JPH1087315A - Layered silicic acid and its production method, layered silicate - Google Patents

Abstract

(57) [Problem] To provide a layered silicic acid, a method for producing the same, and a layered silicate which are made of a silicon dioxide tetrahedron sheet without inversion and have a uniform shape and size. SOLUTION: A clay mineral having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide remains, and the silicon dioxide layer is formed by silicon dioxide. It is composed of layered silicon dioxide having a six-membered ring skeleton, and has crystallographic regularity. The clay mineral is produced by allowing an acid to act on the clay mineral.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layered silicic acid produced from a clay mineral, a method for producing the same, and a layered silicate having a structure similar to that of the layered silicic acid.

[0002]

2. Prior Art In the layered silicate having a layered six-membered ring skeleton on silica, as the natural origin, kanemite _{(NaHSi 2 O 5 · 3H 2} O), makatite (N
_{a 2 Si 4 O 9 · 5H} 2 O), Ayler Ait (Na ₂
Si ₈ O ₁₇ .xH ₂ O), magadiite (Na ₂ Si)
₄ O ₂₉ xH ₂ O), Kenyaite (Na ₂ Si ₂₀ O ₄₁₎
· XH ₂ O) are known.

The same layered silicate artificially synthesized includes α- / β-Na ₂ Si ₂ O ₅ and Li ₂
Si ₂ O ₅ and KHSi ₂ O ₅ are known. The layered silicate can be easily obtained by bringing the above-mentioned layered silicate into contact with an acid. Conversely, a layered silicate can be easily obtained by allowing an alkali metal or the like to act on the layered silicate. Generally, a substance in which protons in silicate bonds in a layered silicic acid are replaced by a cation such as an alkali metal is a layered silicate, and the basic skeleton of both structures is almost the same.

[0004] The crystal structure of the above-mentioned layered silicic acid and layered silicate is known for α- / β-Na ₂ Si ₂ O ₅ , KHSi ₂ O ₅ and macatite, but has been determined for others. Absent. However, the above-mentioned layered silicic acid and layered silicate are similar in various properties to each other.
Each of the above-mentioned layered silicic acid and layered silicate is shown in FIG.
As shown in the figure, the silicon dioxide tetrahedron forms a connected layer while forming a six-membered ring in the plane direction, and the vertices of the silicon dioxide tetrahedron alternately face the front and back of the layer surface. It can be regarded as having a structure in a state. Therefore, the polarity of the front and back of the layer surface becomes uniform.

[0005] Incidentally, it is known that the above-mentioned layered silicate is contained in the following clay minerals. That is, the clay mineral is a substance having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet and an octahedral sheet of another metal oxide as shown in FIGS. is there.
By adding an acid to the clay mineral, metal ions forming the octahedral sheet are eluted, and a layered silicic acid composed of a silicon dioxide tetrahedral sheet can be obtained.

For example, there is known a method for producing activated clay by acid-treating a clay mineral containing montmorillonite as a main component and removing octahedral sheets in the clay mineral to some extent. The activated clay has an increased surface area as compared with the clay mineral used as a raw material, and is excellent in adsorption ability and catalytic ability.

Japanese Patent Application Laid-Open No. 62-36015 discloses that a magnesium silicate clay mineral such as sepiolite is subjected to a more powerful acid treatment. In this case, metal ions in almost all octahedral sheets in the clay mineral used as the raw material are eluted, and amorphous silica can be obtained. The silicic acid remains in the form of a magnesium siliceous clay mineral, which is a raw material, and has a laminar or strip shape.

A recent report (Chem. Mate)
r. According to 1995, 7, 2241), antigolite, a kind of magnesium siliceous clay mineral, is used in an amount of 3 to 5%.
Among the silicic acids obtained by treatment with sulfuric acid of M concentration,
The silicic acid containing MgO by weight was found to be a layered silicic acid having a structure similar to that of the raw material antigolite and having crystallographic regularity.

[0009]

[Problems to be Solved] However, the details (shape and shape) of the silicic acid and
The nature, application, and synthesis method are unknown, and it is particularly useful in industrial applications. Has not yet been obtained.

In the above-mentioned layered silicic acid, since the vertices of the tetrahedron are aligned in the same direction, the polar direction between the layers is aligned in the layer direction, or the layers having high polarity and the layers having close polarity are alternately arranged. When used as a host to form an inclusion compound, it has the industrial property of providing a new inclusion compound in which a guest compound is oriented in a specific direction and is included, or is included every other layer. It is a very useful substance because of its application.

[0011] In addition, a method of obtaining layered silicic acid by acid treatment of a clay mineral exemplified as a conventional technique is described. The clay mineral used in these methods is a magnesium silicate clay mineral such as sepiolite and antigolite. The vertices of the silicon dioxide tetrahedron in the clay mineral are not aligned with the octahedral sheet.

[0012] For this reason, in the above clay mineral, the metal oxide of the octahedral sheet easily comes into contact with the acid, so that the acid treatment is easy. However, the layered silicic acids obtained from the above clay minerals are all in a state where the directions of the vertices of the silicon dioxide tetrahedron are not uniform. That is, the structure of the obtained layered silicic acid is composed of layered silicon dioxide having a layered six-membered ring skeleton of silicon dioxide, and three or more continuous silicon dioxide tetrahedrons on one crystal axis are periodically formed at the top of the layer. The orientation is reversed. That is, the layered silicic acid has a uniform polarity on both sides of the layer surface.

An object of the present invention is to provide a layered silicic acid, a method for producing the same, and a layered silicate which are made of a silicon dioxide tetrahedral sheet without inversion and have a uniform shape and size.

[0014]

A clay mineral having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide is provided. Are layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide and further having crystallographic regularity.

As shown in FIGS. 3 and 4, the clay mineral comprises a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide. As shown in FIGS. 3 and 4, a tetrahedral silicon dioxide sheet is a sheet-like skeleton in which a tetrahedron occupied by oxygen at its apex and silicon at its center forms a six-membered ring to form a six-membered ring. It was made.

The expression "no reversal" means that the vertices of the silicon dioxide tetrahedron are aligned in one direction, so that the polarity distribution of the surface of the silicon dioxide tetrahedron sheet is different between the front and the back. doing.

Further, the metal oxide octahedral sheet is
As shown in FIG. 3 (a), the vertices are oxygen and hydroxide ions,
A large number of octahedrons occupied by metal elements at the center are combined in a plane, forming a sheet-like skeleton.

The clay mineral having a 1: 1 layer structure is, as shown in FIG. 3, a structure in which a single tetrahedral sheet and a single octahedral sheet are paired and a large number of these layers are stacked. Have As shown in FIG. 4, the clay mineral having a 2: 1 layer structure has a structure in which tetrahedral sheets are arranged on both sides of an octahedral sheet as a set, and a large number of these are stacked. It is.

