KR101064999B1 - 3-d structured layered metal double hydroxide-based reservoir, the preparation method thereof and controled-release fertilizer comprising said 3-d structured layered metal double hydroxide-based reservoir - Google Patents

Abstract

The present invention relates to a layered metal bihydride salt having a three-dimensional structure, a method for manufacturing the same, and a slow-acting fertilizer including the layered metal double hydroxide having the three-dimensional structure. More specifically, [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O represented by the chemical formula, and the layered structure of M ^II _(1-x) M ^III _x (OH) ₂ metal double hydroxide has an average of 1 to 10 nm It has a three-dimensional structure to form a card house having a range of pores, the three-dimensional layered metal bihydride salt of the three-dimensional structure, characterized in that the anions (A ^n- ) is inserted into the pores (wherein M ^II is Is a + divalent metal cation, M ^III is a + trivalent metal cation, A ^n- is a hydroxide ion (OH ⁻ ), a nitrate ion (NO ₃ ⁻ ), PO ₄ ^3- , HPO ₄ ^2- and H ₂ PO ₄ ^- and at least one member selected from the group consisting of a, 0 <x <1, z is from 0.1 to 15), a method of manufacturing and packing a layered double metal hydroxyl flame of the three-dimensional structure It relates to a slow release fertilizer, the neutralizing function and at the same time an anionic supported fertilizer / elute the multifunctional agricultural metal material having a function for double hydroxide for acid soils according to the present invention can be developed by using a carrier.

 Exfoliation-Recombination Method, Layered Metal Dihydroxy Hydrochloride, Phosphate, Slow Fertilizer

Description

3-D STRUCTURED LAYERED METAL DOUBLE HYDROXIDE-BASED RESERVOIR, THE PREPARATION METHOD THEREOF AND CONTROLED-RELEASE FERTILIZER COMPRISING SAID 3-D STRUCTURED LAYERED METAL DOUBLE HYDROXIDE-BASED RESERVOIR}

The present invention relates to a layered metal bihydride salt having a three-dimensional structure, a method for manufacturing the same, and a slow-acting fertilizer including the layered metal double hydroxide having the three-dimensional structure. More specifically, [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O represented by the chemical formula, and the layered structure of M ^II _(1-x) M ^III _x (OH) ₂ metal double hydroxide has an average of 1 to 10 nm It has a three-dimensional structure to form a card house having a range of pores, the three-dimensional layered metal bihydride salt of the three-dimensional structure, characterized in that the anions (A ^n- ) is inserted into the pores (wherein M ^II is Is a + divalent metal cation, M ^III is a + trivalent metal cation, A ^n- is a hydroxide ion (OH ⁻ ), a nitrate ion (NO ₃ ⁻ ), PO ₄ ^3- , HPO ₄ ^2- and H ₂ PO ₄ ^- and at least one member selected from the group consisting of a, 0 <x <1, z is from 0.1 to 15), a method of manufacturing and packing a layered double metal hydroxyl flame of the three-dimensional structure It relates to a slow release fertilizer.

On the other hand, the layered inorganic compound has recently received great attention as a carrier for storing various organic and bio functional compounds between layers and releasing them as necessary. Since these compounds are basically similar to the components of the soil that forms the earth's surface, they are environmentally friendly materials with excellent environmental and biocompatibility. Among them, the layered double hydroxide (LDH), which has recently attracted attention, has a layered structure consisting of +2 and + trivalent metal ions. Such a layered metal bihydride compound is [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O (M ^II : Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ , Cu ²⁺ etc ; M ^III : Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ³⁺ , Ni ³⁺ etc.). In the above formula, part of the +2 valent metal ion is replaced by +3 valent ions, so that the metal double hydroxide has a positive charge. Therefore, in order to keep the charge of the whole material neutral, the anion is stabilized in the space between the layers. These layered metal double hydroxides can generally be synthesized by precipitation reaction in aqueous solution or precipitation-ion exchange reaction, all of which are suitable for mass synthesis of samples and are economical methods with low production cost. However, ion exchange cannot increase the amount of loading significantly. Therefore, if not only the space, but also the disorderly stacking of house-of-cards stacking (house-of-cards stacking) is about 2 ~ 5 nm size space can be carried to support a large amount of fertilizer elements. Therefore, the LDH layer synthesized in the present invention may be peeled off in a sheet and synthesized by anionic fertilizer element and recombination method to overcome the limitation that can be supported by the conventional ion exchange method.

