JPH1111945A - Metal hydroxide solid solution and metal oxide solid solution and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a metal hydroxide solid solution and a metal oxide solid solution improved in fluidity, processability, etc., at the time of kneading, etc., with resin. SOLUTION: The solid solutions satisfies the formula Mg1-x M<2+> x (OH)2 (M<2+> is at least one kind bivalent metal ion selected among Mn<2+> , Fe<2+> Co<2+> , Ni<2+> , Cu<2+> and Zn<2+> and (x) is a number in a range of 0.01<=x<0.5) and composed of parallel upper and lower two base faces and outer peripheral six prismoid faces and the prismoid faces exhibit octahedral shape in which an upward inclined plane and a downward inclined plane are disposed alternately, and a ratio of a diameter of a major axis o f the base faces and a thickness between the upper and lower base planes (major axis diameter/thickness) is 1-9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnesium-based metal hydroxide solid solution, a metal oxide solid solution, and a method for producing the same.

[0002]

2. Description of the Related Art In conventional magnesium hydroxide, fine crystals are aggregated to form an aggregate having a secondary particle diameter of about 10 μm to 100 μm on average. Magnesium oxide produced using these as raw materials had only a non-uniform particle size. For this reason, when the above-mentioned magnesium hydroxide or magnesium oxide is used as an additive for a resin, there are disadvantages such as poor dispersibility, insufficient function as an additive, and impairing the original physical properties of the resin. Was.

In order to solve such a problem, a method for producing magnesium hydroxide having good crystal growth (Japanese Patent Publication No. 63-4 / 1988)
No. 8809) and a method for producing highly dispersible magnesium oxide (JP-A-2-141418). Further, a magnesium-based metal hydroxide solid solution and a magnesium-based metal oxide solid solution having higher performance (JP-A-6-41441, JP-A-5-209084, and JP-A-6-157032) have been proposed. It has a certain effect. Further, high aspect ratio magnesium-based metal hydroxide solid solutions and magnesium-based metal oxide solid solutions (Japanese Patent Application Laid-Open No. 8-259235) have been proposed as those having a large particle size for improving the reinforcing property and the like.

[0004]

However, the above-mentioned conventional magnesium hydroxide, magnesium oxide, magnesium-based metal hydroxide solid solution, magnesium-based metal oxide solid-solution, high aspect ratio magnesium-based metal hydroxide solid-solution and magnesium-based metal The oxide solid solution is a thin hexagonal columnar crystal regardless of the crystal grain size. For this reason, when kneaded with a synthetic resin as an additive, the viscosity of the resin increases, the fluidity and processability deteriorate, the molding speed decreases, the productivity decreases, and high-density filling cannot be performed. There is. Further, depending on the application of the corresponding resin, the dispersibility in the resin may be deteriorated due to the shape factor, and the function of the additive may not be sufficiently exhibited.

The present invention has been made in view of such circumstances, and a metal hydroxide solid solution and a metal oxide solid solution having improved fluidity, workability, and the like when kneaded with a resin and the like, and a method for producing these are disclosed. Its purpose is to provide.

[0006]

In order to achieve the above object, a metal hydroxide solid solution of the present invention satisfies the following formula (1) and has a crystal base having two parallel upper and lower base surfaces. And the outer pyramid surface is composed of six pyramid surfaces, and the pyramid surface has an octahedral shape in which upwardly inclined surfaces and downwardly inclined surfaces are alternately arranged. (The major axis diameter / thickness) is 1 to 9. Mg _1-x M ²⁺ _x (OH) ₂ (1) [In the formula (1), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ]

Further, the metal oxide solid solution of the present invention satisfies the following expression (2), and the crystal outer shape has two parallel upper and lower sides.
A pyramidal surface composed of a base surface of the surface and six pyramid surfaces of the outer periphery, wherein the pyramid surface has an octahedral shape in which an upwardly inclined surface and a downwardly inclined surface are alternately arranged. The gist is that the ratio to the thickness between them (major axis diameter / thickness) is 1 to 9. Mg _1-x M ²⁺ _x O (2) [In the formula (2), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ]

The method for producing a metal hydroxide solid solution according to the present invention comprises the steps of: preparing a composite metal oxide represented by the following formula (3) from a carboxylic acid, a metal salt of a carboxylic acid, an inorganic acid, and a metal salt of an inorganic acid. The essence is that a hydration reaction is carried out under strong stirring in an aqueous medium in which at least one selected from the group consisting of: Mg _1-x M ²⁺ _x O (3) [In the formula (3), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ]

Further, the method for producing a metal oxide solid solution according to the present invention comprises:
The sintering is performed at a temperature of 0 ° C. or higher.