The metal elements constituting the octahedron include aluminum (1: 1 layer structure and 2: 1 layer structure), iron (2: 1 layer structure), and magnesium (1: 1 layer structure and 2: 1 layer structure). One-layer structure), nickel (2: 1 layer structure), manganese (2: 1 layer structure), chromium (2: 1 layer structure), and the like.

The following are examples of the above clay minerals.
Examples of the clay mineral having a 1: 1 layer structure include kaolinite, dickite, nacrite, halloysite having an octahedral sheet of Al, chrysotile and lizardite having an octahedral sheet of Mg, and the like.

Further, as the clay mineral having a 2: 1 layer structure, pyrophyllite having an octahedral sheet of Al,
Mica, montmorillonite, beidellite, dioctahedral vermiculite, etc. and talc having Mg octahedral sheet, phlogopite, saponite, hectorite, Mg vermiculite, etc., and trioctahedral vermiculite having Fe octahedral sheet, non Tolonite and the like can be mentioned.

The operation and effect of the present invention will be described below. The layered silicic acid according to the present invention is in a state where the clay mineral having the structure as shown in FIGS. 3 and 4 remains.
That is, as shown in FIG. 1, the above-mentioned layered silicic acid is composed of layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide, and the skeleton of silicon dioxide constituting the layered silicon dioxide is a carbon dioxide present in the clay mineral. It consists of a silicon skeleton.

As shown in FIGS. 3 and 4, the clay mineral is composed of a silicon dioxide tetrahedral sheet and a metal oxide octahedral sheet, and the silicon dioxide tetrahedral sheet constituting the silicon dioxide tetrahedral sheet is formed. The vertices all point in the direction of the octahedral sheet. For this reason, the vertices of the silicon dioxide tetrahedron constituting the layered silicic acid of the present invention, which has inherited the skeleton, are aligned in one direction as shown in FIG.

As described above, the polarity distribution of the layered silicic acid is
It is different on the front and the back of the layer surface and is aligned in one direction between the layers. Further, in the layered silicic acid in which the clay mineral of the 2: 1 layer structure remains, the apex of the silicon dioxide tetrahedron faces the bottom surface of the other silicon dioxide tetrahedron on the adjacent layer surface (FIG. 4B). reference). Therefore, a hydrogen bond is formed between the two layers, and the overall structure is further stabilized.

For this reason, the above-mentioned layered silicic acid is not included in the conventional layered silicic acid because of the non-uniformity of different polarities between the front and back layers. It has the property of inclusion, for example,
It can be used as a carrier having selectivity in size and orientation of catalysts, pigments, pharmaceuticals, etc. and a selective adsorbent.

Further, the above-mentioned layered silicic acid remains in the form of a natural clay mineral having a uniform size and shape as a raw material, so that its size and shape are uniform. As a result, a supported catalyst and an inclusion compound (adsorbent) having a uniform size and shape can be provided, and the effect of exhibiting the action can be obtained more uniformly and stably. In addition,
The above layered silicic acid is considered as a new layered silicic acid.

The fact that the layered silicic acid according to the present invention remains layered and has crystallographic regularity, leaving a silicon dioxide skeleton in the clay mineral, is shown by transmission electron micrographs. It can be confirmed using observation and X-ray diffraction measurement.

As described above, according to the present invention, it is possible to provide a layered silicic acid made of a silicon dioxide tetrahedral sheet without inversion and having a uniform shape and size.

The above-mentioned layered silicic acid contains impurities in the form of metal atoms of 1 to 7 atom% with respect to silicon atoms, and has a specific surface area of 7% determined by the BET method by nitrogen adsorption.
It is preferably from 00 to 50 m ² / g. This indicates that the layered silicate has a high content of silicon dioxide and that there is a space available between layers. Therefore, an effect of acting as a catalyst carrier or an adsorbent having high heat resistance can be obtained.

Next, according to the second aspect of the present invention, the layered silicic acid is a square or polygonal sheet piece, and the sheet diameter of the layered silicic acid is in the range of 10 nm to 50 mm. The sheet diameter of 50% or more of the layered silica is -40 to +4 of the sheet diameter showing the largest distribution among all the layered silicas.
It is preferably within the range of 0%.

As a result, it is possible to obtain the effect of providing a layered silicic acid having various sizes and a uniform sheet shape. If the sheet diameter is less than 10 nm, it may be difficult to laminate the layered silicic acid. On the other hand, if it is larger than 50 mm, it may be difficult to obtain a naturally occurring clay mineral.

Further, only less than 50% of the total layered silicic acid
If it is not included in the range of −40% to + 40% of the sheet diameter showing the largest distribution, the size of the sheet may be uneven.

Next, a third aspect of the present invention relates to the following: a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide.
Manufactures layered silicon dioxide having layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide, with the remains of clay mineral having a one-layer structure or a two-layer structure remaining, and further having a crystallographic regularity In doing so, there is provided a method for producing a layered silicic acid, characterized in that an acid acts on the clay mineral.

According to the present invention, it is possible to obtain an excellent layered silicic acid comprising a silicon dioxide tetrahedral sheet without inversion and having a uniform shape and size. Further, according to the present invention, it is possible to obtain the above-mentioned layered silicic acid having higher industrial value than clay minerals by an easy means of acting an acid. As the clay mineral, the same one as described above can be used.

Next, the manufacturing method according to the present invention will be described in detail. It is generally considered that the reaction conditions under which an acid acts on the clay mineral, that is, the acid treatment, are a lower concentration of the acid, a shorter reaction time, and a reaction under a pressurized condition. However, it basically depends on the type of clay mineral.

For example, in a clay mineral having a 1: 1 layer structure with an octahedral sheet of aluminum oxide (for example, 1
Acid treatment under pressure was preferred (using 2N acid and reaction time of 19 hours), but for clay minerals having a 1: 1 layer structure of octahedral sheets of magnesium oxide (eg, Acid treatment under normal pressure (when 3N acid is used and the reaction time is 4 hours) is preferable to give a layered silicic acid having crystallographic regularity.

It is preferable that the acid used in the acid treatment has such a high solubility in water that aluminum salts and magnesium salts formed as a result of the reaction can be removed in the post-treatment step. Specific examples include aqueous solutions of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and the like, and mixtures thereof.

The concentration of the acid is preferably 3 to 12N. When the acid treatment is performed at a concentration of less than 3N, the elution of aluminum oxide may be insufficient. On the other hand, handling of 12N or more acid may be dangerous. The amount of acid used for this acid treatment is 10
An aqueous solution in which at least 2 mol or more of an acid is dissolved per 0 g is preferable. If the amount of the acid is smaller than this, the metal constituting the octahedral sheet of the clay mineral may not be sufficiently eluted.

