JPH0624970B2 - Method for producing crosslinked clay intercalation compounds with different amounts of pillars - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for controlling the amount of pillars of a crosslinked clay intercalation compound, which has been attracting attention in recent years. It is thought that it will contribute to the further development of the use of.

<Prior Art> Conventionally, a technology for controlling the pillar amount of a crosslinked clay intercalation compound has not been established.

<Problems to be Solved by the Invention> The crosslinked clay intercalation compound is characterized by both the interlaminar distance (1) and the interpillar (pillar) distance (2) shown in FIG. It is known that the interlayer distance changes depending on the size of the pillar (3) and the column distance changes depending on the pillar amount. A conventional method for producing a crosslinked clay intercalation compound is described in JP-A-54-54.
5884, JP-A-54-16386, JP-B-62-12172, JP-B-62-41167 and the like have been published, but these patents do not relate to the amount of pillars of a crosslinked clay intercalation compound. Absent. That is, hitherto, no technique has been established for controlling the amount of pillars of the crosslinked clay intercalation compound. The present invention has conducted intensive studies on a method of controlling the amount of pillars of a crosslinked clay intercalation compound, and as a result, found a method of controlling the amount of pillars by changing the amount of pillar precursor added.

<Means for Solving Problems> The present invention relates to a method for producing crosslinked clay intercalation compounds having different pillar amounts by controlling the addition amount of pillar precursors.

The clay used in the present invention is montmorillonite, but is not limited to this as long as it has the same properties as those described below. The crystal structure of montmorillonite is that the silicic acid tetrahedron-alumina octahedron-silicic acid tetrahedron shares the respective oxygens and is stacked and bonded,
A single crystal layer is formed. This crystal layer is called a silicate layer. A part of aluminum, which is the central metal of the alumina octahedron in the silicate layer, is replaced by magnesium having a smaller positive charge. Further, a part of silicon of the silicic acid tetrahedron is replaced by aluminum having a smaller positive charge. By these substitutions, the silicate layer loses charge balance and is negatively charged. Depending on this negative charge, cations (eg Na ⁺ , C
a ²⁺ ) exist between the silicate layers and are arranged so as to maintain the overall charge balance. When the cation existing between the silicate layers is Na ⁺ , Na-montmorillonite, Ca
^In the case of ²⁺ , it is expressed as Ca-montmorillonite. The cations such as Na ⁺ and Ca ²⁺ existing between the layers can be exchanged with other cations, and the amount of these exchangeable cations is called the cation exchange capacity, and this value is about 130meq / 100g. .

The method for producing the crosslinked clay intercalation compound begins by introducing the pillar precursor between the layers by utilizing the ion exchange property of montmorillonite described above. The method for producing the crosslinked clay intercalation compound will be described in more detail. First, a suspension of water and montmorillonite is prepared. The mixing ratio of them is 10 ml or more of water per 10 g of montmorillonite, and preferably 50 ml or more of water per 10 g of montmorillonite that can be stirred by a magnetic stirrer. When a magnetic stirrer is used, when the mixing ratio is 500 ml of water per 10 g of montmorillonite, stirring for about 10 minutes gives a substantially uniform suspension. Then, an arbitrary amount of the pillar precursor is added to the suspension while stirring. The pillar precursor is a cationic aluminum hydroxide oligomer, an aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O powder dissolved in water, or sodium chloride or water in aluminum chloride or aluminum nitrate. Although there are those prepared by adding an alkali such as ammonium oxide, the present invention only needs to be an aluminum hydroxide oligomer regardless of the preparation method. When the pillar precursor is added to the suspension, montmorillonite ion exchange occurs, and the amount of ion exchange is proportional to the amount of the added pillar precursor.

Explaining the ion exchange of montmorillonite in detail, the exchangeable cation existing between the layers of montmorillonite and the cationic pillar precursor are exchanged.
Therefore, when the ion exchange is completed, the pillar precursor will be present between the montmorillonite layers instead of the exchangeable cations. Further, the amount of pillar precursor is proportional to the amount of ion exchange. Therefore, the present invention succeeded in producing a crosslinked clay intercalation compound having different pillar amounts by utilizing the ion exchange characteristics of these montmorillonites.

