JP2021066630A - Nutrient-releasing sheet containing zeolite composite, method of producing the same, and plant cultivation method - Google Patents

Abstract

To provide a nutrient-releasing sheet containing a zeolite complex which is excellent in sustained-release property of nutrients, a method for producing the same, and a method for cultivating plants.SOLUTION: A nutrient-releasing sheet that contains a complex of a zeolite and an apatite compound, which is highly convenient for carrying around, and is efficient and stable for a long period of time even when the amount of zeolite is small. The sheet can be produced by reacting zeolite with a solution of phosphoric acid or phosphate to yield an apatite-based compound in its surface layer.SELECTED DRAWING: None

Description

The present invention relates to a zeolite complex-containing nutrient release sheet, a method for producing the same, and a method for cultivating a plant.

Regarding the technology for sustaining the efficacy of fertilizer for a long period of time, at least one element of nitrogen and potassium is supported in the pores of the zeolite particles, and at least a part of the surface of the zeolite particles is calcium phosphate mainly composed of apatite. A fertilizer coated with a system compound is disclosed (Patent Document 1).

In Patent Document 1, sustained release properties are imparted to fertilizer by covering the surface of zeolite containing nitrogen or potassium in the pores with a calcium phosphate compound.

However, in recent years, from the viewpoint of improving the efficiency of agriculture, there is an increasing demand for fertilizers that are easy to carry, fertilize and / or collect, are highly convenient, and can maintain their efficacy as fertilizers for a long period of time.
In the present specification, fertilizer means a nutrient substance applied to cultivated soil. In addition to the nine elements of oxygen, hydrogen, carbon, nitrogen, potassium, phosphorus, calcium, magnesium and sulfur, trace elements such as manganese, zinc and iron are required for plant growth. Of the nine elements, fertilizer is used to replenish nitrogen, phosphorus, and potassium (hereinafter, also referred to as three elements of fertilizer), which are particularly deficient in soil. The fertilizer contains one or more of the three elements of the fertilizer.

Japanese Patent No. 5594810

The present invention has been made in view of such circumstances. It is a nutrient release sheet having excellent sustained release of nutrients, is highly convenient when carried, and is efficient and long-term even with a small amount of zeolite. An object of the present invention is to provide a nutrient release sheet capable of stably releasing nutrients throughout.
Nutrients mean the components necessary for the growth of an organism. As the nutrient, for example, the fertilizer can be exemplified.

As a result of diligent studies, the present inventors have found that the above-mentioned problems can be solved by including a complex of zeolite and an apatite-based compound in the nutrient release sheet. The present invention has been completed based on such findings.

The present invention provides the following methods for producing zeolite complex-containing nutrient release sheets [1] to [10], zeolite complex-containing nutrient release sheets [11] to [19], and plant cultivation method [20]. To do.
[1] A zeolite complex-containing nutrient release sheet containing a complex of a zeolite and an apatite compound.
[2] The zeolite complex-containing nutrient release sheet according to [1], wherein the apatite-based compound covers at least a part of the surface of the zeolite.
[3] The zeolite complex-containing nutrient release sheet according to [1] or [2], wherein the apatite-based compound is hydroxyapatite.
[4] The zeolite complex-containing nutrient release sheet according to any one of [1] to [3], wherein the content of the zeolite in the complex is 30% by mass or more.
[5] The zeolite complex-containing nutrient release sheet according to any one of [1] to [4], wherein the content of the apatite compound in the complex is 10% by mass or more.
[6] The zeolite complex-containing nutrient release sheet according to any one of [1] to [5], wherein the zeolite contains at least one selected from the group consisting of nitrogen, potassium, calcium, and phosphorus.
[7] The zeolite complex-containing nutrient release sheet according to any one of [1] to [6], wherein the zeolite is a Ca-type zeolite.
[8] The zeolite complex-containing nutrient release sheet according to any one of [1] to [7], wherein the composition containing the complex and a biodegradable resin is formed into a sheet.
[9] The zeolite complex-containing nutrient release sheet according to any one of [1] to [7], wherein the complex is held by a sheet material made of a liquid-absorbing material.
[10] The sheet material made of the liquid-absorbent material is made of one or more kinds of materials selected from the group consisting of a porous body, a non-woven fabric containing felt, a polymer material, a pulp material and a paper material [9]. ] The zeolite complex-containing nutrient release sheet according to.
[11] The method for producing a nutrient release sheet containing a zeolite complex according to [8], wherein a masterbatch containing the composite and a biodegradable resin is obtained, and the masterbatch or the masterbatch. A method for producing a nutrient release sheet containing a zeolite complex, which comprises a step of forming a sheet by diluting and kneading the mixture with a biodegradable resin.
[12] The zeolite composite according to [11], which comprises a step of immersing the Ca-type zeolite in an alkaline aqueous solution containing at least one element selected from the group consisting of nitrogen, potassium and phosphorus to obtain the complex. A method for producing a body-containing nutrient release sheet.
[13] The zeolite complex-containing nutrient release sheet according to [12], wherein the Ca-type zeolite after being immersed in the alkaline aqueous solution is calcined in a temperature range of 150 ° C. to 800 ° C. in the step of obtaining the complex. Production method.
[14] The method for producing a zeolite complex-containing nutrient release sheet according to [12] or [13], wherein the alkaline aqueous solution contains a phosphoric acid compound.
[15] The method for producing a zeolite complex-containing nutrient release sheet according to [12] or [13], wherein the alkaline aqueous solution contains a potassium compound.
[16] The method for producing a zeolite complex-containing nutrient release sheet according to any one of [12] to [15], wherein the immersion is carried out at 25 to 120 ° C.
[17] The method for producing a zeolite complex-containing nutrient release sheet according to any one of [12] to [16], wherein the immersion is performed a plurality of times.
[18] The method for producing a zeolite complex-containing nutrient release sheet according to [9] or [10], wherein the sheet material contains zeolite containing at least one element of nitrogen and potassium, and the sheet material contains A method for producing a nutrient release sheet containing a zeolite complex, which is formed by contacting phosphate ions.
[19] The method for producing a zeolite complex-containing nutrient release sheet according to [18], wherein the zeolite contains calcium and an aqueous solution of ammonium phosphate is brought into contact with the sheet material.
[20] A plant cultivation method for cultivating a plant using the nutrient released from the zeolite complex-containing nutrient release sheet according to any one of [1] to [10] as fertilizer.