As described above, the metal hydroxide solid solution of the present invention has a crystal outer shape composed of two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, and the pyramid surfaces are upwardly inclined surfaces and downwardly inclined surfaces. Are alternately arranged, and the ratio of the major axis diameter of the basal plane to the thickness between the basal planes (major axis diameter / thickness) is 1
-9. As described above, the crystal has a habit shape completely different from that of a thin hexagonal columnar crystal such as a conventional metal hydroxide solid solution, and has a large crystal growth in the thickness direction. For this reason, when kneaded with a synthetic resin as an additive as compared with a conventional product, the fluidity and processability of the resin are improved, the molding speed is improved, the productivity is extremely improved, and the filling property is also improved. Then, the dispersibility in the resin is improved, and when the resin is used as an additive such as a flame retardant, an ultraviolet absorber, a reinforcing agent, and a heat radiating agent, their functions can be sufficiently exhibited.

In the metal hydroxide solid solution of the present invention, when the major axis diameter of the basal plane is 0.1 to 10 μm on average, the fluidity and workability when kneaded with a synthetic resin as an additive are reduced. The productivity is further improved, and the productivity in the case of performing resin molding and the like is extremely improved.

In the metal hydroxide solid solution of the present invention, when M ²⁺ in the above formula (1) is Zn ²⁺ ,
By dissolving ²⁺ in Mg (OH) ₂ , whiteness is improved and ultraviolet absorption is also excellent.

Further, the metal oxide solid solution of the present invention, like the metal hydroxide solid solution, has a crystal outer shape composed of two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, and It has an octahedral shape in which upward inclined surfaces and downward inclined surfaces are alternately arranged, and the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the basal planes is 1 to 9. is there. As described above, the crystal has a crystal habit shape completely different from that of the conventional oxide and metal hydroxide crystals, and has a large crystal growth in the thickness direction. For this reason, when kneaded with a synthetic resin as an additive as compared with a conventional product, the fluidity and processability of the resin are improved, the molding speed is improved, the productivity is extremely improved, and the filling property is also improved. Then, the dispersibility in the resin is improved, and when the resin is used as an additive such as a flame retardant, an ultraviolet absorber, a reinforcing agent, and a heat radiating agent, their functions can be sufficiently exhibited.

In the metal oxide solid solution of the present invention, when the major axis diameter of the basal plane is 0.1 to 10 μm on average, the fluidity and processability when kneaded with the synthetic resin as an additive are further improved. Thus, productivity in the case of performing resin molding and the like is extremely improved.

In the metal oxide solid solution of the present invention, when M ²⁺ in the above formula (2) is Zn ²⁺ ,
By dissolving ²⁺ in MgO, whiteness is improved and ultraviolet absorption is also excellent.

[0016]

Next, embodiments of the present invention will be described in detail.

The magnesium-based metal hydroxide solid solution of the present invention satisfies the following formula (1), and a divalent metal ion represented by M ²⁺ is dissolved in Mg (OH) ₂ . . Here, x indicates a number in the range of 0.01 ≦ x <0.5. The metal hydroxide solid solution has the same crystal structure as magnesium hydroxide, and has a hexagonal cadmium hydroxide type structure. Mg _1-x M ²⁺ _x (OH) ₂ (1)

Further, the magnesium-based metal oxide solid solution of the present invention satisfies the following formula (2), and a divalent metal ion represented by M ²⁺ is dissolved in MgO. Where x
Indicates a number in the range of 0.01 ≦ x <0.5. The metal oxide solid solution has the same crystal structure as ordinary magnesium oxide and has a cubic Gan-en type structure, but is an oxide retaining the form of the hydroxide solid solution. . Mg _1-x M ²⁺ _x O (2)

In the above equations (1) and (2), M
²⁺ represents at least one divalent metal ion selected from the group consisting of Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ and Zn ²⁺ . Among these, in particular, Zn
²⁺ is preferred. Zn ²⁺ is Mg (OH) ₂ or Mg
This is because by forming a solid solution in O, the whiteness can be improved and the solid solution can be provided with excellent ultraviolet absorbing properties.

