JPH0873211A - Amorphous aluminosilicate and its production - Google Patents

Abstract

PURPOSE: To produce an amorphous aluminosilicate hardly deteriorating an ion exchange performance by heat treating a filter cake, etc., of the amorphous aluminosilicate at less than a specified temp. CONSTITUTION: A slurry of the amorphous aluminosilicate obtained by mixing a starting material is filtered and separated to a mother liquor and the amorphous aluminosilicate, then a sticking mother liquor content is removed by washing. In a heat treatment of a filtered cake, etc., obtained by such a way, the amorphous aluminosilicate is obtained by heat treating at <=60 deg.C as a material temp.. In this amorphous aluminosilicate, a difference between the weight after heating at 900 deg.C for >=1hr and the weight before heating is 15-35wt. % as a ratio per weight before heating, and the ratio of an area of a broad peak is <=40% when a peak at near 20ppm chemical shift obtained by measuring Na-MASNMR is subjected to waveform separation to a sharp peak and the broad peak, and an endothermic peak position by differential thermal analysis is in a range of 110-160 deg.C.

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 which is suitable as a carrier, a remover of free metal ions in an aqueous solution, or as a raw material for synthesizing zeolite, and relates to a novel amorphous aluminosilicate with remarkably improved storage stability.

[0002]

Amorphous aluminosilicates are 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, and, if necessary, adding an additional aqueous solution of sodium hydroxide. In addition, the amorphous aluminosilicate produced by mixing and mixing is separated from the mother liquor by an operation such as filtration, and then excess mother liquor components such as alkali are removed by washing.
In many cases, it is finally dried by some method. In fact, the aluminosilicate produced in this way has a certain degree of oil absorption and ion exchange property, so it is used as an industrial raw material for catalysts or catalyst bases, resin additives, ion exchange agents, etc. Was thought to be useful for.

Amorphous aluminosilicates prepared by the conventional method are unstable, and their ion exchange properties are remarkably deteriorated during storage for a few months even at room temperature, resulting in ion exchange such as removal of free metal ions. Even when it was used as a body, the internal diffusion rate of ions was slow, and the exchange capacity was insufficient, so that the ion exchange performance was not sufficient.

It has been known that conventional amorphous aluminosilicates have been destabilized due to some influence, and that their states gradually change to decrease the ion exchange capacity. The cause of such a decrease in the ion exchange capacity has not been clarified, but some influence on the site contributing to ion exchange,
That is, it is considered that the state of Al atoms contained in the skeleton or the appearance of a surface state that prevents the diffusion of ions is deeply involved.

It has been a very important subject to improve the stability of such an amorphous aluminosilicate.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an amorphous aluminosilicate which does not deteriorate in ion exchange performance.

[0007]

Means for Solving the Problems As a result of intensive studies on the physical properties and ion exchange characteristics of amorphous aluminosilicate, the present inventors have found that the water state of amorphous aluminosilicate and the ion exchange characteristic are closely related to each other. It was found that it is possible to improve the stability by finding out such a relationship and controlling the state of water in the structure, and the present invention has been completed.

That is, in the present invention, the difference between the weight after heating at 900 ° C. for 1 hour or more and the weight before heating is 15% or more and 35% or less with respect to the weight before heating. The ratio of the broad peak area obtained by waveform-separating the peak near the chemical shift of 20 ppm obtained by the measurement into a sharp peak and a broad peak is 40% or less, and the endothermic peak position in the differential thermal analysis is 110 to 160. Present in the range of ° C,
The present invention relates to an amorphous aluminosilicate, which has a large ion exchange capacity and remarkably improved storage stability.

The reason why the water content is required to be not less than 15% and not more than 35% is that it is necessary to reduce the damage by drying under mild drying conditions, and if the amount of unnecessary water is too much, the unit weight is This is to prevent the apparent performance of the hit from being lowered.