On the other hand, in the conventional method for producing a slow-fertilizing fertilizer, a chemical that reduces the solubility of the fertilizer component itself by chemically reacting the fertilizer component with other substances to change into a non-degradable substance that is not easily decomposed by salts or soil microorganisms that are difficult to dissolve in water. And a physical method of slowing the dissolution rate of the fertilizer components by coating the surface of the particles of the fast-acting fertilizer with a poorly soluble substance that can block the contact of water. Products made by chemical methods include Urea-Formaldehyde, Isobuty lidene Diureas (IBDU) and CDU condensed with urea and aldehyde.However, since the manufacturing process is manufactured by chemical synthesis, the process is complicated and production cost The disadvantage is that it is expensive. Unlike the chemical method, the physical method is to control the dissolution rate of the fertilizer by coating the particle surface of the fast-acting fertilizer. Depending on the type of coating material, a small amount of coating material can obtain sufficient sustaining effect, and the dissolution rate can be easily controlled. Therefore, there is an advantage that the manufacturing process is simpler than the chemical method, and research and development are actively conducted in this aspect. The type of coating membrane coated on the surface of fertilizer particles is semi-permeable membrane (thermoplastic synthetic resin) in which the membrane is broken by internal osmotic pressure caused by diffusion, and the fertilizer component is eluted. An impermeable membrane (thermosetting resin) having micropores to elute the fertilizer component, and an impermeable membrane (biodegradable resin) in which the fertilizer component is eluted by decomposing the coating material by physical or chemical activity. The resins used for the above coating are those which use most organic solvents regardless of molecular weight. The use of such a solvent-type resin has a disadvantage in that the coating cost is increased because additional machinery such as a recovery facility for preventing air pollution must be installed to control volatile components generated during coating. Attempts have been made to solve this problem. Korean Patent No. 445536 discloses that the outer surface of the granular fertilizer includes (a) a core polymer emulsion containing a carboxyl group-containing monomer, and (b) a crosslinked shell polymer emulsion and a molecular weight-controlled shell polymer emulsion. A slow-acting granular fertilizer comprising a shell polymer emulsion and coated with a coating composition comprising (a) a reverse core-shell polymer emulsion into which (b) the shell polymer emulsion is inserted into the core polymer emulsion. Is disclosed. However, even if the slow-release fertilizer disclosed in the above document uses a biodegradable resin, it takes a long time to decompose and is not environmentally friendly, and has side effects such as accelerating soil acidification. Therefore, the present inventors have developed and applied for a patent for a slow-acting fertilizer of environmentally friendly material which is excellent in preventing acidity of soil and using the layered metal double hydroxide (see Korean Patent Application No. 10-2008-0054542). However, the slow-acting fertilizer including the layered metal bihydride salt disclosed in the patent application has a two-dimensional structure, so there is a limit to supporting anions between the layers.

Therefore, the technical problem to be achieved by the present invention is a three-dimensional layered metal double hydroxide and its manufacturing method and the three-dimensional layered metal double hydroxide using the three-dimensional layered metal bihydride to prevent soil acidification, improve fertilizer supporting efficiency and eco-friendly To provide a slow-release fertilizer of the material.

In order to achieve the above technical problem, the present invention is represented by the formula of [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O, M ^II _{( 1-x)} M ^III _x (OH) _{2 The} metal double hydroxide has a three-dimensional structure in the form of a card house having pores in the range of 1 to 10 nm on average therein, the anions (A ^n- ) is inserted into the pores Layered metal bihydride salt having a three-dimensional structure, wherein M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, and A ^n- is a hydroxide ion (OH ⁻ ), At least one member selected from the group consisting of nitrate ions (NO ₃ ⁻ ), PO ₄ ^3- , HPO ₄ ^2-, and H ₂ PO ₄ ⁻ , and 0 <x <1, z is 0.1 to 15).

In addition, the present invention is the ^{M II Ca 2+, Mg 2+,} Zn 2+, Ni 2+, Mn 2+, Co 2+, Fe 2+ , and At least one member selected from the group consisting of Cu ²⁺ , and M ^III is at least one member selected from the group consisting of Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ^3+, and Ni ³⁺ It provides a layered metal double hydroxide of a three-dimensional structure characterized by the above.

In another aspect, the present invention provides a layered metal double hydroxide, wherein x is in the range of 0.2 to 0.5.

