JPH0710530A - Amorphous aluminosilicate and its application - Google Patents

Abstract

(57) [Summary] [Structure] The sum of the pore volumes of pores having a diameter of 10 to 60 angstroms measured by a nitrogen adsorption method is 0.01 c.
Amorphous aluminosilicate with m ³ / g or more. A liquid substance absorbent comprising the above-mentioned amorphous aluminosilicate or a free metal ion removing agent in an aqueous solution. [Effect] The pores are not crushed by crushing,
Further, it can withstand heat treatment, and has improved ion exchange properties and oil substance absorption properties.

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 as a raw material for synthesizing zeolite, and the like, which has improved fine pores, and is therefore a liquid substance absorbent and free metal in an aqueous solution. The present invention relates to a novel amorphous aluminosilicate which is particularly suitable as an additive such as an ion scavenger and a resin.

[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 a concrete example, 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, under the conditions described in the publication, pores in a specific range essential for the present invention have not been developed, so that not only reproducibility of the obtained material is poor, but also these characteristics are physical crushing and heating. It is just an apparent performance that easily deteriorates due to factors such as.

[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.

Further, in order to remove free metal ions from the aqueous solution, it is desired that the ion exchange rate and the ion exchange capacity are large at the same time. However, it has been known that conventional amorphous aluminosilicates have a gradual decrease in ion exchange capacity when they are dried at a temperature of 50 ° C. or higher and are exposed to the temperature for a long time even at a temperature of 50 ° C. or lower. There is. The cause of such a decrease in the ion exchange capacity has not been clarified, but it is considered that the state of Al atoms contained in the skeleton is deeply involved.

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.

[0006]

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, according to the present invention, (1) the volume sum of pores having a diameter of 10 angstroms or more and 60 angstroms or less as measured by a nitrogen adsorption method is 0.01 cm.
Amorphous aluminosilicate having a heat resistance of ion exchange property by setting it to ³ / g or more, and (2)
It is intended to mean a liquid substance absorbent comprising an amorphous aluminosilicate described in (1) and a free metal ion removing agent in an aqueous solution.

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 that among the pores measured by the nitrogen adsorption method, the volume sum of pores having a diameter of 10 angstroms or more and 60 angstroms or less develops to 0.01 cm ³ / g or more. It has the above-mentioned pore structure, and although its function is not clear, it imparts heat resistance to the ion exchange property.

On the other hand, in the case of an amorphous aluminosilicate whose pore structure is not improved, it is 10 angstroms or more and 60 or more.
The volume sum of pores having a diameter of angstrom or less is 0.01
It is not more than cm ³ / g, and its deterioration mechanism is not clear, but a decrease in ion exchange capacity is easily caused by heat treatment such as drying.

As described above, the amorphous aluminosilicate having the 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.

Further, 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, and 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 when the yield of the amorphous aluminosilicate produced by mixing is 100%, the slurry concentration is 3%.
It is preferably 0% 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 decreases, and if it is too low, the oil substance absorption capacity decreases. 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. Is to add. The rate of addition of the silica raw material is also important, and if it is too fast, uniform nucleation and growth will not occur and the desired pore structure cannot be obtained. If the composition of the silica raw material is in the above range, it is desirable to control the addition rate so that the addition is completed in 1.5 to 15 minutes. When the addition is carried out for a long time, the development of the pore structure cannot be expected. Furthermore, when adding the silica raw material, it is important to perform sufficient stirring to make the solution as uniform as possible, and it is important to prevent the added Si raw material from being nonuniformly present.

The reaction temperature is preferably around room temperature,
It is desirable to synthesize at a temperature of 50 ° C. or lower. If the reaction is carried out at a high temperature, some of the amorphous aluminosilicate will dissolve.
It is also a fact that it is crystallized into dalite, zeolite, etc., and the absorbency of oily substances, etc. is significantly reduced.

Further, the hydroxide ion concentration ([O
H ^-]) is or too high synthesis yield is remarkably decreased,
The development of pores of 10 Å or more and 60 Å or less is not observed. Therefore, the hydroxide ion concentration in the reaction system is preferably 1.3 mol / kg or less as the free hydroxide ion concentration after the reaction.

