JPH0621013B2 - Method for producing solid solution or complex oxide of calcium oxide - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a solid solution or a complex oxide of calcium oxide, and particularly to a method for producing a solid solution or a complex oxide of calcium oxide useful as a ceramic raw material.

“Prior Art and Its Problems” Conventionally, it has been general that a metal compound as a ceramic raw material is produced by dry synthesis (solid phase reaction). For example, as a solid-phase synthesis method of calcium titanate, a method of mixing titanium oxide and calcium carbonate and firing at high temperature is known. However, it is said that it is very difficult to avoid nonuniformity of the composition in the material as long as it is based on the solid-phase reaction (Temporary Special Issue on Industrial Materials, "High Technology Ceramics", page 22, 1983). Therefore, as an alternative to the solid phase reaction, a wet synthesis method using a liquid phase reaction has been actively studied.

Among the wet methods, the metal alkoxide method is one of the methods that has recently attracted particular attention. Metal alkoxides are easily hydrolyzed to hydroxides. By the way, among metal alkoxides, sodium and potassium alkoxides are easily produced by reacting only by adding a corresponding metal to alcohol, but calcium produces alkoxides unless a catalyst such as iodine or a mercury compound is used. I can't. Therefore, calcium alkoxide is very expensive and it is difficult to use it as a raw material for ceramics on an industrial scale. In addition, calcium alkoxide is a substance that is very sensitive to moisture and carbon dioxide and is difficult to handle.

"Object of the Invention" An object of the present invention is to provide a method capable of efficiently producing a solid solution or complex oxide of calcium oxide by a simple operation at a low cost.

"Structure of the Invention" A method for producing a solid solution of calcium oxide or a complex oxide according to the present invention comprises calcium hydroxide or calcium oxide as sugar,
At least one of sugar alcohol and polyhydric alcohol
It is characterized in that a calcium sol obtained by dissolving it in an aqueous solution containing seeds is reacted with a solution of a metal compound dissolved in water or alcohol.

The calcium sol used in the method of the present invention can be prepared, for example, as follows. That is, a method of preparing an aqueous solution containing at least one of sugar, sugar alcohol, and polyhydric alcohol, and adding calcium hydroxide or calcium oxide thereto to dissolve it, or adding calcium hydroxide or calcium oxide into water And then adding at least one of sugar sugar, alcohol and polyhydric alcohol to dissolve it, at least one of sugar, sugar alcohol and polyhydric alcohol and calcium hydroxide or It can be prepared by a method in which calcium oxide is added to water and mixed at the same time to dissolve it.

In the present invention, as at least one of sugar, sugar alcohol and polyhydric alcohol, for example, glucose,
Fructose, galactose, maltose, sucrose, mannose, sorbose, ribose, xylose,
Those selected from arabinose, lactose, sorbitol, mannitol, glycerin, pentaerythritol and the like can be adopted.

According to the present invention, the presence of at least one of sugar, sugar alcohol and polyhydric alcohol makes it possible to increase the solubility of calcium hydroxide or calcium oxide and form a sol. The concentration of sugar, sugar alcohol, and polyhydric alcohol in the solution is preferably 10% by weight or more, and when it is less than 10% by weight, it becomes difficult to sufficiently dissolve calcium hydroxide or calcium oxide. However, it is not necessary to add sugar, sugar alcohol, and polyhydric alcohol until the saturated concentration is reached.

The calcium sol thus obtained is stable, does not precipitate during storage or transportation, and exhibits high reactivity because it has finely dispersed calcium hydroxide or calcium oxide. Therefore, by using such a calcium sol, various solid solutions or complex oxides of calcium oxide can be easily produced.

In order to form calcium oxide and a solid solution or complex oxide, in the method of the present invention, the above-mentioned calcium sol is reacted with a metal compound soluble in water or alcohol. Examples of usable metal oxides soluble in water or alcohol include metal oxide sols, halides, oxyhalides, nitrates, sulfates, oxynitrates, organic acid salts, alkoxides and acetylacetonates. Typical examples of metals that can be used include copper, magnesium, strontium, barium, aluminum, thallium, silicon, titanium, zirconium, bismuth, chromium, manganese, iron, nickel and cobalt.

As the metal compound which can be used in the method of the present invention or which is soluble in alcohol, titanium compounds and zirconium compounds, more specifically, titanium halides, titanium sulfate, titanium alkoxides (for example, titanium methoxide, titanium ethoxide, Titanium propoxide, titanium butoxide, etc.), titanium acylate, titanium acetylacetonate, titania sol, zirconium oxychloride, zirconium oxynitrate, zirconium alkoxide (eg zirconium methoxide, zirconium ethoxide, zirconium propoxide, zirconium butoxide), zirconium Acetylacetonate, zirconia sol, and the like. If an alkoxide is used, it can be used both in the monomeric state and in the polymeric state.

In the method of the present invention, the metal compound as described above is dissolved in water or alcohol to form a solution, which is then reacted with calcium sol. As the alcohol, methanol, ethanol, propanol, butanol or the like can be used. Other reaction conditions such as reaction temperature may be appropriately selected depending on the situation such as the metal compound used.

When a calcium sol is reacted with a solution of a metal compound that dissolves in water or alcohol by the method of the present invention, the metal compound forms a hydroxide or oxide, which is calcined if necessary to give calcium oxide. To form a solid solution of a metal oxide or a double oxide of calcium oxide and a metal oxide.