Further, the metal hydroxide solid solution and the metal oxide solid solution of the present invention have two parallel upper and lower base surfaces and an outer periphery 6.
The pyramidal surface has an octahedral shape in which upwardly inclined surfaces and downwardly inclined surfaces are alternately arranged.

More specifically, the conventional solid solution of magnesium hydroxide and magnesium-based metal hydroxide has a hexagonal crystal structure, and has a Miller-Bravey index of (00 · 1) as shown in FIG. Base surface 10 consisting of upper and lower surfaces represented by two surfaces, and 6 belonging to a mold surface of {10.0}
It has a hexagonal prism shape whose outer periphery is surrounded by a rectangular cylindrical surface 11. Since the crystal growth in the [001] direction (c-axis direction) is small, it has a thin hexagonal column shape.

On the other hand, as shown in FIG. 2, the metal hydroxide solid solution and the metal oxide solid solution according to the present invention are formed by controlling the crystal habit during the crystal growth so that the upper and lower surfaces represented by the (00 · 1) plane can be formed. The outer periphery is surrounded by a base surface 12 of the surface and six pyramidal surfaces 13 belonging to the {10 · 1} mold surface. The pyramid surface 13 includes an upwardly inclined surface 13a such as a (10 · 1) plane,
It has an octahedral shape having a special crystal habit in which the downwardly inclined surfaces 13b such as (10-1) planes are alternately arranged.
Further, the crystal growth in the c-axis direction is larger than that of the conventional one. FIG. 2 shows a plate-like shape, but FIG. 3 shows that the crystal growth progresses further in the c-axis direction and the crystal habit becomes remarkable and isotropic. Thus, the metal hydroxide solid solution and the metal oxide solid solution of the present invention include those having a shape close to an octahedron. That is, the ratio of the major axis diameter of the basal plane to the thickness between the basal planes (major axis diameter / thickness) is
1-9 are preferred. 7 is more preferable as the upper limit of the ratio between the major axis diameter and the thickness. In the Miller-Bravey index, “1 bar” is indicated as “−1”.

Thus, the metal hydroxide solid solution and the metal oxide solid solution of the present invention have six surfaces surrounding the outer periphery,
It can be seen from the following that the pyramidal surface belongs to {10 · 1}. That is, when the crystals of the metal hydroxide solid solution and the metal oxide solid solution of the present invention are observed with a scanning electron microscope from the c-axis direction, the crystals exhibit three-fold rotational symmetry with the c-axis as a rotation axis. . In addition, the (10 · 1) plane using the measured value of the lattice constant by powder X-ray diffraction and {10 ·
The calculated value of the inter-plane angle with the mold surface of 1 ° almost coincides with the measured value of the inter-plane angle in the scanning electron microscope observation.

Further, the metal hydroxide solid solution and the metal oxide solid solution of the present invention can be obtained by powder X-ray diffraction (11
0) plane half width B ₁₁₀ of a peak of the ratio of the half width B ₀₀₁ of a peak of the (001) plane (B ₁₁₀ / B ₀₀₁₎ is 1.4
That is all. From this, it can be confirmed that the crystallinity in the c-axis direction is good and the thickness has grown. That is, in the conventional crystal of magnesium hydroxide or the like, the crystal in the c-axis direction does not grow, and the peak of the (001) plane is broad and the half width B ₀₀₁ is large. Therefore, (B
The value of ₁₁₀ / _B001 ) becomes smaller. In contrast, in the metal hydroxide solid solution and the metal oxide solid solution of the present invention,
Since the crystallinity in the c-axis direction is good, the peak of the (001) plane is sharp and narrow, and the half-value width B ₀₀₁ is also small. Therefore, the value of ( _B110 / _B001 ) increases.

That is, the metal hydroxide solid solution and the metal oxide solid solution of the present invention have crystal habits completely different from those of the prior art, and have remarkable crystal growth in the c-axis direction. Thus, it has a novel crystal shape that has not been seen before.

The average particle size of the metal hydroxide solid solution and the metal oxide solid solution of the present invention is preferably in the range of 0.1 to 10 μm. The lower limit of the average particle size is more preferably 0.5 μm, and still more preferably 1 μm.
The upper limit is more preferably 5 μm, and still more preferably 3 μm. Further, it is preferable that there is almost no secondary aggregation.