According to the present invention, it is more convenient to carry than conventional fertilizers, that is, fertilizers having the same shape as zeolite used as a raw material (powder granules, crushed matter, fibrous, plate, block, etc.). It is possible to provide a nutrient release sheet having high properties and excellent sustained release of nutrients.

It is an SEM photograph of the nutrient release sheet 1 containing a test zeolite complex. (A) It is a graph which shows the result of dissolution test 1-1 (Example). (B) It is a graph which shows the result of dissolution test 1'-1 (comparative example). (A) It is a graph which shows the result of dissolution test 1-2 (Example). (B) It is a graph which shows the result of dissolution test 1'-2 (comparative example). (A) It is a graph which shows the result of dissolution test 1-3 (Example). (B) It is a graph which shows the result of dissolution test 1'-3 (comparative example). (A) It is a photograph which shows the result of the growth test 1-1 (Example). (B) It is a photograph which shows the result of the growth test 1'-1 (comparative example). It is a graph which shows the result of dissolution test 2-1 (Example). It is a photograph which shows the growth test result by the zeolite complex containing nutrient release sheet which concerns on another embodiment. It is a graph which shows the result of dissolution test 3-1 (Example). (A) It is a photograph which shows the result of the growth test 3-1 (Example). (B) It is a photograph which shows the result of the growth test 3'-1 (comparative example).

Hereinafter, the present invention will be described in detail using embodiments.

The zeolite complex-containing nutrient release sheet of the present invention contains a complex of a zeolite and an apatite-based compound.
The zeolite complex-containing nutrient release sheet according to the embodiment of the present invention is a sheet containing a composite of a zeolite and an apatite compound and a biodegradable resin (hereinafter, also referred to as a biodegradable resin). It is molded into a shape.
The zeolite complex-containing nutrient release sheet according to another embodiment of the present invention comprises a sheet material made of a liquid-absorbing material holding the complex.

[Complex]
The complex preferably has the apatite compound covering at least a part of the surface of the zeolite.
When the surface of the zeolite is covered with an apatite compound, the elements and ions contained in the zeolite are less likely to be released.
For example, when a zeolite containing at least one of the three elements of fertilizer, nitrogen, phosphorus, and potassium, comes into contact with an aqueous solution, these elements and ions containing the elements are gradually released through the aqueous solution, but the surface of the zeolite. By covering at least a part of the above with an apatite compound, the sustained release property is improved.

(Zeolite)
Zeolites preferably contain at least one of the three elements of the fertilizer.
As the zeolite, a zeolite-based compound (hereinafter, Ca-type zeolite) containing a sufficient amount of calcium by substituting a cation in the zeolite, for example, sodium ion or the like with calcium ion (Ca ^{2+) is preferable.}
By using Ca-type zeolite, it is possible to obtain a zeolite complex-containing nutrient release sheet in which the influence of sodium ions, which causes growth disorders of leafy vegetables, is reduced.
The reaction conditions and methods for calcium substitution of zeolite are not particularly limited, but for example, the zeolite is placed in a calcium chloride solution, a calcium hydroxide solution, a calcium nitrate solution or the like (hereinafter referred to as a calcium compound solution) for 10 to 40 hours. After ion exchange is carried out by immersing the sample to a certain extent and the sample is sufficiently washed, the operation of adding zeolite to the calcium compound solution again can be repeated 2 to 10 times to replace the sodium ions with calcium ions. The calcium compound used in this ion exchange may be any calcium compound as long as it is soluble in water, and the concentration is not particularly limited. The temperature of the calcium compound solution at the time of ion exchange may be any temperature from 0 ° C. to the boiling point. It is desirable that such ion exchange be carried out in an alkaline manner, and the pH adjusting solution at this time is preferably, for example, ammonia water, but is not particularly limited thereto.
When Ca-type synthetic zeolite is used, the treatment with the calcium compound solution is not necessary.

The zeolite-based compound can be defined as "crystalline porous aluminosilicate", and at least various compounds included in this definition can be used. For example, as a general formula,
_{(M1, M2 1/2) m (} Al m Si n O 2 (m + n)) · XH 2 O
[In the formula, ^{monovalent cations such as M1: Na +} , K ⁺ , H ⁺ , M2: divalent cations such as Ca ²⁺ , Mg ²⁺ , Sr ²⁺ , m ≦ n, X: arbitrary integers]
It is represented by.

The crystal structure of zeolite is not particularly limited, and examples thereof include various crystal structures represented by a structure code consisting of three letters of the alphabet defined by the International Zeolite Society. Examples of structural codes include LTA, FER, MWW, MFI, MOR, LTL, FAU, BEA, CHA, and HEU codes. When a preferable aspect of the crystal structure is indicated by the name of the crystal structure, preferably A type, X type, β type, Y type, L type, ZSM-5 type, MCM-22 type, ferrierite type, and mordenite type. And at least one selected from the group consisting of chavasite type, more preferably at least one selected from the group consisting of A type, X type and Y type.