In addition, the present invention is ⅰ) M ^II And Coprecipitation of the M ^II metal precursor in a polar solvent to prepare a bulk layered metal double hydroxide of the formula [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ′ ^n- ] _{x / n} zH ₂ O Step (M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, A ′ ^n- is a hydroxide ion (OH ⁻ ) or a nitrate ion (NO ₃ ⁻ ) and 0 <x <1, z 0.1 to 15), ii) at least one solvent selected from the group consisting of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, CCl ₄ , xylene and HCONH ₂ (Formamide) Reacting with and dissolving in the form of a layered metal bihydride salt having a cationic surface charge, and iii) hydroxide ions (OH ⁻ ), nitrate ions (NO ₃ ⁻ ), PO ₄ ^3-, HPO ₄ ^2- and H ₂ PO ₄ ^- adding one or more kinds of anions selected from the group consisting of re-home card in the form by the electrostatic attraction interaction Including summing stage provides a method for producing the double layered metal hydroxyl flame of the three-dimensional structure.

The present invention also provides a method for producing a three-dimensional layered metal double hydroxide salt, characterized in that the anion is at least one member selected from the group consisting of PO ₄ ^3- , HPO ₄ ^2- and H ₂ PO ₄ ⁻ . .

In addition, the present invention is the ^{M II Ca 2+, Mg 2+,} Zn 2+, Ni 2+, Mn 2+, Co 2+, Fe 2+ , and At least one member selected from the group consisting of Cu ²⁺ , and M ^III is at least one member selected from the group consisting of Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ^3+, and Ni ³⁺ It provides a method for producing a layered metal double hydroxide of a three-dimensional structure, characterized in that above.

In addition, the present invention provides a method for producing a layered metal double hydroxide of a three-dimensional structure, characterized in that x is in the range of 0.2 to 0.5.

The present invention also provides a slow-fertilizing fertilizer containing the layered metal double hydroxide of the three-dimensional structure.

The present invention provides a layered metal double hydroxide having a three-dimensional structure and a method of manufacturing the same, which is made of an environmentally friendly material and can be manufactured by a very economical manufacturing method, and furthermore, by using the layered metal double hydroxide having the three-dimensional structure, Provides a slow-release fertilizer with excellent soil acidification effects.

In the following, the present invention is described in more detail.

The layered metal bihydride salt of the three-dimensional structure of the present invention is represented by the chemical formula of [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O, the layered metal Anion (A ^n- ) is inserted between the layers of the double hydroxide salt (In the formula, M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, and A ^n- is a hydroxide ion (OH ^−). ), At least one selected from the group consisting of nitrate ions (NO ₃ ⁻ ), PO ₄ ^3- , HPO ₄ ^2-, and H ₂ PO ₄ ⁻ , and 0 <x <1, z is 0.1 to 15). In the present specification, the expression 'hybrid' refers to a layered metal double hydroxide, and the expression of 'LDH nanosheet' refers to a state in which a metal double hydroxide of a layered structure is dispersed in a solvent in a sheet state, and a 'phosphate- The expression 'LDH hybrid' refers to a layered metal double hydroxide having a three-dimensional structure, especially among the hybrids, and a 'card form' means mesopores in an average range of 1 to 50 nm due to the accumulation of layered structures as seen in clay. Means a three-dimensional structure with a structure with

As described above, the metal double hydroxide of the layered structure can be easily obtained in all the natural elements, it is eco-friendly because the manufacturing cost is low, the manufacturing process is not complicated and the elements forming the natural system. The type of the M ^II and M ^III in a slow release fertilizer containing a layered double metal hydroxyl flame of the invention There is no particular restriction if the respective +2 and +3 valence metal ion, wherein M ^II is Ca ^2+, Mg ^2+, Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ and At least one member selected from the group consisting of Cu ²⁺ , and M ^III is at least one member selected from the group consisting of Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ^3+, and Ni ³⁺ It is preferable that it is above. This is because the metal species are relatively inexpensive and easy to obtain. In addition, x which represents the composition ratio of M ^II and M ^III is freely adjustable in the range of 0-1. In order to maximize the amount of charge carried between the layered structures, x is more preferably in the range of 0.2 to 0.5.

In addition, the z is preferably in the range of 0.1 to 15. Z denotes the number of moles of the crystallized water in the formula, and may vary depending on the dry state.

