JPS59213616A - Amorphous aluminosilicate and its manufacture - Google Patents

Abstract

PURPOSE:To obtain the amorphous aluminosilicate preserving a granular state of the original zeolite by treating an aq. slurry of zeolite with acid or an acidic salt under specified conditions. CONSTITUTION:The objective amorphous aluminosilicate is obtained by reacting an aq. slurry of zeolite with acid or an acidic salt or acid and an acidic salt by keeping at >=4 pH. The zeolite to be used is a substance of which structure of zeolite is decomposed in the acidic treatment. In many cases, the zeolite having <=about 5mol ratio of SiO2/Al2O3 is applied. As the starting material for manufacturing the amorphous aluminosilicate, for example, a type zeolite, X type zeolite, P type zeolite, sodalite, and analcime are especially suitable. In addition, metal-substituted zeolite obtained by substituting a part or a greater part of an Na2O constituent in said zeolites with a cation other than Na<+> by an ion exchange reaction can also be used.

Description

[Detailed description of the invention] Regarding the law.

Conventionally, amorphous aluminosilicate can be used as a filler for synthetic resins and rubber, as a viscosity modifier for paints, and as a pigment for coating paper, similar to fine powder silicic acid (White Carb/) and basic magnesium carbonate. It is mainly produced by reacting an aqueous solution of an alkali with an aqueous solution of an aluminum compound such as aluminum sulfate or sodium aluminate to form a precipitate.

However, externally, the amorphous aluminosilicates obtained by such conventional methods generally have θ, 0/ to θ, os J
It was an extremely bulky powder consisting of agglomerated secondary particles of irregular shape, and its particle size distribution was quite inhomogeneous.

Therefore, its application has been limited to fields characterized by bulky powder made of ultrafine particles.

The present inventors conducted various experiments and tests in order to develop 11 amorphous aluminosilicates with various characteristics not found in conventional amorphous aluminosilicates. As a result, they discovered the surprising fact that by treating certain types of zeolite with acid under appropriate conditions, amorphous aluminosilicate containing substantially the particle state of the original zeolite can be obtained. The present invention was completed by applying the following.

That is, the gist of the present invention is an acid-treated product of zeolite, which has an average particle size of θ, 1 to /011 m, and has a particle size of ////2 of the average particle size. It is an amorphous aluminosilicate characterized by having a uniform particle size distribution such that the particle size portion within the range of 50 cm or more is the total particle size.

Generally, zeolites have the general formula (/, 0±θ, 2) M20
*AJ20. -xsio2'l yH20 (where M is Na or an equivalent monovalent or polyvalent metal, It is an aluminosilicate with a unique crystal structure that can be identified by line diffraction and is known in a variety of forms, including natural minerals and synthetics (usually M is Na).

In addition, zeolites are generally known to have a unique crystal structure (having a unique particle shape and size, as well as unique adsorption performance and ion exchange performance), and a variety of applications that take advantage of these characteristics have been proposed. It's dark.

However, the amorphous aluminosilicate according to the present invention is an acid-treated product that substantially has the skeleton of the basic particle form of the above-mentioned zeolite, and is significantly different from zeolite in terms of physical and chemical performance. It has characteristics.

Therefore, the amorphous aluminosilicate of the present invention will be described in detail below along with its manufacturing method.

According to the study results of the present inventors, A-type zeolite (Na2O・A2,0.・, :l 5in2
1Ita, 5Ho) and X-type zeolite (Na, , O, A
l2O,・ko,! Zeolite types with relatively small component molar ratios (sto2/Az2o,) such as rSiO・Otsu, /HO) become clearly amorphous from an X-ray perspective by being appropriately treated with acid. Nevertheless, it was found that the shape and size of the secondary particles were hardly changed by the acid treatment, and the particle state before the acid treatment was maintained almost unchanged.

The present invention is based on the application of such facts,
When zeolite is treated with acid, some of the cations in the zeolite are eluted and the regularity of the atomic arrangement as a zeolite crystal is completely lost, resulting in an amorphous state. However, the basic particle state of the original zemerite remains Therefore, the properties of this amorphous aluminosilicate are highly dependent on the type and particle state of the original zeolite, and during production, it is first necessary to ensure that the zeolite used as the raw material is suitable. .