The zeolite may be either a natural zeolite or a synthetic zeolite, and the type thereof is not particularly limited.
The type and content of the cations of natural zeolite differ depending on the place of origin. In Japan, deposits rich in mordenite ((Ca, K ₂ , Na ₂ ) [((AlO ₂ ) (SiO ₂ ) ₅ ) ₂ ] · 7H ₂ O) and clinoptilolite ((Ca, Na)) ₂ ) There are deposits containing a large amount of [(AlO ₂ ) ₂ (SiO ₂ ) ₇ ] ・ 16H _{2 O) in various places.} From a practical point of view such as availability, it is preferable to use at least one of mordenite and clinoptilolite.
Many types of crystals are synthesized in synthetic zeolite. The most industrially used synthetic zeolites are type A or type X.

The form of zeolite is not particularly limited, and may be, for example, powdery granules, crushed material, fibrous, plate-like, block-like, or the like. More preferably, it is a crystal having an average particle size of 0.1 to 10 μm. Since such a zeolite has high crystallinity and one particle is large, the solubility of the nutrient contained in the zeolite in the aqueous solution can be further suppressed in combination with the coating effect of the calcium phosphate-based compound. The particle size can be measured by a sedimentation weight method, a centrifugal sedimentation light transmission method, a laser diffraction / light scattering method, or the like. Since it may not be possible to distinguish agglomeration in the flow phase, direct observation with a transmission electron microscope or scanning electron microscope is performed, the average value of the major and minor axes of each particle is calculated, and the lognormal distribution of each fraction is based on the number. It is preferable to obtain the average particle size from.
Further, the diameter distribution of the micropores defined by IUPAC is preferably 0.5 to 2 nm.

(Apatite compound)
The apatite-based compound constituting the complex used in the zeolite complex-containing nutrient release sheet of the present invention is preferably calcium phosphate-based apatite, and particularly preferably hydroxyapatite (HAp). Since calcium phosphate-based compounds generally have low solubility in aqueous solutions, it is possible to gradually release phosphorus through the aqueous solution by using calcium phosphate-based apatite.

As a general formula, apatite-based compounds include _{various compounds such as calcium phosphate-based apatite represented by Ca 10} (PO ₄ ) ₆ X ₂ (X represents a halogen atom or a hydroxyl group). For example, hydroxyapatite: Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ and fluorine apatite: Ca ₁₀ (PO ₄ ) ₆ F ₂ are exemplified.

The apatite compound is preferably a microcrystal having an average diameter of 30 to 500 nm. As a result, a dense coating layer can be formed on the surface of the zeolite, and the solubility of the nutrients contained in the zeolite in the aqueous solution can be further suppressed.

(Contents of zeolite and apatite compounds)
The content of zeolite in the complex is preferably 30% by mass or more and less than 90% by mass, more preferably 60% by mass or more and less than 90% by mass, and most preferably 80% by mass or more and less than 90% by mass. preferable.
By setting the content of zeolite in the complex to 30% by mass or more, nutrients such as fertilizer can be sufficiently contained in the complex.

The content of the apatite compound in the complex is preferably 10% by weight or more.

A zeolite complex-containing nutrient release sheet suitable for fertilizer applications by setting the content of zeolite and apatite compounds in the above range and supporting at least one of the three elements of fertilizer in the pores of the zeolite. Therefore, it is possible to realize a zeolite complex-containing nutrient release sheet that appropriately releases necessary nutrients in a well-balanced manner. The balance of nutrients released from the zeolite complex-containing nutrient release sheet can be appropriately changed by adjusting the nutrients contained in the zeolite and the content of the zeolite and the apatite compound in the complex.
When the zeolite complex-containing nutrient release sheet is used as a fertilizer, calcium is also generally useful as a nutrient for promoting the growth of plants and as food. Therefore, calcium is contained as a component in zeolite or apatite and ingested by cultivated plants. It is preferable to let it.

The complex may contain an inorganic porous body other than zeolite. Preferably, an inorganic porous body having adsorption characteristics is mentioned. Examples of such an inorganic porous body include hydrotalcite, clay minerals, silica gel, alumina gel, aluminosilica gel and the like. Further, these may be contained in two or more kinds.

[Manufacturing method of complex]
A complex can be produced by reacting zeolite with a solution of phosphoric acid or phosphate to form an apatite-based compound on the surface layer.

The method for producing the composite in one embodiment includes a dipping step of immersing the zeolite in an alkaline aqueous solution (hereinafter, alkaline aqueous solution) containing at least one element selected from the group consisting of nitrogen, potassium and phosphorus. The temperature of the alkaline aqueous solution may be any temperature from 0 ° C. to the boiling point, and the immersion time and the concentration of the alkaline aqueous solution may be arbitrary. The pH of the alkaline aqueous solution is preferably 7 to 12.
By this dipping step, nitrogen or potassium is impregnated inside the zeolite by a simple method of immersing in an alkaline aqueous solution containing at least one element selected from the group consisting of nitrogen, potassium and phosphorus, and / or. , Phosphorus can be supported on the surface layer of zeolite in the state of, for example, an apatite compound.

The pressure and temperature during the reaction may be any condition as long as they are equal to or lower than the boiling point of the solution. For example, the reaction temperature when immersing zeolite in an alkaline aqueous solution is preferably in the range of 25 to 120 ° C. As a result, an apatite-based compound can be efficiently formed on the surface layer of zeolite. Further, a neutral or alkaline solution, that is, a solution having a pH of 7 or higher is suitable for producing an apatite-based compound.

The zeolite is preferably a Ca-type zeolite that can be most easily apatite-ized, and the alkaline aqueous solution is preferably a solution containing a phosphoric acid compound, and more preferably a solution containing ammonium phosphate. This makes it possible to easily add nitrogen to the zeolite in the form of ion exchange with calcium contained in the zeolite. Alternatively, the alkaline aqueous solution is preferably a solution containing a potassium compound, and more preferably a solution containing potassium hydroxide. As a result, potassium can be easily contained in the zeolite in the form of ion exchange with calcium contained in the zeolite.