Further, the anion A ^n- in the above formula are not necessarily in this particular limitation, hydroxide ions (OH ^-) consisting of ^-, nitrate ion _{^{(NO 3 -), PO 4}} 3-, HPO 4 2- and H ₂ PO ₄ It is preferable that it is at least 1 type selected from the group. This is because it is advantageous to include N (nitrogen) and / or P (phosphorus) component which is a kind of hydroxide ion or fertilizer component for the neutralization or fertilization effect of acid soil.

The layered metal bihydride salt of the three-dimensional structure of the present invention is ⅰ) M ^II And Coprecipitation of the M ^II metal precursor in a polar solvent to prepare a bulk layered metal double hydroxide of the formula [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ′ ^n- ] _{x / n} zH ₂ O Step (M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, A ′ ^n- is a hydroxide ion (OH ⁻ ) or a nitrate ion (NO ₃ ⁻ ), 0 <x <1) Ii) reacting the layered metal bihydride salt with at least one solvent selected from the group consisting of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, CCl ₄ , xylene and HCONH ₂ (Formamide) the method comprising melting a metallic layer in the form of double hydroxyl flame having an electric charge, and, iii) hydroxyl ion (OH on the layer of metal double hydroxyl flame having a cationic surface charge ^-), nitrate ion _{^{(NO 3 -), PO 4}} 3-, HPO ₄ ^2- and H ₂ PO ₄ ^- as by the addition of at least one anion selected from the group consisting of the step of recombining to form the house card by the electrostatic attraction interaction It may be prepared by a method comprising.

In the coprecipitation step, a carbonate ion may be prepared by adding a tetravalent metal salt such as calcium nitrate (Ca (NO ₃ ) ₂ .4H ₂ O) and a trivalent metal salt such as iron nitrate (Fe (NO ₃ ) ₃ .9H ₂ O). Dissolved in distilled water, and then added with a basic aqueous solution of NaOH to adjust their pH to 12 ± 0.2 and stirred at room temperature for 6 hours to 7 days, preferably 1 to 4 days. It will form a metal double hydroxide. The extra elements left unreacted can be removed by centrifugation, washing and drying.

In the method for preparing a layered metal bihydride salt having a three-dimensional structure according to the present invention, after the coprecipitation step, the layered metal dihydroxide salt is converted into 1-butanol, 1-hexanol, 1-octanol, 1-decanol, CCl ₄ , xylene and Reacting with at least one solvent selected from the group consisting of HCONH ₂ (Formamide) to dissolve (delaminate) in the form of a layered metal bihydride salt having a cationic surface charge. The type of the solvent is not limited as long as it can dissolve the layered metal double hydroxide, but is composed of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, CCl ₄ , xylene and HCONH ₂ (Formamide) At least one selected from the group can be effectively exfoliated, of which formamide is most preferred. The thus peeled Chemistry double layered metal hydroxide is a flame hydroxyl ion (OH ^-), nitrate ion ^{_{(NO 3 -), PO 4}} 3-, HPO 4 2- and H ₂ PO ₄ ^- of at least one anion selected from the group consisting of In the presence of a card house by the electrostatic attraction interaction is recombined (recombination).

In addition, the three-dimensional layered metal bihydride salt thus prepared can be used as a self-fertilizing fertilizer by itself or mixed with other fertilizers.

Hereinafter, the present invention will be described in more detail with reference to examples which are specific embodiments of the present invention.

Example (A = PO of Lamellar Metal Dihydroxide CaFe-A LDH via the Delamination-Recombination Method ₄ ^3- , HPO ₄ ^2- , H ₂ PO ₄ ^-  NO ₃ ^- ) synthesis)

