JPH0710529A - Amorphous aluminosilicate and its application - Google Patents

Abstract

PURPOSE:To provide an amorphous aluminosilicate contg. pores which are not blocked up even by crushing and having improved ion exchange performance and liquid material absorbing property. CONSTITUTION:In this amorphous aluminosilicate, the total pore volume of pores having 10<3>-10<5>Angstrom diameter among pores measured by a mercury press- injection method is >=60% of the total pore volume of all the pores. A liquid material absorbent or a remover for removing free metal ions in an aq. soln. is made of this amorphous aluminosilicate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an inorganic filler or additive for rubber, resin, paper, paint, etc., a carrier for a polymer liquid substance such as an oily substance, a catalyst and a deodorizer. The present invention relates to an amorphous aluminosilicate suitable as a carrier, a remover of free metal ions in an aqueous solution or a synthetic raw material for zeolite, etc., and by having an improved pore structure, a free metal ion remover in an aqueous solution, a resin, etc. The present invention relates to a novel amorphous aluminosilicate which is particularly suitable as an additive for.

[0002]

Amorphous aluminosilicates are conventionally generally prepared by mixing an aqueous solution of sodium aluminate and an aqueous solution of sodium silicate at an appropriate temperature, concentration and mixing ratio.
Further, it was considered that the synthesis could be easily performed by adding an additional sodium hydroxide aqueous solution as needed and mixing.
In fact, the aluminosilicate synthesized in this way is reasonably fine, and to some extent absorbs oily substances,
In order to have ion exchangeability, etc., a catalyst or catalyst base,
It was thought to be useful as an industrial raw material for resin additives and ion exchangers. As specific examples, for example, as a recent synthesis example, Japanese Patent Publication No. 61-2565.
The 3 discloses, the concentration of alkali metal oxides defined constant concentration range, oil absorbency 200 cm ^3/100 g
As mentioned above, it is said that the ion exchange properties obtained are comparable to those of various zeolites. However, the particles of the amorphous aluminosilicate synthesized in this manner are not fully developed, and the properties described here are merely apparent performances which are deteriorated by physical crushing or heating.

[0003]

When the amorphous aluminosilicate prepared by the conventional method is used as a catalyst, for example, it should be uniformly modified as a catalyst (for example, ion exchange with a useful metal ion or However, it was difficult to support such salts and the like, and it was difficult to obtain uniform performance as a catalyst. Further, when used as an ion exchanger for removing free metal ions, the internal diffusion rate of ions is slow and the exchange capacity is insufficient, so that the ion exchange performance is not sufficient. Also, when absorbing oily substances,
The absorption amount, absorption rate, and absorption stability were insufficient. It is considered that these reasons are due to insufficient development of the pore structure. In other words, in conventional amorphous aluminosilicates, the proportion of relatively large pores of 10 ⁵ angstroms or more is large, so even those with apparently sufficient performance may be destroyed by crushing or the like. , Absorption (penetration) of high molecular substances such as oily substances, which are originally crushed and play a role of pores
It is thought that diffusion of ions is becoming difficult.

It has been a very important subject to improve the ion exchange performance of such an amorphous aluminosilicate and the absorbability of an oily substance.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies on physical properties such as the pore structure of amorphous aluminosilicate, ion exchange, and absorption properties of oily substances, and as a result, have found that We found a close relationship between the pore structure and the ion exchange characteristics and oil absorption,
By optimizing the pore structure, ion exchangeability,
It has been found that it is possible to improve the absorption of oily substances. At the same time, they have found that the pore structure can be appropriately controlled without having a great influence on the volume sum of the pores depending on the synthesis conditions, leading to the present invention.

That is, the present invention is: (1) 60 Å or more, 2 × 10, measured by mercury porosimetry.
^The sum of the volume of pores having a diameter of ⁶ angstroms or less and the volume of pores having a diameter of 10 ³ angstroms or more and 10 ⁵ angstroms or less is 60%.
By improving the pore structure as described above, it is possible to maintain the pore structure even by pulverization and the like, and increase the internal diffusion rate during ion exchange,
Further, it is an amorphous aluminosilicate having an improved absorption rate and absorption stability of an oily substance, and a liquid substance absorbent composed of the amorphous aluminosilicate described in (2) and (1) and removal of free metal ions from an aqueous solution. It is intended to be a drug.