The metal hydroxide solid solution of the present invention is, for example,
It can be made as follows. That is, first, a water-soluble M ²⁺ compound is added to an aqueous solution of magnesium hydroxide to obtain a partially solubilized hydroxide as a raw material. This raw material is in the range of 800 to 1500 ° C, preferably 1000 to 1500 ° C.
By firing at a temperature of 1300 ° C., a composite metal oxide is obtained. This composite metal oxide is represented by the following formula (3), and has a BET specific surface area of 10 m ² / g or less, preferably 5 m ² / g or less. At least one selected from the group consisting of a carboxylic acid, a metal salt of a carboxylic acid, an inorganic acid and a metal salt of an inorganic acid is present in the composite metal oxide in an amount of about 0.1 to 6 mol% with respect to the composite metal oxide. The metal hydroxide solid solution of the present invention can be obtained by performing a hydration reaction at a temperature of 40 ° C. or more in a system in an aqueous medium with vigorous stirring. Mg _1-x M ²⁺ _x O (3)

In the above formula (3), M ²⁺ is Mn ²⁺ ,
It shows at least one kind of divalent metal ion selected from the group consisting of Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ and Zn ²⁺ . Of these, Zn ²⁺ is particularly preferred.

In the above method, the raw material is not limited to the partially solubilized hydroxide obtained by the above-mentioned method, and is not particularly limited as long as the raw material can obtain a composite metal oxide by firing. composite metal hydroxide and obtained by precipitation, or magnesium hydroxide, at least a one selected from the group consisting of magnesium oxide and magnesium carbonate, hydroxides of M ^2+, oxides of M ²⁺ and M ² And a mixture thereof with at least one selected from the group consisting of ⁺ salts. In addition, the stirring during the hydration reaction is performed to improve the uniformity and dispersibility, and to improve the contact efficiency with carboxylic acid, inorganic acid and / or a metal salt thereof,
Strong stirring is preferred, and even more powerful high shear stirring. For example, such stirring is preferably performed at a peripheral speed of the rotating blade of 5 m / s or more, and more preferably at a speed of 7 m / s or more, in a rotating blade type stirrer. Further, it is preferable to use a stirring blade having a shape such as a turbine blade or a DS impeller blade having strong shearing force.

The carboxylic acid is not particularly limited, but preferably includes a monocarboxylic acid, an oxycarboxylic acid (oxyacid) and the like. Examples of the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, crotonic acid, and the like. Examples of the oxycarboxylic acid (oxy acid) include glycolic acid, lactic acid, Hydroacrylic acid, α
-Oxybutyric acid, glyceric acid, salicylic acid, benzoic acid,
And gallic acid. The metal salt of the carboxylic acid is not particularly limited, but preferably includes magnesium acetate, zinc acetate and the like.

The inorganic acid is not particularly limited, but preferably includes nitric acid, hydrochloric acid and the like. The inorganic acid metal salt is not particularly limited, but preferably includes magnesium nitrate, zinc nitrate and the like.

Further, the metal oxide solid solution of the present invention is obtained by adding about 40% to the metal hydroxide solid solution obtained as described above.
It can be produced by baking at 0 ° C. or more, preferably 500 to 1200 ° C.

The metal hydroxide solid solution and the metal oxide solid solution of the present invention can be provided with functions such as affinity for resin, acid resistance, water repellency, and ultraviolet absorption by performing various surface treatments. . The metal hydroxide solid solution and the metal oxide solid solution of the present invention are well dispersed in the resin as described above, and can sufficiently exhibit the function even when the function is imparted by the surface treatment as described above.

Examples of the surface treatment agent for increasing the affinity with the resin include higher fatty acids or their alkali metal salts, phosphate esters, silane coupling agents, and fatty acid esters of polyhydric alcohols. Further, in order to increase acid resistance, water repellency, etc., for example, silica coating by hydrolysis of methyl silicate or ethyl silicate, and about 500 to 1000 after silica coating.
Coating with a metal silicate by baking at a temperature of ° C., coating with a silicone oil, a polyfluoroalkyl phosphate salt, or the like is performed. In order to enhance the ultraviolet absorption, for example, titanyl sulfate is subjected to a hydrolysis reaction to coat titanium dioxide.

[0035]

As described above, the present invention has a crystal habit that is completely different from that of a thin hexagonal columnar crystal such as a conventional metal hydroxide solid solution, and crystal growth in the thickness direction. large. For this reason, when kneaded with a synthetic resin as an additive as compared with a conventional product, the fluidity and processability of the resin are improved, the molding speed is improved, the productivity is extremely improved, and the filling property is also improved. And the dispersibility in the resin is improved,
When used as additives such as resin flame retardants, ultraviolet absorbers, reinforcing agents, and heat dissipation agents, their functions can be fully exhibited.

