KR100388097B1 - Process for producing hydroxide - Google Patents

Abstract

Disclosed is a method for producing a crystalline layered mixed metal hydroxide having a suitable particle size for forming a polymer material and the like and forming a thin plate and easily controlling fine characteristics in a relatively large surface area at a high speed. According to the present invention, crystalline M^(II)(OH)₂(M^(II)Is a metal element with +2 oxidation state) and crystalline M^(III)(OH)₃(M^(III)Is a water dispersion of a metal element) compound having a +3 oxidation state,^(II)And M^(III)A water-soluble compound containing a metal element and a compound containing an interlayer anion component are added, and the pH of the mixture solution is adjusted to convert the water-soluble metal component into a viscous gel-type mixed metal hydroxide, wherein the crystalline M^(II)(OH)₂, M^(III)(OH)₃And a crystalline layered mixed metal hydroxide are prepared from a reaction mixture comprising a gel hydroxide metal hydroxide modified from a water-soluble metal component by hydrothermal reaction. The particle size of the layered mixed metal hydroxide as a product is appropriately selected by the type of water-soluble compound added to the reaction, the ratio and method of adding the water-soluble metal compound to the metal hydroxide, the type of the anion component between the layers, the reaction temperature and the reaction time. 2μ range, particle shape from regular hexagonal plate to irregularly shaped plate, specific surface area 20 ~ 90m²/ g range, thickness-to-diameter ratio is flexibly controlled in the range of 10-50.

Description

Process for producing layered mixed metal hydroxide from mixture of crystalline metal hydroxide and water soluble metal compound {Process for producing hydroxide}

The present invention relates to the preparation of a layered mixed metal hydroxide in the form of a hydrotalcite, and more particularly, to a water dispersion of a crystalline metal hydroxide, a compound containing a water-soluble compound and an interlayer anion component is added, and a pH of the mixture solution is added. To convert the water-soluble metal component into a viscous gel-type mixed metal hydroxide, and from the reaction mixture containing the modified viscous gel-type metal hydroxide to undergo a hydrothermal reaction to form a crystalline layered mixed metal hydroxide. It relates to a manufacturing method.

The layered mixed metal hydroxide is a compound having a structure in the form of a hydrotalcite, and means a material having a structure in which anions are fixed between a layer composed of a mixed metal component and a hydroxyl group (OH ⁻ ). Hydrotalcite is a mineral present and has the formula Mg ₆ Al ₂ (OH) ₁₆ CO ₃ 4H ₂ O. Here, Mg and Al metal components are mixed metal components constituting the center plane of the layer, and OH component is a component constituting both upper and lower surfaces of the mixed metal center plane. CO ₃ ^2- ion is an interlayer anion component and 4H ₂ O is It is the number of crystals.

The structure of hydrotalcite can be readily understood from the well known bursite (layered Mg (OH) ₂ ) structure. That is, there is no change in the OH surface of the upper and lower surfaces constituting the Mg (OH) ₂ layer, but some of the Mg ²⁺ component of the Mg ²⁺ of the metal surface inside the layer may be regarded as being substituted with the Al ³⁺ component. In addition, it can be understood as a structure in which a positive charge is generated in the layer by substituted Al ³⁺ and CO ₃ ^2- ions which offset the positive charge are interlayered as interlayer anions. A general chemical formula of a layered mixed metal hydroxide having a structure similar to hydrotalcite may be represented by [M ^(II) _1-X M ^(III) _X ] (OH) ₂ AnH ₂ O, and the metal component of the middle surface of the layer Various chemical changes are possible depending on the kind of M ^(II) , M ^(III) , M ^(III) composition ratio x, and the kind of interlayer anion. Here, the M ^(II) and M ^(III) components are metal components capable of having oxidation numbers of 2+ and 3+, respectively, and A is an interlayer anion which is generally exchangeable with other anions, and the total negative charge is M ^(III). It is determined by the component value x value. Typical x values range from 0.25 to 0.33. Data on the structure and properties of mixed metal hydroxides with structures similar to hydrotalcites are detailed in Cabani et al., Catalysis Today, 11, 173-301 (1991).

High purity layered mixed metal hydroxides are commercially manufactured and applied in various fields as additives, antacids, flame retardants, and the like. In the field using the chemical properties of this material, the basic properties of the material are mainly used. Representative examples include improvement of thermal stability of basic catalyst materials, adsorption removal materials of acidic components contained in polymer materials, adsorption removal materials of acidic pollutants in water, separation materials of anion components using interlayer anion exchange properties, antacids, and polymeric materials. It is used for uses, such as the additive substance for. In the field using structural properties, it is used as a plate-like inorganic component for improving the mechanical properties of the polymer-inorganic composite, a flame retardant imparting component for improving the flame retardancy of the polymer flame retardant, a component for improving the thermal insulation properties of the polymer film.

Commercially used layered mixed metal hydroxides have important physical properties as well as chemical properties according to the composition of the material, and are used in a proper combination of these properties according to each application. That is, in terms of the use of foreign substances, physical properties such as particle size, particle size distribution, surface area, shape of basic particles, etc., in addition to the importance of chemical properties by chemical variables such as material purity, composition and composition ratio, chemical surface treatment of particles, etc. Optimization of properties is also very important.

In general, in the control of physical properties of fine particles, it is more efficient to control these basic properties in the manufacturing process of the material than in the physical method after the material is manufactured, and in the commercial application of layered mixed metal hydroxides. As the field of minute property changes determines the properties of the entire material, development of a manufacturing method for precisely controlling physical properties in the manufacturing phase of layered mixed metal hydroxides is important.

General methods and properties for the preparation of layered mixed metal compounds in the form of hyrotalcite are described in detail in Solid States Ionics. 22,135-141 (1986, et al.). As a typical manufacturing method, the coprecipitation method used by Clays Clay Miner. 28, 50 (1980) can be cited. In this method, a basic substance may be added to a mixed metal component dissolved in an aqueous solution to coprecipitate the mixed metal component with a hydroxide to prepare a layered mixed metal compound in the form of a hydrotalcite. In this way, the product may be prepared in the form of a microcrystalline material or an amorphous gel having a particle size of 0.1 μm or less. By the way, the material produced by this method requires a step of hydrothermally treating the product for commercial application as well as producing secondary particles in which the particle size is too fine and generally primary microcrystals are irregularly aggregated. Furthermore, this method has a disadvantage that the starting material used for the synthesis is relatively expensive, which limits the commercial application.