When synthesized under such conditions, 0.01 cm or more from 10 angstroms to 60 angstroms.
^The intended amorphous aluminosilicate having a pore volume of ³ / g or more can be obtained.

[0019]

The amorphous aluminosilicate having an improved pore structure obtained by the present invention has a thickness of 10 angstroms.
It has a fine pore structure having many pores of not less than 60 angstrom and not more than 60 angstrom, and as a result, the pores are not crushed by pulverization, etc., and can withstand heat treatment, resulting in ion exchangeability. , The absorption of oily substances has been improved.

[0020]

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 nitrogen adsorption method The measurement was carried out using an omnisorb 360-CX manufactured by Coulter.

(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 absorbability As a pretreatment, the oil was crushed 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 Water (11322 g) was placed in a reaction vessel having an internal volume of 20 liters, and while maintaining the temperature at 50 ° C., an aqueous solution of sodium aluminate (Na ₂ O = 19.3% by weight, A
l ₂ O ₃ = 21.9% by weight) is also maintained at 50 ° C.
1 g was added and vigorously stirred. Furthermore, an aqueous sodium silicate solution (Na ₂ O = 4.0 wt%, SiO ₂ was added to the same solution).
= 12.7 wt%) 3739g kept at 50 ℃, about 50
It was charged with vigorous stirring at a rate of 0 g / min. The time required for charging was about 7.5 minutes. The hydroxide ion concentration after the reaction was about 0.4 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 at about 50 ° C., but the pore distribution, ion exchange performance and oil absorption were measured by the above methods. The results are shown in Table 1.

Example 2 11322 g of water was charged into a reaction vessel having an internal volume of 20 liters, and the temperature was maintained at 30 ° C. while Example 1 was placed in the same vessel.
Sodium aluminate solution with the same composition as
The temperature was maintained at 0 ° C., 921 g was added, and the mixture was vigorously stirred. Furthermore, 3739 g of an aqueous solution of sodium silicate was added to the same solution in an amount of 30
The temperature was maintained at 0 ° C., and the mixture 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 of the reaction solution was 0.4 mol / kg. The stirring was continued for 60 minutes from the end of the addition. Immediately thereafter, the obtained slurry was filtered, washed and dried in the same manner as in Example 1, and the pore distribution, ion exchange performance and oily substance absorbency were measured by the above methods. The results are shown in Table 1.

Comparative Example 1 5.7 in the form of NaOH was added to 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 having the same composition as in Example 1 was kept at 65 ° C. and charged 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. From the end of the input,
The stirring was continued for 60 minutes. Immediately thereafter, the slurry obtained was filtered, washed and dried in the same manner as in Example 1 to obtain a pore distribution,
The ion exchange performance and the absorption of the oily substance were measured by the above methods. The results are shown in Table 1.

Comparative Example 2 1.7 in the form of NaOH in a reaction vessel having an internal volume of 20 liters.
Aqueous sodium hydroxide solution having a concentration of 3% by weight, 11322
While maintaining the temperature of 60 ° C., 921 g of an aqueous solution of sodium aluminate having the same composition as in Example 1 was also maintained at 60 ° C., and the mixture was vigorously stirred.
Further, 3739 g of an aqueous sodium silicate solution having the same composition as in Example 1 was kept at 60 ° C. and charged into the same solution 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 0.7 mol / kg. From the end of the input,
Stirring was continued for 20 minutes. Immediately thereafter, the slurry obtained was filtered, washed and dried in the same manner as in Example 1 to obtain a pore distribution,
The ion exchange performance and the absorption of the oily substance were measured by the above methods. The results are shown in Table 1.

[0029]

[Table 1]

Claims (3)

[Claims] 1. The sum of pore volumes of pores having a diameter of 10 to 60 angstroms measured by a nitrogen adsorption method is 0.01.
Amorphous aluminosilicate with cm ³ / g or more. 2. Amorphous aluminosilicate according to claim 1.
Liquid substance absorbent consisting of 3. Amorphous aluminosilicate according to claim 1.
An agent for removing free metal ions from an aqueous solution of