Next, the gist of the present invention will be described in more detail.
In the present invention, in a general method for producing an amorphous aluminosilicate by reacting an alkali metal aluminate aqueous solution with an alkali metal silicate aqueous solution, the temperature, concentration ratio, addition method of the solution, etc. are optimized. It was clarified that the pore structure of the amorphous aluminosilicate obtained by the method greatly changed. Here, the improved pore structure means the proportion of pores having a diameter of 10 ⁵ angstroms or more, out of pores having a diameter of 60 angstroms or more and 2 × 10 ⁶ angstroms or less, which is measured by a mercury penetration method. Less than 10 ³ angstroms and 10 ⁵ angstroms
It has a pore structure in which the volume ratio of pores having a diameter of not more than 60% is 60% or more, and it reduces pores that are too large and increases the proportion and amount of pores effective for diffusion. It is a thing.

On the other hand, in an amorphous aluminosilicate having an unimproved pore structure, pores of 10 ⁵ Å or more are extremely developed or evenly distributed throughout. For example, those having extremely developed pores of 10 ⁵ angstroms or more are apparently excellent in the absorbability of an oily substance and the ion exchange property. However, in those having such a pore structure, the pores are destroyed by operations such as pulverization and kneading, or the pore structure is lost due to consolidation. As a result, gaps for absorbing oily substances and pores for ionic diffusion are lost, making it difficult to use for these purposes.

As described above, the amorphous aluminosilicate having an improved pore structure has both excellent ion exchange property and oil substance absorbability. The composition of the amorphous aluminosilicate obtained in the present invention has a general formula of 0.7 to 1.5 (M ₂ O) · Al ₂ O ₃ · 0.5 to 12.
0 (SiO ₂ ) (wherein M represents an alkali metal ion).

The method for producing the amorphous aluminosilicate of the present invention will be described below.

In the present invention, the synthetic raw materials are, for example, an aqueous solution of alkali metal aluminate and an aqueous solution of alkali metal silicate. If necessary, both solutions are diluted with an aqueous solution of alkali metal hydroxide and used.

As the both aqueous solutions, a commercially available aqueous solution of alkali metal aluminate or an aqueous solution of alkali metal silicate may be used, or hydroxides of alkali sources such as aluminum hydroxide and silica sources such as silicic acid may be used. Both solutions may be dissolved and prepared by subjecting them to heat treatment together with an aqueous solution of an alkali metal salt. As the alkali metal salt used, a sodium salt is generally used industrially, but the sodium salt is not particularly limited. The concentration of the solution used as the aluminum raw material and the silica raw material is not particularly limited, but the slurry concentration is 1 when the yield of the amorphous aluminosilicate produced by mixing is 100%.
It is preferably 5% by weight or less.

The mixing ratio of both components is not particularly limited, but if the Si / Al ratio is too high, the ion exchange capacity will decrease, and if it is too low, the oil substance absorption capacity will decrease. Therefore, it is preferable to mix the Si / Al ratio in the range of 0.25 or more and 6.00 or less. However, such an atomic ratio is not an essential requirement in the present invention. This is because it is possible to prepare an amorphous aluminosilicate having a desired pore structure even outside the range of these atomic ratios.

However, a particularly important point in mixing these raw materials is to add water or sodium hydroxide aqueous solution and aluminum raw material into the reaction vessel first to reduce the aluminum raw material concentration as much as possible, and gradually add the silica raw material to it. Is to add. The rate of addition of the silica raw material is also an important point. If it is too fast, uniform nucleation and growth will not occur and the desired pore structure or specific surface area cannot be obtained. If the addition rate of the silica raw material is within the above composition range,
Addition time of 1.5 minutes or more is desirable. In addition, it is important to thoroughly stir the silica raw material so that the solution becomes uniform in the shortest possible time, and the added Si raw material may be nonuniformly present or partially have a high concentration. It is important that the generated amorphous aluminosilicate is not partially stagnant.

The reaction temperature is preferably room temperature or higher and 70 ° C. or lower.