The starting material, the Ca-Fe-nitrate LDH, [ Ca II (1-x) Fe III x (OH) 2] [NO 3 -] x / n zH calcium nitrate salt to _{2 O, Ca (NO 3)} 2 · 4H After preparing a mixed aqueous solution of ₂ O and iron nitrate, Fe (NO ₃ ) ₃ · 9H ₂ O was adjusted to a hydrogen ion concentration of 12 ± 0.2 and then reacted for 1 day while stirring at room temperature to synthesize. All reaction conditions were carried out in a nitrogen atmosphere. The obtained layered metal double hydroxide was centrifuged and washed with distilled water and dried at room temperature for 1 day. Ca-Fe-NO ₃ (-1) LDH having a two-dimensional layered structure was strongly stirred with HCONH ₂ (Formamide) solvent for 2 days to synthesize Ca-Fe-LDH nanosheet colloid. The exfoliated LDH nanosheet colloid was reacted with an aqueous solution in which three kinds of phosphates (PO ₄ ^3- , HPO ₄ ^2- , H ₂ PO ₄ ⁻ ) were dissolved to synthesize a hybrid compound. Since exfoliated LDH nanosheets have cations and phosphates have negative ions, they can be bonded by electrostatic attraction. Stir for 12 hours to evenly react. The hybrid compound precipitated by recombination was washed several times with ethanol and distilled water, and then dried in an oven at 60 degrees for 12 hours.

1 is a schematic view showing a peeled recombination method of the method for producing a layered metal double hydroxide of a three-dimensional structure of the present invention. Two-dimensional Ca-Fe-LDH nanosheets prepared by synthesizing the layered metal dihydrate Ca-Fe-NO ₃ (-1) LDH, a starting material synthesized by coprecipitation, and separating the layered metal dihydrate into sheets in a predetermined chemical environment. nanosheet) colloids can be synthesized. The resulting LDH nanosheet colloid has a positively charged surface and can be recombined with anionic fertilizer elements and electrostatic attraction. In this case, the anionic fertilizer element is loaded in the pores of 1 to 10 nm, preferably 2 to 5 nm, formed between the nanosheets and the nanosheets as well as the interlayer space.

FIG. 2 shows synthesized bulk layered metal bihydrides, exfoliated layered metal dihydrates, and phosphates having different oxidation numbers (H ₂ PO ₄ (-1), HPO ₄ (-2), and PO ₄ (-3) The crystal structure of the three-dimensional layered metal double hydroxide after recombination with) was analyzed by powder X-ray diffraction (XRD) ((a) Ca-Fe-NO ₃ (-1) LDH, (b) Ca-Fe-H ₂ PO ₄ (-1) LDH, (c) Ca-Fe-HPO ₄ (-2) LDH, (d) Ca-Fe-PO ₄ (-3) LDH.). As can be seen in Figure 2 Ca-Fe-NO ₃ (-1) LDH shows a well-developed XRD peak, which is consistent with the structure of the layered metal double hydroxide of hexagonal structure. The lattice constant determined by least square fitting analysis was determined to be a = 5.87 Å and c = 26.02 경우 for Ca-Fe-NO ₃ (-1) LDH. However, no Bragg peak was observed in the X-ray diffraction analysis of the colloidal LDH nanosheet colloid. It can be determined that the amorphous structure (amorphous) by separating into a single sheet of LDH nanosheets. The thus peeled Chemistry LDH nanosheets and the anion is phosphate ^{_{(PO 4 3-, HPO 4 2-}} , H 2 PO 4 -) and recombination of X-ray diffraction analysis results of a may also confirmed that a non-crystalline structure. This is the result of the dissociation of the two species in the case of delamination-recombination reactions, resulting in a crystalline form. The result of this X-ray pattern is that, as reported in previous literatures, the three-dimensional layered metal bihydride is present in the form of a house of cards. FIG. 3 is a photograph of a slow-fertilizing fertilizer including a layered metal double hydroxide of a three-dimensional structure of the present invention obtained after a peeling reaction and a recombination reaction. As shown in the left photograph of FIG. 3, two-dimensional Ca-Fe-LDH nano-structures in which the lattice layer is further separated through a peeling process after Ca-Fe-NO ₃ (-1) LDH reacts with HCONH ₂ (Formamide) solvent You can see that it is colloided into sheets. Transmission of the laser beam confirmed that these colloidal suspensions exhibited a tyndall phenomenon. On the other hand, as a result of reacting with phosphate which is an anion, it can be confirmed that the precipitate is recombined by electrostatic attraction (right of FIG. 3). FIG. 4 is an image photograph of the morphology of each hybrid under a scanning electron microscope. As shown in Figure 4, the initial starting material Ca-Fe-NO ₃ (-1) LDH (Fig. 4a) was confirmed in the form of a two-dimensional plate-like structure. However, the slow-release fertilizer (FIGS. 4b, c, d) containing the layered metal double hydroxide of the three-dimensional structure of the present invention after reaction with phosphate was identified in the form of a large mass of microns. This shows that the slow-acting fertilizer including the layered metal double hydroxide of the three-dimensional structure of the present invention is formed in the form of a card collection shown in FIGS. 1 and 2. FIG. 5 is a result of analyzing the ratio between phosphorus (P) element support and component elements in a slow-fertilizer fertilizer containing a three-dimensional layered metal bihydride salt of the present invention through energy dispersive X-ray spectroscopy (EDS). As shown in Figure 5, in the case of the slow-acting fertilizers (a, b, c) including the three-dimensional layered metal double hydroxide of the present invention recombined with phosphate, it can be seen that phosphorus (P) is detected. As a result, it can be confirmed that the phosphate is effectively supported in the pupil generated in the form of a card house composed of LDH layers as well as LDH interlayer space due to recombination.