Further, the apatite-based compound that coats the zeolite can be formed with a desired coating ratio and film thickness by appropriately adjusting the concentration, reaction temperature, and reaction time of the aqueous solution of the phosphate to be immersed.

Next, the product is washed, filtered and separated, and dried to obtain a complex in which the entire surface or a part of the zeolite particle surface is covered with an apatite compound. The drying may be any drying method such as freeze-drying or heat-drying with a dryer.
The complex contains at least phosphorus among the three elements of fertilizer, and other elements can be optionally contained.

After the dipping step, a firing step of firing in a temperature range of 150 ° C. to 800 ° C. may be included. As a result, the crystallization of the apatite-based compound is promoted and the elution rate can be further reduced, so that the effect as a fertilizer can be continued for a longer period of time.

[Zeolite complex-containing nutrient release sheet]
<Embodiment 1>
The zeolite complex-containing nutrient release sheet according to one embodiment of the present invention is formed by molding a composition containing the complex and a biodegradable resin into a sheet shape.
The content of the complex in the zeolite complex-containing nutrient release sheet is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass or more. The higher the content of the complex in the zeolite complex-containing nutrient release sheet, the higher the nutrient content per unit mass of the zeolite complex-containing nutrient release sheet.
The biodegradable resin in the zeolite complex-containing nutrient release sheet is preferably 10% by mass to 50% by mass. By setting the content of the biodegradable resin in the zeolite complex-containing nutrient release sheet to 10% by mass or more, the shape of the zeolite complex-containing nutrient release sheet can be maintained and the strength can be ensured. By setting the content of the biodegradable resin in the zeolite complex-containing nutrient release sheet to 50% or less, the content of the complex in the zeolite complex-containing nutrient release sheet can be sufficiently ensured.

In the zeolite complex-containing nutrient release sheet of the present embodiment, the complex is kneaded into a biodegradable resin. As described above, the complex contains at least phosphorus among the three elements of the fertilizer and can optionally contain other elements. Therefore, when the zeolite complex-containing nutrient release sheet of the present embodiment is used as a fertilizer. , The element contained in the complex is gradually released by decomposition of the biodegradable resin or ion exchange by contact with water, and the effect as fertilizer can be expected for a long period of time after the sheet is installed, and fertilizer application and / or The collection work can be simplified.
By adjusting the thickness, shape, type of biodegradable resin, and blend ratio of the sheet, the biodegradability can be adjusted, the strength of the sheet, the release duration of the elements contained in the complex, and the like can be adjusted.

(Biodegradable resin)
The biodegradable resin according to the present invention is not particularly limited, and a biodegradable resin of a microorganism-producing system, a natural product system, or a chemically synthesized system can be appropriately used.
The microbial production system means a biodegradable resin that utilizes polyester accumulated in the body in the process of metabolism by microorganisms such as bacteria, molds, and algae, and is an aliphatic resin such as biopolyester (eg, PHB / V). Includes polyesters, bacterial cellulose, microbial polysaccharides such as purulan and curdran.
The natural product system means a biodegradable resin derived from a natural product, and includes those obtained by modifying chitosan, cellulose, starch, cellulose acetate, starch and the like to give thermoplasticity.
The chemically synthesized system means a biodegradable resin obtained by polymerizing chemically and biologically synthesized monomers. You can freely design the type, combination, molecular weight, etc. of the monomer. Biodegradable resins of chemically synthesized type can be classified into hard type and soft type. The hard system contains polylactic acid. The soft system includes aliphatic polyesters such as polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), aromatic modified aliphatic polyesters (PBAT), polyvinyl alcohol (PVA), and the like. included.
Of the above, the aromatic-modified aliphatic polyester is suitable for the application of the present embodiment because it is easy to disperse and highly fill the complex, and is also excellent in stretchability and transparency.

Zeolite complex-containing nutrient release sheets are provided with other biodegradable materials, such as bamboo, reeds, kenaf, as needed to control strength, water resistance, durability (biodegradability rate), etc. An appropriate amount of plant fiber such as bagasse, wood flour, paper, etc. can be added.

(Production method)
The method for producing the zeolite complex-containing nutrient release sheet of the present embodiment is not particularly limited as long as the composite can be uniformly dispersed in the biodegradable resin to form a sheet. For example, the composite and the biodegradable resin can be obtained. An example can be exemplified as a method in which a master batch containing the above is prepared, and the master batch or the master batch diluted and kneaded with a biodegradable resin is formed into a sheet by extrusion molding or injection molding.

<Embodiment 2>
The zeolite complex-containing nutrient release sheet according to another embodiment of the present invention comprises a sheet material made of a liquid-absorbing material holding the complex.

The content of the complex in the zeolite complex-containing nutrient release sheet is preferably 10% by mass or more, more preferably 30% by mass or more, and most preferably 50% by mass or more. The higher the content of the complex in the zeolite complex-containing nutrient release sheet, the higher the nutrient content per unit mass of the zeolite complex-containing nutrient release sheet.

The liquid-absorbing material is not particularly limited, but a material capable of reversibly absorbing and draining liquid is preferable, and is composed of a porous body, a non-woven fabric containing felt, a polymer material, a pulp material, and a paper material. More preferably, it is one or more materials selected from the group. Specific examples thereof include zeolite sheets, polyurethane sheets, polyurethane foams, polyurethane sponges, polypropylene urethane sponges, nylon non-woven fabrics, polyolefin non-woven fabrics, melamine foams, cotton-like pulps, and liquid absorbent papers, but are limited to these examples. It's not a thing.

