JPS6212612A - Production of clay derivative having porous structure - Google Patents

Abstract

PURPOSE:To produce a clay derivative having high water resistance, improved film forming property and stabilized porous structure, by previously reacting silica sol with one or more of a water-soluble multivalent metal salt and titanium oxide hydrosol and reacting the resultant product with smectite. CONSTITUTION:Silica is converted into polysilicic acid, silica hydrosol and organic silica sol obtained by hydrolyzing a compound expressed by the formula (R is 1-5C straight-chain or branched chain alkyl group). One or more of water- soluble multivalent metal salts and titanium oxide hydrosol are previously reacted with the silica sol to give a product, which is then reacted with smectite to produce the aimed clay derivative having a porous structure.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for producing a clay derivative having a porous structure, and more specifically, it relates to a method for producing a clay derivative having a porous structure. A method for producing a composite of a clay mineral and silica/butyric polyvalent metal fine particles having a distance determined by measurement, which is the sum of the thickness of the clay silicate layer (approximately 9.6A and the interlayer void distance) Regarding. The aim is to provide a new inorganic powder that has a porous structure with a stable and adjustable pore size and is useful as a sorbent, a catalyst, a catalyst carrier, a membrane forming material, an encapsulating agent, a heat insulating agent, etc. It's there.

[Prior art] Smectite, represented by montmorillonite and beidellite, is a group of minerals that make up clay and has a single layered structure, in which exchangeable cations such as sodium, potassium, calcium, and magnesium are present. In order to
It is well known that various organic or inorganic ions and polar molecules are introduced between the layers. Normally, water molecules in the atmosphere are adsorbed to smectite, and 3.
There is a gap (interlayer void) of about 0 to 5.8 layers,
In the living space due to adsorption of water molecules, moisture is easily desorbed not only by heating but also by vacuum degassing operation.
It cannot exist in stability.

On the other hand, attempts have been made to insert bulky polynuclear metal ions as pillars between one layer to support the living room and create a stable porous body. That is, in this method, water-soluble polynuclear metal ions or polynuclear hydroxide metal ions produced by hydrolyzing metal ions with alkali are introduced into the living room of smectite, and then thermally decomposed to build oxide pillars between the layers. Aluminum (C:lay old net, 12.229~
23 [1 (+977), ), Chromium (Amer, M
iner,, 64°830~835(+979),)
, GIaysCla7 Mine
r,, 27.119-124 (1979),), using polynuclear metal ions such as iron [JP-A-58-55.332], the interlayer void is 5-8 A, the specific surface M is 200-40.
A method for obtaining a porous material with a porous material of 0.002/g is known.

[While the invention is to be solved 8] However, when these porous bodies are actually used as adsorbents, catalyst carriers, encapsulating agents, heat insulating agents, etc., the interlayer gap is 5 to 8 A. It was too small and insufficient for application to molecules with large effective diameters. In addition, the conventional method has restrictions on the types of metals that can be used, and for example, it has not been possible to introduce silica or titanium oxide, which is prized as a pigment due to its high refractive index, into living rooms. This is an attempt to solve these problems all at once.

[Means for solving the problem] Under such circumstances, the present inventors have developed a method that has high heat resistance stability and
A support that should be introduced into a living room in order to obtain a clay derivative with a large living distance and a wide specific surface area is stable even at temperatures above 500°C.

It was considered that silica which has various polymerization forms and can be converted into an oxide having a large degree of polymerization, that is, a high molecular weight, is suitable. However, when comparing the pH of various hydroxides and oxides that do not have a surface potential of 1, that is, the zero charge point, Al(OH)
35.1. Zr0z 10.5°Ti02B, 7.
Si (h 1.8, therefore silica is put, s
In the above, as a result of being negatively charged, 1 it is not introduced between the clay layers, which are originally negatively charged, due to electrostatic repulsion, so,
As a result of various studies to maintain positive charge on the silica surface, we found that silicon alkoxide Si(OR)n (R represents a linear or branched alkyl group having 1 to 5 carbon atoms) was hydrolyzed. (To distinguish from commercially available silica hydrosols and organic silica sols, the polymer of silicic acid obtained by hydrolysis of silicon alkoxide is referred to as polysilicic acid for convenience), silica sols such as silica hydrosols and organic silica sols. value or 4
1 selected from the group consisting of a water-soluble metal salt of 1 and 1 selected from the group consisting of Ti(OR)s (where R is as previously described) or a titanium oxide hydrosol obtained by hydrolyzing the same and then peptizing it with an acid. By using silica and oxidized polyvalent metal hydrosil which can be obtained by reacting seeds or more, a clay derivative with a porous structure having a larger separation distance and a wider specific surface area than before can be changed, and the obtained clay derivative is also water resistant. The present invention was completed based on the discovery that the film has high properties, high heat resistance, and excellent film forming performance.