The reaction time of the acid treatment is preferably 4 to 20 hours. If the reaction time is less than 4 hours, the metal oxide constituting the octahedral sheet of the clay mineral may not be sufficiently eluted. Further, after 20 hours, the reaction of the acid treatment sufficiently reaches equilibrium, so that no further reaction time is required. The reaction temperature of the acid treatment is not particularly limited, but is preferably 70 to 150 ° C.

In particular, as a method of acid treatment under a pressurized condition, it is preferable to immerse a clay mineral in these aqueous acid solutions and heat and stir under a pressurized condition. In this case, an autoclave can be used as a pressurized reactor.
Further, as a method of acid treatment under normal pressure conditions, it is preferable to immerse the clay mineral in these acid aqueous solutions and heat and stir under normal pressure conditions in a reactor equipped with a cooling concentrator. In addition, it is particularly preferable that the acid treatment under normal pressure conditions is performed by using a 3 to 6N acid at 80 to 100 ° C for 4 to 12 hours.

Next, the shape and size of the layered silicic acid can be selected by selecting the clay mineral. That is, according to the present invention, many types of clay minerals can be used as a raw material, and layered silicic acid having different sizes and shapes can be obtained by selecting the type of the clay mineral.

Further, by selecting either use of a clay mineral having a 1: 1 structure or use of a clay mineral having a 2: 1 structure, a layered silicic acid having a different polarity distribution can be obtained. That is, the layered silicic acid obtained from the clay mineral having a 1: 1 structure has reversed polarity on both sides (see FIG. 1). The layered silicic acid obtained from the clay mineral having a 2: 1 structure has the same polarity on both sides.

Next, a fifth aspect of the present invention relates to a clay mineral having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide. Is composed of layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide and further having no crystallographic regularity.

The layered silicic acid according to the present invention is the same as the layered silicic acid according to claim 1, except that it does not have crystallographic regularity, that is, it is amorphous. And
The above-mentioned layered silicate is amorphous and has a property that the interval between layers is not uniform, but rather the layering is greatly disturbed, so that delamination is very easy.
It can be uniformly mixed with other compounds to provide a new composite compound.

Next, as in the sixth aspect of the present invention, the layered silica is a square or polygonal sheet piece, and the sheet diameter of the layered silica is in the range of 10 nm to 50 mm. The sheet diameter of 50% or more of the layered silica is -40 to +4 of the sheet diameter showing the largest distribution among all the layered silicas.
It is preferably within the range of 0%.

According to this, as in the case of the second aspect, it is possible to provide a layered silicic acid having various sizes and a uniform sheet shape. Further, other details are the same as those of the second aspect.

Next, a seventh aspect of the present invention is a clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide. In which layered silicon dioxide having a layered six-membered ring skeleton of silicon dioxide and having a layered six-membered ring skeleton and having no crystallographic regularity is produced. In the method for producing layered silicic acid.

The method for producing layered silicic acid according to the present invention is the same as the method for producing layered silicic acid according to claim 3, except that it has no crystallographic regularity, ie, it is amorphous. . According to the present invention, as in the first aspect, an excellent layered silicic acid made of a silicon dioxide tetrahedral sheet without inversion and having a uniform shape and size can be obtained. Further, according to the present invention, it is possible to obtain the above-mentioned layered silicic acid having higher industrial value than clay minerals by an easy means of acting an acid.

Next, the manufacturing method according to the present invention will be described in detail. The reaction conditions for applying an acid to the clay mineral, that is, for performing the acid treatment, are generally higher than those in claim 3 in order to lose crystallographic regularity from the obtained layered silicic acid. Concentrations of acid, longer reaction times and reactions under pressurized conditions may be suitable. However, basically, it depends on the type of clay mineral, and it is possible to obtain an amorphous layered silicic acid even under conditions of normal pressure, lower concentration of acid and shorter reaction time.

However, a clay mineral having a 1: 1 layer structure with an octahedral sheet of aluminum oxide (for example, 1
The acid treatment under pressure (when using 2N acid and the reaction time is 19 hours) cannot lose the crystallographic regularity. For example, the reaction time is 4 hours using 3N acid. The acid treatment under normal pressure conditions (assuming the above conditions) resulted in a layered silicic acid having no crystallographic regularity. The reaction conditions for acid treatment of various clay minerals could not be defined by the amount of octahedral sheet metal atoms remaining in the obtained layered silica.

It is preferable that the acid used in the above acid treatment has such a high solubility in water that aluminum salts and magnesium salts generated as a result of the reaction can be removed in the post-treatment step. Specific examples include aqueous solutions of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and the like, and mixtures thereof.

The concentration of the acid is preferably 3 to 12N. If the acid treatment has a concentration of less than 3N, the elution of aluminum oxide may not be sufficient. On the other hand, handling of 12N or more acid may be dangerous. In particular, when an acid of 8 to 12N is used, the reaction rate is increased, which is more preferable. The amount of acid used in this acid treatment is at least 2 m per 100 g of clay mineral.
It is preferably an aqueous solution in which at least ol of the acid is dissolved.
If the amount of the acid is smaller than this, the metal constituting the octahedral sheet of the clay mineral may not be sufficiently eluted.

The reaction time of the acid treatment is preferably 8 to 20 hours. When the reaction time is less than 8 hours, among the metal oxides constituting the octahedral sheet of the clay mineral, especially the metal oxides other than magnesium, ie, the oxides of aluminum and iron, are not sufficiently eluted, and the layered silicic acid is not sufficiently dissolved. The amount of the metal atoms of the remaining metal oxide is 3 at.
om% may not be able to be reduced. Further, after 20 hours, the reaction of the acid treatment sufficiently reaches equilibrium, so that no further reaction time is required. In addition,
For the same reason as above, the reaction temperature of the above acid treatment is 90 ° C.
It is preferable that it is above.

As a method of acid treatment under normal pressure conditions, a clay mineral is immersed in an aqueous solution of these acids and heated and stirred in a reactor equipped with a cooling concentrator under normal pressure conditions. preferable. It is particularly preferable that the reaction is carried out at a reflux temperature of 100 ° C. or higher by a sufficient heating operation. As a method of acid treatment under pressurized conditions, it is preferable to immerse the clay mineral in these aqueous acid solutions and heat and stir.
In this case, an autoclave can be used as a pressurized reactor. The reaction temperature in this case is 120
It is particularly preferred that the temperature is not lower than ° C.