That is, the zeolite used as a raw material in the method of the present invention is of a type having a relatively small component molar ratio (S102/8220.), such as A-type zeolite and It is necessary to have uniform fineness.

That is, the zeolite that is the subject of the present invention is one whose zeolite structure decomposes when treated with an acid, and in the case of zeolite, a zeolite whose SiO2/AJ20. (molar ratio) is about S or less is applied.

In this case, the uniform fine particle state of zeolite means that the average particle size is 0. / to 704 m, and the average particle size is /
It means having a particle size distribution such that the particle size portion in the range of //2 to ///- of the average particle size exceeds 50% of the total.

From this point of view, various types of zeolite suitable as raw materials for producing the amorphous aluminosilicate of the present invention are pointed out as long as they have the above-mentioned physical properties. For example, type A zeolite , X-type zeolite, P-type zeolite, sodalite, analcyme, etc. are particularly suitable, and one or more of these can be used.

Further, uniform fine zeolite particles having the above-mentioned particle size can be prepared by various methods. Synthetic zeolites such as A-type zeolite and Xm zeolite obtained by methods such as No. 37/3 and JP-A-57-ItA3// are particularly suitable.

Furthermore, it is also possible to use metal-substituted zeolites in which a part or most of the Na2O component in these zeolites is replaced with cations other than Na+ through an ion exchange reaction.

In this case, the type of cation other than Na+ is H”
, heptavalent cations such as Li++ K+, Mg”+Ca
” + Sr ” r B a” r Zrr ”
Various types of cations such as covalent cations such as r Cd 2++ Pb 2+ can be used, and the various performances of the zeolite particles can be adjusted depending on the type of cations and the degree of M exchange.

Although various methods are possible for acid-treating such zeolite, it can usually be carried out as follows.

Stir and gradually add the acid or acidic solution to this, making sure that the p[() of the suspension is always maintained at 9 or higher, and the final value is lower than the pI+ value. After adjusting the amount added so that it does not become too low, solid-liquid separation and washing are performed, and steps such as drying and pulverization are added as necessary.

Examples of acidic substances used here include mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, and sulfurous acid; organic acids such as formic acid, acetic acid, oxalic acid, and citric acid; and sodium bisulfate, etc. Examples include various acid salts such as acidic sodium phosphate, but are not limited thereto.

When an acid is gradually added to an aqueous suspension of zeolite, the relationship between the amount of acid added and the pH of the suspension is often like the curve in Figure 1, and as the acid is added, 1TSH decreases rapidly at the beginning, then shows a plateau near pHll, and then shows a sharp decrease again near pHj.

If an acid or an acidic substance is used in such an amount that the final pH of the suspension is less than 9, the skeleton of the raw zeolite particles will be significantly destroyed, resulting in a significant change in the shape and size distribution of the particles, or the entire particle may be destroyed. The use of excess fungi must be avoided, as it may dissolve or disappear, making it completely inappropriate.However, even when using less Ett O) (il or acidic substances, their rapid addition should be avoided for a short period of time or This should be avoided since it may result in locally lowering the pH of the suspension below 100 g, which may change the shape and size distribution of the particles.

In this case, the degree of amorphization is governed by the amount of acid or acidic substance added, and in the case of poly(), the final pH of the suspension
It becomes completely amorphous when the added amount makes the O value about 5.5.

Generally, the degree of amorphization is evaluated by the presence or absence and strength of diffraction lines in an X-ray diffraction diagram. The height of the diffraction line is //'2 of the original zeolite
It is considered to be virtually amorphous, including those with a drop below.

In the present invention, the particle size and distribution of the amorphous aluminosilicate are measured and expressed by the Coulter counter method.

As part or most of the cations present in the zeolite are eluted with acid treatment of the zeolite, the chemical composition of the amorphous aluminosilicate according to the present invention is A-' 2 O.
Although the amount of cationic components such as Na and O is significantly lower than 1 mol per 1 mol of S component, it has some cation layering ability (ζ), so it is possible to adsorb various cations.