As an example of a method of controlling the shape of a product, U.S. Patent No. 4,351,814 discloses a method for producing a needle-like final product using a needle-shaped basic magnesium compound, the needle-like hydrotalcite material prepared by this method. Silver is known to be suitable for use in flame retardant additives of polymeric materials. In addition, U. S. Patent No. 5,437, 720 discloses a technique for producing and using spherical layered mixed metal hydroxides of various particle sizes. U.S. Patent No. 5,399,329 discloses a method for producing an extremely thin and flexible material having a diameter-to-thickness ratio of about 500 to 1,000 by applying a carboxylic acid anion as a layered anion component in the synthesis of the mixed metal hydroxide. The material of this shape can be used for applications such as a catalyst carrier, and it is known that the mechanical strength of the support prepared from this material is very excellent. U. S. Patent No. 5,250, 279 discloses a method for producing a material having a small particle size and regular shape by using a compound such as a divalent metal hydroxide and an alkali metal aluminate. U. S. Patent No. 5,730, 951 describes two kinds of metals. the interlayer negative ions from the particulate powder material including the element OH ^- ions in this way you do IX to form a light with a variety of anions therefrom are capable of producing a substance fixed to the interlayer it has been proposed.

The above-mentioned method for producing a hydrotalcite-type layered mixed metal hydroxide is considered for the purpose of controlling the shape and size of the material to be produced, the economical efficiency of raw material selection and the reaction step, and the use of the mixed metal hydroxide synthesized. This suggests that an appropriate method of preparation should be used selectively. That is, the mixed metal hydroxide in the form of hydrotalcite is a material that is applied to various fields as mentioned, and it is very important to control the shape and size of particles and the distribution of particles suitable for securing economic feasibility and use at the manufacturing stage .

Therefore, depending on the purpose of use of the layered mixed metal hydroxide, the development and application of a suitable manufacturing method satisfying the above physical properties is very important in terms of commercial use of the layered mixed metal hydroxide. For example, in the field of using a layered mixed metal hydroxide in the field of improving the thermal stability of a polymer material including an acidic catalyst residue such as polyethylene or polypropylene, a material having a large surface area and excellent ability to capture acidic components This may optionally be applied.

According to the Republic of Korea Patent Publication No. 98-082133 in the field of using a hydrotalcite-type material that is added to the polymer material for the purpose of improving thermal stability, the shape of the additive material is a thin plate and a large surface area, the shape is regular Compared with the use of granular or relatively thick plate-like materials with a small surface area, the heat-resistance characteristics of polymer materials are improved and the adsorption amount of acidic materials is also relatively high. It can be seen that the use of layered mixed metal hydroxides with an appropriate size distribution is important for the purpose of increasing the efficiency of this material.

Therefore, the present invention pays attention to the necessity of producing a mixed metal hydroxide having finely controlled physical properties in accordance with the purpose of the field of application, physical, such as the size, surface area, shape, ratio of thickness to diameter of the layered mixed metal hydroxide Recognizing the importance of a method that allows for flexible and easy control of properties, a commercial manufacturing method has been developed that can achieve this goal.

The present invention has been made to solve the conventional problems and problems as described above, the object of the present invention is to form a thin plate with a suitable particle size in order to add to a polymer material, etc. It is to provide a method for producing an easy crystalline layered mixed metal hydroxide at a high speed.

In order to achieve the above object, the present invention,

The crystalline M ^(II) (OH) ₂ metal hydroxide and the crystalline M ^(III) (OH) ₃ metal hydroxide are dispersed in water, and the water-soluble M ^(II) compound and the water-soluble M ^(III) compound are dissolved in the M ^(II) To each of (OH) ₂ and M ^(III) (OH) ₃ in the same molar ratio, a water-soluble compound capable of supplying an interlayer anion is added to the reaction system, and the pH of the reactant solution is controlled to secrete from the water-soluble metal compound. A layered mixed metal hydroxide, comprising forming a viscous mixture containing qualitative metal hydroxide and easily controlling the physical size, specific surface area, and particulate physical parameters of the final product through a hydrothermal reaction step. It provides a method of manufacturing.

The M ^(II) is a metal element having an oxidation number of 2 + is selected from the group consisting of Mg, Ca, Zn, Ni, Cu and mixtures thereof, the M ^(III) is a metal element having an oxidation number of 3 + Al, Cr, Fe and mixtures thereof.

The water-soluble M ^(II) compound and the water-soluble M ^(III) compound is melted to each water M ^(II) metal element or M ^(III) to be capable of supplying an anion or cation containing a metal element M ^(II) element and a M ^{(III) It} consists of a compound containing the hydrochloride, sulfate, nitrate, cyan salt, carboxylic acid compound, oxo anion, and oxo hydroxide anion of each component of an element.

Water soluble M^(II)Compound And The Water Soluble M^(II)As the compound for supplying a compound, the crystalline M^(II)(OH)₂Metal hydroxide and the crystalline M^(III)(OH)₃Water-soluble M by adding inorganic acid to each metal hydroxide^(II)With inorganic acid salts M^(II)Inorganic acid salts are formed and used in the reaction mixture, wherein the inorganic acid is the total M^(II)Ingredients and M^(III)It is equally used in the range of 5-30 mol% with respect to each component.

The water-soluble ^{compounds, Cl -, Bl -, CO} 3 2-, BO 3 3-, NO 3 -, PO 4 3-, P 2 O 7 4-, SO 4 2-, WO 4 2-, M O O ₄ ^2- , CrO ₄ ^2- , Cr ₂ O ₇ ^2- , silicate anions, polyphosphate anions, heteropolyacid anions, and carboxylic acid anions.

The amount of the interlayer anion component is used in the range of 100% to 200% with respect to the amount capable of supplying the negative charge amount corresponding to the total number of moles of the M ^(III) component.

In the step of adjusting the pH of the reactant solution, an alkali metal hydroxide solution is used to control the pH of the reaction mixture in the range of 9 to 14 to form a mixture including the viscous amorphous metal hydroxide gel.

The hydrothermal reaction is carried out for a reaction time of 30 minutes to 4 hours under a reaction temperature of 150 to 170 ℃ and a reaction pressure of 4 to 10 atm.

The crystalline M ^(II) (OH) ₂ metal hydroxide and the crystalline M ^(III) (OH) ₃ metal hydroxide are used in a total weight ratio of 10% to 30% of the total reactant mass.