Under the above reaction conditions, delamination of the clay mineral proceeds, so that when the octahedral sheet of the metal oxide is eluted and removed, the silicon dioxide tetrahedral sheet is crystallized. Loss of regularity. However, even in this state, the silicon dioxide tetrahedral sheet remains the silicon dioxide skeleton in the clay mineral, and the orientation of the vertices of the silicon dioxide tetrahedron is inherited by the obtained layered silica.

Next, by selecting the clay mineral, the shape and size of the layered silicic acid can be selected. That is, as in the case of the fourth aspect, many types of clay minerals can be used as a raw material, and by selecting the type of the clay mineral, layered silicic acid having different sizes and shapes can be obtained.

Further, by selecting whether to use a clay mineral having a 1: 1 structure or to use a clay mineral having a 2: 1 structure, it is possible to obtain layered silicic acid having a different polarity distribution. That is, the layered silicic acid obtained from the clay mineral having a 1: 1 structure has reversed polarity on the front and back of the layer surface, and the direction of the polarity between the layers is aligned in the layer direction (see FIG. 1). The layered silicic acid obtained from the clay mineral having a 2: 1 structure has reversed polarity on the front and back surfaces of the layer, and layers having high polarity and layers having low polarity are alternately arranged.

A ninth aspect of the present invention relates to a clay mineral having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide. Is a layered silicate comprising layered silicon dioxide having a layered six-membered ring skeleton of silicon dioxide and having crystallographic regularity.

The layered silicate according to the present invention can be produced by a method in which an alkali metal compound is allowed to act on the layered silicic acid according to claim 1 to exchange protons of silanol groups with alkali metal cations. It is a layered silicate. The layered silicate has the same structure as the original layered silicate, and therefore has the same features, functions and effects as the layered silicate according to the first aspect.

As described above, by using the layered silicate according to the present invention, the layered silicate according to the present invention has the property of having different polarities on the front and back of the layer surface which is not present in the conventional layered silicate.・ Size of pigments, pharmaceuticals, etc.
It can be used as a carrier having selectivity such as orientation and an adsorbent having selectivity. Further, it can be used as a coating agent capable of controlling the surface polarity and imparting heat resistance.

Next, as in the tenth aspect of the present invention, the layered silicate is a square or polygonal sheet piece, and the sheet diameter of the layered silicate is in the range of 10 nm to 50 mm. The sheet diameter of 50% or more of the total phyllosilicate is less than the sheet diameter showing the largest distribution among all the phyllosilicates.
It is preferably in the range of 40 to + 40%.

[0062] Thus, as in the case of the second aspect, a layered silicate having various sizes and a uniform sheet shape can be provided. Further, other details are the same as those of the second aspect.

The invention of claim 11 provides a clay mineral having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide. Is a layered silicate comprising layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide and having no crystallographic regularity.

The phyllosilicate is the same as the phyllosilicate according to the ninth aspect, except that the phyllosilicate has no crystallographic regularity, ie, is amorphous. And since the above-mentioned layered silicate is amorphous, the layer interval is not uniform,
Rather, it has the property that the delamination is very easy because the lamination is greatly disturbed, and this can be used to uniformly mix with other compounds to provide a new composite material.

Next, as in the twelfth aspect of the present invention, the layered silicate is a square or polygonal sheet piece, and the sheet diameter of the layered silicate is in the range of 10 nm to 50 mm. The sheet diameter of 50% or more of the total phyllosilicate is less than the sheet diameter showing the largest distribution among all the phyllosilicates.
It is preferably in the range of 40 to + 40%.

According to the present invention, as in the tenth aspect, a layered silicate having various sizes and a uniform sheet shape can be provided. The other details are also the same as those of the tenth aspect.

The method for producing the layered silicate will be described below. The layered silicate is obtained by reacting an alkali metal compound on the layered silicic acid having the crystallographic regularity according to claim 1 or the layered silicic acid having no crystallographic regularity according to claim 5. And an ion exchange step of exchanging protons of silanol groups with alkali metal cations.

Next, the ion exchange step will be described. It is preferable that the alkali metal compound used in the ion exchange step is a substance such that a compound comprising an anion portion and a proton of the alkali metal compound formed as a result of the reaction has a sufficiently low acidity. Specifically, hydroxides, carbonates, bicarbonates, acetates and the like of alkali metals can be used.

The concentration of the alkali metal compound is
Although not particularly limited, it is preferable to use one having 1N or less. Thereby, hydrolysis of the silicon dioxide skeleton can be suppressed. The reaction temperature in the ion exchange step is not particularly limited, but is preferably set to a temperature equal to or lower than room temperature. Thereby, hydrolysis of the silicon dioxide skeleton can be suppressed.

The reaction time required for the above ion exchange step is 3
Preferably, it is within 0 minutes. When the reaction time is longer than 30 minutes, hydrolysis of the silicon dioxide skeleton may be promoted.

[0071]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment A layered silicic acid according to an embodiment of the present invention and a method for producing the same will be described with reference to FIGS. As shown in FIGS. 1 and 3, the layered silicic acid of the present example is a clay mineral 3 having a 1: 1 layer structure of a silicon dioxide tetrahedral sheet 19 without inversion and an octahedral sheet 2 of aluminum oxide, ie, kaolinite. Is a layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide and further having crystallographic regularity.

As shown in FIG. 3, the clay mineral 3 comprises a silicon dioxide tetrahedral sheet 19 without inversion and an octahedral sheet 2 of aluminum oxide. Then, one tetrahedral sheet 19 and one octahedral sheet 2 form a set,
These have a structure in which many are laminated. Here, the silicon dioxide tetrahedral sheet 19 is shown in FIGS. 3 (a) and 3 (b).
As shown in the figure, the tetrahedron 11 occupied by oxygen at the apex 10 and silicon at the center forms a six-membered ring and is bonded in a large number of planes.
It has a sheet-like skeleton.

Note that "no inversion" means that the vertices 10 of the silicon dioxide tetrahedron 11 are aligned in one direction,
Therefore, the polarity distribution on the surface of the layered silicic acid 1 is different between the front and the back. Further, as shown in FIG. 3 (a), the aluminum oxide octahedral sheet 2 has a large number of octahedrons 21 occupied by oxygen and hydroxide ions at the apexes and aluminum at the center, and is formed into a sheet shape. It is a skeleton.

As a reference example, FIG. 2 shows a conventional layered silica 9. Unlike the layered silicic acid 1 of the present embodiment according to the present invention, the conventional layered silicic acid 9 does not have the same direction of the apex 10 of the silicon dioxide tetrahedron 11.

Next, a method for producing the layered silicic acid according to this example will be described. Kaolinite from Georgia was used as kaolinite as the clay mineral. First, 30
A mixture of 25 g of kaolin and 100 ml of 12N sulfuric acid was charged into two autoclaves each having a 0 ml Teflon container and sealed. Then, 12
The mixture was heated in a constant temperature drying oven with stirring at 0 ° C. for 19 hours. After cooling, the solid product filtered from the contents of the container is
Washing was performed on the funnel using 1,000 ml of ion-exchanged water.