Table 1 shows the element content results of each hybrid compound measured by EDS elemental analysis.

The Ca / Fe molar ratio of Ca-Fe-NO ₃ (-1) LDH, the initial starting material, was about 1.98. However, the Ca / Fe molar ratio after reaction with each phosphate by the exfoliation-recombination method was almost similar to the initial molar ratio only after hybridization of K ₂ HPO ₄ and K ₃ PO ₄ . On the other hand, in the case of LDH nanosheets reacted with KH ₂ PO ₄ , the molar ratio of Ca / Fe was lowered to 0.28, which indicates that a large amount of LDH was decomposed during the reaction. This is due to lower the overall solution pH in comparison to other phosphate reaction solution, LDH nanosheets proton ion upon hybridization in a solvent by a KH ₂ PO ₄ emits two H ⁺ in the reaction compared to the phosphate of two different species (H ⁺ Attacked by) seems to have been partially disassembled. In addition, when reacting with three phosphates by EDS analysis, the use of K ₂ HPO ₄ phosphate maintains the lattice of the initial LDH more consistently than the other two phosphate species and has the most optimized state in terms of phosphate content. You can judge. In addition, it was found that about 1.5 times more than the phosphate contained in the hybrid fertilizer carrier previously developed by ion exchange (Korean Application No. 10-2008-0054542), the meso-cavity of the exfoliation-recombination technique does not occur in the ion exchange method. It can be judged that this results in the formation of, which leads to the inclusion of large amounts of phosphate.

Test Example (Neutralization Test of Acidic Environment of Phosphate-LDH Hybrid)

The acid rain lies in the range of about pH 5. Therefore, the initial solution was made acidic solution of about pH 5 and the test subject was confirmed the pH of about 2 hours after loading the Ca-Fe-HPO ₄ (-2) LDH hybrid. The change in pH was observed after 2 hours after the addition of the slow-acting fertilizer containing the three-dimensional layered metal bihydride salt prepared in Example in an acidic solution having a pH of about 5, which is the same as the acid rain. Figure 6 is an image of the effect on the prevention of soil acidification of the three-dimensional layered metal bihydride salt of the present invention: (a) before the reaction at pH = 5.07, (b) after the addition of the three-dimensional layered metal bihydride salt It is the photograph which became pH = 7.08 after time. As shown in the left photograph of FIG. 6, the pH of the solution before addition of the three-dimensional layered metal bihydride salt shows a value of about 5.07, while the three-dimensional layered metal dihydroxide salt was used (the amount of the sample using 0.1 g 2 hours after addition (right of FIG. 6), the pH value was about 7.08, showing a near neutral pH value. The weakly acidic solution used decomposes the crystals of LDH to dissolve the -OH groups on the surface with the release of the phosphate supported in the LDH. The large amount of H ⁺ ions in the solution can be interpreted to bind with OH ^- ions to neutralize the acidic solution. Therefore, when the layered metal bihydride salt of the three-dimensional structure of the present invention is fertilized in acidic soil as a slow fertilizer, it can be determined that the fertilizer spraying effect and the ability to neutralize the excess acidic soil.

