JP2001206716A - Granular body and or molding of modified alumina and/or hydrated alumina, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a granular body and/or molding of modified alumina and/or hydrated alumina, that a bonding state of a multiple metal aluminum hydroxide salt is stable and rigid and surface properties such as adsorptivity, solid acidity or solid basicity in addition to mechanical strength and wear resistance are remarkably modified, and the manufacturing method. SOLUTION: The granular body and/or molding of the modified alumina and/or the hydrated alumina contains the multiple metal aluminum hydroxide salt containing an aluminum portion originating from alumina or hydrated alumina and a univalent or bivalent metallic portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified alumina, a hydrated alumina powder or a compact, and a method for producing the same. More specifically, the present invention relates to a method for chemically or thermally treating a composite metal aluminum hydroxide salt. The present invention relates to a modified modified alumina or hydrated alumina powder or molded article. still,
The composite metal aluminum hydroxide salt in the present invention,
Representative examples include hydrotalcite and hydrotalcite analogs.

[0002]

2. Description of the Prior Art It has long been known to treat various inorganic particles with composite metal aluminum hydroxide salts such as hydrotalcite or hydrotalcite analogs.

[0003] JP-A-2-51416 discloses zinc borate characterized by being treated with a hydrotalcite compound. In this zinc borate, while maintaining the flame retardancy of zinc borate. It also describes that a decrease in thermal stability is prevented.

Japanese Patent No. 2893541 is characterized in that the surface of a powdery nucleus (excluding zinc borate) is coated with hydrotalcite or hydrotalcite and one or more other powders. Hydrotalcite coated powders are described.

[0005] JP-A-5-125223 discloses that
(A) Amorphous silica, amorphous silica in which each particle independently has a distinct cubic or spherical primary particle shape and a primary particle diameter of 0.3 to 20 μm as measured by electron microscopy -Core particles composed of alumina or amorphous or crystalline aluminosilicate, (B) fine particles of hydrotalcite and (C) organic binders, most of the fine particles of hydrotalcite being nucleated via an organic binder. The coated particles are characterized in that they cover the surface of the particles.

[0006]

SUMMARY OF THE INVENTION These proposals in the prior art will achieve the advantages of hydrotalcite and the advantages of core particles by physically coating the surface of the core particles with hydrotalcite. It is assumed that. However, these physical coating methods have a problem that the coating state of hydrotalcite is not stable and can not be said to be strong, and is still unsatisfactory for the purpose of modifying the properties of the core particles. Things.

The present inventors have succeeded in synthesizing a composite metal aluminum hydroxide in situ in a powder or a compact made of active alumina or hydrated alumina, and obtained by this treatment. In the modified alumina or hydrated alumina powder or molded product, the bonded state of the composite metal aluminum hydroxide salt is stable and strong, and the alumina or hydrated alumina powder or molded product itself is used. Has also been found to be significantly improved.

[0008] That is, an object of the present invention is to provide a modified alumina or hydrated alumina powder obtained by synthesizing a composite metal aluminum hydroxide in situ on a powder or a compact made of active alumina or hydrated alumina. To provide a body or a molded body. Another object of the present invention is to provide a composite metal aluminum hydroxide salt in which the bonding state is stable and strong, and the mechanical strength and abrasion of the alumina or hydrated alumina powder or the compact itself. It is an object of the present invention to provide a modified alumina or hydrated alumina powder or molded article in which surface properties such as adsorptivity, solid acid, solid basicity and the like have been remarkably modified.

[0009]

According to the present invention, there is provided a powder or molded article comprising active alumina or hydrated alumina, and a powder or a molded article synthesized in situ on the powder or molded article.
A modified alumina, a hydrated alumina powder, or a molded article, comprising a composite metal aluminum hydroxide salt containing an aluminum component derived from the alumina or hydrated alumina and a monovalent or divalent metal component. Provided. In the modified alumina or hydrated alumina powder or molded article of the present invention, 1. The composite metal aluminum hydroxide salt is contained in an amount of 0.1 to 30% by weight as a monovalent to divalent metal oxide on an oxide basis. 2. A powder or a compact made of active alumina or hydrated alumina has a BET specific surface area of 80 m ² / g or more; 3. The composite metal aluminum hydroxide salt contains a magnesium component; 4. the composite metal aluminum hydroxide salt has a carbonate anion; 5. the composite metal aluminum hydroxide salt is mainly composed of magnesium aluminum hydroxide carbonate; The outer surface of a powder or a compact in which the composite metal aluminum hydroxide salt is made of alumina or hydrated alumina, and
6. be present on the inner surface; It is preferable that the BET specific surface area is 80 to 500 m ² / g and the pore volume is 0.1 to 1.5 ml / g. In the present invention, a powder or a compact comprising active alumina or hydrated alumina is dispersed or immersed in an aqueous medium containing a state in which a water-soluble salt of a monovalent or divalent metal is dissolved. At a pH of 7 to 12,
A method for producing a modified alumina or hydrated alumina powder or molded article, characterized by reacting the powder or molded article with a water-soluble salt and subjecting it to heat treatment if necessary. In the above production method, the reaction is preferably performed at a temperature of 20 to 200 ° C.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Function] The modified alumina or hydrated alumina powder or molded article of the present invention comprises a powder or molded article made of active alumina or hydrated alumina. It is characterized in that it contains a composite metal aluminum hydroxide salt containing an aluminum component derived from the alumina or hydrated alumina and a monovalent or divalent metal component, or a heat-treated product thereof, which is synthesized in situ on the molded body. .

Synthesized in situ means that the place where the composite metal aluminum hydroxide salt is synthesized is limited to the place of the base alumina, hydrated alumina powder, or compact.

