JPH06104564B2 - Membrane intercalation compound 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 membranous intercalation compound obtained from an acid-treated product of layered polysilicate magadiite and kenyaite, and a process for producing the same.

[0002]

2. Description of the Related Art Layered silicates are one of the substances that are expected to be applied to functional materials based on their special structure. As such, various applications such as catalysts, fillers, and adsorbents have been developed. In addition, inter-layer modification by intercalation is a field in which development of composite materials including new catalysts and porous materials is progressing.

At present, the target layered silicates include natural smectite clay minerals and fluorine mica synthesized by the melting method. It is also possible to produce a thin film material from these materials. However, in order to utilize the layered silicates from now on, not only the preparation of new host compounds but also functional materials in which these material forms are controlled and efficient synthetic processes for these are required.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have focused their attention on the ion exchange reaction of synthetic layered polysilicate magadiite and kenyaite and the layered polysilicic acid which is an acid-treated product thereof, and as a result of intensive studies, It was found that it is possible to prepare a film-like layered polysilicate or a film-like polysilicic acid.

Layered polysilicates and layered polysilicic acids are similar to clay minerals in that they are layered compounds, and are equivalent to zeolites in that they have micropores, and their crystalline structure is an interesting siliceous material having properties intermediate between them. It is an acid substance. Further, the interlayer ion of the layered polysilicate is mainly sodium, but it can be exchanged with another alkali metal or the like.
There are various layered polysilicates and layered polysilicic acids depending on the stacking mode of SiO ₄ tetrahedra, but magadiite and kenyaite and their acid-treated products are common compounds.

Synthetic magadiite and kenyaite are 1
It is generated as spherical secondary particles in which plate-like crystal fragments which are secondary particles are densely aggregated. In addition, these acid-treated products retain their original spherical shape even when interlayer ions are leached. Furthermore, the layered polysilicate magadiite can be exchanged with many ions including alkali metals other than Na, but it takes a long time to complete the exchange,
It has been pointed out that not all exchanges may be achieved due to a long reaction time. On the other hand, regarding the ion exchange reaction of the acid-treated product of magadiite (referred to as H-magadiite), there is a report on the exchange reaction between H and Na, but almost no exchange reaction by other ions is performed. At this time, it is known that H-type magadiite completely returns to magadiite by a NaOH solution or a Na ₂ CO ₃ solution having a certain concentration or more. However, no change in particle morphology has been reported by the ion exchange, while maintaining the original spherical morphology of densely packed plate-like crystal fragments. Furthermore, there are few reports on ion exchange of the acid-treated products of Kenyaite.

The present invention was made on the basis of the above-mentioned findings, and its purpose is to carry out the ion exchange of the original layered polysilicic acid of the synthetic layered polysilicate magadiite and the acid treatment product of Kenyaite in an alkaline solution. The purpose is to change the morphology and create a novel membranous compound.

[0008]

Means for Solving the Problems That is, the present invention relates to a membranous layered polysilicate obtained by ion-exchange of acid-treated products of synthetic magadiite and kenyaite, a method for producing the same, and a membranous layered polysilicate obtained by the acid treatment. Acid and its preparation method.

The synthetic magadiite and kenyaite according to the present invention are not particularly limited in their history as long as they are composed of an aggregate of plate crystals synthesized by a wet method. The acid treatment condition for producing the layered polysilicic acid is to use a mineral acid such as hydrochloric acid of 6N or less, keep the pH at 2 or less during the dissolution reaction, and finally elute almost all the magadiite and kenyaite interlayer ions. The reaction temperature may be around room temperature, and 100 ° C. or lower is sufficient even if the temperature is increased to accelerate the reaction rate. The stirring is sufficient if the uniformity of the entire system can be maintained.

In the ion exchange reaction, an alkaline solution such as KOH, LiOH, NH ₄ OH or the like or an alkaline solution in which various metals are dissolved is used to replace the protons which are the interlayer ions of the layered polysilicic acid. The amount of metal ion required to exchange protons to obtain the target membranous substance is
The amount may be 0.001 mol or more, more preferably 0.002 mol, based on 1 g of the layered polysilicic acid, and it is desirable to exchange most of the Na ions contained in the starting material. The reaction temperature is usually room temperature, but the temperature may be increased to increase the ion exchange rate. The stirring is sufficient if the uniformity of the entire system can be maintained.

The solid substance synthesized under the above conditions is separated from the mother liquor by a conventional method, then, after washing with water, it is applied onto a flat flat glass, Teflon or ceramics plate, or poured into a mold and dried. And collect. At this time, if necessary, a binder is added, pressure molding or the like is performed, and the film-like layered polysilicate is recovered.

Further, by pickling the film-like layered polysilicate, the interlayer ions can be leached again to produce the film-like layered polysilicic acid. At this time, the reaction temperature is usually around room temperature, and the reaction time can be determined based on the leaching amount.

[Action]

The membranous layered polysilicate and the membranous layered polysilicic acid according to the present invention are based on the fact that the particle morphology of synthetic magadiite and synthetic kenyaite reflects secondary particles. That is, the primary particles are tabular flaky crystals, and the composite is observed as spherical secondary particles in which they are aggregated. From this, when the secondary particles are disassembled into primary particles and these are oriented in a fixed direction, a film-like substance is formed.