On the other hand, when zeolite is treated with acid, most of the water present in the zeolite remains as it is, but when heated above 1.330°C, most of it is irreversibly dehydrated and the original zeolite's water adsorption ability is almost completely reduced. It disappears. Therefore, it is possible to adjust the moisture content of the acid-treated +Ji product to various values by changing the drying and firing conditions.

The content of the amorphous aluminosilicate according to the present invention is as follows, but it also includes those subjected to modification treatment as necessary to further improve the quality characteristics of the amorphous aluminosilicate. .

Typical examples of such improvements include:
A continuous coating of dense and fine amorphous silica, or a deposit of fine white metal hydrated oxides, such as aluminum, titanium, zirconium, antimony, etc., or a surface active agent, or a dispersion. Examples include modifying the surface of particles such as agents.

Therefore, for example, when performing phosphor coating treatment, acid or acidic salts are added to an aqueous suspension of zeolite to perform the acid treatment, and then activated silica sol is gradually added at a temperature of Aθ°C or higher, or an alkali silicate solution is added. By gradually adding silica and acid to generate active silica, the particle surface can be covered with a dense amorphous silica film.

The amount of silica added or generated at this time is
In the case of 2 to 30% by weight, a sufficient coating effect can be obtained for amorphous aluminosilicate.

Regardless of the type of original zeolite used as a raw material, the surface of amorphous aluminosilicate particles coated with silica is extremely inert, making them more resistant to light, heat, chemicals, etc. It is solid.

Similarly, in the coating treatment of G metal hydrated oxide, a corresponding metal salt aqueous solution may be added to deposit the hydroxide produced by hydrolysis.

As is clear from the above description, the following are the main features of the amorphous aluminosilicate of the present invention.

(1) Consists of uniform particles with an average particle size of 0°/Olim, moderate bulk and oil absorption, and
Easily disperses into individual primary particles.

+21 The content of Na2O components and other cations is low, and the pH is close to neutral at 17.

(3) It has some cation exchange ability and can absorb any cation and absorb N.

(4) Unlike the original zeolite, it has almost no water adsorption properties, so the water content can be adjusted over a wide range depending on the purpose.

(5) It is itself non-toxic and does not harm the environment.

(6) The amorphous aluminosilicate of the present invention, which has such characteristics that the particle surface can be made significantly inert by undergoing a modification treatment, has the disadvantages of Na-zea 1 phyto. Since the harmful effects of certain alkalis are virtually negligible, they are not only suitable as additives for synthetic resins and rubber, extender pigments for paints and printing inks, and processing agents for paper, but also for other purposes. It is possible that various new uses other than zeolite will be developed, and it can be said to be an extremely interesting new material.For example, it is extremely effective as an anti-bronching agent for synthetic resin films.

Examples will be shown below, and evaluation of the results (+lIi) was performed using the following test method.

Oil absorption: JISK s/o/-7g, 79 particle size s: Measured using a Coulter Counter (manufactured by Cole Coo Electronics Co., Ltd.) with an aperture tube diameter of θ μm.

[Ca ion exchange capacity Calcium chloride solution (3o o rn as CaO; j
Add 1 g of zeolite sample (calculated as anhydride) to A/l, stir and react at -3°C, and after 75 minutes, quickly filter and separate the zeolite to remove calcium (Cab) in the solution.
The concentration of dissolved calcium is analyzed, and the decrease in dissolved calcium due to anti-f15 is calculated, and this is taken as the Ca ion exchange capacity.

[Composition analysis]

By atomic absorption spectrophotometry.

