujasite-type zeolite of the present invention obtained in Example 1.

FIG. 2 is an electron micrograph showing a structure of a ceramic material made of faujasite-type zeolite obtained in Comparative Example 1.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Takeuchi 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture Inside the Wakamatsu Plant of Catalytic Chemicals Co., Ltd. (56) Reference JP-A-59-184726 (JP, A) JP-A-52-94899 (JP, A) JP-A-62-138319 (JP, A) JP-A-62-105918 (JP, A) JP-A-7-42071 (JP, A) JP-A-2-116614 (JP, A) JP 59-227715 (JP, A) JP 6-219728 (JP, A) JP 5-329375 (JP, A) JP 49-13720 (JP, B1) (JP 58) Fields investigated (Int.Cl. ⁷ , DB name) C01B 39/00 JSTPlus (JOIS)

Claims (3)

(57) [Claims] 1. A faujasite-type zeolite which is a plate-like body having an average particle diameter of 0.5 μm or less and an aspect ratio of 2 or more. 2. (a) The fine particles of the dispersoid are M ₂ O / Al ₂ O ₃ = 0.8 to 3.0 SiO ₂ / Al ₂ O ₃ = 5 to 16 in terms of oxide molar composition ratio (wherein M is an alkali metal) and an aqueous SiO ₂ -Al ₂ O ₃ composite oxide sol in the range of (b) oxide molar composition ratio of M ₂ O / Al ₂ O ₃ = 17 ± 3 SiO ₂ / Al ₂ O ₃ = 17 ± 3 H ₂ O / Al ₂ O ₃ = 200 to 3,000 (where M represents an alkali metal), a transparent aqueous solution containing no gel, (c) Alkali metal oxides for all Al ₂ O ₃ (M ₂ O
/ Al ₂ O ₃ ) molar ratio is in the range of 2.3 to 3.3, when the alkali metal oxide is insufficient, an insufficient alkali source is added and mixed, and (d) the resulting mixture A method for producing a faujasite-type zeolite, which comprises heat-aging at a temperature at which crystallization occurs for a time sufficient for crystallization. 3. The mixing ratio of the SiO ₂ —Al ₂ O ₃ composite oxide sol and the transparent aqueous solution containing no gel is S.
The molar ratio of Al ₂ O _{3 in the} iO ₂ —Al ₂ O ₃ composite oxide sol to Al ₂ O ₃ in the transparent aqueous solution is 1: 0.005
The method for producing a faujasite-type zeolite according to claim 2, wherein the range is 1: 0.3.