(Production method)
The method for producing the zeolite complex-containing nutrient release sheet of the present embodiment is not particularly limited as long as the complex can be held in the sheet material made of the liquid-absorbent material.
The zeolite complex-containing nutrient release sheet of the present embodiment is, for example, a sheet material (“Cs catcher 24” manufactured by Siegrite Co., Ltd.) in which a natural zeolite clinoptilolite (CLI) is retained in a non-woven fabric (hereinafter, CLI). (Sheet) is brought into contact with an aqueous solution of calcium nitrate ^{to prepare a Ca-type CLI sheet in which sodium ions in clinoptilolite} are replaced with Ca 2+, and the Ca-type CLI sheet is placed in an aqueous solution of ammonium phosphate to react. An apatite compound can be produced on the surface layer of CLI to obtain a CLI / HAp complex sheet.

Examples of the present invention will be shown below, and the present invention will be described in more detail. The present invention is not limited to these examples.

[Example 1]
<Preparation of test zeolite complex-containing nutrient release sheet 1>
A sheet material (“Cs catcher 24” manufactured by Siegrite Co., Ltd.) (hereinafter referred to as CLI sheet) in which natural zeolite clinoptilolite (CLI) is held on a non-woven fabric (felt) is brought into contact with a calcium nitrate solution to make clinopti. A Ca-type CLI sheet in which sodium ions in lolite ^{are replaced with Ca 2+} is prepared, and the Ca-type CLI sheet is placed in an aqueous ammonium phosphate solution and reacted to generate an apatite-based compound on the surface layer of CLI, and CLI / A test zeolite complex-containing nutrient release sheet 1 which is a HAp complex sheet was prepared.
When the surface of the test zeolite complex-containing nutrient release sheet 1 was observed by SEM photography (scanning electron micrograph, 45 ° tilt observation), as shown in FIG. 1, filamentous hydroxide apatite particles were observed. It was.
As a result of EDX chemical analysis, the Ca / P molar ratio was 1.8, which was close to the Ca / P molar ratio of 1.67 for hydroxyapatite. This result suggests the formation of hydroxyapatite and indicates that the CLI / HAp complex sheet could be prepared.

<Dissolution test 1-1>
Ten 1.0 cm × 1.0 cm test zeolite complex-containing nutrient release sheets 1 (CLI / HAp complex amount 0.014 g / sheet) were prepared and placed in a centrifuge tube together with 30 ml of tap water. The centrifuge tube was stirred (room temperature, 50 rpm), and the solutions in the centrifuge tube were sampled at 0, 4, 8, 12, 16, 20, and 24 hours after the start of stirring to analyze the liquid phase. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 2 (a).

<Dissolution test 1-2>
One 10.0 cm × 10.0 cm test zeolite complex-containing nutrient release sheet 1 (CLI / HAp complex amount 1.4 g / sheet) was prepared, and the test zeolite complex-containing nutrient release sheet 1 was used. The liquid phase was analyzed by sprinkling 100 ml / time of water and sampling the solution that passed through the sheet. This operation was repeated 18 times. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 3 (a).

<Dissolution test 1-3>
One 10.0 cm × 10.0 cm test zeolite complex-containing nutrient release sheet 1 (CLI / HAp complex amount 1.4 g) was prepared.
10 kg of CLI particles (“Itaya zeolite Z-35” manufactured by Siegrite Co., Ltd., average particle diameter: 3 to 5 mm) are brought into contact with about 13 L of calcium nitrate of 0.3 M and stirred at 300 rpm for 1 hour, and then a Na electrode is used. ^{The Na +} concentration in the solution was measured. The calcium nitrate aqueous solution contacted with 10 kg of CLI particles was discarded, a new calcium nitrate aqueous solution was prepared, and the same amount of CLI particles were ion-exchanged again. ^{This operation was repeated until the Na +} concentration in the solution became 250 mg / L or less to prepare Ca-type CLI particles.
300 g of the Ca-type CLI particles as a medium was placed in the lower part of the container (10 cm × 10 cm × 10 cm).
The test zeolite complex-containing nutrient release sheet 1 (CLI / HAp complex amount 1.4 g) was placed on the upper part of the medium. 100 ml of tap water was brought into contact with the zeolite complex-containing nutrient release sheet 1 every day, the solution was sampled, and the liquid phase was analyzed. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 4 (a).

[Comparative Example 1]
<Preparation of CLI / HAp composite particles>
Fabricated Ca type the CLI particles 500g and contacting 24 hours of 0.5M ammonium phosphate solution 1L at 80 ° C., the _NH ^{4 +} ion exchange in ^{Ca 2+} and phosphoric acid aqueous solution of ammonium present in the pores of the zeolite HAp was formed on the surface of zeolite to prepare CLI / HAp composite particles.

<Dissolution test 1'-1>
1.0 g of CLI / HAp composite particles prepared in Comparative Example 1 was prepared and placed in a centrifuge tube together with 30 ml of tap water. The centrifuge tube was stirred (room temperature, 50 rpm), and the solutions in the centrifuge tube were sampled at 4, 8, 12, 16, 20, and 24 hours after the start of stirring to analyze the liquid phase. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 2 (b).

<Dissolution test 1'-2>
50.0 g of CLI / HAp composite particles prepared in Comparative Example 1 were prepared, 100 ml / time of water was sprinkled on the CLI / HAp composite particles, and the passed solution was sampled to analyze the liquid phase. This operation was repeated 27 times. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 3 (b).