However, it was confirmed that the disassembly of the secondary particles did not occur when the acid-treated product was prepared from the layered polysilicate magadiite. Furthermore, even if the acid-treated product is ion-exchanged with an alkaline solution containing Na, the morphology of the secondary particles remains. from these things,
It is impossible to disassemble the secondary particles at the same time as the production of the layered polysilicic acid to form the layered polysilicic acid.
A method of exchanging with a metal ion other than a was examined.

This is because the hydration state varies depending on the metal ion, and the interaction between the solvent and the particles changes, so the isoelectric point of the particles changes, and the repulsive force between the particles increases, and the secondary particles are disassembled. Is thought to occur.

Further, in the case of a film-like substance containing ions other than alkali metal between the layers, it is possible to change the interlayer distance, and it can be expected that the range of application will be further expanded.

[0017]

EXAMPLES The present invention will be described below based on examples.

Example 1 1 g of layered polysilicic acid obtained by treating synthetic magadiite with 2N hydrochloric acid for 6 hours was added with 0.001N potassium hydroxide solution 1600c.
Add to c and perform ion exchange reaction at room temperature for 1 hour. After the treatment was completed, the liquid phase was separated by filtration and washed with water. At this time, a part of the product was recovered, dried at 40 ° C., and then measured by X-ray diffractometry, whereby it was confirmed that H-magadiite had changed to K-magadiite. Further, it was possible to apply the remaining sample on a glass plate and air-dry it to form a film. As a result of SEM observation of a part thereof, it was confirmed that the primary particles of magadiite were densely aggregated and had a film-like morphology.

Example 2 1 g of layered polysilicic acid obtained by the same operation as in Example 1 was
Add 1600cc of 001N lithium hydroxide solution and carry out ion exchange reaction at room temperature for 1 hour. After the treatment was completed, the liquid phase was separated by filtration and washed with water. At this time, some of the product was recovered and
After drying at C, measurement by X-ray diffraction confirmed that H-magadiite had changed to Li-magadiite. Further, it was possible to apply the remaining sample on a glass plate and air-dry it to form a film. As a result of SEM observation of a part thereof, it was confirmed that the primary particles of magadiite were densely aggregated and had a film-like morphology.

Example 3 60 g of 1 g of layered polysilicic acid obtained by the same operation as in Example 1
Then, 12 cc of 0.1N potassium hydroxide, lithium hydroxide or ammonia aqueous solution is added dropwise to the pure water, and an ion exchange reaction is performed at room temperature for 1 hour. After the treatment was completed, the liquid phase was separated by filtration and washed with water. At this time, some of the products were recovered and
In dried, it was measured by X-ray diffractometry H- magadiite are each K- magadiite, Li- magadiite or NH ₄ - was confirmed to be changed to magadiite. Further, it was possible to apply the remaining sample on a glass plate and air-dry it to form a film. As a result of SEM observation of a part thereof, it was confirmed that the primary particles of magadiite were densely aggregated and had a film-like morphology.

Example 4 1 g of layered polysilicic acid obtained by treating synthetic kenyaite with 2N hydrochloric acid for 6 hours was added to 60 cc of pure water, 12 cc of 0.1N potassium hydroxide solution was added dropwise, and ion exchange reaction was carried out at room temperature for 1 hour. I do. After the treatment was completed, the liquid phase was separated by filtration and washed with water.
At this time, a part of the product was recovered, dried at 40 ° C., and then measured by X-ray diffractometry. As a result, it was confirmed that H-kenyaite was changed to K-kenyaite. Further, it was possible to apply the remaining sample on a glass plate and air-dry it to form a film. SEM observation of a part of this revealed that the primary particles of Kenyaite were densely aggregated,
It was confirmed to have a membranous morphology.

[0022]

INDUSTRIAL APPLICABILITY Since the layered polysilicate magadiite and kenyaite have micropores based on their peculiar layered structure, they can be expected to be used in many fields such as chemical industry, ceramic industry and medicine. For example, catalyst carrier, filler,
It is considered to be applicable to adsorbents, deodorants, enzyme sensors, microbial separation, etc. In addition, since intercalation is possible with organic or inorganic substances by intercalation reaction, various catalysts, porous materials, etc. can be produced by various composite materials, enzyme sensors, microbial separation agents, pharmacologically active substances, or pillar formation between layers. It can be expected to be useful as a layered compound in the case of

The crystalline layered polysilicic acid obtained by acid treatment of this is composed of only silica, and is used in applications where amorphous silica has been used, such as catalysts, catalyst carriers, fillers, adsorbents, deodorants, etc. On the other hand, there is a possibility that it is possible to impart higher performance, and further, it is useful as a layered compound for the creation of various functional materials including composite materials by the intercalation reaction utilizing a special structure as described above. Can be expected. Furthermore, if these layered polysilicates and layered polysilicic acids can be formed into a film, they are expected to be applied as higher-performance materials for the above applications.

Claims (2)

[Claims] 1. A membranous intercalation compound obtained from the acid-treated products of layered polysilicate magadiite and kenyaite. 2. The method for producing the membranous material according to the above 1, wherein the acid-treated products of layered polysilicate magadiite and kenyaite are treated with an alkaline solution, and the treated products are acid-treated.