As mentioned above, in the method for producing a crystalline layered mixed metal hydroxide according to the present invention, crystalline M^(II)(OH)₂(M^(II)Is a metal element with +2 oxidation state) and crystalline M^(III)(OH)₃(M^(III)Is a water dispersion of a metal element) compound having a +3 oxidation state,^(II)And M^(III)A water-soluble compound containing a metal element and a compound containing an interlayer anion component are added, and the pH of the mixture solution is adjusted to convert the water-soluble metal component into a viscous gel-type mixed metal hydroxide.^(II)(OH)₂, M^(III)(OH)₃And a crystalline layered mixed metal hydroxide were prepared from a reaction mixture containing a viscous gel-type metal hydroxide modified from a water-soluble metal component by hydrothermal reaction.

In the present invention, the particle size of the layered mixed metal hydroxide which is a product by appropriate selection of the type of water-soluble compounds added to the reaction, the ratio and method of adding the water-soluble metal compound to the metal hydroxide, the type of the anion component between the layers, the reaction temperature and the reaction time It was flexibly controlled in the range of 0.2 to 2 mu, the particle shape from the regular hexagonal plate to irregular plate shape, the specific surface area in the range of 20 to 90 m ² / g, and the thickness to diameter ratio in the range of 10 to 50.

Hereinafter, the manufacturing method of the crystalline layered mixed metal hydroxide according to the present invention will be described in detail.

In the present invention, a high purity metal hydroxide fine powder supplied at a relatively low price was selected as the main raw material. In addition, since the metal hydroxide raw material already includes the hydroxyl functional group (OH ⁻ ) in the raw material, there is an advantage in that the burden of additionally supplying the OH ⁻ component to the reaction system in the process of preparing the mixed metal hydroxide is reduced.

In the present invention, in order to prevent excessive growth of product particles due to a relatively slow reaction when only crystalline metal hydroxides are used as raw materials, water-soluble compounds containing these metal elements in a reactant in which crystalline solid metal hydroxides are dispersed and After adding a compound containing an interlayer anion component, and adjusting the pH of the reaction mixture (-log value of hydrogen ion concentration) to basic, converting the water-soluble metal component compound into a viscous mixed gel hydroxide, and then reacting The mixture is converted to crystalline mixed metal hydroxides.

Crystalline M ^(II) (OH) ₂ , M ^(III) (OH) _{3 A} mixture of a metal hydroxide and a viscous gel-type metal hydroxide is converted into a crystalline layered mixed metal hydroxide with controlled physical properties. Hydrothermal reaction is used in the step. In the hydrothermal reaction step, the metal hydroxide in the form of gel rapidly forms a certain number of crystal nuclei to control the physical properties of the reaction product.

Furthermore, the present invention provides the specific surface area and particle shape of the layered mixed metal hydroxide as a product by adjusting the type of water-soluble compounds, the addition ratio of the water-soluble metal compound to the metal hydroxide, the type of interlayer anions, the reaction temperature, and the reaction time in the reaction step. In addition, the particle size can be flexibly controlled in a certain range. The method of the present invention for controlling the properties of the reaction product by using a water-soluble metal component in the metal hydroxide has the following advantages over the method using only the metal hydroxide or reacting only the water-soluble metal component with alkali. That is, the relatively slow reaction rate and excessive particle growth caused by the slow reaction rate when only the metal hydroxide is used as the raw material can be avoided.

In the method of directly reacting a water-soluble metal compound with alkali, there are problems such as formation of ultrafine particles and formation of irregular secondary aggregates by agglomeration of ultrafine particles, using relatively expensive raw materials, and having a size suitable for commercial applications. In order to grow additional hydrothermal reactions are required. On the contrary, in the present invention in which a layered mixed metal hydroxide is prepared by using a mixed metal hydroxide and a water-soluble metal component and controls physical properties, an appropriate amount of crystal nucleus is formed by gelling an appropriate amount of water-soluble metal component and forming an appropriate amount of crystal nuclei in the initial hydrothermal reaction. The particle size, surface area and shape of the product can be flexibly and easily controlled.

Metal hydroxides that can be used in the present invention is a crystalline layered compound as M ^(II) component of M ^(II) (OH) ₂ Mg, Ni, Zn, Cu. Ca or a raw material in which these components are mixed may be used, and Al, Fe, Cr metal components may be used as the M ^(III) component of the M ^(III) (OH) ₃ compound.

The molar ratio of M ^(II) (OH) ₂ to M ^(III) (OH) ₃ used in the present invention can be used in the range of 2 to 3, preferably a molar ratio in the range of 2 to 2.5 is used. Can be. Compounds containing water-soluble M ^(II) and M ^(III) metal components that can be used in the present invention include Mg, Ni, Zn, Cu, Ca, Al, Fe, Cr, hydrochloride, nitrate, sulfate, phosphate containing Cr It may be selected from compounds including an anion component containing cyan salt, carboxylate, oxo or hydroxyl ligand. Among these water-soluble metal compounds, MgCl ₂ 6H ₂ O, MgSO ₄ 7H ₂ O, Mg (NO ₃ ) ₂ 6H ₂ O, and the like may be used as the water-soluble compound containing the Mg component as the M ^(II) component. NiCl ₂ 6H ₂ O, Ni (NO ₃ ) ₂ 6H ₂ O, etc. may be used as the compound, and CuCl ₂ 2H ₂ O, Cu (NO ₃ ) ₂ 2.5H ₂ O, etc. may be used as the compound containing the Cu component. Ca (NO ₃ ) ₂ 4H ₂ O and the like may be selectively used as the compound including the Ca component, and as the water-soluble compound including the Al component as the M ^(III) component, AlCl ₃ 6H ₂ O, Al (NO ₃ ) ₃ 9H ₂ O, NaAlO ₂ compounds can be used, and as the compound containing the Fe component FeCl ₃ 9H ₂ O, Fe (NO ₃ ) ₃ 9H ₂ O compound can be used, a compound containing Cr component As the CrCl ₃ 9H ₂ O, Cr (NO ₃ ) ₃ 9H ₂ O compounds can be used.

In the present invention, the water-soluble metal compound is added to the reaction system in the step of adding the aforementioned water-soluble metal compound to the reaction system to form a water dispersion, or each metal hydroxide is reacted in advance with an appropriate molar ratio of inorganic acid to react with the reactor. The method of injecting in can be used to show the effect of adding a water-soluble metal compound. For example, when Mg and Al components are used as the M ^(II) component and the M ^(III) component, Mg (OH) ₂ and Al (OH) ₃ , and the water-soluble MgCl ₂ 6H ₂ O water-soluble AlCl ₃ 6H ₂ O compound to the reactor To react with Mg (OH) ₂ and HCl solution in an appropriate molar ratio, and react Al (OH) ₃ and HCl solution in an appropriate molar ratio, respectively. It is possible to apply a method of preparing the reaction mixture by mixing the reactants in the reactor. At this time, the molar ratio of the water-soluble metal compound to the crystalline metal hydroxide may be changed in the range of 5 to 50%, and optionally when the 10 to 30% range is used, physical properties such as particle shape, size and surface area change. Effective in terms of

In the present invention, the input amount of the crystalline metal hydroxide, which is the main reaction raw material, may be selected and used in the range of 10 to 30% with respect to the total weight of the water reactant, and when used within the range of 20%, uniform mixing of the reactants and smooth delivery of the product. It is advantageous in terms of the back.