In the present invention, when the major axis diameter of the base surface is 0.1 to 10 μm on average, the fluidity and processability when kneaded with a synthetic resin as an additive are further improved,
The productivity in the case of performing resin molding and the like is extremely improved.

Further, in the present invention, when M ²⁺ in the formula (1) and (2) is Zn ²⁺ is the Zn ²⁺ M
By forming a solid solution in gO or Mg (OH) ₂ , whiteness is improved and ultraviolet absorption is also excellent.

Next, examples will be described together with comparative examples.

[0039]

Embodiment 1 First, a mixed solution of magnesium nitrate and zinc nitrate (Mg ²⁺ = 1.6 mol / liter, Zn ²⁺ = 0.1 mol / l).
(4 mol / L) 20 L was placed in a 50 L reaction vessel, and 20 L of 2.0 mol / L Ca (OH) ₂ was added thereto with stirring to cause a reaction. Then, the obtained white precipitate was filtered, washed with water and dried.
This dried product was pulverized with a ball mill and 12
Baking was performed at 00 ° C. for 2 hours. The fired product was pulverized by a ball mill and passed through a 200 mesh sieve by a wet method.
This calcined product was placed in a 20-liter container containing 10 liters of 0.01 mol / liter acetic acid and the oxide concentration was set at 10%.
0 g / liter was added. Then, while stirring at a peripheral speed of the turbine blade of 10 m / s with a high-speed stirrer (trade name: Homomixer, manufactured by Tokushu Kika Co.), 90
The hydration reaction was allowed to proceed at 4 ° C. for 4 hours. This reactant is 500me
sh, then filter, wash and dry,
A metal hydroxide solid solution of the present invention was obtained.

The above metal hydroxide solid solution was observed with a scanning electron microscope, and as a result, it was found to have an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the base surface is about 1.2.
μm, and the thickness between the basal planes was about 0.36 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 3.
It was 3. FIG. 4 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side. It turns out that it is a cadmium hydroxide structure.

[0041]

Example 2 Magnesium hydroxide slurry (Mg (O
H) ₂ 100 g / l) 20 liters were placed in a 30 liter reaction vessel, and 3.4 liters of 2.0 mol / l ZnCl ₂ was added thereto with stirring to cause a reaction. The obtained white precipitate was filtered, washed with water and dried. The dried product was pulverized with a ball mill and then fired at 1100 ° C. for 2 hours using an electric furnace. The fired product was pulverized by a ball mill and passed through a 500 mesh sieve by a wet method. The fired product was treated with 0.03 mol / l acetic acid 1
Oxide concentration of 1 in a 20 liter container containing 0 liter
It was added so as to be 00 g / liter. Then, using a stirrer with an edge turbine blade, the hydration reaction was allowed to proceed at 90 ° C. for 6 hours while stirring at a peripheral speed of the edge turbine blade of 12 m / s. The reaction product was sieved through a 500 mesh sieve and subsequently filtered, washed with water and dried to obtain a metal hydroxide solid solution of the present invention.

The above metal hydroxide solid solution was observed by a scanning electron microscope, and as a result, it was found to have an octahedral shape with a pyramidal surface on the outer periphery. In addition, the major axis diameter of the basal plane is about 2.4.
μm, and the thickness between the basal planes was about 0.37 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 6.
It was 5. FIG. 5 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side. It turns out that it has a cadmium hydroxide structure.

[0043]

Embodiment 3 First, a mixed solution of magnesium nitrate and zinc nitrate (Mg ²⁺ = 1.6 mol / liter, Zn 2 ⁺ = 0.
20 liters (4 mol / l) was placed in a 50 liter reaction vessel, and 2.0 mol / l of Ca (OH) ₂ 20 liter was added thereto with stirring to cause a reaction. Then, the obtained white precipitate was filtered, washed with water and dried. This dried product was pulverized with a ball mill and then dried using an electric furnace.
It was baked at 0 ° C. for 2 hours. The fired product was pulverized by a ball mill and passed through a 200 mesh sieve by a wet method. This calcined product was treated with 0.08 mol / liter of n-butyric acid 10
Oxide concentration of 10 liters in a 20 liter container
0 g / liter was added. The hydration reaction was allowed to proceed at 90 ° C. for 4 hours while stirring at a peripheral speed of the turbine blade of 10 m / s using a high-speed stirrer (trade name: homomixer). The reaction product was sieved through a 500 mesh sieve and subsequently filtered, washed with water and dried to obtain a metal hydroxide solid solution of the present invention.