That is, one aspect of the present invention is to react silica sols with one or more selected from the group consisting of trivalent or tetravalent water-soluble metal salts and titanium oxide hydrosol to produce silica/polyvalent metal hydrosil oxide, This is a method of producing a clay derivative having a porous structure by reacting this with smectite.

The clay mineral used in the present invention is preferably water-swellable smectite such as montmorillonite, but it is not limited to natural clay minerals, and synthetic clay minerals may also be used. Various artificial fluorine layered silicates having the following properties can also be used. These natural and synthetic clay minerals have a 4I crystal structure formed by stacking two-dimensional silicates with a thickness of approximately 8.8A, but the shape of the crystallites is due to the two-dimensionality of the bonds. Reflecting this, it is plate-shaped, and a two-dimensional gap similar to a living room inside the crystal is formed at the grain boundaries where crystal grains overlap. Note that the term "interlayer" as used in the present invention includes not only silicate living spaces inside crystallites but also grain boundaries between such crystallites.

In addition, in the present invention, the silica/polyvalent metal oxide hydrosyl to be inserted into the smectite living room is Si(OR)s
Silica sols selected from the group consisting of polysilicic acid, silica hydrosol, and organic silica sol obtained by hydrolyzing (R is as described above), water-soluble salts of titanium, zirconium, aluminum, and iron, and Ti (OR) 4 [R is as already mentioned]
Alternatively, it can be obtained by the action of one or more selected from the group consisting of titanium oxide hydrosols obtained by hydrolyzing this and then peptizing it with an acid. Si
(OR)a is preferably silicon tetraethoxide in which R is an ethyl group, which is available at low cost.

Hydrolysis of silicon tetraethoxide is carried out by adding a mixture of ethanol as a solvent, water as a decomposition agent, and acid as a catalyst and heating the mixture from room temperature to 80°C. Hydrolysis conditions are arbitrarily selected depending on the polymerization form and degree of polymerization, i.e., molecular weight, of the polysilicic acid to be prepared (Ceramics Journal, Iku, 242-247 (11384)
), that is, the broadcast text is H2O/Si(OC2Hs)s
Below, a chain polymer is generated and H2O/Si(
In OC2Hs)s~5, a chain polymer is produced in the early stage of polymerization, but a three-dimensional network polymer is produced in the latter stage. Furthermore, it has been reported that when H20/Si(OC2Hs)s = 20, a three-dimensional network polymer is formed from the initial stage.The hydrolytic polymerization of silicon tetraethoxide in the present invention is
The above H20/S i (OC2Hs)a = 2 ~
Although it is possible to conduct the polymerization under conditions outside the range of 20, H2O/Si(OC2Hs)4= can be carried out without causing rapid viscosity increase and gelation, and in a convenient and appropriate polymerization time.
2 to 20 is desirable, and for the same reason, Si(OC2
The concentration of Hs)4 is preferably 30 to 70%, and as the catalyst acid, inexpensive mineral acids such as hydrochloric acid, nitric acid, and sulfuric acid are used.

Next, as a silica source, we can use not only polysilicic acid obtained by hydrolyzing silicon tetraethoxide as described above, but also colloidal particles with a diameter of 1 to 100 sJ using water as a dispersion medium.
It is possible to use a commercially available silica hydrosol of L or an organic silica sol using an organic solvent such as methanol, ethanol or isopropyl alcohol as a dispersion medium.

Furthermore, it goes without saying that the object of the present invention can also be achieved by using several types of polysilicic acid, silica hydrosol and organic silica sol in combination.