The solid product obtained and 500 ml of 1N hydrochloric acid were added to a 1 liter separable
The mixture was placed in a flask and heated in a water bath at 90 ° C. for 1 hour while stirring with a stirring motor. Thereafter, the solid product filtered from the contents of the flask was washed on a funnel with 2000 ml of warm ion-exchanged water, and lyophilized to obtain 24.0 g of the product. Hereinafter, the above product is referred to as NK-1
Call it p.

From the results of elemental analysis of Embodiment 9 described later, it was found that the above product was a silicic acid mainly composed of silicon. Further, from the results of transmission electron micrograph observation of Example 11 described later, it was found that silicate skeletons in the clay mineral used as the raw material remained. Further, from the result of observation of the X-ray diffraction pattern of Embodiment 10 described later, it was found that it had crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

The operation and effect of this embodiment will be described. The layered silicic acid 1 according to the present example is in a state where the remains of the clay mineral 3 having the structure as shown in FIG. 3 remain. That is, as shown in FIG. 1, the layered silicic acid 1 is composed of a layered silicon dioxide having a layered six-membered ring skeleton made of silicon dioxide. The skeleton of the silicon dioxide constituting the layered silicon dioxide is the clay mineral 3.
It consists of the silicon dioxide skeleton that was present inside.

As shown in FIG. 3, the clay mineral 3 comprises a silicon dioxide tetrahedral sheet 19 and an octahedral sheet 2 of aluminum oxide, and the silicon dioxide tetrahedral sheet constituting the silicon dioxide tetrahedral sheet 19 is formed. Vertex 10 of 11
All point in the direction of the octahedral sheet 2. For this reason, the apex 10 of the silicon dioxide tetrahedron 11 constituting the layered silicic acid 1 of the present invention that inherits the skeleton of this skeleton is shown in FIG.
As shown in the figure, they are aligned in one direction.

As described above, the polarity distribution of the layered silicic acid 1 is different on the front and the back of the layer surface, and is in a state of being aligned in one direction between the layers. For this reason, the above layered silicic acid has different polarities on the front and back of the layer surface which is not included in the conventional layered silicic acid, and since the polarity is uniform in one direction between the layers, the inclusion guest compound is oriented in one direction in the layer direction. It has the property of acting as a layered inclusion host that can be included between layers, and is used, for example, as a carrier having selectivity in size and orientation of catalysts, pigments, pharmaceuticals, etc., and a selective adsorbent be able to.

The layered silicic acid is produced from natural kaolinite having a uniform size and shape with its shape remaining, so that its size and shape are uniform. As a result, since the catalyst carrier and the adsorbent have a uniform size and shape, the catalytic action and the adsorbent action can be uniformly exhibited. The above layered silicic acid is considered to be a new layered silicic acid.

Therefore, according to this example, it is possible to provide a layered silicic acid made of a silicon dioxide tetrahedral sheet without inversion and having a uniform shape and size.

Embodiment 2 In this embodiment, an acid is applied under normal pressure to chrysotile, which is a clay mineral having a 1: 1 layer structure of a silicon dioxide tetrahedral sheet without inversion and an octahedral sheet of magnesium oxide, A method for producing a layered silicic acid having crystallographic regularity will be described. The chrysotile is, for example, Calidria Asbestos manufactured by Union Carbide.
s) H. P. P. Was used.

First, chrysotile 200 ground in a mortar
g and 3 ml of 3N hydrochloric acid in a 2 liter separable flask equipped with a cooling tube.
The mixture was heated in a water bath at 0 ° C. for 4 hours while stirring with a stirring motor. Next, the solid product obtained by filtering the contents of the flask by hot filtration was heated to a temperature of about 70 to 90 ° C. with 1N hydrochloric acid.
Washing was performed on the funnel using 00 ml and 2000 ml of warm ion-exchanged water.

The obtained solid product and 1N hydrochloric acid (1200 m)
The liter was placed in a 2 liter separable flask equipped with a cooling tube and heated in a water bath at a water bath temperature of 90 ° C. for 1 hour while stirring with a stirring motor. Thereafter, the solid product filtered from the contents of the flask was washed on a funnel with 2000 ml of warm ion-exchanged water, and lyophilized to obtain 84.5 g of the product. Hereinafter, the above product is referred to as N
Called C-2a.

The above product was found to be a silicon-based silicic acid from the results of elemental analysis shown in Example 9 described later. Transmission electron micrographs showed that silicate remains in the clay mineral used as the raw material. In addition, observation of an X-ray diffraction pattern shown in Example 10 to be described later revealed that it had crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 3 In this embodiment, an acid is applied under pressure to chrysotile, which is a clay mineral having a 1: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of magnesium oxide. Next, a method for producing a layered silicic acid having no crystallographic regularity will be described.

As the above chrysotile, Embodiment 2
The same one was used. First, 20 g of chrysotile crushed in a mortar and 40 ml of 12N sulfuric acid were sealed in an autoclave having a 100 ml Teflon container. Thereafter, the mixture was heated in a constant temperature drying oven with stirring at 120 ° C. for 19 hours. After allowing to cool, the solid product filtered from the contents of the above-mentioned container is filtered on a funnel with deionized water 6
Washed using 00 ml.

The obtained solid product and 350 ml of 1N hydrochloric acid were placed in a 500 ml separable flask equipped with a cooling tube, and heated in an oil bath at an oil bath temperature of 100 ° C. for 1 hour while stirring with a stirring motor. . Thereafter, the solid product filtered from the contents of the flask was washed on a funnel with 500 ml of warm ion-exchanged water, and freeze-dried to obtain 3.4 g of the product. Hereinafter, the above product is referred to as N
Called C-3p.

The above product was found to be silicic acid mainly composed of silicon from the result of elemental analysis shown in Example 9 described later. In addition, observation of a transmission electron microscope photograph shown in Example 11 described later revealed that silicate skeletons in the clay mineral used as the raw material remained. Further, observation of an X-ray diffraction pattern shown in Example 10 described later revealed that there was no crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 4 In this embodiment, an acid is applied under normal pressure to kaolinite, a clay mineral having a 1: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an aluminum oxide octahedral sheet. Next, a method for producing layered silicic acid having no crystallographic regularity will be described.

As the above kaolinite, Embodiment 1
The same one was used. First, the kaolinite 50.0
g and 200 ml of 12N sulfuric acid were placed in a 500 ml separable flask equipped with a condenser and heated in an oil bath at an oil bath temperature of 120 ° C. for 19 hours while stirring with a stirring motor. The solid product filtered from the contents of the flask by hot filtration was washed on a funnel using 300 ml of warm ion-exchanged water at about 70 to 90 ° C.