<Dissolution test 1'-3>
50.0 g of CLI / HAp composite particles prepared in Comparative Example 1 were prepared. 300 g of Ca-type CLI as a medium was placed in a container of 10 cm × 10 cm × 10 cm. 50.0 g of the CLI / HAp composite particles were placed on the upper part of the medium. 100 ml of tap water was brought into contact with the CLI / HAp composite particles every day, the solution was sampled, and the liquid phase was analyzed. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement results are shown in FIG. 4 (b).

_{As shown in FIGS. 2, 3 and 4, the amount of NH 4} ⁺ ion elution is larger in the apatite-ized sheet than in the apatite-ized CLI particles. That is, the apatite-ized sheet has an advantage that the amount of ion elution is large as described above, although the weight is overwhelmingly smaller than that of the apatite-ized CLI particles.
The apatite-ized sheet has the same or higher performance as the apatite-ized CLI particles, but also has the advantage of being easy to carry and handle and highly convenient.

<Growth test>
Three commercially available Japanese mustard spinach seeds were placed in each rock wool (2 cm x 2 cm x 3 cm), and tap water was added to half the height of the rock wool and soaked. After allowing it to stand in a dark room at 20 ° C. for 2 days, it was immersed in a commercially available fertilizer solution (“Hyponica” manufactured by Kyowa Co., Ltd.), and Komatsuna seedlings were grown over a week while irradiating with red LED light. Using this seedling, a growth test was conducted by the following method.
<Growth test 1-1>
Under the planter (22.5 cm × 62 cm × 18 cm), 3 kg each of CLI and the Ca-type CLI particles were placed as a medium. A test zeolite complex-containing nutrient release sheet 1 (10.0 cm × 10.0 cm) suitable for the size of the planter was placed on the upper part of the medium. Twelve (vertical 2 rows, horizontal 6 rows) of the above seedlings were planted in a place where a hole was made in the test zeolite complex-containing nutrient release sheet 1 and the lower medium was exposed. 100 ml of tap water was given every day, and the growth of Japanese mustard spinach was observed over 20 days while irradiating with red LED light. Photographs of seedlings on days 1, 10 and 20 are shown in FIG. 5 (a).
<Growth test 1'-1>
Under the planter (22.5 cm × 62 cm × 18 cm), 3 kg each of CLI and the Ca-type CLI particles were placed as a medium. 50.0 g of CLI / HAp composite particles were placed on the upper part of the medium, and 12 seedlings (2 rows vertically and 6 rows horizontally) were planted. 100 ml of tap water was given every day, and the growth of Japanese mustard spinach was observed over 20 days while irradiating with red LED light. A photograph of the seedlings on the 20th day is shown in FIG. 5 (b).

The zeolite composite content (1.4 g) of the test zeolite composite-containing nutrient release sheet 1 (10 cm × 10 cm) used in the growth test shown in FIG. 5 (a) was determined in the growth test shown in FIG. 5 (b). Despite being less than the amount of CLI / HAp composite particles used (50.0 g), from FIG. 5, the degree of growth on the 20th day was almost the same, and the degree of plant growth per weight was higher for the sheet. It can be confirmed that it is excellent in transportation, easy to handle, and convenient.

[Example 2]
<Preparation of test zeolite complex-containing nutrient release sheet 2>
(Making a masterbatch)
A twin-screw extruder with a diameter of 30 mm containing 1.2 kg of synthetic zeolite (“Molecular Sieve 5A Powder” manufactured by Union Showa Co., Ltd.) and 1.8 kg of biodegradable aromatic modified aliphatic polyester (“Ecoflex” manufactured by BASF). It is supplied to (L / D = 47), melt-kneaded in a twin-screw extruder at a resin temperature of 200 ° C. and a rotation speed of 100 rpm, extruded, processed into pellets, and contains 40% by mass of synthetic zeolite. A masterbatch was made.
(Preparation of Ca-type zeolite 5A sheet)
The above masterbatch was supplied to an extruder, melt-kneaded so that the maximum temperature became 230 ° C., extruded, and processed into pellets to obtain a biodegradable resin composition. Then, the obtained pellets were vacuum dried at 60 ° C. for 40 hours. The dried pellets are melt-extruded at an extrusion temperature of 215 ° C. using a single-screw extruder with a screw diameter of 90 mm equipped with a T-die with a width of 1000 mm, and a Ca mold with a thickness of 400 μm is used on a cast roll set at 40 ° C. A zeolite 5A sheet was prepared.
(Preparation of test zeolite-containing nutrient release sheet)
A test zeolite complex-containing nutrient which is a zeolite 5A / HAp composite sheet obtained by contacting the Ca-type zeolite 5A sheet in 1 L of a 0.5 M ammonium phosphate aqueous solution to generate an apatite compound on the surface layer of the zeolite 5A. A release sheet 2 was prepared.

<Dissolution test 2-1>
Ten 1.0 cm × 1.0 cm test zeolite complex-containing nutrient release sheets 2 (zeolite 5A / HAp complex amount 0.14 g) were prepared and placed in a centrifuge tube together with 30 ml of tap water or distilled water. .. The centrifuge tube was stirred (room temperature, 50 rpm), and the solutions in the centrifuge tube were sampled at 1, 6, 11, 16 and 21 hours after the start of stirring to analyze the liquid phase. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. In FIGS. 6 (a) The measurement results of the NH ₄ ⁺ concentration, shows the measurement results of the concentration of phosphate ions in Figure 6 (b).

From the comparison between FIGS. 2A and 6, the sheet made from "Molecular Sheave 5A" manufactured by Union Showa Co., Ltd. after being made into a biodegradable sheet and then made into apatite is better than the sheet made into apatite (CLI felt). Large amount of ion elution. It can be confirmed that the elution of phosphate ions is particularly large in the sheet obtained by converting "Molecular Sheave 5A" manufactured by Union Showa Co., Ltd. into a biodegradable sheet and then apatite.
As shown in FIG. 6 _{, the elution amount of NH 4} ⁺ ions is larger in tap water and P is in distilled water. By simply changing the fluid used, the type of ions that you want to preferentially elute can be controlled.