The Na-MAS NMR results show the results related to the interaction of sodium ions with water. It is difficult to explain exactly what these results indicate, but it seems to be information on the damage done to the agent during processes such as drying. The reason is that if the ratio of the area of the broad peak is 40% or less, no change occurred during storage, especially the decrease of the ion exchange capacity was observed, but if the ratio of the area exceeds 40%, the room temperature is increased. This is because the change gradually occurs, and a decrease in ion exchange capacity is observed.

Further, regarding the peak position of the differential thermal analysis, it is unknown what the peak position directly means. However, the amorphous aluminosilicate having a peak position in the differential thermal analysis in the range of 110 to 160 ° C. has a large ion exchange capacity, and no decrease in the ion exchange capacity is observed. On the other hand, the peak position of the differential thermal analysis is 110 to 160 ° C.
The amorphous aluminosilicate that does not exist in the range of 1) has a low ion exchange capacity, or has a low ion exchange capacity even if the ion exchange capacity is large to some extent. Less than,
The method for producing the amorphous aluminosilicate of the present invention will be described.

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 aqueous solution of alkali metal silicate may be used, or an aluminum source such as aluminum hydroxide or a silica source such as silicic acid may be used as a hydroxide. Both solutions may be prepared by subjecting the solution to heat treatment together with an aqueous solution of an alkali metal salt.

As the alkali metal salt used, a sodium salt is usually used industrially, but the sodium salt is not particularly limited. Regarding the concentration of the solution which becomes the aluminum raw material and the silica raw material, the slurry concentration is preferably 30% by weight or less when the yield of the amorphous aluminosilicate produced by mixing is 100%.

The mixing ratio of both components is Si / Al.
If the ratio is too high, the ion exchange capacity will decrease, and if it is too low, the oil substance absorption capacity will decrease. Therefore, the Si / Al ratio is preferably mixed in the range of 0.5 or more and 70 or less.

The reaction temperature is preferably around room temperature,
It is desirable to synthesize at a temperature of 60 ° 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.

The slurry of amorphous aluminosilicate obtained by mixing the raw materials is filtered to separate the mother liquor and the amorphous aluminosilicate, and then the mother liquor component further attached is removed by washing. The filter cake thus obtained is dried in the usual way. For example, the cake may be left standing and dried. Alternatively, the filter cake may be slurried by adding stirring power, and for example, spray-dried. However, in any drying method, it is important to control the water content after drying within the range of 18% by weight to 35% by weight. At the same time, it is necessary to avoid drying that would destabilize the water present in the structure.

Specifically, when statically drying, it is necessary to avoid exposure to high temperatures for a long time. For example,
Prolonged drying at temperatures above 60 ° C should be avoided. When spray drying, the ambient temperature does not matter, but the lower the better, the agent temperature must be 60 ° C.
It is necessary to adjust the drying conditions so as to be as follows.

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

[0020]

EXAMPLES Each measuring method in Examples and Comparative Examples is as follows.

(1) Method for measuring water content About 3 g of an amorphous aluminosilicate sample is accurately weighed in a crucible, heated at a temperature of 900 ° C. for 1 hour or more, and then allowed to cool to accurately measure the weight loss. taking measurement. The ratio obtained by dividing the amount of decrease by the weight before heating is expressed as a percentage.

(2) Na-MASNMR measurement conditions: A 45 ° pulse of 23Na was applied for a waiting time of 2 seconds to perform integration 64 times. The obtained peak was waveform-separated, and the area ratio of the sharp peak and the broad peak was obtained.

(3) Method of differential thermal analysis Using alumina as a standard sample, about 20 mg of amorphous aluminosilicate was heated from room temperature to 115 at a heating rate of 10 ° C./min.
Heating was performed to 0 ° C. The peaks were found in two places, a low temperature of 200 ° C. or lower and a high temperature part near 1000 ° C. Here, the peak position of the low temperature part below 200 ° C. was measured.