The constituent aluminum component in the composite metal aluminum hydroxide salt to be synthesized is supplied from solid alumina or hydrated alumina powder or molded product. Is supplied from a metal salt dissolved in a reaction medium, and the synthesis reaction of the composite metal aluminum hydroxide salt in the present invention is a solid-liquid reaction, It is understood that the reaction is limited to the location of the hydrated alumina powder or molded product, and that the recombination reaction on the surface of the active alumina or hydrated alumina substrate is completely different from the conventional coating. I understand. According to the present invention, an active alumina or hydrated alumina powder or molded article containing a composite metal aluminum hydroxide salt formed in situ is converted into activated alumina by heat treatment. At the same time, the in situ formed composite metal aluminum hydroxide salt can be converted to an x-ray amorphous heat treatment.

The formation of the composite metal aluminum hydroxide salt by this recombination reaction can be confirmed by an X-ray diffraction image or a scanning electron micrograph of the modified alumina, the hydrated alumina powder or the compact, It can also be confirmed from a chemical analysis of the powder or the compact.

FIG. 2 of the accompanying drawings is a scanning electron micrograph (magnification: 20000) showing the particle structure (cross-section inside the compact) of a dried pellet of the modified hydrated alumina compact according to the present invention.
FIG. 1 is a scanning electron micrograph (magnification: 20,000) showing the particle structure (fraction inside the molded body) of the dried product of the hydrated alumina molded pellet before modification. FIG. 3 shows the modified hydrated alumina compact pellets fired (600 ° C. × 3
h) is a scanning electron micrograph (magnification: 20,000 times) showing a cross section inside the molded body in the case of h).

As shown in FIGS. 1 to 3, high-resolution scanning electron micrographs show that the fine particle structure of the untreated hydrated alumina compact and the modified hydrated alumina compact (modified compact) were obtained. (Internal split plane). A submicron fine structure, which is considered to be due to hydrated alumina primary particles, is observed on the inner surface of the molded body before the treatment, whereas scales peculiar to the hydrotalcite analog are found on the inner surface of the molded body after the treatment. A crystalline grain structure is observed. FIG. 14 shows a photograph taken at a magnification of 5,000 times of a scanning electron micrograph showing a cross section inside the molded body when the modified hydrated alumina molded body pellet was fired (600 ° C. × 3 h). .

FIG. 4 of the accompanying drawings shows X-ray diffraction images of untreated hydrated alumina (A), modified hydrated alumina (M) according to the present invention, and modified alumina (C) according to the present invention. It is shown. From these X-ray diffraction images, in the modified hydrated alumina particles (M) according to the present invention, the X-ray diffraction image of the raw material hydrated alumina and the X-ray diffraction of the composite metal aluminum hydroxide salt (hydrotalcite analog) were obtained. This shows that the composite metal aluminum hydroxide salt is formed on the surface of the hydrated alumina particles. On the other hand, in the modified alumina (C), the X-ray diffraction image of the composite metal aluminum hydroxide salt has disappeared. You can see that it is done. Further, FIG.
Is untreated alumina (calcined product of hydrated alumina: A),
1 shows X-ray diffraction images of unfired modified alumina (M) according to the present invention and modified alumina (C) according to the present invention. From these X-ray diffraction images, the unsintered modified alumina particles (M) according to the present invention show an X-ray diffraction image of the raw material alumina and an X-ray diffraction image of the composite metal aluminum hydroxide salt. The fact that a composite metal aluminum hydroxide salt is formed becomes apparent. on the other hand,
In the modified alumina (C), as in Example 1 of the present invention, the X-ray diffraction image of the composite metal aluminum hydroxide salt disappeared. It can be seen that the material has been denatured or crystallized.

In the present invention, a structure in which a powder or a compact of active alumina or hydrated alumina is used as a base, and a composite metal aluminum hydroxide salt is synthesized on the surface thereof by a recombination reaction. Due to the above characteristics, in addition to the advantage that the function originally possessed by alumina or hydrated alumina and the function originally possessed by composite metal aluminum hydroxide salt can be imparted to the surface of alumina or hydrated alumina particles, However, a particular additional advantage is achieved by maintaining the shape of the raw alumina or hydrated alumina powder or compact.

Active alumina or hydrated alumina chemically has a solid acid or solid basicity and is widely used as an adsorbent or catalyst for polar molecules or a catalyst carrier. As an adsorbent, it has a hygroscopic property, and in addition to dehumidification of hydratable gas and dehydration of liquid, deacidification of liquid, adsorption of phosphate ion, adsorption of fluorine ion, arsenate ion and other polar gases It has been used and studied for adsorption removal of water. In addition, it has excellent self-sintering properties, has high particle strength as a molded product, and is used as an inorganic binder for other materials. There are many uses and research examples for catalysts and catalyst carriers, but typical applications are dehydration, dehydrogenation, C-C
It promotes a condensation reaction and a decomposition reaction involving a bond, a C—N bond and a C—S bond. In the dehydration reaction, it is used for polymerization reaction of various hydrocarbons, isomerization, hydrogenation, reforming, aromatization, etc., including synthesis of esters from alcohols.
As the catalyst carrier, there is a desulfurization reaction carrier, carrier for hydrogen peroxide synthesis, for oxychlorination carrier, a catalyst carrier for automobile exhaust gas, NO _X decomposition carrier (catalyst).
Physically, 50 to 350 m ² / g, which is almost the same as activated clay
Surface area, and suitable mesopores and macropores can be provided by a molding method, and excellent in heat resistance. Other uses include compounding agents for resins, fillers for papermaking,
It is also used as a raw material for ceramics, pharmaceuticals, and abrasives. The shapes are powder (granules), spherical particles, cylinders,
It covers a wide variety of areas, such as cylinders, honeycombs, fibers, and membranes (sheets). The properties and advantages of these aluminas and hydrated aluminas can be diverted to the modified alumina and hydrated alumina powders or molded articles of the present invention.