In addition, the hydroxide ion concentration ([O
H ^-]), the fine pores is too low does not develop. Therefore, the hydroxide ion concentration of the reaction system is 1.4 mol / k as the free hydroxide ion concentration after the reaction.
It is preferably g or more.

When synthesized under such conditions, the objective amorphous aluminosilicate having a pore structure improved to 10 ³ Å or more and 10 ⁵ Å or less can be obtained.

[0018]

Amorphous aluminosilicate pore structure obtained with improved by the present invention exhibits, 10 ³ Å - arm or more, has a fine pore structure with many pores 10 ⁵ Å or less, as a result , The pores are not crushed by pulverization, etc., and the ion exchange property and oil substance absorption property are improved.

[0019]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples.

The respective measuring methods in Examples and Comparative Examples are as follows.

(1) Method of measuring pore distribution by mercury porosimetry The measurement was performed using a Poresizer-9310 manufactured by Micromeritics.

(2) Method for measuring ion exchange performance The ion exchange performance was measured by adding 1 liter of an aqueous calcium chloride solution (500 mg / liter in terms of calcium carbonate).
Add 1 g of amorphous aluminosilicate on an anhydrous basis and add
Stir for 10 minutes at 5 ° C. Then, the solid content is separated by filtration, and the calcium remaining in the filtrate is removed by EDTA.
The amount of calcium exchanged per 1 g (anhydrous) of amorphous aluminosilicate measured by titration with an aqueous solution was CaCO ₃
Even if converted to

(3) Method for measuring oily substance absorbency As pretreatment, the oil was pulverized with a cooking cutter until the maximum particle size became 75 μm or less, and the linseed oil method was used in accordance with JIS K6221.

Example 1 5.7 in the form of NaOH in a reaction vessel having an internal volume of 20 liters
An aqueous solution of sodium hydroxide having a concentration of 4% by weight, 11322
g, and while maintaining the temperature at 55 ° C., an aqueous solution of sodium aluminate (Na ₂ O = 19.3 wt%,
(Al ₂ O ₃ = 21.9% by weight) was also maintained at 55 ° C., 921 g was added, and the mixture was vigorously stirred. Furthermore, an aqueous solution of sodium silicate (Na ₂ O = 4.0% by weight, S
iO ₂ = 12.7 wt%) 3739 g kept at 55 ° C.
It was charged at a rate of 500 g / min with vigorous stirring. The time required for charging was 7.5 minutes. The hydroxide ion concentration after the reaction was about 1.4 mol / kg. Stirring was continued for 20 minutes from the end of charging. Immediately thereafter, the obtained slurry was filtered, and the slurry volume of 2
The cake was washed on the filter with twice the amount of deionized water. The obtained cake was dried at about 80 ° C., but the pore distribution, ion exchange performance and oily substance absorbency were measured by the above methods. The results are tabulated.

Example 2 5.7 in the form of NaOH in a reaction vessel having an internal volume of 20 liters
An aqueous solution of sodium hydroxide having a concentration of 4% by weight, 11322
While maintaining the temperature of 65 ° C., 921 g of an aqueous solution of sodium aluminate having the same composition as in Example 1 was also maintained at 65 ° C. and 921 g was vigorously stirred.
Further, 3739 g of an aqueous sodium silicate solution was kept at 65 ° C. in the same solution, and was added at a rate of 500 g / min with vigorous stirring. The time required for charging was 7.5 minutes. The hydroxide ion concentration of the reaction solution was 1.4 mol / kg. The stirring was continued for 60 minutes from the end of the addition. Immediately thereafter, the obtained slurry was filtered, and the cake was washed on the filter with ion-exchanged water twice the volume of the slurry. The obtained cake was dried in the same manner as in Example 1, and the pore distribution, ion exchange performance and oil substance absorbency were measured by the above methods. The results are tabulated.

[0026]

[Table 1]

Claims (3)

[Claims] 1. Among the pores measured by mercury porosimetry,
The volume sum of pores having a diameter of 10 ³ angstroms or more and 10 ⁵ angstroms or less is 60% of the total volume of pores.
The above is an amorphous aluminosilicate. 2. Amorphous aluminosilicate according to claim 1.
An oil-based substance absorbent. 3. Amorphous aluminosilicate according to claim 1.
An agent for removing free metal ions from an aqueous solution of