Next, the above solid product and 1N hydrochloric acid 500
ml in a 500 ml separable flask equipped with a condenser, and at a water bath temperature of 90 ° C. for 1 hour.
The mixture was heated in a water bath with stirring by a stirring motor. afterwards,
The solid product filtered from the contents of the flask was washed on a funnel with 500 ml of warm ion-exchanged water, and lyophilized to obtain 21.6 g of the product. The above product is converted to N
Called K-4a.

The above product was found to be a silicic acid mainly composed of silicon from the result of elemental analysis of Example 9 described later. Transmission electron micrographs showed that silicate remains in the clay mineral used as the raw material. Further, from the result of observation of the X-ray diffraction pattern of Example 10 described later, it was found that there was no crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 5 In this embodiment, an acid is applied under normal pressure to hectorite which is a clay mineral having a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of magnesium oxide. Next, a method for producing layered silicic acid having no crystallographic regularity will be described. Then, as shown in FIG. 4, the clay mineral 4 is made of a silicon dioxide tetrahedral sheet 19 having no inversion.
And an octahedral sheet 2 of magnesium oxide. The octahedral sheet 2 has a structure in which a plurality of tetrahedral sheets 19 are arranged on both front and back surfaces of the octahedral sheet 2 as a set.

Next, a method for producing the layered silicic acid according to the present example will be described. As the hectorite, a standard sample of the American Clay Association was used. First, Hectorite 20
0.5 g and 1600 ml of 3N hydrochloric acid were placed in a 2-liter separable flask equipped with a cooling tube, and kept at a water bath temperature of 30 ° C. for 0.5 hour. After that, water bath temperature 9
The mixture was heated in a water bath at 0 ° C. for 4 hours while stirring with a stirring motor.

The solid product filtered from the flask by hot filtration was washed with hot 1N hydrochloric acid (1000 m
The mixture was washed on a funnel using 1 liter and 2000 ml of warm ion-exchanged water. The solid product and 1N hydrochloric acid 1
600 ml was placed in a 2 liter separable flask equipped with a condenser, and the water bath temperature was 90 ° C. for 1 hour.
The mixture was heated in a water bath with stirring by a stirring motor. The solid product filtered from the contents of the flask was washed on a funnel with 3000 ml of warm ion-exchanged water, and lyophilized to obtain 72.6 g of the product. The above product is converted to NH-
5a.

The above product was found to be a silicon-based silicic acid from the results of elemental analysis shown in Example 9 described later. Transmission electron micrographs showed that silicate remains in the clay mineral used as the raw material. Further, observation of an X-ray diffraction pattern shown in Example 10 described later revealed that there was no crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 6 In this example, vermiculite, which is a clay mineral having a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of aluminum / iron / magnesium oxide, is usually used. A method for producing a layered silicic acid having no crystallographic regularity by applying an acid under pressure will be described.

As the vermiculite, vermiculite produced in China was used. First, 40.0 g of vermiculite was added to 5
In a 00 ml beaker, 100 ml of a 30% hydrogen peroxide solution was added, and an oxidation treatment was performed. As a result, the vermiculite generated heat and its volume expanded.

After leaving the above beaker at room temperature for 1 hour,
Was placed in a constant temperature oven for 3 days to ripen the above reaction. It is considered that the expansion phenomenon caused by the above reaction is caused by the interlayer water boiling due to the heat of oxidation of the iron component in the vermiculite composition, which causes the expansion of the interlayer spacing and the delamination.

Next, the oxidized vermiculite and 1200 ml of 3N hydrochloric acid were placed in a 2-liter separable flask equipped with a cooling tube, and stirred in a water bath at a water bath temperature of 95 ° C. for 8 hours with a stirring motor. And heated. The solid product separated from the contents of the flask by hot filtration was heated to a temperature of about 70 to 90 ° C. with hot 1N hydrochloric acid 600.
Washing was performed on the funnel using ml and 800 ml of warm ion-exchanged water.

The above solid product and 400 ml of 1N hydrochloric acid were placed in a 2-liter separable flask equipped with a cooling tube, and heated in a water bath at a water bath temperature of 90 ° C. for 1 hour while stirring with a stirring motor. Thereafter, the solid product obtained by filtering the contents of the flask is filtered on a funnel into warm ion-exchanged water 2.
Washing using 000 ml and freeze-drying gave 14.7 g of the product. Hereinafter, the above product is referred to as NV-6a.

The above product was found to be silicic acid mainly composed of silicon from the result of elemental analysis shown in Example 9 described later. In addition, observation of a transmission electron microscope photograph shown in Example 11 described later revealed that silicate skeletons in the clay mineral used as the raw material remained. Further, it was found from the observation of the X-ray diffraction pattern shown in Embodiment 10 described later that there was no crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 7 In this embodiment, a vermiculite which is a clay mineral having a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of an oxide of aluminum, iron and magnesium is added. A method for producing a layered silicic acid having no crystallographic regularity by applying an acid under pressure will be described.

The same vermiculite as used in the sixth embodiment was used. First, the above vermiculite 2
5.0 g was placed in a 500 ml beaker, and 200 ml of a 30% hydrogen peroxide solution was added thereto, and the vermiculite was oxidized in the same manner as in Embodiment 6.

[0107] Half of the oxidized vermiculite and 200 ml of 12N sulfuric acid were sealed in an autoclave having a 300 ml Teflon container. Thereafter, the mixture was heated in a constant temperature drying oven with stirring at 120 ° C. for 19 hours. After allowing to cool, the solid product filtered from the contents of the above-mentioned container is filtered on a funnel with deionized water 600
Washed using ml.

The solid product and 800 ml of 1N hydrochloric acid were placed in a 1 liter separable flask equipped with a condenser, and heated in a water bath at a water bath temperature of 100 ° C. for 1 hour while stirring with a stirring motor. Thereafter, the solid product filtered from the contents of the flask was washed on a funnel with 2000 ml of warm ion-exchanged water, and lyophilized to obtain 5.1 g of the product. The product is called NV-7p.

The above product was found to be silicic acid mainly composed of silicon from the results of elemental analysis shown in Example 9 described later. In addition, observation of a transmission electron microscope photograph shown in Example 11 described later revealed that silicate skeletons in the clay mineral used as the raw material remained. Further, observation of an X-ray diffraction pattern of Example 10 described later revealed that there was no crystallographic regularity. From the above, it was found that the above product was the layered silicic acid according to this example.