On the other hand, the composite metal aluminum hydroxide salt of hydrotalcites comprises a positively charged basic layer composed of an octahedron of a composite oxide composed of aluminum and a monovalent or divalent metal, and an anion and water. A layered compound consisting of a negatively charged intermediate layer and a solid acid,
Shows properties as a solid base and exhibits anion exchangeability.
Therefore, these composite metal aluminum hydroxide salts are also used as stabilizers, adsorbents, deodorants, heat ray absorbers, flame retardants or flame retardant assistants, catalysts or catalyst carriers for various resins. As a reaction using a composite metal aluminum hydroxide salt as a catalyst, a halogen exchange reaction (interlayer ion is Cl), an alkoxysilane exchange reaction (interlayer ion is Cl), a C ₁ reaction, and the like are known. Examples of the catalytic reaction using the calcined product include an aldol condensation reaction and a polymerization reaction of propylene or the like using the calcined product as a carrier.

In the present invention, the composite metal aluminum hydroxide salt is formed on the active alumina or hydrated alumina powder or granule in situ, so that both are present in a very short distance and in a tight state. As a result, the chemical adsorption and catalytic action of the composite metal aluminum hydroxide salt can be maximized by utilizing the excellent adsorptivity of alumina or hydrated alumina. In addition, in the present invention, since the composite metal aluminum hydroxide salt is synthesized in situ in the preformed granules or shaped bodies of alumina or hydrated alumina, the alumina or hydrated alumina is used. The bonding state between the substrate and the composite metal aluminum hydroxide salt or the like is extremely strong. For example, even under the condition where the particles of the powder or the molded body rub against each other, the composite metal aluminum hydroxide salt or the like may fall off. There is no advantage.

In the modified alumina or hydrated alumina powder or molded article of the present invention, the composite metal aluminum hydroxide salt may be present on the outer surface of the powder or the molded article, It may be present on the internal surface of the body or molded article, or in a combination thereof. The scanning electron micrographs shown in FIGS. 1 and 3 described above show a form in which the composite metal aluminum hydroxide salt is present on the inner surface of the compact, but the scanning electron micrograph of the particle structure shown in FIG. Shows that a composite metal aluminum hydroxide salt is formed on the outer surface of the hydrated alumina compact. FIG. 6 is a scanning electron micrograph showing the outer surface of the compact before modification. is there.

In the present invention, the composite metal aluminum hydroxide salt is contained in an amount of 0.1 to 30% by weight, especially 5 to 20% by weight as the above monovalent to divalent metal oxide on an oxide basis. It is desirable to have been. If the content of the composite metal aluminum hydroxide salt is less than the above range, the degree of modification becomes insufficient and the strength of the molded body is unfavorably reduced as compared with the case where the content is in the above range.

The modified alumina or hydrated alumina powder or molded article of the present invention has a BET specific surface area of 80 to 50.
0 m ² / g, especially 100 to 350 m ² / g, and a pore volume of 0.1 to 1.5 ml / g, especially 0.15 to 1.2 ml / g, the synergistic effect of the combination of both. Preferred for effective expression. The modified alumina or hydrated alumina according to the present invention exhibits a slightly reduced BET specific surface area and pore volume as compared with untreated alumina or hydrated alumina. This is obvious from the fact that part of the outer surface and the inner surface of the alumina, hydrated alumina powder, or the compact having the activity of the raw material is effectively used for producing the composite metal aluminum hydroxide salt. I can say the result. When the specific surface area or the pore volume is below the above range, the degree of modification is unsatisfactory as compared with the case where the specific surface area or the pore volume is within the above range, while even if the specific surface area and the pore volume are above the above range, there is a tendency to lose an additional advantage. It is in.

FIG. 8 of the accompanying drawings shows the pore distribution curves of the untreated alumina and the modified alumina according to the present invention as measured by the BET method. Table 2 shows the specific surface area, pore volume, and the like according to the BET method in the examples.

According to the present invention, a composite metal aluminum hydroxide salt or the like is formed on an active alumina powder or hydrated alumina powder or formed body in situ,
The strength of the powder or the molded article can be remarkably improved, and as shown in Table 1, the particle strength of the powder or the molded article is more than doubled as compared with the dried product by the modification treatment. The fact that you do.

[Alumina or hydrated alumina] The active alumina or hydrated alumina used in the present invention is reactive with a water-soluble compound of a monovalent or divalent metal. Excluding hydrated alumina and alumina, alumina excluding κ, θ, and α types are preferably used.

[0027] The powdery or molded product comprising alumina or hydrated alumina having activity to be used is generally 80 m ² /
g or more, in particular, having a BET specific surface area of 100 to 500 m ² / g also enables formation of a composite metal aluminum hydroxide salt. It is also preferable in terms of physical properties.

The hydrated alumina is generally called aluminum hydroxide, and includes boehmite, boehmite gel, pseudoboehmite gel, bayerite, diaspore, gibbsite, norstrandite, amorphous hydrated alumina and the like. Of course, they can also be used in the form of a mixture of two or more.

Boehmite, a typical example of an active hydrated alumina, is Al ₂ O ₃ .H ₂ O
Is an aluminum hydroxide represented by the following composition: Boehmite gel, pseudo-boehmite gel (pseudo-boeh
mite) is gel-like in nature, and generally shows a broad X-ray diffraction image similar to boehmite.
It is suitably used for the purpose of the present invention. Gibbsite, on the other hand, is an aluminum hydroxide represented by the composition of Al ₂ O ₃ .3H ₂ O, which has little activity and is not suitable for the purpose of the present invention as it is. By converting to (γ-alumina), it can be sufficiently used for the purpose of the present invention. In addition, the activity of gibbsite can be imparted by acid treatment, and the one imparted with such activity can be sufficiently used for the purpose of the present invention.

