JPS63190776A - Manufacture of interlayer bridging material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention a) Technical Field The present invention relates to a method for producing porous interlayer cross-linked products having various pore sizes by inserting inorganic particles between the layers of a smectite mineral and then drying. It is.

b) Conventional techniques and problems Conventionally, methods using smectite minerals and metal salts have been attempted as a method for producing porous materials.

Smectite-type minerals include montmorillonite, bentonite, chlorite, hectorite, beidellite, and synthetic mica.

All of these have common properties, but these properties will be explained using montmorillonite as an example.

Montmorillonite has crystals stacked in a triple structure of silicic acid tetrahedrons, alumina octahedrons, and silicate tetrahedrons to form a single layer.

In the alumina octahedral crystal described above, part of the a/I/mina is replaced by magnesium, which has a small charge, so that the layer surface has a negative charge. In response to this negative charge, montmorillonite has similar properties to large cationic minerals.

Attempts have been made to utilize this swelling property to introduce inorganic particles between the layers. For example, in JP-A-54-5884 and JP-A-54-16886, there is a production method in which a smectite mineral is mixed with water and an inorganic substance, and the inorganic substance is introduced between the layers.

In this production method, the interlayer distance is Q, 4 nm, so when used for separation, adsorption, or catalyst, a porous material with a long interlayer distance is obtained.

However, it has the following drawbacks. This is not only because the surfaces of smectite minerals and inorganic particles have the same negative charge, but also between the layered particles formed by overlapping layers, forming a porous body with a complex structure.

Porous bodies with such a structure have various interlayer distances and a wide distribution of pores, making them unsuitable as separation materials or catalysts for separating or producing specific molecules.

Furthermore, since the method of firing the polymer to form pores is used, there is a large amount of carbon, which is the residue of firing the polymer, inside the porous body, so it is useful as a catalyst from this point of view as well. In some cases, catalysts cannot be expected to be sufficiently effective in esterification or production of gasoline, etc., because carbon is harmful in most cases.

C) Purpose of the Invention As a result of intensive research aimed at solving the above-mentioned drawbacks, the present inventors have found that at least one or a mixture of inorganic particles and metal hydroxides, metal chlorides, metal sulfides, and metal nitrides can be prepared in an aqueous solution state. mixed, then the smectite mineral as is,
Alternatively, when swollen with water and dried, mainly 4n cross-linked between layers.
It has been found that a microporous material having a pore diameter of m or more can be obtained.

d) Structure of the Invention The smectite mineral in the present invention can be selected from montmorillonite, bentonite, chlorite, beidellite, hectorite, synthetic mica, and a mixture of one or more of these substituted analogs. .

The inorganic particles are fine particles (silica colloid) in which silicic acid is polymerized by desalting sodium silicate with a strongly acidic ion exchange resin and, if necessary, deoxidizing with a basic ion exchange resin. The size of the particles is 4 to 50 nm.

Regarding the production of the present invention, first, the silica colloid solution in which inorganic particles are dispersed is in an acidic state (pH 1 to 7 or less).
It is.

The surface of the inorganic particles in this solution is mostly composed of silano-ρ groups and has a reduced surface charge. After adding the smectite mineral and stirring and mixing, since the cacolloid particles tend to bond, a metal compound is added to prevent this and at the same time to change the sign of the surface charge of the inorganic fine particles.

This metal compound is preferably a compound that reacts with the silica colloid so that the surface charge of the silica colloid becomes a cation. That is, since the surface charge of the smectite mineral is a cation, it is desirable that the surface charge of the silica colloid be a cation in order to cause an interlayer crosslinking reaction.

This cationic silica colloid solution may be added to the smectite mineral either in a powdered state or after being swollen with water. After adding the colloidal solution to the smectite mineral and stirring thoroughly, inorganic particles are introduced between the crystal layers of the smectite mineral, and the negative charges on the surface of the smectite mineral react with the positively charged inorganic particles to which the metal compound has been added, resulting in the formation of the smectite mineral. Inorganic fine particles are bonded to the surface of the layer.

°″*B y, <'yp"v, *opmhmtv
□2: The interlayers of the minerals crosslinked by the 2' particles, that is, the Ito-type minerals, are swollen by water and the spaces between the layers are widened. The amount of water required for swelling is at least Q,4rnl per gram of the same mineral, and the upper limit is practically 30ml.

Inorganic particles range from 0.001 to smectite minerals
Preferably it is 50% by weight. In the case where the amount is less than the above, inorganic particles are not distributed between the crystal layers of the smectite mineral, so it is not possible to make the entire body porous. In addition, if there is too much inorganic particles, all the inorganic particles are buried between the crystal layers of the smectite mineral, making it impossible to produce a porous body.

The metal compound was desalted using an ion exchange resin (PH1~
7 or less) 0.0001 to 10% by weight based on inorganic fine particles
It is preferable that In other words, when a large amount of metal compounds are present, metal ions react with the negative charge of smectite minerals, forming metal smectite minerals, and the swollen interlayers contract and close, making it impossible for inorganic particles to be introduced, and interlayer crosslinks are formed. Not done.