In addition to titanium tetraisopropoxide or titanium oxide hydrosol obtained by hydrolyzing it and peptizing it with acid, titanium sources include titanium tetrachloride, titanium oxysulfate, and other inexpensive water sources. Soluble titanium salts are also available. Furthermore, it goes without saying that several of the above titanium sources may be used in combination.

Titanium oxide hydrosol is prepared by using titanium alkoxide Ti(OR)4 [R is as mentioned above], generally cheap and easily available impropoxide in which R is an isopropyl group. A white precipitate formed by adding it to a 4-fold molar acid solution is gradually dissolved in the acid to obtain a clear solution. In addition to the method described above in which titanium alkoxide is added to an acid solution and the hydrolysis and peptization reactions proceed simultaneously, a method is also adopted in which titanium alkoxide is hydrolyzed in advance and then a predetermined amount of acid is added to peptize the titanium alkoxide. Ru. Furthermore, the desired titanium oxide hydrosol can also be obtained by introducing titanium alkoxide into a polysilicic acid solution that previously contains the acid required for peptization.

The acid used for peptization may be an organic acid or an inorganic acid, but mineral acids such as hydrochloric acid, nitric acid and sulfuric acid are preferred;
Room temperature is sufficient for the reaction temperature at that time. Examples of water-soluble salts of zirconium include zirconium oxychloride, zirconium tetrachloride, and zirconium oxynitrate, but zirconium oxychloride is preferred because it is inexpensive, easily available, and easy to handle. Examples of salts of aluminum and iron include hydrochloric acid, sulfuric acid, and zirconium oxychloride. In addition to mineral acid salts such as nitric acid, double salts such as iron oxide and aluminum alum, and complex ion solutions such as polyaluminum chloride and trinuclear iron acetate ions are also used.

Silica/polyvalent metal hydrosil oxide is a silica source selected from polysilicic acid obtained by hydrolyzing silicon alkoxide, reprinted silica hydrosol, and organic silica sol, water-soluble salts of titanium, zirconium, aluminum, and iron, and titanium oxide hydrosilica. It can be obtained by the action of one or more selected from the group consisting of sols.

The reaction temperature at this time is preferably room temperature to 80°C.

The molar ratio of Si to polyvalent metal is 0.5 to 40.
The number may be within the range of 1 to 20, but #1 to 20 is preferable when considering thermal properties and film forming performance.

The clay derivative having a porous structure of the present invention can be produced, for example, by adding the above-mentioned silica/polyvalent metal hydrosyl oxide to an aqueous suspension of smectite under stirring, heating if necessary to accelerate the reaction, and then using a conventional method. Wash and dehydrate to remove the product.
Manufactured by drying. At this time, the concentration of the smectite suspension is preferably 0.1 to 5 w/ma% (hereinafter simply expressed as %), and the amount of silica/polyvalent metal hydrosyl oxide added is determined by the cation exchange capacity of the smectite (hereinafter simply expressed as %). C
5 to 4 as (Si+Ti) for (abbreviated as EC)
The amount is preferably 0 times, and the temperature during production is preferably room temperature to 60°C.

According to the method of the present invention, the degree of polymerization of polysilicic acid obtained by hydrolysis of silicon tetraethoxide and silica 1
By changing the ratio of polyvalent metal to Si in polyvalent metal hydrosyl monoxide, the living distance and specific surface area could be controlled. Clay composites with the largest interlayer voids were obtained when silicon and polyvalent metal were used in amounts of 10~30 and 1~3 times the CEC of clay, respectively. That is, the distance between the living room is 25~45^, the specific surface! 113
A porous body of 00 to 400 m2/H was able to be produced.

[Effects of the Invention] The clay derivative having a porous structure of the present invention obtained in this way has a large distance, and the size of the distance can be adjusted, so that an object of a desired size can be attached to it. It can be supported in gaps, is extremely stable, and has high water resistance, heat resistance, and excellent film forming properties, so it can be used as an adsorbent, catalyst, catalyst carrier, pigment, encapsulant, It can be widely used in various applications such as film forming materials, coating agents, and heat insulating agents.