<Growth test>
Three commercially available Japanese mustard spinach seeds were added to each rock wool, and tap water was added to half the height of the rock wool and soaked. After allowing to stand in a dark room at 20 ° C. for 2 days, the seedlings of Japanese mustard spinach were grown by immersing them in a commercially available fertilizer solution and irradiating them with red LED light for 1 week. Using this seedling, a growth test was conducted by the following method.
<Growth test 2-1>
Put 240 g of soil medium (Togawa Heiwa Farm Co., Ltd., potting soil for flowers and vegetables) in the lower part of the container (10 cm x 10 cm x 10 cm), and put the test zeolite complex-containing nutrient release sheet 2 (10 cm x 10 cm) on the upper part. It was.
The seedlings were planted in a place where a hole was made in the central portion of the nutrient release sheet 2 containing the test zeolite complex and the soil medium in the lower portion was exposed.
100 ml of tap water was given every day, and the growth of Japanese mustard spinach was observed over a month while irradiating with red LED light.
A photograph of the seedlings on the 30th day is shown in FIG.
From FIG. 7, it can be confirmed that Komatsuna grows sufficiently in the same manner as in Example 1 (Growth Test 1-1) by using the zeolite complex-containing nutrient release sheet 2.

[Example 3]
<Preparation of test zeolite complex-containing nutrient release sheet 3>
(Preparation of complex)
_{0.5 M ammonium phosphate / potassium hydroxide mixed solution (NH 4} ⁺ / K ⁺ molar ratio: 1) prepared by adjusting 0.5 g of synthetic zeolite (“Molecular Sieve 5A Powder” manufactured by Union Showa Co., Ltd.) to pH 9 with phosphoric acid. ) Soaked in 50 ml and reacted at 40 ° C. for 8 hours. The sample after the reaction was thoroughly washed with distilled water and dried in a dryer for 24 hours to synthesize a zeolite / apatite complex. After melting the powder of the zeolite / apatite composites, distillation - Mizuwashizuku conventional method performs chemical composition analysis by (NH 4 ^₊₎ and ICP emission spectrometry, ammonium is three major essential element fertilizer, phosphorus, potassium, respectively It was confirmed that 1.74, 2.41, 5.46 mass% were present.
(Making a masterbatch)
1.2 kg of the zeolite / apatite composite and 1.8 kg of biodegradable aromatic-modified aliphatic polyester (“Ecoflex” manufactured by BASF) are supplied to a twin-screw extruder (L / D = 47) having a diameter of 30 mm. Then, melt-kneading was performed in a twin-screw extruder at a resin temperature of 200 ° C. and a rotation speed of 100 rpm, and the mixture was extruded and processed into pellets to prepare a master batch containing 40% by mass of the composite.
(Preparation of test zeolite complex-containing nutrient release sheet 3)
The above masterbatch was supplied to an extruder, melt-kneaded so that the maximum temperature became 230 ° C., extruded, and processed into pellets to obtain a biodegradable resin composition. Then, the obtained pellets were vacuum dried at 60 ° C. for 40 hours. The dried pellets are melt-extruded at an extrusion temperature of 215 ° C. using a single-screw extruder with a screw diameter of 90 mm equipped with a T-die with a width of 1000 mm, and a cast roll set at 40 ° C. for testing with a thickness of 400 μm. A zeolite complex-containing nutrient release sheet 3 was prepared.

<Dissolution test 3-1>
Ten 1.0 cm × 1.0 cm test zeolite complex-containing nutrient release sheets 3 (zeolite 5A / HAp complex amount 0.14 g) were prepared and placed in a centrifuge tube together with 30 ml of tap water or distilled water. .. The centrifuge tube was stirred (room temperature, 50 rpm), and the solutions in the centrifuge tube were sampled at 1, 6, 11, 16 and 21 hours after the start of stirring to analyze the liquid phase. NH ₄ ⁺ concentration indophenol blue method, phosphoric acid ion concentration was measured by the molybdenum method. The measurement result of NH ₄ ⁺ concentration is shown in FIG.

From the comparison of FIGS. 6 and 8, after the "Molecular Sheave 5A" manufactured by Union Showa Co., Ltd. was apatite-ized, rather than the sheet made by apatite after making the "Molecular Sheave 5A" manufactured by Union Showa Co., Ltd. into a biodegradable sheet. It can be confirmed that the biodegradable sheet has a higher sustained release property. Ion elution behavior can be controlled by the sheet manufacturing method.

<Growth test>
Three commercially available Japanese mustard spinach seeds were added to each rock wool, and tap water was added to half the height of the rock wool and soaked. After allowing to stand in a dark room at 20 ° C. for 2 days, the seedlings of Japanese mustard spinach were grown by immersing them in a commercially available fertilizer solution and irradiating them with red LED light for 1 week. Using this seedling, a growth test was conducted by the following method.
<Growth test 3-1>
Put 240 g of soil medium (Togawa Heiwa Farm Co., Ltd., potting soil for flowers and vegetables) in the lower part of the container (10 cm x 10 cm x 10 cm), and put the test zeolite complex-containing nutrient release sheet 3 (10 cm x 10 cm) on the upper part. It was. The seedlings were planted in a place where a hole was made in the central part of the nutrient release sheet 3 containing the test zeolite complex and the soil medium in the lower part was exposed. 100 ml of tap water was given every day, and the growth of Japanese mustard spinach was observed over a month while irradiating with red LED light. A photograph of the seedlings on the 30th day is shown in FIG. 9 (a).