When there are few metal compounds, the surface of these inorganic particles does not change to a positive charge, so they repel each other with the negative charge of the smectite mineral, and no inorganic particles are introduced between the layers.
No porous body is generated.

The aqueous solution containing inorganic particles, metal compounds and smectite minerals is dried at 30-110°C, and if necessary,
Bake at 300-600°C. As a result, a microporous interlayer crosslinked material with a large interlayer distance, which firmly binds the sysmectite mineral and the inorganic particles and also eliminates the water absorption of the smectite mineral, can be obtained.

In the production of this interlayer crosslinked microporous material, silica colloid, which is an inorganic substance, is prepared by the special method described above, so that the inorganic substance and smectite mineral react with each other, compared to the conventional method. Because of the strong bonding, a porous body with a pore size suitable for the purpose is uniformly produced depending on the size of the inorganic particles, resulting in a microporous body with a pore size of 1 nm or more, and its total specific surface area is about 200 to 500 m' /g, and has a nitrogen capacity of about 0.1-0.36 m1/g.

e) Function of the Invention These microporous materials are inexpensive and relatively easy to produce, so they are useful for separation of liquids and gases, and as supports for adsorbents and catalysts.

r) Examples of the invention Example 18 Strongly acidic ion exchange resin (No. manufactured by DOWEX) was added to 100 ml of 3.0% sodium silicate solution.

5 Qwxl 2 ) Add 2.1 g of L, stir, mix, and desalt. The pH of the desalted solution was 2.6.

This solution is further deoxidized using a weakly basic ion exchange resin. This solution had a pH of 4.2.

After adding 2 g of montmorillonite to 10 ml of this silica colloid solution and stirring and mixing, the mixture was left to dry in a drying mold at 52° C. for 18 hours. The results of wide-angle X-ray analysis of the product were 4.4 nm, and the specific surface area, pore diameter, nitrogen capacity,
As a result of examining the specific volume and porosity using the nitrogen adsorption/desorption method, the average pore diameter was 4.4 nm, and the specific surface area was 380 rr at a pore diameter of 2 nm. /g, and the nitrogen capacity is 0.24ml/g
The specific volume was o, 451/g, and the porosity was 0.53.

Example 2゜Example 1. Add 2 g of montmorillonite to 20 ml of the silica colloid solution prepared in step 1 and mix with stirring for 440 i/day.
In addition, the nitrogen capacity is 0.29 m1/g, and the specific volume is 0.4
8 d/g, and the porosity was 0.60.

Example 3゜Example 1. As a result of an investigation using the elementary adsorption/desorption method in which 2 g of montmorillonite was added to 5 ml of the silica colloid solution prepared in 1XI and mixed with stirring, the average pore diameter was 4.4 nm, and the specific surface area was 410-7 g at a pore diameter of 2 nm. Also,
Nitrogen capacity is 0.28rrLI/g, specific volume is o, 45
d/g, and the porosity was 0.62.

7 g, specific volume was 0.48 d/g, and porosity was 0.58.

Example 5 Strongly acidic ion exchange resin (manufactured by DOWEX Co., Ltd. No. 5 Q) was added to 100 ml of 3.0% sodium silicate solution.
Add 2.0 g of wx 12), stir and mix,
Desalinate. The pH of the desalted solution was 3.3. This solution is further deoxidized using a weakly basic ion exchange resin.

This solution had a pH of 5.6. After adding 2 g of montmorillonite powder to 19 ml of this silica colloid solution and stirring and mixing, the nitrogen capacity was 0.36.
m1/g, specific volume 0.46 cd/g, porosity 0.78
Met.

Example 6 A strongly acidic ion exchange resin (No. manufactured by DOWEX) was added to 100 ml of a 3.0% sodium silicate solution.

Add 2.0g of 50WX12), stir, mix, and desalt. The pH of the desalted solution was 2.5.

Synthetic mica (
Adding 2g of powder of NaTS (manufactured by Tobie Industries) is 4.0nm.
Also, as a result of examining the specific surface area, pore diameter, nitrogen capacity, specific volume, and porosity using the nitrogen adsorption/desorption method, the pore diameter was found to be 4.4 on average.
nm, the specific surface area is 380 m'' at a pore diameter of 2 nm.
7g, nitrogen capacity is 0.35m1/g1 specific volume is o,
4sd/g1 The porosity was 0.73.

designated agent Director, Nagoya Industrial Technology Testing Institute, Agency of Industrial Science and Technology Shunji Nagase

Claims (3)

[Claims] (1) A method for producing a microporous material using an interlayer crosslinked material, which comprises mixing a smectite mineral, an inorganic particle, a metal compound, and water, and then drying the mixture. (2) The method according to claim 1, wherein the smectite-type mineral is selected from the group consisting of montmorillonite, bentonite, beidellite, hectorite, synthetic mica and substituted analogs, and mixtures thereof. (3) The inorganic particles are a silica colloid in which fine particles of silicic acid polymerized by desalting and deoxidizing a sodium silicate solution using an ion exchange resin are aged, and are produced according to claim 1. Law.