[Example] EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1 x ta/-JLz3ml,! : 2) 111% to 1
72.5 ml of (1) G mixture was added to 10.4 ml of silicon tetraethoxide and stirred at room temperature for 2 hours to obtain a polysilicic acid solution. Separately, 1.48 g of titanium tetraisopropoxide was added to 20 l of IN hydrochloric acid, and the mixture was stirred for 30 minutes until the white precipitate was dissolved to obtain a transparent sol.

This sol was added to the previously prepared polysilicic acid solution and stirred at room temperature for 10 minutes to obtain a transparent silica/titanium oxide hydrosol. This sol was mixed with montmorillonite from Yamagata Prefecture (
Manufactured by Kunimine Industries, product name "Kunivia F" cation exchange capacity fi 100ml Ia/100g) 5.0g to 6
001 was dispersed in water over 10 minutes while stirring, and stirring was continued for 1 hour at 50°C. The main component is centrifuged, washed with water, and dried to a grayish white powder7.
I gained 9g. The obtained powder is 67.5% as SiO2.
, 4.8% as Ti07.

Example 2 A polysilicic acid solution was obtained in the same manner as in Example 1. To this solution was added 1.8 g of a 25 w/w % titanium tetrachloride aqueous solution diluted with 4N hydrochloric acid and stirred at room temperature for 10 minutes to obtain a transparent silica titanium oxide hydrosol. Using this sol, the same procedure as in Example 1 was carried out to obtain an off-white powder.

Example 3 In Example 2, a solution of polysilicic acid was obtained by changing the stirring time to 15 hours. Furthermore, 4° Og of a 20 w/w % titanium oxysulfate solution was added to this solution instead of the titanium tetrachloride solution, and the same procedure as in Example 2 was repeated to obtain an off-white powder.

Example 4 In Example 1, ethanol 31 and 2N hydrochloric acid 7.51
A solution of polysilicic acid was obtained using the mixed solution and 31.2 g of silicon tetraethoxide. Separately, 4.2 g of titanium impropoxide was added to IN salt 1% j 80ffi1 and stirred for 30 minutes until the white precipitate formed was dissolved.
I got a transparent sol. Using this sol, the same procedure as in Example 1 was carried out to obtain a white powder.

Example 5 In Example 2, 2.01% of ethanol and 1.01% of 2N hydrochloric acid were used.
A solution of polysilicic acid was obtained using a mixed solution of No. 51 and 6.2 g of silicon tetraethoxide. 25 w/w% in this solution
15.2 g of titanium tetrachloride solution was added and the same procedure as in Example 2 was carried out to obtain a white powder.

Example 6 In Example 1, ethanol 181. A mixture of 0.81 parts of water and 1.0 parts of 0.5N hydrochloric acid was mixed with 10 parts of silicon tetraethoxide. - Added to 4g and stirred at 80°C for 4 hours to obtain a solution of polysilicic acid. The following was carried out in the same manner as in Example 1,
A grayish white powder was obtained.

Example 7 Ethanol 31, water 3.51 and 0.5N hydrochloric acid 11
The mixed solution was added to 10.4 g of silicone tetraethoxide and stirred at 80° C. for 90 minutes to obtain a solution of polysilicic acid. Add 3.8% of 25w/w% titanium tetrachloride solution to this solution.
The procedure was repeated in the same manner as in Example 2, and a grayish-white powder was obtained.

Example 8 Silica hydrosol (manufactured by Catalysts & Chemicals Industry Co., Ltd., trade name S-208
, SiOz content 1119.4w/w%) 2 to 15.5g
7.8 g of 5 w/w % titanium tetrachloride solution was added and heated at 60° C. for 20 minutes to obtain a solution of silica Φ titanium oxide hydrosol. Add 5g of montmorillonite to 6g of this sol solution.
The mixture was added to a solution of No. 001 dispersed in water, heated at 60° C. for 2 hours, and the same procedure as in Example 1 was carried out to obtain a white powder.

Example 9 Organic silica sol (
Manufactured by Catalyst Chemical Industry, product name 03CAL-1232, Si0
2 (31.4 w/w%) was used and the same procedure as in Example 8 was carried out to obtain a white powder.