In the present invention, after the water-soluble metal compound is supplied, the interlayer anion component may be introduced into the reactor to supply the interlayer anion component. As the interlayer anion component, an anion component supplied to the reaction system by a water-soluble metal compound may be used, or another anion component having high selectivity may be further supplied to the reaction system. For example, when a metal chloride is used as a water-soluble metal compound in a reaction system, Cl ^- ions present as an anion component may be used as an interlayer anion, and when a NO ₃ ^- ion compound is used, NO ₃ ^- ions may be used as an interlayer anion component. Can be applied as When removing an anion component supplied by a water-soluble metal compound as an interlayer anion and preparing another kind of layered anion having high selectivity, a compound containing the anion may be added to the reaction system.

For example, when CO ₃ ^2- ions are applied as interlayer anions, compounds that serve as various CO ₃ ^2- ion sources such as Na ₂ CO ₃ , H ₂ CO ₃ , NaHCO _3, and the like can be further fed to the reaction system. The amount of anion used as the interlayer anion should be supplied at least 100% with respect to the amount necessary to offset the positive charge of the interlayer layer, and may optionally be used within the range of 200%. Anions which can be used as the interlayer anion component in the present invention is _{^{Cl -, Br -, BO 3}} 3-, CO 3 2-, NO 3-, PO 4 3-, P 2 O 7 4-, SO 4 2-, WO ₄ ^2- , MoO ₄ ^2- , CrO ₄ ^2- , Cr ₂ O ₇ ^2- , various water soluble polyphosphate anions such as cyclic hexaphosphate and cyclic octaphosphate, various heteropolyacid anions, carboxyl anion And the like, and compounds that supply these anion components can be used. Alkali metal ions, ammonium or protons and the like can be used in the present invention as the cation component of the compounds containing these interlayer anions.

The present invention is to adjust the pH of the reactant mixed with the crystalline metal hydroxide, the appropriate amount of water-soluble metal compound, the interlayer anion compound as the main reaction raw material in the range of 10 to 13 to convert the water-soluble metal component in the reactive component to the metal hydroxide in the form of gel Steps. The water-soluble metal ions are converted into gel form by the OH ⁻ component supplied in the step of controlling pH, and the reaction mixture is in the form of a viscous microparticle dispersion. Adjusting the pH of the reactants to the range of 10-14 provides the amorphous metal hydroxide gel from the water-soluble metal ions while supplying the OH ⁻ component required for the reaction system, followed by the mixed metal from the amorphous metal hydroxide gel at the start of the hydrothermal reaction. It is an important step in controlling the number of hydroxide crystal forming nuclei (seeds). Alkali metal hydroxides may be used to adjust the pH of the reactants, and a method of slowly adding an aqueous NaOH solution in a concentration range of 10 to 20% to the reactants is preferable.

In the present invention, the step of adjusting the pH of the reaction mixture is generally carried out after supplying the interlayer anion component. However, the step of supplying the interlayer anion component may be changed after adjusting the pH of the reactant. By supplying the interlayer anion component after pH adjustment, it is possible to form a gel of a more uniform metal hydroxide component in the reaction system, thereby diversifying the particle size control method.

In the present invention, a method of reacting the reaction mixture at high pressure and high temperature to convert the reaction mixture consisting of crystalline metal hydroxide, viscous gel type metal hydroxide, and interlayer anion component into crystalline layered mixed metal hydroxide having a large surface area. Use Since the control of the reaction temperature and reaction time is an important variable that affects the size change of the particle size and the surface area of the final product, it is an important part of the present invention.

The reaction temperature usable in the present invention can be selected and applied in the range of 150 to 180 ° C, preferably 160 to 170 ° C. The reaction pressure can be used to control the equilibrium steam pressure at the reaction temperature, the reaction proceeds in the range of 4 to 10 atm depending on the reaction temperature. The reaction time of the present invention can be used in the range of 30 minutes to 5 hours from the time to reach the reaction temperature. The optimum reaction time depends on the reaction temperature and the amount of water-soluble metal compound added. However, when the reaction temperature is relatively high or the fraction of water-soluble metal compound is large, the reaction time can be shortened. When used in the range of 10 to 30 mole% relative to the metal hydroxide, the reaction can be terminated within 2 hours.

The layered mixed metal hydroxide prepared in the high pressure reactor according to the method of the present invention is cooled to 90 ° C. or lower, and then transferred to a pressure filtration and washing apparatus to remove water-soluble impurities in the solution, dried in an air heating furnace at 100 ° C., and ground. The final product can be prepared in the form of a fine powder.

The layered mixed metal hydroxide prepared by the method of the present invention is characterized by a regular hexagonal plate shape or irregular plate shape in particle shape and a diameter to diameter ratio in the range of 20 to 50. The basic particle size of the layered mixed metal hydroxide prepared by the method of the present invention varies depending on the metal component of the layer, the ratio of addition of a water-soluble metal compound and the type of anion, but the Mg and Al elements are used as the metal component constituting the layer. When used and CO ₃ ^2- ions are used as interlayer anions, the distribution of particles can usually be controlled in the range 0.2 to 2.0 μ, and in selective conditions mixed metals with particle distribution in a narrow distribution in the range 0.2 to 1.0 μ Hydroxide can be prepared.

The particle size distribution range of the particles produced in the reaction system using the same components and reaction conditions, but not using a water-soluble metal compound, and does not include a gel-forming step by pH control. Compared to ˜10 μ, the method of the present invention is shown to be effective in terms of controlling the shape and size of the particles. In addition, the method of the present invention has the feature that it can be easily produced to the extent that the surface area of the layered mixed metal hydroxide is significantly increased. The specific surface area of the mixed metal hydroxide having a particle distribution in the range of 0.2 to 2 mu synthesized by the method of the present invention can be controlled in the range of about 20 to 90 m ² / g.