Embodiment 8 In this embodiment, a method for producing a layered silicate by reacting an alkali metal compound on the layered silicic acid obtained in Example 2 will be described. First, the layered silicic acid (NC-2) obtained in Embodiment 2 was placed in a plastic 500 ml beaker.
a) 10 g was taken, 200 ml of ion-exchanged water was added, and the mixture was dispersed by stirring at room temperature with a magnetic stirrer.

To this dispersion was added 300 ml of a 1N aqueous sodium hydroxide solution, and the mixture was further stirred at room temperature for 30 minutes. The reaction mixture was dialyzed against ion-exchanged water for one day, and then lyophilized to obtain 10.5 g of a product. From the results of elemental analysis, it was found that the above product was a silicate mainly composed of silicon and sodium. Also,
Transmission electron micrograph observation revealed that some silicate remains in the clay mineral used as the raw material. From the above, it was found that the layered silicate according to the present invention was obtained.

Embodiment 9 In this embodiment, elemental analysis was performed on the clay mineral used as a raw material and each product obtained in Embodiments 1 to 7. First, Al, Fe, M for silicon atom (Si)
Tables 1 and 2 show the atom% of g and Ti, that is, the ratio of the octahedral metal atoms contained. According to the table, when the clay mineral is subjected to an acid treatment under normal pressure or under pressure, the ratio of metal atoms constituting the octahedron in the clay mineral is reduced to 5 atom% or less with respect to silicon atoms, and silicate Was obtained. However, it was not possible to judge the crystallographic regularity only by the amount of octahedral metal atoms remaining in the obtained silicic acid.

[0113]

[Table 1]

[0114]

[Table 2]

Embodiment 10 In this embodiment, an X-ray diffraction (XRD) pattern was observed for the clay mineral used as a raw material and the layered silicic acid obtained by acid treatment on the clay mineral. Each XRD pattern is summarized for each clay mineral series and is shown in FIGS. 5 to 15. From the XRD patterns, the presence or absence of crystallographic regularity of each layered silicic acid was examined.

FIG. 5 is an XRD pattern of chrysotile, and FIG. 6 is an XRD pattern of NC-2a obtained in the second embodiment.
FIG. 7 shows the NC-
It is a 3p XRD pattern. And N according to FIG.
The XRD pattern of C-2a includes the XRD of chrysotile.
Three peaks (7.25, 3.63, 2.35 °) based on the regularity in the layer direction similar to the pattern (FIG. 5) were observed. However, in the XRD pattern of NC-3p according to FIG. 7, only a broad halo peak was observed, and no peak based on crystallographic regularity was observed.

Next, FIG. 8 shows an XRD pattern of kaolinite, FIG. 9 shows an XRD pattern of NK-1p obtained in the first embodiment, and FIG. 10 shows an XRD pattern of NK-4a obtained in the fourth embodiment. It is. The NK-1p XRD pattern shown in FIG. 9 has three peaks (7.13, 3.57, 2.38 °) based on the same layer direction regularity as the kaolinite XRD pattern (FIG. 8).
Was observed. However, the NK-4a X shown in FIG.
Only a broad halo peak was observed in the RD pattern, and no peak based on crystallographic regularity was observed.

Next, FIG. 11 shows an XRD pattern of hectorite, and FIG. 12 shows NH-5 obtained in the fifth embodiment.
7 is an XRD pattern of FIG. Then, according to FIG.
H-5a XRD pattern includes hectorite XRD
No peak was observed in the pattern (FIG. 10), and only a broad halo peak was observed. Therefore, NH-
5a was found to have no crystallographic regularity.

The XR of hectorite shown in FIG.
In the D pattern, besides the peak based on the crystal structure,
A peak of calcium carbonate as a contaminant was observed. In addition, the XRD pattern of NH-5a shown in FIG. 12 shows a peak at 3.35 ° and several fine peaks, which are based on α-quartz contained in the raw material.

Next, FIG. 13 shows the XRD of vermiculite.
FIG. 14 shows the NV obtained in the sixth embodiment.
FIG. 15 shows an XRD pattern of NV-7p obtained in the seventh embodiment. Then, the XRs of NV-6a in FIG. 14 and NV-7p in FIG.
In the D pattern, no peak based on the regularity in the layer direction similar to that observed in the XRD pattern of vermiculite (FIG. 13) was observed, and only a broad halo peak was observed. Therefore, it was found that NV-6a and NV-6p did not have crystallographic regularity.

Embodiment 11 In this embodiment, the products obtained in Embodiments 1, 3, 6, and 7 were observed with a transmission electron microscope photograph.
16 is an NK-1p according to the first embodiment, FIG. 17 is an NC-3p according to the third embodiment, and FIG. 18 is a sixth embodiment.
FIG. 19 shows an NV-6a according to the seventh embodiment.
V-7p.

As shown in FIG. 16, NK-1p has a sheet diameter of about 1
It has a layered structure in which several 0 μm sheets are stacked.
It was found that the size of the sheet was uniform and that the silicon dioxide sheet remains in the raw material kaolinite. Further, since a Moire pattern was observed in this photograph, it was found that the layered structure of NK-1p had regularity.

In the same figure, a mesh-like object and a thin gray sheet piece can be confirmed so as to overlap the object, and the thin sheet piece is NK-1p. The mesh object (many circles on a gray background) is an enlarged view of the stage on which the sample to be observed in the transmission electron microscope is enlarged. This is a phenomenon that generally occurs when the value is increased. Also, the thin sheet pieces in the figure look like one sheet at a glance, but this is actually a state in which a plurality of sheet pieces are overlapped. The above description also applies to other photographs.

FIG. 17 shows that NC-3p has a layered structure in which a band-shaped sheet is wound into a rod or tube having a diameter of about 30 nm, the diameter is uniform, and that the raw material clay mineral chrysotile It was found that the silicon dioxide sheet remains.

Further, FIG. 18 shows that NV-6a has a layered structure in which several sheets having a sheet diameter of about 7 to 11 μm are stacked, and the sheets are uniform in size, and the raw material clay mineral It was found that silicon dioxide sheet remains in the vermiculite. In addition, NV-6
In a, the moiré pattern based on the layer direction regularity observed in NK-1p was not observed. That is, N
V-6a was found to have no crystallographic regularity.

Further, as shown in FIG. 19, NV-7p has a layered structure in which several sheets each having a sheet diameter of about 7 to 11 μm are stacked. It was found that silicon dioxide sheet remains in the vermiculite. In addition, NV-7
In p, the moiré pattern based on the regularity in the layer direction observed in NK-2p was not observed. That is, N
V-7p was found to have no crystallographic regularity.