In the present invention, a commercially available hydrated alumina having activity or a pseudo-boehmite gel type hydrated alumina can be used. The quasi-boehmite gel type hydrated alumina is excellent in that it has high activity and gives activated alumina having large particle strength, but, of course, the present invention is not limited to these examples.

On the other hand, as the alumina, generally, active alumina is used.
a) is used, and a medium to low temperature range (800
Γ, η, ρ, χ, δ-type intermediate alumina which is a calcined product at or below (° C.). X-ray diffraction shows relatively sharp diffraction lines of κ, θ, α-type alumina which is a crystal type in a high temperature region, and this stable alumina is not suitable for the purpose of the present invention. Alumina of γ, η, ρ, 型, and δ types, which are crystal forms in the middle and low temperature range, generally show a broad diffraction pattern and are suitably used for the purpose of the present invention.

The alumina or hydrated alumina having the above-mentioned activity is used as a modifying substrate of the present invention in the form of powder or granules. For example, hydrated alumina particles can be obtained as spherical or amorphous particles by a sol-gel reaction known per se, and if necessary, calcined at a temperature of 800 ° C. or lower to obtain alumina powder. It becomes granules. Further, by mixing alumina or hydrated alumina with a granulation medium such as water according to the molding method, rolling granulation, extrusion granulation, by applying a known granulation method such as tableting, spherical, It is possible to produce a cylindrical, prismatic, ring-shaped, tablet-shaped, or lump-shaped molded article. Although the particle size of these powders or compacts is not particularly limited, it is generally 20 particles.
It is in the range of μm to 30 mm. Of course, the present invention can also be applied to a honeycomb-shaped formed body of alumina or hydrated alumina. 9 to 12 show morphological photographs of the hydrated alumina powder or molded article of the present invention.

[Modified powder or molded article and method for producing the same] The modified powder or molded article of the present invention is a monovalent or bivalent powder or molded article made of alumina or hydrated alumina.
Containing the water-soluble salt of a multivalent metal in a dispersed state or immersion state in an aqueous medium containing a dissolved state, and reacting the water-soluble salt with the powder or the molded product at a pH of 7 to 12. It is manufactured by heat-treating this if necessary.

As the water-soluble salt of a monovalent or divalent metal, an alkali metal such as Li, Na and K and an alkaline earth metal component such as Mg are preferably used, but are not limited to the above examples. Conventionally, any water-soluble salt of a monovalent or divalent metal capable of forming a composite metal aluminum hydroxide salt can be used. As the water-soluble salt, water-soluble salts such as halides such as chlorides, organic acid salts such as nitrates, sulfates, and acetates are used. Of these, magnesium nitrate, magnesium chloride and magnesium sulfate are particularly preferred.

These water-soluble salts should be used in an amount which gives a total of 0.1 to 30% by weight, based on the oxide, of a monovalent or divalent metal oxide.

The reaction is preferably carried out under conditions where the pH of the reaction system is 7 to 12. For this purpose, an alkali such as urea, ammonium carbonate, aqueous ammonia, sodium carbonate, sodium hydrogen carbonate, sodium hydroxide or the like is reacted. Can be added to the system. When the pH of the reaction system falls below the above range,
Since the production of the composite metal aluminum hydroxide salt tends to decrease as compared to the case where the pH is in the above range, the yield of the reformed product is lowered when the pH is higher than the above range. Absent.

Although the reaction temperature is sufficient even at room temperature, it is generally desirable to carry out the reaction at a temperature of 20 to 200 ° C. for about 0.5 to 48 hours. The concentration of alumina or hydrated alumina powder or molded powder in the whole reaction solution is 5 to 50% by weight.
The degree is appropriate, and the alumina or hydrated alumina powder or molded article is immersed in a monovalent or divalent metal aqueous solution,
After a predetermined amount of alkali is gradually added to obtain a target pH range, the mixture is heated to the above temperature range, and the reaction is preferably performed with stirring or shaking for a predetermined time. Here, the formation mechanism of the composite metal aluminum hydroxide salt in the present invention is unknown in detail, but alkali is immersed in the alumina or hydrated alumina powder or molded article immersed in a monovalent or divalent metal aqueous solution. When added, some aluminum is eluted on the surface of the alumina particles, or the substitution reaction with a monovalent or divalent metal is apt to occur, and the C dissolved in the reaction solution
O ₂ or CO ₂ from the air, anions (Cl, SO ₃ , NO ₂ ) of the magnesium salt to be used, etc., are incorporated into the reactants, whereby the formation of the composite metal aluminum hydroxide salt proceeds. it is conceivable that. In addition, in this operation, adding a heating operation at the time of immersion or alkali addition is not limited at all. The present invention does not limit the formation mechanism of these composite metal aluminum hydroxide salts.

The resulting modified alumina or hydrated alumina powder or molded product is separated from the reaction mother liquor by a solid-liquid separation operation such as filtration or decantation, washed with water, and dried.
If necessary, bake the product.

The heat treatment (firing) of the modified alumina, the hydrated alumina powder, or the compact is generally 150 to 1200.
C., particularly at a temperature of 200 to 800.degree. C. for about 0.5 to 12 hours. The composite metal aluminum hydroxide salt in the reformed product generally releases water contained at a temperature of 200 ° C. or higher and further releases carbonate. As one of the disadvantages of the composite metal aluminum hydroxide salt, for example,
There is a problem of foaming due to the release of moisture and the like when blended in a resin, but such a problem is solved in this heat-treated product. The heat treatment also increases the strength of the solid base, which brings significant advantages to the adsorption of acidic substances and the catalytic reaction using the solid base. The surface activity and the adsorption activity of alumina or hydrated alumina serving as a substrate are also increased by firing under the above conditions, which contributes to the improvement of various properties of the modified product.