The solid solution produced by the method of the present invention includes calcium-stabilized zirconium magnesium oxide solid solution calcium oxide, cobalt solid solution calcium oxide, nickel solid solution calcium oxide, and the like, and the complex oxide includes calcium titanate [CaTiO ₃ Or CaO / Ti
O ₂ ], calcium zirconate [CaZrO ₃ or CaO.ZrO ₂ ], calcium aluminate, calcium silicate, calcium manganate, calcium chromate, and a complex oxide with iron.

The produced solid solution or complex oxide can be separated as a powder by means such as filtration or centrifugal spray drying.

"Examples of the Invention" Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1 100 g water and 30 g glucose in a 200 ml beaker
Was added and stirred well to prepare an aqueous glucose solution. When 1.1 g of calcium oxide was added to this aqueous solution and stirred well, a transparent sol was obtained.

Titanium butoxide polymer (Nippon Soda Co., Ltd.)
Made, brand name B7) 4.8 g isopropyl alcohol 1
When the solution dissolved in 5 g was poured in, a reaction took place and a suspension was obtained. The suspension was dried on a hot plate and then calcined in an electric furnace at 1200 ° C. for 1 hour. When X-ray diffraction of the obtained powder was performed, X-ray shown in FIG.
A line diffraction pattern was obtained. This was in agreement with the X-ray diffraction pattern of calcium titanate.

Example 2 10 ml of water and 1 g of sucrose were placed in a 200 ml beaker and well stirred to prepare a sucrose aqueous solution. When 0.1 g of calcium oxide was added to this and stirred well, a transparent sol was obtained. 2.5 g of zirconium oxynitrate was poured into this sol in a solution dissolved in 30 ml of water, evaporated to dryness in an ashing furnace, ashed, and then baked in an electric furnace at 1300 ° C. for 1 hour. When the obtained powder was subjected to X-ray diffraction, the X-ray diffraction diagram shown in FIG. 2 was obtained. This was in agreement with the X-ray diffractogram of calcium stabilized zirconia (cubic).

Example 3 100 ml of water and 10 g of xylose were put into a 200 ml beaker and well stirred to prepare an aqueous xylose solution. When 1.3 g of calcium oxide was added to this and stirred well, a transparent sol was obtained. To this sol, 7 g of zirconium tetrabutoxide (trade name TBZR, manufactured by Nippon Soda Co., Ltd.) was poured into a solution prepared by dissolving 16 g of isobutyl alcohol, evaporated to dryness in an ashing furnace, and after ashing, 1300 ° C. in an electric furnace.
It was baked for 1 hour. When the obtained powder was subjected to X-ray diffraction, the X-ray diffraction diagram shown in FIG. 3 was obtained.

Example 4 50 ml of water and 5 g of xylose were placed in a 200 ml beaker and well stirred to prepare an aqueous xylose solution. When 0.7 g of calcium oxide was added to this and stirred well, a transparent sol was obtained. 2.3 g of manganese chloride tetrahydrate was poured into this sol in a solution prepared by dissolving 50 ml of water, evaporated to dryness in an ashing furnace, ashed, and then baked in an electric furnace at 1100 ° C. for 1 hour. When X-ray diffraction of the obtained powder was performed,
The X-ray diffraction pattern shown in the figure was obtained.

Example 5 Instead of using the aqueous solution of manganese chloride in Example 4, a solution prepared by dissolving 1.4 g of aluminum chloride hexahydrate in 50 ml of water was used, and the same operation as described below was carried out. As shown in FIG. A line diffraction pattern was obtained.

Example 6 When 1 g of calcium oxide was added to the same xylose aqueous solution as that prepared in Example 4 and well stirred, a transparent sol was obtained. 1 g of iron nitrate nonahydrate was added to 50 g of this sol.
It was poured into a solution dissolved in ml, evaporated to dryness and ashed in an ashing furnace, and then baked in an electric furnace at 1200 ° C. for 1 hour. When the obtained powder was subjected to X-ray diffraction, the X-ray diffraction diagram shown in FIG. 6 was obtained.

"Effect of the Invention" According to the method of the present invention, a solid solution or complex oxide of calcium oxide can be easily and efficiently produced by a wet method. Moreover, since an expensive raw material such as calcium alkoxide is not used, a solid solution or complex oxide of calcium oxide can be produced at low cost. Furthermore, according to the method of the present invention, since it is produced from a solution, a high-purity solid solution or complex oxide can be obtained.

Therefore, according to the present invention, it is possible to provide a high quality solid solution or complex oxide suitable for use in the field of fine ceramics and the like.

[Brief description of drawings]

1 is an X-ray diffraction pattern of calcium titanate produced in Example 1, FIG. 2 is an X-ray diffraction diagram of calcium-stabilized zirconia produced in Example 2, and FIG. 3 is zirconium produced in Example 3. X-ray diffraction pattern of calcium acidate, FIG. 4 is an X-ray diffraction pattern of calcium manganate produced in Example 4, FIG. 5 is an X-ray diffraction pattern of calcium aluminate produced in Example 5, and FIG. 6 is 7 is an X-ray diffraction diagram of a composite oxide with iron produced in Example 6. FIG.

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Claims (2)

[Claims] 1. A solution of a metal compound in which calcium sol obtained by dissolving calcium hydroxide or calcium oxide in an aqueous solution containing at least one of sugar, sugar alcohol and polyhydric alcohol is dissolved in water or alcohol. A method for producing a solid solution or complex oxide of calcium oxide, which comprises reacting with 2. A metal oxide sol, a halide, an oxyhalide, a nitrate, a sulfate, an oxynitrate, an organic acid salt, an alkoxide or an acetylacetonate is used as the metal compound soluble in water or alcohol. 1. The method for producing a solid solution or complex oxide according to 1.