Unlike the method of the present invention, when the mixed metal hydroxide is synthesized by the coprecipitation method and compared with the specific surface area of the layered mixed metal compound in which the particle size is controlled in the range of 0.5 to 1.0 μ by the hydrothermal treatment method, in the range of 10 to 20 m ² / g. In addition, it shows that the method of the present invention can be usefully applied to the preparation of materials that can be applied to various applications due to the increased surface area and wide range of control. Despite the relatively large particle size synthesized by the method of the present invention compared to the layered mixed metal hydroxide prepared by the coprecipitation and hydrothermal reaction methods, it is possible to prepare a product having a large surface area in the synthesis step of the method of the present invention. It means that a plate material having a relatively thin thickness is formed.

<Comparative Example 1-1>

Using only water-soluble metal compounds to prepare a layered mixed metal hydroxide by the coprecipitation method and hydrothermal treatment method, wherein CO ₃ ^2- is used as an interlayer anion.

First, 46.15 g of Mg (NO ₃ ) ₂ 6H ₂ O (0.18 mole) and 33.76 g of Al (NO ₃ ) ₃ 9H ₂ O (0.09 mole) are dissolved in 250 mL of distilled water to form an A solution. 21.6 g of NaOH (0.54 mole) Is dissolved in 250 mL of distilled water to form a solution B. 7.21 g of Na ₂ CO ₃ (0.068 mol) is dissolved in 150 mL of distilled water to form a C solution.

Next, C solution is placed in a 1 L beaker and A and B solutions are slowly added simultaneously over an hour. At this time, the reaction temperature is maintained at 50 ℃ and the pH of the reactants to maintain a 10 by adjusting the addition rate of the B solution.

The reaction product was filtered to separate the white solid product which was then transferred to 1 L of high pressure reactor and 500 mL of distilled water was added. The hydrothermal reaction is carried out at 170 ° C. for 2 hours. After completion of the reaction, the reaction product is cooled to 90 ° C. and filtered to separate the solid reaction product. The separated solid product is dispersed-filtered five times in 500 mL of distilled water, and the final filtrate is dried at 100 ° C. for 12 hours to obtain the final product in the form of a white fine powder.

The separated samples are analyzed by X-ray diffraction and scanning electron microscopy, and the samples pretreated in a vacuum at 150 ° C. are analyzed by nitrogen adsorption. The phase, measured specific surface area, particle size, and shape of the sample are shown in Table 1 below.

<Comparative Example 1-2>

Metal hydroxides Mg (OH) ₂ and Al (OH) ₃ are used, water-soluble compounds are not used, and CO ₃ ^2- is used as an interlayer anion.

In a 1 L high-pressure reactor, 40.25 g (0.69 mol) of ₂ micron crystalline powder Mg (OH) _{2 and} 26.5 g (0.34 mol) of ₂ micron crystalline powder Al (OH) ₃ are dispersed in 600 mL distilled water. 21.0 g (0.25 mol) of NaHCO ₃ was added to the dispersion, followed by stirring for 10 minutes. Then, the high pressure reactors were combined and the reaction was performed at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 1-1>

The metal hydroxide uses Mg (OH) ₂ and Al (OH) ₃ , the water-soluble compound uses MgCl ₂ 6H ₂ O and AlCl ₃ 6H ₂ O, 25%, and CO ₃ ^2- is used as an interlayer anion.

In a 1 L high pressure reactor, 30.33 g (0.52 mole) of ₂ μ size crystalline powder Mg (OH) _{2 and} 20.28 g (0.26 mole) of ₂ μ size crystalline powder Al (OH) ₃ are dispersed in 600 mL distilled water. 34.56 g (0.17 mol) of MgCl ₂ 6H ₂ O and 19.31 g (0.08 mol) of AlCl ₃ 6H ₂ O are added to the dispersion, followed by stirring for 10 minutes, followed by 21.0 g (0.25 mol) of NaHCO ₃ . To this was slowly added 98 g of 20% NaOH solution (0.46 mol) to the reactor. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product is isolated and analyzed in the same manner as in 1-1. The analysis results are shown in Table 1 below.

<Example 1-2>

The metal hydroxide uses Mg (OH) ₂ and Al (OH) ₃ , supplies 10% of a water-soluble compound to the reactants by HCl addition method, and uses CO ₃ ^2- as an interlayer anion.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 µl distilled water with 40.25 g (0.69 mol) of ₂ g crystalline powder Mg (OH) ₂ and 11.9 ml of 35% HCl solution (0.138 mol HCl), and dispersion b having a size of ₂ µ 26.5 g (0.34 mole) of crystalline powder Al (OH) ₃ is prepared by dispersing 200 mL distilled water and reacting 8.91 mL of 35% HCl solution (0.102 mole HCl).

21.0 g (0.25 mole) NaHCO ₃ is added to the reaction mixture. 30 g of 20% NaOH solution (0.15 mol NaOH) is slowly added to the reactor. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Comparative Example 2>

Metal hydroxide using Mg (OH) ₂ and Al (OH) _3, and a water-soluble compound is not used, and a combination of CO ₃ ^2- which is supplied from the CO ₂ with the interlayer negative ion.

In a 1 L high-pressure reactor, 40.25 g (0.69 mol) of ₂ micron crystalline powder Mg (OH) _{2 and} 26.5 g (0.34 mol) of ₂ micron crystalline powder Al (OH) ₃ are dispersed in 600 mL distilled water. Combine the high pressure reactor and slowly add about 7.5 g of CO ₂ (0.17 mole and about 4200 mL at room temperature) to a pressure of 5 atmospheres. After completing the CO _{2 addition} , the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 2-1>

Metal hydroxide is Mg (OH) ₂ using the Al (OH) _3, and a water-soluble compound is used for MgCl ₂ 6H ₂ O and _{AlCl 3 6H 2 O, 25%} , the interlayer CO ₃ ^2- which is supplied from the CO ₂ Used in combination with anions.

In a 1 L high pressure reactor, 30.33 g (0.52 mole) of ₂ μ size crystalline powder Mg (OH) _{2 and} 20.28 g (0.26 mole) of ₂ μ size crystalline powder Al (OH) ₃ are dispersed in 600 mL distilled water. 34.56 g (0.17 mole) of MgCl ₂ 6H ₂ O and 19.31 g (0.08 mole) of AlCl ₃ 6H ₂ O were added to the dispersion, followed by stirring for 10 minutes, followed by 116 g of 20% NaOH solution (0.58 mole). To slow down. After the viscous reaction mixture is formed, the high pressure reactor is combined and slowly added about 7.5 g of CO ₂ (0.17 mol and about 4200 mL at room temperature) to 5 atm. After completing the CO _{2 addition} , the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 2-2>

Metal hydroxide using Mg (OH) ₂ and Al (OH) _3, and it supplies the 5% water-soluble compound with HCl was added to the reaction method, and a combination of CO ₃ ^2- which is supplied from the CO ₂ with the interlayer negative ion.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 µl distilled water with 40.25 g (0.69 mol) of ₂ g crystalline powder Mg (OH) ₂ and 5.94 ml of 35% HCl solution (0.068 mol HCl). 26.5 g (0.34 mol) of crystalline powder Al (OH) ₃ are prepared by dispersing in 200 mL distilled water and reacting 4.46 mL of 35% HCl solution (0.051 mol HCl). To the reaction is slowly added 24 g of 20% NaOH solution (0.12 mol NaOH) to the reactor.