Test example (supported phosphate dissolution test of phosphate-LDH hybrid)

In order to evaluate the phosphate elution functionality of phosphate-supported layered metal bihydride salts, phosphate ion dissolution was studied by ion chromatography in a buffer solution of about pH 5.0. A buffer solution (acetate buffer solution, 5.0 <pH <5.5) was used to prevent the neutralization of pH in the pH range of the pH similar to acid rain.Phosphate ions were collected by time at 0.1g / L per sample. Analyzed. Phosphates eluted from all phosphate-supported hybrids are detected in the form of ions of PO ₄ ^3- , which are present in the presence of H ₂ PO ₄ (-1) and HPO ₄ (-2) It is converted, because instability in the form of PO ₄ ^3- is detected by the detector as PO ₄ ^3- ions. The graph of FIG. 7 measures the phosphate elution of each phosphate-supported hybrid with time. In the initial 1 hour of the supported anion, the higher the negative charge of the phosphate, the higher the amount of elution, and as time passed, all the phosphate-supported LDH hybrids released a certain amount every time. It was also confirmed that no toxic ions were formed that could affect other environments. In addition, as shown in the graph of FIG. 7, the higher the negative charge of the supported anion was confirmed that the dissolution rate is faster. From this, it can be seen that the dissolution rate can be controlled by controlling the charge of the anion. However, these emissions are somewhat different from those of phosphorus in elemental analysis of EDS. This is due to various factors. From the results of the elemental analysis of EDS (Table 1), the molar ratio of K / P is 0.20, 0.18, 0.08 in order of low negative charge of phosphate. Ca-Fe-H ₂ PO ₄ (-1) -LDH, Ca-Fe-HPO ₄ (-2) than Ca-Fe-PO ₄ (-3) -LDH in the pores generated after recombination of LDH and phosphate The presence of large amounts of K ⁺ in the -LDH hybrids indicates that the phosphate (H ₂ PO ₄ ^-1 , HPO ₄ ^2- ) is converted into PO ₄ ^3- and released in the pores of two phosphate-supported LDH hybrids. It can be suggested that K ⁺ interferes. So still a large amount of K ⁺ -H ₂ PO ₄ ^-1 , 2K ⁺ -HPO ₄ ^2- like The presence of phosphate species is believed to remain in the LDH pupil. 8 is a view showing a schematic view that can be seen at a glance the performance of the slow-acting fertilizer containing a three-dimensional layered metal double hydroxide of the present invention.

The result of the present invention is that it can carry a fertilizer of 1.5 times or more as compared to the carrier synthesized by the above-described ion exchange method (Korean Application No. 10-2008-0054542). In addition, the results of neutralizing the acidic environment in acidic solutions under conditions such as the rate of elution and rate of phosphate over time, and acid rain, suggest that the LDH-based fertilizer carrier proposed by this study can be effectively functioned. I could confirm it. Therefore, as can be seen in Figure 8 can be determined that the LDH-based inorganic fertilizer carrier is a multi-functional eco-friendly material having a neutralizing acid soil action with a slow fertilizing function.

The embodiments of the present invention described above should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

1 is a schematic diagram of a method for exfoliation and recombination of a layered metal dihydroxide of a three-dimensional structure of the present invention.

FIG. 2 shows synthesized bulk layered metal bihydrides, exfoliated layered metal dihydrates, and phosphates having different oxidation numbers (H ₂ PO ₄ (-1), HPO ₄ (-2), and PO ₄ (-3) Powder X-ray diffraction analysis (XRD) of the crystal structure of the three-dimensional layered metal bihydride salt after recombination with (a) Ca-Fe-NO ₃ (-1) LDH, (b) exfoliated Ca -Fe-LDH (c) Ca-Fe-H ₂ PO ₄ (-1) LDH, (d) Ca-Fe-HPO ₄ (-2) LDH, (e) Ca-Fe-PO ₄ (-3) LDH

Figure 3 is a schematic diagram of the peeling and recombination of the layered metal double hydroxide and anionic phosphate, and images: (a) the peeling-recombination schematic, (b) the colloid of the layered metal double hydroxide peeled off in a single sheet The photo on the right hand side which causes the phenomenon of tind by the laser beam and the image on the right side of the fertilizer containing the three-dimensional layered metal bihydride salt of the present invention precipitated after recombination with anionic phosphate

4 is a scanning electron micrograph (SEM) of the morphology of each hybrid: (a) Ca-Fe-NO ₃ (-1) LDH, (b) Ca-Fe-H ₂ PO ₄ (-1) LDH, (c) Ca-Fe-HPO ₄ (-2) LDH, (d) Ca-Fe-PO ₄ (-3) LDH

Figure 5 shows the energy dispersive X-ray spectra of each hybrid: (a) Ca-Fe-H ₂ PO ₄ (-1) LDH, (b) Ca-Fe-HPO ₄ (-2) LDH , (c) Ca-Fe-PO ₄ (-3) LDH