[Comparative Example 2]
<Preparation of test zeolite-containing nutrient release sheet>
(Making a masterbatch)
A twin-screw extruder with a diameter of 30 mm containing 1.2 kg of synthetic zeolite (“Molecular Sieve 5A Powder” manufactured by Union Showa Co., Ltd.) and 1.8 kg of biodegradable aromatic modified aliphatic polyester (“Ecoflex” manufactured by BASF). It is supplied to (L / D = 47), melt-kneaded in a twin-screw extruder at a resin temperature of 200 ° C. and a rotation speed of 100 rpm, extruded, processed into pellets, and contains 40% by mass of synthetic zeolite. A masterbatch was made.
(Preparation of test zeolite-containing nutrient release sheet)
The above masterbatch was supplied to an extruder, melt-kneaded so that the maximum temperature became 230 ° C., extruded, and processed into pellets to obtain a biodegradable resin composition. Then, the obtained pellets were vacuum dried at 60 ° C. for 40 hours. The dried pellets are melt-extruded at an extrusion temperature of 215 ° C. using a single-screw extruder with a screw diameter of 90 mm equipped with a T-die with a width of 1000 mm, and a cast roll set at 40 ° C. for testing with a thickness of 400 μm. A zeolite-containing nutrient release sheet was prepared.

<Growth test 3'-1>
240 g of soil medium (Togawa Heiwa Farm Co., Ltd., potting soil for flowers and vegetables) was placed in the lower part of the container (10 cm × 10 cm × 10 cm), and a test zeolite-containing nutrient release sheet (10 cm × 10 cm) was placed on the upper part. The seedlings were planted in a place where a hole was made in the center of the test zeolite-containing nutrient release sheet and the soil medium in the lower part was exposed. 100 ml of tap water was given every day, and the growth of Japanese mustard spinach was observed over a month while irradiating with red LED light. A photograph of the seedlings on the 30th day is shown in FIG. 9 (b).

From FIG. 9, the degree of plant growth is higher in the zeolite complex-containing nutrient release sheet (FIG. 9 (a)) than in the zeolite-containing nutrient release sheet (FIG. 9 (b)), which is a sheet containing non-complex zeolite. It can be confirmed that it is excellent.

The zeolite complex-containing nutrient release sheet according to the present invention is "easy to carry, fertilize and / or recover, and is more convenient than particles", "excellent in sustained release of nutrients", and "in soil". It has characteristics such as "biodegradable low environmental load" and is suitable as a sheet-like sustained release fertilizer in agriculture.

Claims (20)

Zeolite complex-containing nutrient release sheet containing a complex of zeolite and apatite-based compound. The zeolite complex-containing nutrient release sheet according to claim 1, wherein the apatite-based compound covers at least a part of the surface of the zeolite. The zeolite complex-containing nutrient release sheet according to claim 1 or 2, wherein the apatite compound is hydroxyapatite. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 3, wherein the content of the zeolite in the complex is 30% by mass or more. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 4, wherein the content of the apatite compound in the complex is 10% by mass or more. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 5, wherein the zeolite contains at least one selected from the group consisting of nitrogen, potassium, calcium, and phosphorus. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 6, wherein the zeolite is a Ca-type zeolite. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 7, wherein the composition containing the complex and a biodegradable resin is formed into a sheet. The zeolite complex-containing nutrient release sheet according to any one of claims 1 to 7, wherein the complex is held by a sheet material made of a liquid-absorbing material. The ninth aspect of the present invention, wherein the sheet material made of the liquid-absorbent material is made of one or more kinds of materials selected from the group consisting of a porous body, a non-woven fabric containing felt, a polymer material, a pulp material and a paper material. Zeolite composite-containing nutrient release sheet. The method for producing a zeolite complex-containing nutrient release sheet according to claim 8.
A zeolite composite comprising a step of obtaining a masterbatch containing the composite and a biodegradable resin, and a step of diluting and kneading the masterbatch or the masterbatch with a biodegradable resin into a sheet. A method for producing a body-containing nutrient release sheet. The zeolite complex-containing nutrient according to claim 11, which comprises a step of immersing the Ca-type zeolite in an alkaline aqueous solution containing at least one element selected from the group consisting of nitrogen, potassium and phosphorus to obtain the complex. A method for manufacturing a release sheet. The method for producing a zeolite complex-containing nutrient release sheet according to claim 12, wherein in the step of obtaining the complex, the Ca-type zeolite after being immersed in the alkaline aqueous solution is calcined in a temperature range of 150 ° C. to 800 ° C. The method for producing a zeolite complex-containing nutrient release sheet according to claim 12 or 13, wherein the alkaline aqueous solution contains a phosphoric acid compound. The method for producing a zeolite complex-containing nutrient release sheet according to claim 12 or 13, wherein the alkaline aqueous solution contains a potassium compound. The method for producing a zeolite complex-containing nutrient release sheet according to any one of claims 12 to 15, wherein the immersion is carried out at 25 to 120 ° C. The method for producing a zeolite complex-containing nutrient release sheet according to any one of claims 12 to 16, wherein the immersion is performed a plurality of times. The method for producing a zeolite complex-containing nutrient release sheet according to claim 9 or 10.
The sheet material contains a zeolite containing at least one element of nitrogen and potassium, and the sheet material contains a zeolite.
A method for producing a zeolite complex-containing nutrient release sheet, which comprises contacting the sheet material with phosphate ions. The method for producing a zeolite complex-containing nutrient release sheet according to claim 18, wherein the zeolite contains calcium and an aqueous solution of ammonium phosphate is brought into contact with the sheet material. A plant cultivation method for cultivating a plant using the nutrient released from the zeolite complex-containing nutrient release sheet according to any one of claims 1 to 10 as fertilizer.

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