As a result of observing the above metal hydroxide solid solution with a scanning electron microscope, it was found to have a substantially regular octahedral shape. The major axis diameter of the basal plane was about 2.5 μm, and the thickness between the basal planes was about 2.2 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) was 1.1. FIG. 6 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side. It turns out that it has a cadmium hydroxide structure.

[0045]

Example 4 The metal hydroxide solid solution obtained in Example 1 was fired in an electric furnace at 900 ° C. for 2 hours to obtain a metal oxide solid solution of the present invention.

As a result of observing the above metal oxide solid solution with a scanning electron microscope, it was found to have an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the basal plane is about 1.2μ.
m, and the thickness between the basal planes was about 0.36 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 3.3.
Met. FIG. 7 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium oxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side.

[0047]

Example 5 In Example 1, 10 liters of 0.01 mol / l hydrochloric acid was used instead of 10 liters of acetic acid 0.01 mol / l. Otherwise in the same manner as in Example 1, a metal hydroxide solid solution of the present invention was obtained.

The above metal hydroxide solid solution was observed by a scanning electron microscope, and as a result, it was found to have an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the basal plane is about 1.1.
μm, and the thickness between the basal planes was about 0.51 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 2.
It was 2. FIG. 8 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side. It turns out that it is a cadmium hydroxide structure.

[0049]

Example 6 In Example 1, 10 l of 0.26 mol / l nitric acid was used instead of 10 l of 0.01 mol / l acetic acid. Otherwise in the same manner as in Example 1, a metal hydroxide solid solution of the present invention was obtained.

The metal hydroxide solid solution was observed with a scanning electron microscope. As a result, the solid solution exhibited an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the basal plane is about 1.0.
μm, and the thickness between the basal planes was about 0.69 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 1.
It was 4. FIG. 9 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side. It turns out that it is a cadmium hydroxide structure.

[0051]

EXAMPLE 7 In Example 1, 0.004 mol / l of magnesium acetate and 0.001 m of zinc acetate were used instead of 10 liters of acetic acid of 0.01 mol / l.
10 liter of an aqueous solution having a composition of ol / liter was used. Otherwise in the same manner as in Example 1, a metal hydroxide solid solution of the present invention was obtained.

The metal hydroxide solid solution was observed with a scanning electron microscope, and as a result, it was found to have an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the basal plane is about 1.1.
μm, and the thickness between the basal planes was about 0.31 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 3.
It was 5. FIG. 10 shows a scanning electron micrograph of the metal hydroxide solid solution. The powder X-ray diffraction of the metal hydroxide solid solution showed that the diffraction pattern was
A diffraction pattern similar to that of magnesium hydroxide was obtained except that it was slightly shifted to a lower angle side, indicating that the structure was a hexagonal cadmium hydroxide type structure.

[0053]

Example 8 In Example 1, 0.01 mol of acetic acid was replaced by 10 liter of acetic acid of 0.01 mol / liter.
Per liter and 10 liters of an aqueous solution having a composition of 0.01 mol / liter of nitric acid. Otherwise in the same manner as in Example 1, a metal hydroxide solid solution of the present invention was obtained.

Observation of the above metal hydroxide solid solution with a scanning electron microscope revealed that the metal hydroxide solid solution had an octahedral shape with a pyramidal surface appearing on the outer periphery. In addition, the long axis diameter of the basal plane is about 1.0.
μm, and the thickness between the basal planes was about 0.52 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 1.
Nine. FIG. 11 shows a scanning electron micrograph of the metal hydroxide solid solution. The powder X-ray diffraction of the metal hydroxide solid solution showed that the diffraction pattern was
A diffraction pattern similar to that of magnesium hydroxide was obtained except that it was slightly shifted to a lower angle side, indicating that the structure was a hexagonal cadmium hydroxide type structure.

[0055]

Example 9 In Example 1, 0.01 mol of acetic acid was used instead of 10 liters of acetic acid of 0.01 mol / liter.
Per liter and 10 liters of an aqueous solution having a composition of magnesium nitrate 0.005 mol / l. Otherwise in the same manner as in Example 1, a metal hydroxide solid solution of the present invention was obtained.