After the viscous reaction mixture is formed, the high pressure reactor is combined and slowly added 7.5 g of gas CO ₂ (0.17 mol CO ₂ and about 4200 mL at room temperature). After the CO ₂ supply is completed, the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 2-3>

Metal hydroxide using Mg (OH) ₂ and Al (OH) _3, and it supplies the 10% water-soluble compound with HCl was added to the reaction method, and a combination of CO ₃ ^2- which is supplied from the CO ₂ with the interlayer negative ion.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 μl distilled water with 40.25 g (0.69 mole) of ₂ g crystalline powder Mg (OH) ₂ and 11.88 mL of 35% HCl solution (0.136 mole HCl). 26.5 g (0.34 mole) of crystalline powder Al (OH) ₃ is prepared by dispersing 200 mL distilled water and reacting 8.91 mL of 35% HCl solution (0.102 mole HCl). 47.2 g of 20% NaOH solution (0.236 mol NaOH) is slowly added to the reactor.

After the viscous reaction mixture is formed, the high pressure reactor is combined and slowly added 7.5 g of gas CO ₂ (0.17 mol CO ₂ and about 4200 mL at room temperature). After completion of the CO ₂ supply, the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 3-1>

As the metal hydroxide, Mg (OH) ₂ and Al (OH) ₃ are used, and the water-soluble compound is MgCl ₂ 6H ₂ O and AlCl ₃ 6H ₂ O, 25%, and MgCl ₂ 6H ₂ O and AlCl ₃ 6H ₂ O Cl ⁻ supplied from is used in combination as an interlayer anion.

In a 1 L high-pressure reactor, 30.33 g (0.52 mole) of ₂ μ size crystalline powder Mg (OH) _{2 and} 20.28 g (0.26 mole) of ₂ μ size crystalline powder Al (OH) ₃ are dispersed in 600 mL distilled water. 34.56 g (0.17 mole) MgCl ₂ 6H ₂ O and 19.31 g (0.08 mole) AlCl ₃ 6H ₂ O were added to the dispersion, followed by stirring for 10 minutes, followed by 64 g of 20% NaOH solution (0.32 mole) slowly added to the reactor. Add. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 3-2>

As the metal hydroxide, Mg (OH) ₂ and Al (OH) ₃ are used, the reaction product is supplied with 10% water-soluble compound by HCl addition method, and BO ₃ ^3- supplied from H ₃ BO ₃ is used as a combination of interlayer anions. do.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 μl distilled water with 40.25 g (0.69 mole) of ₂ g crystalline powder Mg (OH) ₂ and 11.88 mL of 35% HCl solution (0.136 mole HCl). 26.5 g (0.34 mole) of crystalline powder Al (OH) ₃ is prepared by dispersing 200 mL distilled water and reacting 8.91 mL of 35% HCl solution (0.102 mole HCl). 112 g of 20% NaOH solution (0.56 mol NaOH) is slowly added to the reaction mixture to the reaction mixture. Then 13.6 g of H ₃ BO ₃ (0.22 mol H ₃ BO ₃ ) is added. After the viscous reaction mixture is formed, the reactors are combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 3-3>

The metal hydroxide uses Mg (OH) ₂ and Al (OH) ₃ , supplies 10% water-soluble compounds to the reactants by HCl addition method, and SiO ₃ ^2- supplied from Na ₂ SiO ₃ 9H ₂ O as an interlayer anion. Use in combination.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 μl distilled water with 40.25 g (0.69 mole) of ₂ g crystalline powder Mg (OH) ₂ and 11.88 mL of 35% HCl solution (0.136 mole HCl). 26.5 g (0.34 mole) of crystalline powder Al (OH) ₃ is prepared by dispersing 200 mL distilled water and reacting 8.91 mL of 35% HCl solution (0.102 mole HCl). 47.6 g of 20% NaOH solution (0.238 mol NaOH) is slowly added to the reactor. Then 42.6 g of Na ₂ SiO ₃ 9H ₂ O (0.15 mol Na ₂ SiO ₃ 9H ₂ O) is added. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 3-4>

The metal hydroxide uses Mg (OH) ₂ and Al (OH) ₃ , supplies 10% water-soluble compound to the reactants by HCl addition method, and PO ₄ ^3- supplied from Na ₃ PO ₄ 12H ₂ O as an interlayer anion. Use in combination.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 400 μl distilled water with 40.25 g (0.69 mole) of ₂ g crystalline powder Mg (OH) ₂ and 11.88 mL of 35% HCl solution (0.136 mole HCl). 26.5 g (0.34 mole) of crystalline powder Al (OH) ₃ is dispersed in 200 mL distilled water and prepared by reacting 8.91 mL of 35% HCl solution (0.102 mole HCl). 47.6 g of 20% NaOH solution (0.238 mol NaOH) is slowly added to the reactor. Then 57.0 g of Na ₃ PO ₄ 12H ₂ O (0.15 mol Na ₃ PO ₄ 12H ₂ O) is added. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 4-1>

Mg (OH) ₂ and Cr (OH) ₃ are used as metal hydroxides, and 10% of water-soluble compounds are supplied to the reactants by HCl addition, and CO ₃ ^2- supplied from NaHCO ₃ is used in combination as an interlayer anion.

In a 1 L high-pressure reactor, a mixture of Dispersion a and Dispersion B prepared in the following two ways is prepared. Dispersion a is 40.25 g (0.69 mol) of 10 g of crystalline powder Mg (OH) 2 in 400 mL distilled water. Prepared by reacting 11.88 mL of 35% HCl solution (0.136 mol HCl), dispersion b was dispersed in 200 mL distilled water with 25.03 g of Cr (OH) ₃ (0.34 mol) of 10μ size crystalline powder. Prepared by reacting% HCl solution (0.102 mol HCl). Then 21.0 g of NaHCO ₃ (0.25 mol NaHCO ₃ ) is added. 30 g of 20% NaOH solution (0.15 mol NaOH) is slowly added to the reaction mixture to the reaction mixture. After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

<Example 4-2>

As the metal hydroxide, Zn (OH) ₂ and Al (OH) ₃ are used, the reaction product is supplied with 10% water-soluble compound by HCl addition method, and Cl ⁻ supplied from HCl is used in combination as an interlayer anion.