The modified alumina or hydrated alumina powder or molded article according to the present invention utilizes the above-mentioned properties to make use of the above-mentioned properties, thereby stabilizing various kinds of resins, flame retardant for various kinds of resins or flame retardant assistants, and halogen-based catalyst residues. It is useful as a scavenger, various adsorbents, various deodorants, carriers for medicines and agricultural chemicals, base materials for cosmetics, catalysts, catalyst carriers and the like.

[0041]

The present invention will be described with reference to the following examples. The physical properties were measured by the following methods.

(1) Powder X-ray Diffraction Measured by an X-ray diffractometer using a rate meter EMG-D2 manufactured by Rigaku Corporation.

(2) Specific surface area, pore volume Measured by Sorptomatic Series 1900 manufactured by Carlo Elba.

(3) Adsorption test and transmittance 1 g of a sample was accurately weighed to 1/100 g with a tabletop electronic balance in a glass screw bottle having an internal volume of 50 ml, and 0.1% of naphthol yellow S prepared beforehand was used. 2% aqueous solution
0 ml, and after performing static adsorption for 1 month at room temperature,
The solid-liquid separation was performed briefly, and the transmittance spectrum was measured with a spectrophotometer. The spectrophotometer is manufactured by JASCO Corporation
V-560 UV-visible spectrophotometer was used.

(4) Chemical analysis JIS. M. Performed according to 8855.

(5) Crushing strength Model 1011 manufactured by Aiko Engineering Co., Ltd.
Was measured by

[0047] (6) by applying the measurement principle of the CO ₂ analysis Shuretta method, the CO ₂ generated by acid decomposition was analyzed by Gastec Co. detector tube type gas measuring instrument.

(7) Average Particle Size The average particle size was measured using a Particle Size Analyzer Model LS230 manufactured by Coulter.

[Sample Preparation] The alumina or hydrated alumina used in the examples was prepared as follows.

(Sample 1) Commercially available aluminum hydroxide (crystal type: boehmite gel Al ₂ O ₃ = 75 wt% particle size 50)
After adding 800 ml of industrial water to 1000 g and sufficiently kneading, a molding die (2.0 mmφ diameter) is set in an extruder.
Was set and extruded. After the molded product was dried at 150 ° C., a dried pellet having a particle diameter of about 2 mmφ was obtained (this was
S-1).

(Sample 2) A portion of the dried pellet (S-1) obtained in Sample 1 was fired at 600 ° C. for 3 hours to obtain a molded pellet (γ-alumina). 2).

(Sample 3) Commercially available aluminum hydroxide (crystal type: dibsite Al ₂ O ₃ = 65% by weight) Particle size
After adding 160 ml of industrial water to 1000 g and sufficiently kneading, a molding die (2.0 mmφ) was added to an extruder.
(Diameter) was set and extruded. Molded product is 150 ° C
After drying, a dried pellet having a particle diameter of about 2 mmφ was obtained (this is referred to as S-3).

(Sample 4) A portion of the dried pellet (S-3) obtained in Sample 3 was fired at 600 ° C. for 3 hours to obtain a molded pellet (γ-alumina) (this is referred to as S-4). ).

(Sample 5) Commercially available aluminum hydroxide (crystal form: boehmite gel Al ₂ O ₃ = 75 wt% particle size 50)
μm) as a raw material to obtain a molded product by rolling granulation (this is S-
5).

(Sample 6) The crystal type was boehmite gel (Al
A commercially available aluminum hydroxide is ₂ O ₃ = 72 wt% particle diameter 50 [mu] m), the crystal form is gibbsite _{(Al 2 O} 3 = 6
A molded product was obtained by tumbling granulation using a powder obtained by mixing commercially available aluminum hydroxide (5% by weight, particle size: 50 μm) at a weight ratio of 1 to 1 (this is referred to as S-6).

(Sample 7) A part of the dried pellets obtained in Sample 6 was baked at 600 ° C. for 3 hours to obtain molded pellets (γ
Alumina) was obtained (this was designated as S-7).

(Sample 8) Commercially available aluminum hydroxide (crystal form: boehmite gel Al ₂ O ₃ = 75 wt% particle size 50)
) was used as a raw material to obtain 200 g of a ring-shaped molded product (particle size: about 5 mmφ x 5 mm) (Table S-8).

(Sample 9) A portion of the ring-shaped molded product (S-8) obtained in Sample 8 was calcined at 600 ° C. for 3 hours to obtain a ring-shaped molded product (γ-alumina) (this was S- 9).

(Sample 10) After preparing an inorganic colloidal solution of alumina, which is a known technique, a spherical alumina hydrogel is granulated by a sol-gel reaction, and a dried spherical alumina hydrate compact (particle size) About 50-500 μm)
(This is designated as S-10).

(Sample 11) A part of the spherical alumina hydrate compact (S-10) obtained in Sample 10 was calcined at 600 ° C. for 3 hours to obtain a spherical alumina compact (γ alumina). S-
11).