Example-/! Tofu a-A zeolite 509 in a 1oOcc beaker
7. Weigh and add water and 20θg. ．． ．． Slurry with zeolite concentration 2θ, 2! i0J was prepared. The pE of this slurry was 7.The slurry was stirred and 2sog of sulfuric acid was gradually added thereto over about S minutes, and stirred for 7 hours after the addition. After continuing (during this time, the pH of the slurry was always maintained at a higher level), the Na-
An acid-treated product of type A zeolite was obtained. An electron micrograph (SEi) of this acid-treated product is shown in Figure 2. When this acid-treated product was analyzed by X-ray diffraction (X, R, D, ), no diffraction patterns were observed, indicating that it was amorphous. It is clear that it is a quality aluminosilicate.The particle size distribution, average particle diameter, Ca ion exchange capacity, acid treatment conditions, composition, etc. of this processed product are shown in the table.
/ Shown in /.

The raw material Na-A zeolite can be obtained by reacting a silicic acid waste liquid and a sodium aluminate solution without back mixing to form a gel, and then heating and aging it (JP-A-Sho! i7-/ Otsu Otsu 3// issue). The particle size distribution, average particle diameter, Ca ion exchange capacity, composition, etc. of the obtained r* a -A type zeolite are also shown in Table 1. In addition, this Na-, A-type zeolite was analyzed by electron microscopy (SE).
M) First photo? As shown in the figure.

From these photographs and particle size distribution, it is clear that there is almost no change in the zeolite grains before and after acid treatment.

Example-7! Example-/The same Na-A zeolite as in Example-/ was used, except that 2% sulfuric acid was used instead of glutinous sulfuric acid.
Acid treatment was carried out in exactly the same manner as in 7. In the acid-treated product obtained, the X, R, D, and Na-A type zeolite diffraction peaks were analyzed to have decreased in intensity to approximately It is clear that there are many. The particle size of this acid-treated product is U, semi-average particle diameter, Ca
The ion exchange capacity and composition 41'J- are also shown in Table-/.

Further, an electron microscope (Sl=:M) photograph is shown in FIG.

Example-J The same Na-A zeolite as in Example-/ was used, and the acid treatment was carried out in the same manner as in Example-/, except that 70% phosphoric acid was used instead of 70% sulfuric acid. The obtained acid-treated product was analyzed by X, R, and D, and it was clear that it was a diffraction peak (no peak was observed, it was an amorphous aluminosilicate). Particle size distribution, semi-average particle diameter, Ca ion exchange capacity, composition, etc. are also shown in Table 7.

Example - Using the same Na-A zeolite as Example -/,
The acid treatment was carried out in exactly the same manner as in Example 1, except that the sulfurized tooth was separated by about 3θ and added. The acid-treated products obtained were No diffraction peaks of a, -A type zeolite are observed, and it is clear that it is an amorphous aluminosilicate.The particle size distribution, average particle diameter, Ca ion exchange capacity, composition, etc. of this acid-treated product were It is also shown in Table 1. In addition, the electron microscopy (SJΣM) photograph is shown in Table S.
As shown in the figure. Based on the composition in Table 1, examples in which acid addition was added slowly - Example 1 - Example 1 - Amorphous aluminosilicon salt resistant
It is characterized by a lower Na2O content compared to No. 3, and by adjusting the acid addition time, it is possible to control the Na2O content of the amorphous aluminosilicate produced to some extent.

Example-5 Na-X zeolite (average particle size λ, Sμ, and particle size range Ω from ↑/2 of the particle size to l− of the average particle size) The particle size part of the concave circle is more than % of the total SO example)
A slurry was prepared in the same manner as above. Then j % I
Hydrochloric acid was gradually added over 5 minutes so that the pH of the slurry did not fall below q, and the addition was terminated at 7. Next, filtration, washing with water, drying and pulverization were performed in a conventional manner to obtain an acid-treated product of Na-X zeolite. When this acid-treated product was subjected to electron microscopy (II), particulates exactly the same as the original zeolite remained, and the particle size was also measured, and the appearance was almost the same as the original zeolite. Although no difference from zeolite particles was observed, it was found to be amorphous by X-Report JJT (X, R, D) analysis.

Example-6 The powder of the dairy processed product of Example/ was the same as Example 1 (Slur 1,
1- key 95. 5% as SiO□ as a dispersant
Add a small amount of sodium silicate aqueous solution (JIS, No. 7)
Hq, g, the temperature was maintained at 90°C, and the same sodium silicate aqueous solution as above was added to the slurry at 81°C.
0. As a result, fine amorphous silica was deposited by gradually adding the silica at the same time so as to give lθ weight ht% based on the total amount. Next, after straining with sulfuric acid, the mixture was filtered and separated, washed with water, dried and ground in a conventional manner to obtain a silica-coated amorphous aluminosilicate.