Example 10 In Example 1, 1.51 ethanol and 191 2N salt
．． 5ml of mixed solution and 5.2g of silicone tetraethoxide
A solution of polysilicic acid was obtained using Example 8
Add 7.7 g of the silica hydrosol used in and 7.6 g of 25 w/w % titanium tetrachloride solution and stir at room temperature for 10 minutes to obtain a silica/titanium oxide hydrosol. Disperse 5 g of montmorillonite in 801 water. The mixture was heated at 80° C. for 5 hours, and the same procedure as in Example 1 was carried out to obtain a white powder.

Example 11 In Example 1, titanium tetraisopropoxide and 1
'L! Zirconium oxychloride solution (Zr(:20% as 14) was used instead of titanium oxide hydrosol prepared from acid.
Containing) 5.1g was used in the same manner as in Example 1,
A grayish white powder was obtained.

Example 12 In Example 8, 25 w/w% titanium tetrachloride solution? ,
8. The procedure was repeated in the same manner as in Example 8 except that 10.2 g of the zirconium oxychloride solution of Example 11 was used instead of 10.2 g of the zirconium oxychloride solution of Example 11, to obtain an off-white powder.

Example 13 In Example 1, 2Q instead of titanium oxide hydrosol
Using 4.1 g of w/w% ferric chloride solution, the actual flow side 1
A brown powder was obtained in the same manner as above.

Example 14 In Example 2, 1.9 g of 25 w/v% titanium tetrachloride
The procedure was repeated in the same manner as in Example 2 except that 3.3 g of a 20 w/w % aluminum chloride solution and 3.8 g of a 25 w/w % titanium tetrachloride solution were used instead, to obtain a white powder.

Reference Example 1 A polysilicic acid solution was obtained in the same manner as in Example 1. This solution was reacted with montmorillonite in the same manner as in Example 1 to obtain a gray powder.

Reference Example 2 In Example 2, only titanium oxide hydrosol was reacted with montmorillonite, and the same procedure as in Example 1 was carried out to obtain an off-white powder.

Reference Example 3 In Example 2, only titanium tetrachloride was reacted with montmorillonite without using polysilicic acid, and the same procedure as in Example 2 was repeated to obtain an off-white powder.

Tables 1-1 and 1-2 show a list of Examples of the present invention, and the living distance measured by X-ray powder diffraction and the specific surface area measured by nitrogen gas adsorption method for the products obtained in the Examples and Reference Examples. The porous clay derivatives of the present invention, which were measured and the results were shown, all have large living distances and specific surface areas, while in the case of reference examples lacking either silica or titanium oxide components, Those values were extremely small.

(Leaving space below) Test Example 1 In order to investigate the heat resistance stability of the samples produced in Examples 1 and 7, the samples were treated in air at a temperature of 200 to 800°C for 4 hours, and then cooled to room temperature to determine the interlayer distance. Changes in specific surface area were investigated. The results are shown in Table 2.

(Hereinafter in the margin) Table 2 (Hereinafter in the margin) As is clear from Table 2, the porous clay derivative of the present invention has excellent heat resistance stability, and even when heated to 600°C, there is no shrinkage in the living distance or a decrease in the specific surface area. It was very little.

Claims (1)

[Claims] 1. A product obtained by reacting a silica sol with one or more selected from the group consisting of a water-soluble polyvalent metal salt and a titanium oxide hydrosol, and reacting the product with smectite. A method for producing a clay derivative having a characteristic porous structure. 2. Silica sols are Si(OR)_4 [R is carbon number 1~
5 representing a linear or branched alkyl group], the porous structure according to claim 1 selected from the group consisting of polysilicic acid, silica hydrosol, and organic silica sol. A method for producing a clay derivative having 3. The method for producing a clay derivative having a porous structure according to claim 1, wherein the water-soluble polyvalent metal salt is selected from the group consisting of titanium, zirconium, aluminum and iron salts. 4. Titanium oxide hydrosol is Ti(OR)_4 [R represents a linear or branched alkyl group having 1 to 5 carbon atoms]
Alternatively, a method for producing a clay derivative having a porous structure according to claim 1, which is obtained by hydrolyzing this and then peptizing it with an acid.