Example 1 100 g of sample S-1 was weighed into a 500 ml glass beaker, and a magnesium chloride aqueous solution prepared in advance (56 g of magnesium chloride hexahydrate manufactured by Wako Pure Chemical Industries, Ltd. was dissolved in 100 ml of industrial water). Aqueous solution: concentration about 17%), and immersed at room temperature for 3 hours.
It was set in a thermostat with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80
ml was added. The pH at the end of the pouring was 9.39 / 20.2 ° C. After checking the pH, again at 40 ° C in a thermostat with shaking tow machine
And kept at 40 ° C. for 16 hours with shaking tow. After the completion of the reaction, the pH was 9.21 / 25.1. The reaction product was sufficiently washed with water and dried at 150 ° C. overnight. When the obtained dried product (referred to as EX-1-1) was subjected to powder X-ray diffraction, a diffraction peak of a hydrotalcite-like product was observed. It was confirmed that a product was formed. In addition, the crushing strength of the obtained dried product was more than twice as high as that of the unmodified dried product, and an adsorption test was carried out using naphthol yellow S (acid dye with negative charge). However, (the results are shown in FIG. 13), it was found that the dried product without modification did not adsorb, whereas the dried product obtained in this example adsorbed naphthol yellow S. Further, the dried product (EX-1-1) was fired at 600 ° C. for 3 hours to obtain modified alumina molded article particles (hereinafter referred to as EX-1-2).
The MgO content of the composite oxide compact particles was 11.1% as a result of chemical composition analysis.

(Example 2) 80 g of sample S-2 was weighed into a 500 ml glass beaker, and 56 g of magnesium chloride hexahydrate manufactured by Wako Pure Chemical Industries was dissolved in a previously prepared aqueous magnesium chloride solution (100 ml of industrial water). Aqueous solution: concentration of about 17%), and immersed at room temperature for 3 hours, and then set in a thermostat equipped with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80 m
1 was added. The pH at the end of the pouring was 9.41 / 21.0 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat equipped with a shaking tow machine, and the shaking tow was maintained at 40 ° C. for 16 hours. The pH after the completion of the reaction was 9.32 / 24.5 ° C. After sufficiently washing the reaction product with water, it was dried at 150 ° C. overnight. When the obtained dried product (referred to as EX-2-1) was subjected to powder X-ray diffraction, a diffraction peak of a hydrotalcite-like substance was observed. It was confirmed that a product was formed. In addition, the crushing strength of the obtained dried product was about twice as high as that of the non-modified dry product, and an adsorption test with naphthol yellow S was performed. Was not adsorbed, whereas the dried product obtained in this example was adsorbed. In addition, dried product (EX-2-
MgO content of magnesium-containing composite oxide compact particles (hereinafter referred to as EX-2-2) obtained by firing 1) at 600 ° C. for 3 hours was 11.9%.

(Reference Example 1) 100 g of sample S-3 was weighed into a 500 ml glass beaker, and 56 g of magnesium chloride hexahydrate manufactured by Wako Pure Chemical Industries was dissolved in a previously prepared aqueous magnesium chloride solution (100 ml of industrial water). Aqueous solution: concentration about 17%), and immersed at room temperature for 3 hours.
It was set in a thermostat with a shaking tow machine. While shaking at 20 ° C, 25% aqueous ammonia (Wako Pure Chemical Industries, Ltd .: reagent grade 1)
80 ml were poured. PH at the end of pouring is 9.28 / 20.4 ° C
Met. After confirming the pH, again in a thermostat with shaking tow
The temperature was raised to 0 ° C., and the shake tow was maintained at 40 ° C. for 16 hours. After the completion of the reaction, the pH was 9.23 / 25.7 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. When the obtained dried product (referred to as RF-1-1) was subjected to powder X-ray diffraction, a clear diffraction peak of a hydrotalcite analog was not observed. In addition, when a qualitative adsorption test was performed using Naphthol Yellow S, it was found that almost no adsorption was observed. Furthermore, the MgO content of the shaped particles (hereinafter referred to as RF-1-2) obtained by firing the dried product (RF-1-1) at 600 ° C. for 3 hours was 3.0%.

Example 3 68 g of sample S-4 was weighed into a 500 ml glass beaker, and 56 g of magnesium chloride hexahydrate manufactured by Wako Pure Chemical Industries was dissolved in a previously prepared aqueous magnesium chloride solution (100 ml of industrial water). (Aqueous solution: concentration: about 17%) was added and immersed at room temperature for 3 hours, and then set in a thermostat equipped with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80 m
1 was added. The pH at the end of the pouring was 9.28 / 20.2 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat equipped with a shaking tow machine, and the shaking tow was maintained at 40 ° C. for 16 hours. After the completion of the reaction, the pH was 9.27 / 22.9 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. The resulting dried product (this
EX-3-1) was subjected to powder X-ray diffraction. As a result, a diffraction peak of a hydrotalcite analog was recognized, and the obtained dried product had a surprising crushing strength, and also adsorbed naphthol yellow S. It was confirmed that it did. The dried product (EX-3-1) was fired at 600 ° C. for 3 hours to obtain magnesium-containing composite oxide molded particles. The MgO content of the composite oxide compact particles (referred to as EX-3-2) was 11.5% as a result of chemical composition analysis.

Example 4 100 g of sample S-5 was weighed into a 500 ml glass beaker, and 120 ml of a previously prepared aqueous solution of magnesium chloride having a concentration of about 28% (manufactured by Wako Pure Chemical Industries) was added. After being immersed for 3 hours, it was set in a thermostat equipped with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80 m
1 was added. The pH at the end of the pouring was 9.33 / 20.8 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat equipped with a shaking tow machine, and the shaking tow was maintained at 40 ° C. for 16 hours. After the completion of the reaction, the pH was 8.741 / 25.3 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. The resulting dried product (this
EX-4-1) was subjected to powder X-ray diffraction. As a result, a diffraction peak of a hydrotalcite analog was observed, and it was confirmed by SEM observation that a hydrotalcite analog was generated. In addition, the crushing strength was more than twice as high as that of the dried product without modification, and it was found that naphthol yellow S was also adsorbed. In addition, dried products (EX
-4-1) was calcined at 600 ° C. for 3 hours to obtain magnesium-containing composite oxide compact particles (hereinafter referred to as EX-4-2). The MgO content of the composite oxide compact particles was 9.4% as a result of chemical composition analysis.