In a 1 L high-pressure reactor, a mixture of Dispersion a and Dispersion B prepared in the following two ways is prepared. Dispersion a consists of 68.58 g (0.69 mole) of 10 n crystalline powder Zn (OH) ₂ in 400 mL distilled water. Prepared by reacting 11.88 mL of 35% HCl solution (0.136 mol HCl), and dispersing b was dispersed in 2μg crystalline powder Al (OH) ₃ 2μg (0.34 mol) in 200 mL distilled water and 35% of 8.91 mL Prepared by reacting HCl solution (0.102 mol HCl). 68 g of 20% NaOH solution (0.34 mol NaOH) is then slowly added to the reactor. To the reaction mixture is added 38.4 mL of 35% HCl solution (0.442 mol HCl). After the viscous reaction mixture is formed, the high pressure reactor is combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product is isolated and analyzed in the same manner as shown in 1-1 above. The analysis results are shown in Table 1 below.

<Example 4-3>

As the metal hydroxide, Ni (OH) ₂ and Al (OH) ₃ are used, the reaction product is supplied with 10% water-soluble compound by HCl addition method, and CO ₃ ^2- supplied from NaHCO ₃ is used as an interlayer anion.

Dispersion a and dispersion b prepared by the following two methods are mixed in a 1 L high pressure reactor. Dispersion a was prepared by reacting 63.98 g (0.69 moles) of 10 μm crystalline powder Ni (OH) _{2 with} 11.88 mL of 35% HCl solution (0.136 moles HCl) in 400 mL distilled water, and dispersion b was made of ₂ μ size. 26.5 g (0.34 mol) of crystalline powder Al (OH) ₃ are prepared by dispersing in 200 mL distilled water and reacting 8.91 mL of 35% HCl solution (0.102 mol HCl). 21.0 g (0.25 mole) NaHCO ₃ is added to the reaction mixture. 29.6 g of 20% NaOH solution (0.148 mol NaOH) is then slowly added to the reactor. After the viscous reaction mixture is formed, the reactors are combined and the reaction proceeds at 170 ° C. for 120 minutes.

After completion of the reaction, the solid product was isolated and analyzed in the same manner as in Comparative Example 1-1. The analysis results are shown in Table 1 below.

Results and Discussion

The products prepared by the methods of Comparative Examples 1-1 and 1-2 have particle sizes ranging from 1 to 2 μ and 5 to 10 μ, respectively, and the specific surface areas are 12 m ² / g and 18 m ² / g, respectively. the particle size of the materials prepared in examples 1-1 and 1-2 using the method of the present invention are each 0.5~1μ scope and range 0.5~2μ specific surface area is indicated by each of 36m ² / g and 33m ² / g, The results show that a material with reduced particle size and increased surface area was produced.

The product prepared by the Experimental Example method of Comparative Example 2 (= water-soluble metal compound unused method) has a particle size of 5 ~ 10μ range, the specific surface area of 15m ² / g and the reaction product contains an unreacted metal hydroxide reaction rate Shows relatively slow. On the other hand, in Example 2-1, Example 2-2, and Example 2-3 using the method of the present invention (= method in which the water-soluble metal compound is included in the reaction system), the particle size of the prepared material was 1 to 2 mu, respectively. It was in the range of 0.2 ~ 2μ range, 0.2 ~ 2μ range, specific surface area of 36m ² / g, 27m ² / g, 32m ² / g, respectively, and unreacted product was not included in the reaction product. Thus, using the method of the present invention, it is shown that it is possible to produce materials in which the reaction rate is relatively increased, the particle size is reduced, and the surface area is increased.

Example 3-1 to 3-4 is a reaction example in which the type of interlayer anion is changed in the process of producing a layered mixed metal hydroxide by producing a water-soluble metal compound in the reaction system by adding HCl solution to the metal hydroxide. to be.

When anions such as Cl ⁻ , BO ₃ ^{3 −} , SiO ₃ ^{2 −} , and PO ₄ ³ − were used as interlayer anion components, plate-shaped mixed metal hydroxides having a large surface area and small particle sizes were prepared. However, when using a PO ₄ ^3- anion, the product was examined by X-ray diffraction method, showing that the diffraction peak was hardly found and was converted to an amorphous material. However, when the particle shape of the foreign material was examined by electron microscopy, it showed a hexagonal plate-like appearance, indicating that the regular distribution was disturbed inside the material.

In Examples 4-1 to 4-3, the metal component of the metal hydroxide was changed in the process of producing the layered mixed metal hydroxide by producing a water-soluble metal compound in the reaction system by adding HCl solution to the metal hydroxide. Yes.

In addition to Mg / Al, Mg / Cr, Zn / Al, Ni / Al, etc. are used as a combination of metals to form the layer, but the particle size is small, but the material has a relatively thick layer and a relatively small surface area. Shows that it can be. In the Ni / Al combination, however, a crystalline material having a different structure in addition to the layered mixed metal hydroxide was formed as the main product.