Embodiment 12 In this embodiment, the specific surface area of each product obtained in Embodiments 1 to 7 was measured by the BET method using nitrogen adsorption. The results are shown in Table 3. According to this, NC- which is a layered silicic acid having crystallographic regularity
The specific surface area of 2a, NK-1p is 520-70 m ² / g
Met. On the other hand, the specific surface area of the other layered silica having no crystallographic regularity was 440 to 70 m ² / g. Thus, it was found that it was not possible to determine the presence or absence of crystallographic regularity of the layered silicic acid from the value of the specific surface area.

[0128]

[Table 3]

[0129]

As described above, according to the present invention, there is provided a layered silicic acid, a method for producing the same, and a layered silicate comprising a silicon dioxide tetrahedral sheet without inversion and having a uniform shape and size. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a structure of a layered silicic acid without inversion, in which (a) the vertices of a silicon dioxide tetrahedron are aligned in one direction, and (b) a structure of the layered silicic acid in Embodiment 1; FIG.

FIG. 2 is a plan view illustrating a structure of a layered silicic acid having a reversal in which the vertices of a silicon dioxide tetrahedron are aligned in one direction in a conventional example, and FIG. FIG.

FIG. 3 is a clay mineral (= kaolinite) having a 1: 1 layer structure of (a) a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal (= aluminum) oxide according to the first embodiment. FIG. 2B) is a crystal structure diagram, and FIG.

FIG. 4 is a clay mineral (= hectorite) having a 2: 1 layer structure of (a) a silicon dioxide icosahedral sheet without inversion and an octahedral sheet of another metal (= magnesium) oxide in Example 5; Plane explanatory view illustrating the structure of ()),
(B) An explanatory diagram of a layered structure in a layer direction for explaining the structure of the clay mineral.

FIG. 5 is a diagram showing an X-ray diffraction (XRD) pattern of chrysotile according to a tenth embodiment.

FIG. 6 is a diagram showing an X-ray diffraction (XRD) pattern of NC-2a according to the tenth embodiment.

FIG. 7 is a diagram showing an X-ray diffraction (XRD) pattern of NC-3p in Embodiment 10;

FIG. 8 is a diagram showing an X-ray diffraction (XRD) pattern of kaolinite in Embodiment 10.

FIG. 9 is a diagram showing an X-ray diffraction (XRD) pattern of NK-1p in Embodiment 10;

FIG. 10 is a diagram showing an X-ray diffraction (XRD) pattern of NK-4a in the tenth embodiment.

FIG. 11 is a cross-sectional view of hectorite X in Embodiment 10;
FIG. 3 is a diagram showing a line diffraction (XRD) pattern.

FIG. 12 is a diagram showing an X-ray diffraction (XRD) pattern of NH-5a in Embodiment 10;

FIG. 13 is a diagram showing an X-ray diffraction (XRD) pattern of vermiculite in the tenth embodiment.

FIG. 14 is a diagram showing an X-ray diffraction (XRD) pattern of NV-6a according to the tenth embodiment.

FIG. 15 is a diagram showing an X-ray diffraction (XRD) pattern of NV-7p in the tenth embodiment.

FIG. 16 is a drawing substitute photograph (magnification: 12000) of NK-1p in Example 11;

FIG. 17 is a drawing substitute photograph (magnification: 120,000) of NC-3p in the eleventh embodiment.

FIG. 18 is a drawing substitute photograph (magnification: 6000) of NV-6a in the eleventh embodiment.

FIG. 19 is a drawing substitute photograph (magnification: 6000) of NV-7p in the eleventh embodiment.

[Explanation of symbols]

 1,9. . . 18. layered silicic acid, . . 1. silicon dioxide tetrahedral sheet; . . Octahedral sheet of metal oxide, 3,4. . . Clay minerals,

Claims (12)

[Claims] 1. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet without inversion and an octahedral sheet of another metal oxide remains, and is formed by silicon dioxide. A layered silicic acid comprising layered silicon dioxide having a layered six-membered ring skeleton and further having crystallographic regularity. 2. The layered silicic acid according to claim 1, wherein the layered silicic acid is a square or polygonal sheet piece, and the sheet diameter of the layered silicic acid is in a range of 10 nm to 50 mm. The above-mentioned sheet diameter is in the range of -40 to + 40% of the sheet diameter showing the largest distribution among all the layered silicic acids. 3. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide remains, and is formed by silicon dioxide. A method for producing a layered silicic acid comprising a layered silicon dioxide having a layered six-membered ring skeleton, and further comprising, when producing a layered silicic acid having crystallographic regularity, an acid acting on the clay mineral. 4. The method for producing layered silicic acid according to claim 3, wherein the shape and size of the layered silicic acid are selected by selecting the clay mineral. 5. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet without inversion and an octahedral sheet of another metal oxide remains, and is formed by silicon dioxide. A layered silicic acid comprising layered silicon dioxide having a layered six-membered ring skeleton and further having no crystallographic regularity. 6. The layered silica according to claim 5, wherein the layered silica is a square or polygonal sheet piece, and the sheet diameter of the layered silica is in the range of 10 nm to 50 mm, and 50% of the total layered silica is The above-mentioned sheet diameter is in the range of -40 to + 40% of the sheet diameter showing the largest distribution among all the layered silicic acids. . 7. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet without inversion and an octahedral sheet of another metal oxide remains, and is formed by silicon dioxide. A method for producing a layered silicic acid comprising a layered silicon dioxide having a layered six-membered ring skeleton and further comprising, when producing a layered silicic acid having no crystallographic regularity, an acid acting on the clay mineral. 8. The method for producing a layered silicic acid according to claim 7, wherein the shape and size of the layered silicic acid are selected by selecting the clay mineral. 9. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide remains, and the silicon dioxide is formed by silicon dioxide. A layered silicate comprising layered silicon dioxide having a layered six-membered ring skeleton and further having crystallographic regularity. 10. The phyllosilicate according to claim 9, wherein the phyllosilicate is a square or polygonal sheet piece, and the sheet diameter of the phyllosilicate is in the range of 10 nm to 50 mm. The sheet diameter of 50% or more of the sheet diameter is -40 to + of the sheet diameter showing the largest distribution among all the layered silicates.
A layered silicate characterized by being in the range of 40%. 11. A clay mineral body having a 1: 1 layer structure or a 2: 1 layer structure of a silicon dioxide tetrahedral sheet having no inversion and an octahedral sheet of another metal oxide remains, and is formed by silicon dioxide. A layered silicate comprising a layered silicon dioxide having a layered six-membered ring skeleton and further having no crystallographic regularity. 12. The phyllosilicate according to claim 11, wherein the phyllosilicate is a square or polygonal sheet piece, and the phyllosilicate has a sheet diameter in a range of 10 nm to 50 mm. The sheet diameter of 50% or more of the sheet diameter is -40 to + of the sheet diameter showing the largest distribution among all the layered silicates.
A layered silicate characterized by being in the range of 40%.