Example 5 100 g of sample S-6 was weighed into a 500 ml glass beaker, and 120 ml of a previously prepared aqueous solution of magnesium chloride having a concentration of about 23% (manufactured by Wako Pure Chemical Industries) was added. After being immersed for 3 hours, it was set in a thermostat equipped with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80 m
1 was added. The pH at the end of the pouring was 9.87 / 19.8 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat equipped with a shaking tow machine, and the shaking tow was maintained at 40 ° C. for 16 hours. After the completion of the reaction, the pH was 9.43 / 22.5 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. The resulting dried product (this
EX-5-1) was subjected to powder X-ray diffraction. As a result, a diffraction peak of a hydrotalcite analog was recognized, and it was confirmed by SEM observation that a hydrotalcite analog was generated. The crushing strength was twice or more the strength when compared with the dried product without modification, and it was found that naphthol yellow S was also adsorbed. Further, the dried product (EX-5-1) is calcined at 600 ° C. for 3 hours to obtain a magnesium-containing composite oxide compact (hereinafter referred to as EX-5-2).
I got The MgO content of the composite oxide compact particles was 8.2%.

Example 6 80 g of sample S-9 was collected in a 500 ml glass beaker, and 120 ml of a previously prepared aqueous solution of magnesium chloride having a concentration of about 23% (manufactured by Wako Pure Chemical Industries) was added. After being immersed for 3 hours, it was set in a thermostat equipped with a shaking tow machine. While shaking at 20 ° C., 25% ammonia water (Wako Pure Chemical Industries, Ltd .: 1st grade) 80 m
1 was added. The pH at the end of the pouring was 9.84 / 19.9 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat equipped with a shaking tow machine, and the shaking tow was maintained at 40 ° C. for 16 hours. After the completion of the reaction, the pH was 9.48 / 20.2 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. The resulting dried product (this
EX-6-1) was subjected to powder X-ray diffraction. As a result, a diffraction peak of a hydrotalcite analog was recognized, and it was confirmed from SEM observation that a hydrotalcite analog was generated. It was also confirmed that naphthol yellow S was also adsorbed. In addition, dried product (EX-6-1)
By firing for a time, magnesium-containing composite oxide compact particles (hereinafter referred to as EX-6-2) were obtained. The MgO content of the composite oxide molding die particles was 9.0%.

Example 7 100 g of sample S-10 was weighed into a 500 ml glass beaker, and 120 ml of a previously prepared aqueous solution of magnesium chloride having a concentration of about 28% (manufactured by Wako Pure Chemical Industries) was added. After immersion for 3 hours, it was set in a thermostat. While stirring with a stirrer at 20 ° C,
140 ml of 25% ammonia water (Wako Pure Chemical Industries: 1st grade)
Was added. The pH at the end of the pouring was 9.51 / 19.2 ° C. After confirming the pH, the temperature was raised again to 70 ° C.
Stirring was maintained at 0 ° C. for 3 hours. PH after reaction is 8.69 / 2
3.0 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. The obtained dried product (referred to as EX-7-1) was subjected to powder X-ray diffraction. As a result, a diffraction peak of a hydrotalcite analog was recognized, and the hydrotalcite analog was formed by SEM observation. Was confirmed, and it was found that naphthol yellow S was also adsorbed. Further, in order to confirm the carbonate anion in the dried product obtained from this example,
As a result of performing CO ₂ analysis, 0.35% of CO ₂ was determined. The CO ₂ of Comparative Example 7 (S-10) was 0.02%. Further, the dried product (EX-7-1) was calcined at 600 ° C. for 3 hours to obtain magnesium-containing composite oxide molded particles (hereinafter referred to as EX-7-2). As a result of chemical composition analysis, the MgO content of the composite oxide compact particles was 15.6%.

Example 8 100 g of sample S-1 was weighed into a 500 ml glass beaker, and the concentration of 2 was adjusted in advance.
200 g of a 0% aqueous magnesium nitrate solution (magnesium nitrate hexahydrate manufactured by Wako Pure Chemical Industries, Ltd.) was added, immersed at room temperature for 3 hours, and then set in a thermostat. While stirring with a stirrer at 20 ° C., 80 ml of 25% aqueous ammonia (manufactured by Wako Pure Chemical Industries) was added. PH at the end of pouring is 9.56 / 1
9.7 ° C. After confirming the pH, the temperature was raised again to 40 ° C. in a thermostat and kept at 40 ° C. for 20 hours. P after reaction
H was 9.67 / 25.0 ° C. After the reaction product is washed with water, 15
Dry at 0 ° C. overnight. When the obtained dried product (referred to as EX-8-1) was subjected to powder X-ray diffraction, a diffraction peak of a hydrotalcite analog was recognized, and the hydrotalcite analog was formed by SEM observation. Was confirmed. Further, the dried product (EX-8-1) was calcined at 600 ° C. for 3 hours to obtain magnesium-containing composite oxide molded article particles (
EX-8-2). M of the composite oxide compact particles
The gO content was 10.1%.

Example 9 100 g of sample S-1 was weighed into a 500 ml glass beaker, and a concentration of 1 was prepared in advance.
216 g of a 5% aqueous magnesium sulfate solution (magnesium sulfate heptahydrate manufactured by Wako Pure Chemical Industries, Ltd.) was added, and immersed at room temperature for 3 hours, and then set in a thermostat. While stirring with a stirrer at 20 ° C., 80 ml of 25% aqueous ammonia (manufactured by Wako Pure Chemical Industries, Ltd .: first grade) was added. The pH at the end of the addition is 1
0.06 / 20.1 ° C. After confirming the pH, again in a thermostat
The temperature was raised to 0 ° C., and the mixture was stirred and maintained at 40 ° C. for 20 hours. After the completion of the reaction, the pH was 9.33 / 24.9 ° C. The reaction product was washed with water and dried at 150 ° C. overnight. Further, the obtained dried product (referred to as EX-9-1) is calcined at 600 ° C. for 3 hours,
Magnesium-containing composite oxide compact particles (this is EX-9
-2). MgO of the composite oxide compact particles
The content was 8.1%.