Table 1. Product Analysis Summary

Example Number M ^(II) / M ^(III) / anion component Water-soluble M ^(II) , M ^(III) Compound Type and Mole% Used: (m) Interlayer anion supply compound Main product (by-product) Product particle size range (μ) Specific surface area (m ² / g) Particle shape (thickness to diameter ratio range) Comparative example 1-1 Mg / Al / CO ₃ Mg (NO ₃ ) ₂ 6H ₂ OAl (NO ₃ ) ₃ 9H ₂ O (100) Na ₂ CO ₃ HT 0.5-1 12 Hexagonal Plate (10-20) 1-2 Mg / Al / CO ₃ Do not use NaHCO ₃ HT 5-10 18 Regular Plate (20-30) Example 1-1 Mg / Al / CO ₃ MgCl ₂ 6H ₂ OAlCl ₃ 6H ₂ O (25) NaHCO ₃ HT 0.5-1 36 Regular Plate (30-50) 1-2 Mg / Al / CO ₃ HCl addition method (10) NaHCO ₃ HT 0.5-2 33 Regular Plate (10-20) Comparative Example 2 Mg / Al / CO ₃ Do not use CO ₂ HT (unreacted) 5-10 15 Irregular Plate (30-50) Example 2-1 Mg / Al / CO ₃ MgCl ₂ 6H ₂ OAlCl ₃ 6H ₂ O (25) CO ₂ HT 1-2 36 Irregular Plate (30-50) 2-2 Mg / Al / CO ₃ HCl addition method (5) CO ₂ HT 0.2-2 27 Irregular Plate (30-50) 2-3 Mg / Al / CO ₃ HCl addition method (10) CO ₂ HT 0.2-2 32 Irregular Plate (30-50) 3-1 Mg / Al / Cl MgCl ₂ 6H ₂ OAlCl ₃ 6H ₂ O (25) MgCl ₂ 6H ₂ OAlCl ₃ 6H ₂ O HT 0.2-1 62 Regular Plate (20-30) 3-2 Mg / Al / BO ₃ HCl addition method (10) H ₃ BO ₃ HT 0.5-1 60 Irregular Plate (20-30) 3-2 Mg / Al / SiO ₃ HCl addition method (10) Na ₂ SiO ₃ 9H ₂ O HT 1-2 86 Irregular Plate (20-30) 3-4 Mg / Al / PO ₄ HCl addition method (10) Na ₃ PO _{4 12} H ₂ O Amorphous material 1-2 19 Irregular Plate (20-30) 4-1 Mg / Cr / CO ₃ How to add HCl (10) NaHCO ₃ HT 0.5-1 17 Irregular Plate (10-20) 4-2 Zn / Al / Cl How to add HCl (10) HCl HT 0.2-1 15 Irregular, regular mixed plate (10-20) 4-3 Ni / Al / CO ₃ HCl addition method (10) NaHCO ₃ Unreacted substance (HT) - - -

HT: Hydrotalcite-type layered mixed hydroxide

As mentioned above, in the method for producing a crystalline layered mixed metal hydroxide according to the present invention, by using a metal hydroxide and a water-soluble metal compound, it is possible to flexibly control the reaction rate, the particle size and the shape, accordingly various and fine Since the layered mixed metal hydroxide having easily controlled physical properties can be easily manufactured, it is advantageous in terms of securing economical efficiency.

The layered mixed metal hydroxide prepared by the present invention can be easily prepared even a material having a relatively large surface area, a thin layer and a wide surface area compared to the particle size, and when the material is applied as a polymer additive, As the area of the interface increases, there is an advantage that a desired addition effect can be obtained even using a small amount.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand that you can.

Claims (13)

The crystalline M ^(II) (OH) ₂ metal hydroxide and the crystalline M ^(III) (OH) ₃ metal hydroxide are dispersed in water, and the water-soluble M ^(II) compound and the water-soluble M ^(III) compound are dissolved in the M ^(II) (OH) ₂ and M ^(III) (OH) ₃ are each added in the same molar ratio, wherein M ^(II) consists of a first metal element having an oxidation number of 2+, and the M ^(III) Is composed of a second metal element having an oxidation number of 3+, and a water-soluble compound capable of supplying an interlayer anion is added to the reaction system, and the pH of the reaction mixture is controlled in the range of 9-14 using an alkali metal hydroxide solution. A viscous mixture containing amorphous metal hydroxide is formed from the compound and prepared by a hydrothermal reaction step for 30 minutes to 4 hours at a reaction temperature of 150 to 170 ° C. and a reaction pressure of 4 to 10 atmospheres. Layered mixed metal hydroxide, characterized in that Method. delete The method of claim 2, wherein the first metal element is made of a metal element selected from the group consisting of Mg, Ca, Zn, Ni, Cu and mixtures thereof, and the second metal element is Al, Cr, Fe and these Method for producing a layered mixed metal hydroxide, characterized in that consisting of a metal element selected from the group consisting of a mixture of. The method according to claim 1, wherein the water-soluble M ^(II) compound and the water-soluble M ^(III) compound are each dissolved in water to supply an anion or cation containing M ^(II) metal element or M ^(III) metal element A method for producing a layered mixed metal hydroxide, comprising a compound comprising a hydrochloride, sulfate, nitrate, cyan salt, carboxylic acid compound, oxo anion and oxo hydroxide anion of each of ^(II) and M ^(III) elements. 5. The method of claim 4 wherein said water soluble M^(II)Compound And The Water Soluble M^(II)As the compound for supplying a compound, the crystalline M^(II)(OH)₂Metal hydroxide and the crystalline M^(III)(OH)₃Water-soluble M by adding inorganic acid to each metal hydroxide^(II)With inorganic acid salts M^(II)A method for producing a layered mixed metal hydroxide, wherein the inorganic acid salt is formed in a reaction mixture. 6. The method for producing a layered mixed metal hydroxide according to claim 5, wherein the inorganic acid is used in the same amount in the range of 5 to 30 mole% with respect to the total M ^(II) component and the M ^(III) component. The method for producing a layered mixed metal hydroxide according to claim 1, wherein the molar ratio of the total M ^(II) component and the total M ^(III) component is 2: 1 to 3: 1. The method of claim 1, wherein the water-soluble ^{compound, Cl -, Bl -, CO} 3 2-, BO 3 3-, NO 3 -, PO 4 3-, P 2 O 7 4-, SO 4 2-, WO 4 ^2- , M _O O ₄ ^2- , CrO ₄ ^2- , Cr ₂ O ₇ ^2- , silicate anion, polyphosphate anions, heteropolyacid anions, layered mixed metals comprising a compound containing carboxylic anions Process for the preparation of hydroxides. _2. The molar% m of the water soluble M ^(II) compound and the water soluble M ^(III) compound for each of M ^(II) (OH) ₂ and M ^(III) (OH) ₃ is the total M ^A method for producing a layered mixed metal hydroxide, which is used equally in the range of 5 <m <30% with respect to 100% of the mole ratio of each of the component ^(II) or the component M ^(III) . Where m = number of moles of water-soluble M ^(II) compounds x 100 / (number of moles of formula (M ⁾ ( ^II ) ₂ + number of moles of water-soluble M ^(II) compounds) = Number of moles of water-soluble M ^(III) compounds x 100 / (M ^(III) (OH) _{3 number of} moles of formula + number of moles of water-soluble M ^(II) compounds) The layered mixed metal according to claim 1, wherein the amount of the interlayer anion component is used in a range of 100% to 200% with respect to an amount capable of supplying a negative charge amount corresponding to the total number of moles of the M ^(III) component. Process for the preparation of hydroxides. delete delete The method according to claim 1, wherein the crystalline M ^(II) (OH) ₂ metal hydroxide and the crystalline M ^(III) (OH) ₃ metal hydroxide are used in a total weight ratio of 10% to 30% of the total reactant mass. Method for producing a layered mixed metal hydroxide, characterized in that.