Comparative Example-/For comparison, a commercially available amorphous aluminosilicate (Zeol
Fig. A shows the electron microscopy (SEM) photograph of ex), and the table shows the particle size distribution, average particle diameter, Ca ion exchange capacity, composition, etc.
It is also shown in 7.

All of the acid-treated zeolites shown in Table 1 have a particle size of O.
, S~S μm, and the oil absorption is less than so ml/loo l.
, #m, % oil fjik / 00 mlJ//
00I1 or higher). As can be seen from Figure 2 to Figure 2, the particle shape of the zeolite acid-treated product of the present invention maintains the original zeolite shape, whereas the commercially available amorphous aluminosilicate Salt is 0.0! It is clear that the particles are irregular aggregates of fine particles of 11 m or less in size.

This shows that approximately 30% of the particle size distribution measurements of Comparative Example -/ are O, Gμ or more, indicating that the fine primary particles are agglomerated.

Using the same Na-A zeolite as in Comparative Example-Example M-/, 11% sulfuric acid was added for acid treatment in the same manner as in Example-7, and further sulfuric acid was added to prepare a mixed slurry. After adjusting the pH to 3.0, stirring was continued for 1 hour. Thereafter, the acid-treated product was obtained by filtration, washing with water, drying, and pulverization using conventional methods. An electron micrograph (S/A) of the acid-treated product obtained is shown in Figure 7.
The figure shows that particles dissolve and agglomerate due to pH drop during acid treatment. Blockage occurred, and many aggregated coarse particles of 70μ or more were present, and the skeleton of the bulk zeolite had disappeared.In this case, not only was the yield of the acid-treated product low, but the water The dispersibility of the suspension was also extremely poor.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship between the amount of hydrochloric acid added and the pH of the suspension when the nuclide is gradually added to an aqueous suspension of A-type zeolite, and Fig. 2 is a diagram showing the relationship between the amount of hydrochloric acid added and the pH of the suspension. Figure 3 shows the A-type zeolite used as the raw material in Example 1 of the present invention, Figure 3 shows the result of Example 1, and Figure S shows the result of Example G using an electron microscope (SEM). Figures showing photographs, Figure @A, and Figure 7 are diagrams showing electron microscope (SEM) photographs of the results of Comparative Example 1 and Comparative Example 2, respectively. ”IOHCI (cc) Figure 2 Figure 3 Figure 4 Figure 5~

Claims (1)

[Scope of Claims] (1) An acid-treated product of zeolite, which has an average particle size of 0.
/ to 70 μm, and has a uniform particle size distribution such that the particle size portion within the particle size range of 2 to 77 μm of the average particle size accounts for 50% or more of the total particle size. Amorphous aluminosilicate. The amorphous aluminosilicate according to claim 1, wherein the i2+ zeolite is seven or more types selected from A-type zeolite, X-type zeolite, pJ, F1 theolite, sodalite, and analcyme. . (3) Zeolite) is a zeolite in which part or most of the Na2O component is substituted with cations other than Na+! The amorphous aluminosilicate according to item 1. (4) The scope of the patent fl'f, in which a zeolite treated product is coated with a film of dense amorphous silica
Amorphous aluminosilicate described in /. (5) Into the aqueous slurry of zeolite, pl-]
A method for producing an amorphous aluminosilicate, which comprises reacting an acid or an acidic salt, or an acid and an acidic salt while maintaining q or more. (6) The amorphous aluminosilicate according to claim S, wherein the zeolite is one or more types selected from A-type zeolite, XS zeolite, P-type zeolite, sodalite, and analcyme. manufacturing method. (7) The zeolite is a zeolite in which a part or most of the Na2O component is substituted with cations other than Na+.
-444 A method for producing the amorphous aluminosilicate described in item S.