Figure 6 is an image of the effect on the soil acidification of the three-dimensional layered metal double hydroxide of the present invention: (a) before the reaction at pH = 5.07, (b) the layered metal double hydroxide of the three-dimensional structure of the present invention PH = 7.08 2 hours after addition

Fig. 7 shows phosphate ion elution ion chromatography under buffer condition of 5.0 <pH <5.5 in order to evaluate the phosphate release functionality supported on the layered metal bihydride of the three-dimensional structure of the present invention: (●) Ca-Fe-H ₂ PO ₄ (-1) LDH, (▲) Ca-Fe-HPO ₄ (-2) LDH, (■) Ca-Fe-PO ₄ (-3) LDH

Figure 8 is a schematic diagram of the soil acidification prevention and fertilizer fertilization effect of the slow-acting fertilizer containing a three-dimensional layered metal double hydroxide of the present invention

Claims (8)

[M ^II _(1-x) M ^III _x (OH) ₂ ] [A ^n- ] _{x / n} zH ₂ O, represented by the chemical formula of layered M ^II _(1-x) M ^III _x (OH) ₂ The metal double hydroxide has a three-dimensional structure in the form of a card house having mesopores having an average of 1 to 10 nm range therein, the three-dimensional structure characterized in that the anions (A ^n- ) is inserted into the voids Layered metal bihydride salts (wherein M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, A ^n- is hydroxide ions (OH ⁻ ), nitrate ions (NO ₃ ⁻ ), PO ₄ ^3- , HPO ₄ ^2- and H ₂ PO ₄ ^- and at least one member selected from the group consisting of 0 <x <1 and z are 0.1 to 15). The method of claim 1, M ^II is Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ and At least one member selected from the group consisting of Cu ²⁺ , and M ^III is at least one member selected from the group consisting of Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ^3+, and Ni ³⁺ The layered metal double hydroxide of the three-dimensional structure characterized by the above. The method of claim 1, X is in the range of 0.2 to 0.5 layered metal double hydroxide of a three-dimensional structure. ^II ) M ^II And Coprecipitation of the M ^II metal precursor in a polar solvent to prepare a bulk layered metal double hydroxide of the formula [M ^II _(1-x) M ^III _x (OH) ₂ ] [A ′ ^n- ] _{x / n} zH ₂ O Step (M ^II is a + divalent metal cation, M ^III is a + trivalent metal cation, A ′ ^n- is a hydroxide ion (OH ⁻ ) or a nitrate ion (NO ₃ ⁻ ) and 0 <x <1, z Is 0.1 to 15), Ii) cationic surface charge by reacting the layered metal dihydroxide salt with one or more solvents selected from the group consisting of 1-butanol, 1-hexanol, 1-octanol, 1-decanol, CCl ₄ , xylene and HCONH ₂ (Formamide) Dissolving in the form of a layered metal double hydroxide having a iii) above with a cationic surface charge on the layer of metal double hydroxyl hydroxide ion in the flame (OH ^-), nitrate ion _{^{(NO 3 -), PO 4}} 3-, HPO 4 2- and H ₂ PO ₄ ^- 1, selected from the group consisting of Method of producing a three-dimensional layered metal double hydroxide comprising the step of recombination in the form of a card house by the electrostatic attraction interaction by adding more than one anion. 5. The method of claim 4, The anion is a method of producing a layered metal double hydroxide of three-dimensional structure, characterized in that at least one member selected from the group consisting of PO ₄ ^3- , HPO ₄ ^2- and H ₂ PO ₄ ⁻ . The method according to claim 4 or 5, M ^II is Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Ni ²⁺ , Mn ²⁺ , Co ²⁺ , Fe ²⁺ and At least one member selected from the group consisting of Cu ²⁺ , and M ^III is at least one member selected from the group consisting of Fe ³⁺ , Al ³⁺ , Cr ³⁺ , Mn ³⁺ , Ga ³⁺ , Co ^3+, and Ni ³⁺ Method for producing a layered metal double hydroxide of a three-dimensional structure, characterized in that above. The method according to claim 4 or 5, Wherein x is in the range of 0.2 to 0.5, characterized in that the layered metal double hydroxide salt of a three-dimensional structure. A slow-acting fertilizer comprising the layered metal double hydroxide of the three-dimensional structure according to any one of claims 1 to 3.

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