JPS63190775A - 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, part of the alumina is replaced by magnesium, which has a small charge, so that the layer surface has a negative charge. Alkali metal ions (Na'') corresponding to this negative charge are interposed between the layers of the triple crystal structure to neutralize the charge on the layer surface.

Therefore, montmorillonite has a large cation exchange capacity. In addition, the interlayer absorbs a large amount of water due to the hydration reaction of Na+, and the interlayer becomes significantly wider and swells. Other smectite minerals have similar properties.

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. The surfaces of the smectite mineral and the inorganic particles have the same negative charge, so they repel each other, and the terminals of the phase smectite mineral react with the positive charge and the negative charge of the inorganic material, so the inorganic particles are not only interlayers, but layer particles formed by overlapping layers. It also exists between the two, 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 found that inorganic particles are mixed in an aqueous solution state, then smectite minerals are added as they are or smectite minerals swollen with water are added, and the mixture is stirred. It has been found that when the material is then dried, a microporous material with interlayer crosslinking and mainly having pore diameters of 4 nm 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. .

Inorganic particles are fine particles made of polymerized silicic acid (silica colloid)
It is. Usually, the silica colloid solution is alkaline by adding sodium hydroxide or ammonia, and acidic by adding acetic acid or hydrochloric acid. Its size is 4~5 Q
They are nanoparticles.

Regarding the production of the present invention, first, an amount of alkali or acid corresponding to the negative charge of the silica colloid is added to a silica colloid solution in which inorganic particles are dispersed in order to obtain a stable colloidal state.

When this alkali or acid is desalted or deoxidized with a strongly acidic or strongly basic ion exchange resin, if it is alkaline, P
It is desalted and deoxidized to a pH of 1 to 7 or less, and in the case of acidic, a pH of 7 to 9 or less.

Furthermore, if necessary, if desalted, treatment with a weakly basic ion exchange resin will bring the pH to 4 to 7 or less, and if deoxidized, desalted with a weakly acidic ion exchange resin will bring the pH to 4 to 7.

The surface of the inorganic particles in this solution is mostly composed of nranol groups, and the surface charge is reduced. Silica colloid particles with very low surface charge are likely to bond, so to prevent this, store them in a cool place.

When adding this silica colloid solution to the smectite mineral, it may be in a powdered state or it may be 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 smectite mineral closes the interlayers due to the hydrogen smectite mineral due to H+ in the silica colloidal solution. is sandwiched between layers and crosslinked by inorganic particles, an interlayer crosslinked structure is formed,
A porous body is generated.

In smectite minerals, water swells the interlayers and widens the space between the layers. The amount of water required for swelling is at least 0.4 ml per gram of the same mineral, and the upper limit is practically 30 ml.

Inorganic particles range from 0.001 to smectite minerals
Preferably it is 50% by weight. If the amount is less than the above, the inorganic particles will not be distributed between the crystal layers of the smectite mineral, making it impossible 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.

Containing inorganic particles and smectite minerals, the inorganic substances and smectite minerals react and are strongly bonded, so depending on the size of the inorganic particles, a porous body with a pore diameter suitable for the purpose is uniformly produced. It is a microporous material with a diameter of 4 nm or more, and its total specific surface area is approximately 200 to 500 nm.
ty//g, and has a nitrogen capacity of about 0.1 to 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.

f) Add 9.5 g of the inventive example, stir, mix and desalt. The pH of the desalted solution was 3.3. This solution is further deoxidized using a weakly basic ion exchange resin. This solution has a pH of 4.
It was 8.

Did you add 2 g of montmorillonite powder to 1 Q ml of this silica colloid solution and stir and mix? /g
Also, the nitrogen capacity is 0.28 ml 7g, and the specific volume is 0.
44 d/g, and the porosity was 0.64.

Example 2゜20ml solution of the silica colloid solution prepared in Example 1
Add 2 g of montmorillonite to f, mix and mix 4,4
nm, and the specific surface area is 300 cm at a pore diameter of 2 nm.
In addition, the nitrogen capacity is 0.30 m1/g, and the specific volume is 0.4
5 d/g, and the porosity was 0.67.

Example 3゜Example 1. 50ml of silica colloid solution prepared in
Add 2g of montmorillonite to the fl solution and mix with stirring 4.4
The nmk specific surface area is 330 m' at a pore size of 2 nm.
/g, and the nitrogen capacity is 0.32 ml 7g.

The specific volume was 0.48 d/g and the porosity was 0.67.

Example 4゜Example 1. Add 1-2 g of montmorillonite to 5 ml of the silica colloid solution prepared above and mix with stirring to obtain a 4.4 nm
, the specific surface area is 270rr at a pore diameter of 2 nm? /
In addition, the nitrogen capacity is 0.28 m1/g, and the specific volume is 0.4
2 cd/g, and the porosity was 0.67.

Example 5゜ 3.2% silica colloid solution (Catalyst Kasei, No.

8I-350) Strongly acidic ion exchange resin (Dowex No. 50wx 12) 2.0 per 100ml
g″tfA is added, stirred, mixed, and desalted. The pH of the desalted solution was 2.6. This solution was further deoxidized with a weakly basic ion exchange resin. This solution was is 4.2
Met.

2 g of montmorillonite powder was added to 10 ml of this silica colloid solution and mixed with stirring.The specific surface area was 320 m1/g at a pore diameter of 2 nm.
Nitrogen capacity is 0.36 m1/g, specific volume is 0.51 i/g,
The porosity was 0.71.

Example 6. 3.2% silica colloid solution (Catalyst Kasei, No, S
Strongly acidic ion exchange resin (manufactured by DOWEX Co., Ltd. No. 5 owx 12) 9
．． Add 5g, stir, mix and desalt. The pH of the desalted solution was 3.3. This solution is further deoxidized using a weakly basic ion exchange resin. This solution has a pH of 4.8
Met.

2 g of synthetic mica powder (NaTS manufactured by Topy Industries) was added to 1 Q ml of this silica colloid solution, mixed with stirring, and then left to dry in a dry oven at 50° C. for 16 hours. Results of wide-angle X-ray analysis of the product: 0.29 m1/g
The specific volume was 0.48c4/g, and the porosity was 0.60.

Claims (3)

[Claims] (1) A method for producing a microporous material using an interlayer crosslinked material, which comprises mixing a smectite mineral, inorganic particles, 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 production method according to claim 1, wherein the inorganic particles are desalted and deoxidized using an ion exchange resin in a silica colloid solution in which fine particles of polymerized silicic acid are dispersed.