Observation of the metal hydroxide solid solution with a scanning electron microscope revealed that the metal hydroxide solid solution had an octahedral shape with a pyramidal surface on the outer periphery. In addition, the long axis diameter of the base surface is about 1.2.
μm, and the thickness between the basal planes was about 0.59 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) is 2.
It was 0. FIG. 12 shows a scanning electron micrograph of the metal hydroxide solid solution. The powder X-ray diffraction of the metal hydroxide solid solution showed that the diffraction pattern was
A diffraction pattern similar to that of magnesium hydroxide was obtained except that it was slightly shifted to a lower angle side, indicating that the structure was a hexagonal cadmium hydroxide type structure.

[0057]

Comparative Example 1 First, a mixed solution of magnesium nitrate and zinc nitrate (Mg ²⁺ = 1.6 mol / liter, Zn 2 ⁺ = 0.
20 liters (4 mol / l) was placed in a 50 liter reaction vessel, and 2.0 mol / l of Ca (OH) ₂ 20 liter was added thereto with stirring to cause a reaction. Then, the obtained white precipitate was filtered, washed with water and dried. This dried product was pulverized with a ball mill and then dried using an electric furnace.
It was baked at 0 ° C. for 2 hours. The fired product was pulverized with a ball mill and sieved through a 200 mesh by a wet method. The calcined product was added to a 20-liter container containing 10 liters of 0.15 mol / liter acetic acid so as to have an oxide concentration of 100 g / liter. Then, the hydration reaction was allowed to proceed at 90 ° C. for 4 hours while stirring at a peripheral speed of the propeller blade of 4 m / s using a stirrer with a propeller blade. The reaction is sieved through a 500 mesh screen, followed by filtration,
It was washed with water and dried to obtain a dried product.

As a result of observing the obtained dried product with a scanning electron microscope, it was found to have a thin hexagonal column shape. Also,
The major axis diameter of the basal plane was about 5.5 μm, and the thickness between the basal planes was about 0.40 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) was 13.8. FIG. 13 shows a scanning electron micrograph of the metal hydroxide solid solution.
Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side.

[0059]

Comparative Example 2 A mixed solution of magnesium nitrate and zinc nitrate (Mg ²⁺ = 0.9 mol / liter, Zn ²⁺ = 0.1 m
ol / liter) 1 liter was placed in a 3 liter reaction vessel, and 2.04 mol / liter of Na was stirred while stirring.
One liter of OH was added to react. Next, this reaction product was emulsified in an aqueous solution of sodium chloride having a chloride ion concentration of 1 mol / liter, and placed in a 3-liter autoclave equipped with a stirrer and subjected to hydrothermal treatment at 150 ° C. for 2 hours.
Thereafter, the resultant was filtered, washed with water, and dried to obtain a dried product.

As a result of observing the obtained dried product with a scanning electron microscope, it was found to have a thin hexagonal column shape. Also,
The major axis diameter of the basal plane was about 0.66 μm, and the thickness between the basal planes was about 0.18 μm. Therefore, the ratio of the major axis diameter to the thickness (major axis diameter / thickness) was 3.7. FIG. 14 shows a scanning electron micrograph of the metal hydroxide solid solution. Further, as a result of performing powder X-ray diffraction on the metal hydroxide solid solution, a diffraction pattern similar to that of magnesium hydroxide was obtained except that the diffraction pattern was slightly shifted to a lower angle side.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the external shape of a conventional metal hydroxide solid solution, wherein (a) is a plan view and (b) is a side view.

FIG. 2 is an explanatory view showing an example of the outer shape of a metal hydroxide solid solution of the present invention, wherein (a) is a plan view and (b) is a side view.

FIG. 3 is an explanatory view showing another example of the outer shape of the metal hydroxide solid solution of the present invention, wherein (a) is a plan view and (b) is a side view.

FIG. 4 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 1.

FIG. 5 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 2.

FIG. 6 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 3.

FIG. 7 is a scanning electron micrograph showing a metal oxide solid solution of Example 4.

FIG. 8 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 5.

FIG. 9 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 6.

FIG. 10 is a scanning electron micrograph showing a metal hydroxide solid solution of Example 7.

FIG. 11 is a scanning electron micrograph showing a metal oxide solid solution of Example 8.

FIG. 12 is a scanning electron micrograph showing a metal oxide solid solution of Example 9.

FIG. 13 is a scanning electron micrograph showing the metal oxide solid solution of Comparative Example 1.

FIG. 14 is a scanning electron micrograph showing a metal hydroxide solid solution of Comparative Example 2.