(4) 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

(5) Method for measuring absorbency of oily substance As a pretreatment, it was crushed with a cooking cutter until the maximum particle size became 75 μm or less, and linseed oil method was carried out in accordance with JIS K 6221 to obtain an amorphous aluminosilicate 1
It was also determined by converting the amount of oily substance absorbed per (00 g anhydrous).

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.
3 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. From the end of the input,
The stirring was continued for 60 minutes. Immediately thereafter, the obtained slurry was filtered, and after removing the mother liquor, it was washed on the filter with ion-exchanged water in an amount twice that of the slurry. The cake obtained was slurried and spray dried. The agent temperature during drying is 60
° C. The water content, the NMR measurement, the differential thermal analysis, the ion exchange performance and the oil absorption of the obtained amorphous aluminosilicate powder were measured by the above methods. The results are shown in Table 1.

[0027]

[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 50 ° C. while Example 1 was placed in the same vessel.
Sodium aluminate solution with the same composition as
The mixture was kept at 0 ° C, 263 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 stirring was continued for 60 minutes from the end of the addition. Immediately thereafter, the obtained slurry was filtered, and after removing the mother liquor, it was washed on the filter with ion-exchanged water in an amount twice that of the slurry.
The cake obtained was slurried and spray dried. The agent temperature during drying was 45 ° C. The water content, the NMR measurement, the differential thermal analysis, the ion exchange performance and the oil absorption of the obtained amorphous aluminosilicate powder were measured by the above methods. The results are shown in Table 1. Comparative Example 1 Water (11322 g) was charged into a reaction vessel having an internal volume of 20 liters, and Example 1 was placed in the same vessel while maintaining the temperature at 50 ° C.
Sodium aluminate solution with the same composition as
The mixture was kept at 0 ° C, 263 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 stirring was continued for 60 minutes from the end of the addition. Immediately thereafter, the obtained slurry was filtered, and after removing the mother liquor, it was washed on the filter with ion-exchanged water in an amount twice that of the slurry.
The cake obtained was slurried and spray dried. The agent temperature during drying was 65 ° C. The water content, the NMR measurement, the differential thermal analysis, the ion exchange performance and the oil absorption of the obtained amorphous aluminosilicate powder were measured by the above methods. The results are shown in Table 1. Comparative Example 2 Water (11322 g) was charged into a reaction vessel having an internal volume of 20 liters, and Example 1 was placed in the same vessel while maintaining the temperature at 50 ° C.
Sodium aluminate solution with the same composition as
The mixture was kept at 0 ° C, 263 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 stirring was continued for 60 minutes from the end of the addition. Immediately thereafter, the obtained slurry was filtered, and after removing the mother liquor, it was washed on the filter with ion-exchanged water in an amount twice that of the slurry.
The cake obtained is heated at 130 ° C and 10% relative humidity for 2
After being dried for 4 hours, the water content, differential thermal analysis, ion exchange performance and oil absorption were measured by the above methods. The results are shown in Table 1.

[0029]

INDUSTRIAL APPLICABILITY The amorphous aluminosilicate having a controlled water content obtained according to the present invention maintains storage stability, especially ion exchange performance for a long time.

Claims (2)

[Claims] 1. The difference between the weight after heating at 900 ° C. for 1 hour or more and the weight before heating is 15% by weight or more and 35% by weight or less with respect to the weight before heating, and Na-M
20 pp chemical shift obtained by ASNMR measurement
When the peak around m is waveform-separated into a sharp peak and a broad peak, the ratio of the area of the broad peak is 40% or less, and the endothermic peak position in the differential thermal analysis is in the range of 110 to 160 ° C. Standard alumino silicate. 2. The temperature of the agent in heat treatment such as drying is 60 ° C.
The method for producing an amorphous aluminosilicate according to claim 1, wherein the heat treatment is performed at the following temperature.