(Comparative Examples 1 to 7) Each performance was evaluated using the samples shown in Tables 1 and 2.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

The present inventors have succeeded in synthesizing a composite metal aluminum hydroxide in situ with a powder or a granule made of alumina or hydrated alumina. In the modified alumina or hydrated alumina powder or formed body obtained by the present invention, the bonding state of the composite metal aluminum hydroxide salt is stable and strong,
The modification of alumina or hydrated alumina powder or the compact itself has also been remarkable. That is, while the properties such as the strength and abrasion of the alumina or the hydrated alumina powder or the molded article itself are remarkably improved, the modified alumina or the hydrated alumina powder or the molded article is Surface activity, adsorbability,
Deodorizing performance and the like are remarkably improved.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph (magnification: 20,000 times) showing the particle structure (cross section inside a molded body) of a dried product of a hydrated alumina molded body pellet before modification (Example 1).

FIG. 2 is a scanning electron micrograph (magnification: 20,000 times) showing the particle structure (cross-section inside the molded body) of a dried pellet of the modified hydrated alumina molded body according to the present invention (Example 1).

FIG. 3 is a scanning electron micrograph (magnification: 20,000 times) showing an internal fracture section of a hydrated alumina molded body pellet after modification (600 ° C. × 3 h) when the pellet is fired (Example 1).

FIG. 4 shows X-ray diffraction images of untreated hydrated alumina (A), modified hydrated alumina (M) according to the present invention, and modified alumina (C) according to the present invention (Example). 1).

FIG. 5: Untreated alumina (calcined product of hydrated alumina:
A) shows X-ray diffraction images of unfired modified alumina (M) according to the present invention and modified alumina (C) according to the present invention (Example 2).

FIG. 6 is a scanning electron micrograph (magnification: 20,000 times) showing the outer surface of a molded body before modification (Example 1).

FIG. 7 is a scanning electron micrograph (magnification: 20,000 times) showing the outer surface of a molded article after modification according to the present invention (magnification: 20000 times) (Example 1).

FIG. 8 shows pore distribution curves measured by the BET method for untreated alumina and modified alumina according to the present invention (Example 1).

FIG. 9 is an example (EX-1-2) showing a form of a modified alumina molded article of the present invention.

FIG. 10 is an example (EX-5-2) showing a form of a modified alumina molded article of the present invention.

FIG. 11 is an example (EX-6-2) showing a form of a modified alumina molded article of the present invention.

FIG. 12 is an example (EX-7-2) showing a form of a modified alumina molded article of the present invention.

FIG. 13 is a diagram showing the results of an adsorption test of the product of the present invention with naphthol yellow S (Example 1).

FIG. 14 is a scanning electron micrograph (magnification: 5000 times) showing an internal fracture cross section of a modified hydrated alumina molded body pellet when calcined (600 ° C. × 3 h) (Example 1).

Continued on the front page F term (reference) 4G030 AA07 AA36 BA32 GA11 GA21 GA27 GA35 4G076 AA02 AA21 AB02 AB04 AB06 AC06 BA11 BA43 BD01 BD02 BE11 BF05 CA02 CA12 CA28 CA29 DA25 FA10

Claims (11)

[Claims] Claims: 1. A powder or a granule made of active alumina or hydrated alumina, and an aluminum component derived from the alumina or hydrated alumina synthesized in situ on the powder or granule. A modified alumina or hydrated alumina powder or molded article comprising a composite metal aluminum hydroxide salt containing a monovalent or divalent metal component. 2. The composite metal aluminum hydroxide salt as an oxide of the monovalent or divalent metal on an oxide basis,
The modified alumina or hydrated alumina powder or molded article according to claim 1, which is contained in an amount of 0.1 to 30% by weight. 3. A BE or powder comprising an active alumina or hydrated alumina having a BE of 80 m ² / g or more.
3. The modified alumina or hydrated alumina powder or molded article according to claim 1 or 2, having a T specific surface area. 4. The modified alumina, hydrated alumina powder, or compact according to claim 1, wherein the composite metal aluminum hydroxide salt contains a magnesium component. . 5. A composite metal aluminum hydroxide salt having a carbonate anion.
5. A modified alumina, a hydrated alumina powder, or a molded article according to any one of items 1 to 4. 6. The modified alumina or hydrated alumina according to claim 1, wherein the composite metal aluminum hydroxide salt is mainly composed of magnesium aluminum hydroxide carbonate. Powder or granules. 7. The modified alumina or hydrated alumina powder according to any one of claims 1 to 6, wherein the composite metal aluminum hydroxide salt is present on the surface of a powder or a compact made of alumina or hydrated alumina. Granules or compacts. 8. The modified alumina according to claim 1, wherein the composite metal aluminum hydroxide salt is present on the outer surface and the inner surface of a powder or a compact made of alumina or hydrated alumina. Or hydrated alumina powder or molded product. 9. A BET specific surface area of 80 to 500 m ² /
9. The modified alumina or hydrated alumina powder or molded article according to claim 1, wherein the g and the pore volume are 0.1 to 1.5 ml / g. 10. A dispersion or immersion of a powder or granules of active alumina or hydrated alumina in an aqueous medium containing a state in which a water-soluble salt of a monovalent or divalent metal is dissolved. Included and pH of 7-12
In, the powder or the molded body and a water-soluble salt to react,
A method for producing a modified alumina, a hydrated alumina powder, or a molded product, which is heat-treated if necessary. 11. The method according to claim 10, wherein the reaction is carried out at a temperature of from 20 to 200 ° C.