Claims (14)

[Claims] 1. A crystal which satisfies the following formula (1) and has a crystal outer shape comprising two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, wherein the pyramidal surfaces are upwardly inclined surfaces and downwardly inclined surfaces. Are alternately arranged, and the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the upper and lower basal planes is 1 to 9
A metal hydroxide solid solution, characterized in that: Mg _1-x M ²⁺ _x (OH) ₂ (1) [In the formula (1), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ] 2. The long axis diameter of the basal plane is 0.1 to 10 on average.
The metal hydroxide solid solution according to claim 1, which has a diameter of 1 µm. 3. The metal hydroxide solid solution according to claim 1, wherein M ^{2+ in the} formula (1) is Zn ²⁺ . 4. A crystal which satisfies the following formula (2) and has a crystal outer shape composed of two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, wherein the pyramid surfaces are upwardly inclined surfaces and downwardly inclined surfaces. Are alternately arranged, and the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the upper and lower basal planes is 1 to 9
A metal oxide solid solution, characterized in that: Mg _1-x M ²⁺ _x O (2) [In the formula (2), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ] 5. The long axis diameter of the basal plane is 0.1 to 10 on average.
The metal oxide solid solution according to claim 4, which has a diameter of µm. 6. The metal oxide solid solution according to claim 4, wherein M ^{2+ in the} formula (2) is Zn ²⁺ . 7. A crystal which satisfies the following formula (1) and has a crystal outer shape comprising two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, wherein the pyramidal surfaces are upwardly inclined surfaces and downwardly inclined surfaces. Are alternately arranged, and the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the upper and lower basal planes is 1 to 9
Wherein the composite metal oxide represented by the following formula (3) is prepared from a group consisting of carboxylic acid, a metal salt of a carboxylic acid, an inorganic acid, and a metal salt of an inorganic acid. A method for producing a metal hydroxide solid solution, wherein a hydration reaction is carried out under strong stirring in an aqueous medium in which at least one selected material coexists with the composite metal oxide in an amount of 0.1 to 6 mol%. Mg _1-x M ²⁺ _x (OH) ₂ (1) [In the formula (1), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. Mg _1-x M ²⁺ _x O (3) [In the formula (3), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ] 8. The long axis diameter of the basal plane is 0.1 to 10 on average.
The method for producing a metal hydroxide solid solution according to claim 7, which has a particle size of μm. 9. The method for producing a metal hydroxide solid solution according to claim 7, wherein M ^{2+ in the} formula (3) is Zn ²⁺ . 10. The composite metal oxide represented by the formula (3) has a BET specific surface area of 10 m ² / g or less.
10. The method for producing a metal hydroxide solid solution according to any one of claims 9 to 9. 11. A crystal which satisfies the following expression (2) and has a crystal outer shape comprising two parallel upper and lower base surfaces and six outer peripheral pyramid surfaces, wherein the pyramid surfaces are upwardly inclined surfaces and downwardly inclined surfaces. Are alternately arranged, and the ratio (major axis diameter / thickness) of the major axis diameter of the basal plane to the thickness between the upper and lower basal planes is 1 to
9. A method for producing a metal oxide solid solution according to claim 9, wherein the composite metal oxide represented by the following formula (3) is selected from the group consisting of carboxylic acids, metal salts of carboxylic acids, inorganic acids, and metal salts of inorganic acids. The hydration reaction is carried out under strong stirring in an aqueous medium in which at least one of the selected metal oxides coexists with the above complex metal oxide in an amount of 0.1 to 6 mol%, and then this is fired at a temperature of 400 ° C. or more. A method for producing a metal oxide solid solution. Mg _1-x M ²⁺ _x O (2) [In the formula (2), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. Mg _1-x M ²⁺ _x O (3) [In the formula (3), M ²⁺ is Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni
²⁺ , at least one divalent metal ion selected from the group consisting of Cu ²⁺ and Zn ²⁺ , wherein x is 0.01 ≦ x <
Indicates a number in the range of 0.5. ] 12. The long axis diameter of the basal plane is 0.1 to 1 on average.
The method for producing a metal oxide solid solution according to claim 11, which has a thickness of 0 µm. 13. The method for producing a metal oxide solid solution according to claim 11, wherein M ^{2+ in the} formula (3) is Zn ²⁺ . 14. The composite metal oxide represented by the formula (3) has a BET specific surface area of 10 m ² / g or less.
14. The method for producing a metal oxide solid solution according to any one of 1 to 13.