After adding an arbitrary amount of the pillar precursor to the suspension while stirring, it is aged for about 1 to 24 hours at room temperature or while heating. Then, the clay obtained by filtration is dried to obtain a crosslinked clay intercalation compound having an arbitrary amount of aluminum hydroxide as pillars. Further, when this is heated at 500 ° C. for about 1 hour, the dehydration reaction of the aluminum hydroxide of the pillar proceeds to form a crosslinked clay intercalation compound having aluminum oxide in the pillar. The heating temperature is 700 ° C. or lower at which the crystal structure of montmorillonite is not destroyed.

<Effect of the Invention> A crosslinked clay intercalation compound having pores of a two-dimensional structure is expected to have the same function as zeolite, and its use has been studied in many fields in the past. The present invention relates to a method for producing a crosslinked clay intercalation compound in which the amount of pillars supporting a two-dimensional structure is changed, and this brings about an improvement in the function of the crosslinked clay intercalation compound and the development of a new function.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1 To 500 ml of distilled water was added 3.0 g of Na-montmorillonite, and the mixture was thoroughly stirred with a magnetic stirrer. 0.39 ml of a 10 wt% aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O was added little by little to the obtained suspension while stirring, and the mixture was left standing at room temperature for 24 hours. Subsequently, filtration is performed, and the obtained product is mixed in an oven at 60 ° C for 3 times.
After drying for a day, crush it in a mortar and put it in an electric furnace in an air atmosphere for 50 minutes.
The mixture was heated at 0 ° C. for 1 hour to prepare a crosslinked clay intercalation compound.
When the amount of pillars was determined by a fluorescent X-ray analysis method, it was 0.02 g of aluminum oxide per unit weight of clay.

Example 2 A crosslinked clay intercalation compound was prepared in the same manner as in Example 1 except that 2.3 ml of a 10 wt% aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O was used. When the amount of pillars was quantified by a fluorescent X-ray analysis method, it was 0.07 g of aluminum oxide per unit weight of clay.

Example 3 A crosslinked clay intercalation compound was prepared in the same manner as in Example 1 except that 5.0 ml of a 10 wt% aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O was used. When the amount of pillars was determined by a fluorescent X-ray analysis method, it was 0.14 g of aluminum oxide per unit weight of clay.

Example 4 A crosslinked clay intercalation compound was prepared in the same manner as in Example 1 except that 10 ml of a 10 wt% aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O was used. When the amount of pillars was quantified by fluorescent X-ray analysis,
There was 0.25 g of aluminum oxide per unit weight of clay.

Example 5 Crosslinking was performed in the same manner as in Example 1 except that a 10 wt% aqueous solution of Al ₂ (OH) ₅ Cl · 2.4H ₂ O was used in an amount of 15 ml in excess of 10 ml corresponding to the cation exchange capacity of Na-montmorillonite. A clay intercalation compound was prepared. When the amount of pillars was quantified by a fluorescent X-ray analysis method, it was 0.25 g of aluminum oxide per the same unit weight of clay as the result in Example 4.

[Brief description of drawings]

FIG. 1 shows a conceptual diagram of a crosslinked clay intercalation compound. In the figure, (1) is an interlayer distance, (2) is an inter-pillar distance, (3) is a pillar, and (4) is a silicate layer.

Claims (6)

[Claims] 1. A method for producing a crosslinked clay intercalation compound having different pillar amounts, which comprises controlling the addition amount of pillar precursors. 2. The production method according to claim 1, wherein the pillar precursor is an aluminum hydroxide oligomer. 3. The method according to claim 1, wherein the pillar is aluminum hydroxide and / or aluminum oxide. 4. The amount of pillars is 0.40 g or less per unit weight of clay when the pillars are aluminum hydroxide.
The manufacturing method according to claim 1. 5. The method according to claim 1, wherein the amount of the pillars is 0.25 g or less per unit weight of clay when the pillars are aluminum oxide. 6. The method according to claim 1, wherein the clay of the crosslinked clay intercalation compound is montmorillonite.